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1
Jackson, Claire. "Aspects of reproduction in the four-striped field mouse, Rhabdomys pumilio". Thesis, Rhodes University, 2000. http://hdl.handle.net/10962/d1005319.
Testo completoAbstract (sommario):
Rhabdomys pumilio, in the Eastern Cape of South Africa, does not use short day length as an inhibitory cue for reproductive activity, and, despite previous records indicating that these mice are strictly seasonal in their reproduction, litters have been found during the winters of some years,both in the Eastern Cape and in the Western Cape. This led me to believe that the reproductive activity of Rhabdomys pumilio is more opportunistic and that the cue or cues used to control reproduction are less predictable and, or more variable than the photoperiod cue used by many seasonally reproducing rodents. Two experiments were conducted, investigating the influence of low ambient temperature (15⁰C)and reduced food availability on the reproductive activity of both male and female four striped field mice. Mice were maintained in one of four conditions (food restricted at 15⁰C, food restricted at 26⁰C, ad lib. food at 15⁰C, and ad lib. food at 26⁰C) for 4 (males) and 8 weeks (females)(photoperiod 12L:12D, humidity 40%). Results indicated that the males reduced their reproductive activity slightly when exposed to either low temperature or low food availability and that maximum inhibition of reproduction occurred when mice were exposed to both low temperature and low food availability. However, female reproductive activity was inhibited when exposed to low food availability, irrespective of the temperature. Both sexes of mice showed varying abilities to resist fat loss and, in the males, the size of the fat store had a significant effect on reproduction. This varying ability to resist fat loss could be related to levels of activity and in the females (where activity was quantified), high activity scores were significantly associated with reproductive inhibition. These results support the hypothesis that reproduction in Rhabdomys pumilio is opportunistic and controlled by the availability of energy. I propose that the females will be more sensitive to reproductive inhibition due to their far greater post-fertilization responsibilities, where the reproductive activity of the females is rapidly inhibited by a reduction in food availability, while the males are less readily inhibited by low food availability or low temperature, unless the change in the controlling factors is severe enough, or prolonged, at which stage their reproductive activity will cease. The significance of opportunistic reproduction in the seasonal but unpredictable climate of the study area is discussed.
2
Cantrill, Steven. "The population dynamics of the house mouse (Mus domesticus) in a dual crop agricultural ecosystem". Thesis, Queensland University of Technology, 1992.
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3
Thayer, Kristina A. "Prenatal exposure to low doses of estrogen : reproductive effects in male and female mice and implications for regulation of endocrine disrupting environmental chemicals /". free to MU campus, to others for purchase, 1999. http://wwwlib.umi.com/cr/mo/fullcit?p9951127.
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4
Ruhlen, Rachel L. "Diets, estrogen environment of the fetus, and development of the reproductive tract and other systems /". free to MU campus, to others for purchase, 2003. http://wwwlib.umi.com/cr/mo/fullcit?p3091965.
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5
Agyeman, Duah Osei. "Effect of litter size manipulation on lactation, and offspring's reproduction and susceptibility to obesity". Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources. Restricted ; no access until January 30, 2010. Online version available for University members only until May 11, 2010, 2009. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=26022.
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6
Gamo, Yuko. "Effects of reproduction on body temperature and physical activity". Thesis, University of Aberdeen, 2009. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=130928.
Testo completoAbstract (sommario):
Daily changes in body temperature as well as physical activeness from mating to pregnancy were illustrated in MF1 mice. Body temperature and physical activity gradually declined as pregnancy advanced while energy intake and body mass increased in late pregnancy. Diurnal and nocturnal locomotor activity and body temperature were significantly lower in late pregnancy than in non-reproductive and mating phases. Despite low physical activity, inactive body temperature was relatively high through late pregnancy. This suggests that pregnant mice tend to increase thermogenesis against a drop of body temperature. Energy intake increased remarkably after parturition and reached a plateau in late lactation suggesting a limit of energy intake. Litter size and litter mass significantly influenced maternal energy intake and body mass (P<0.05). However, daily pup mass gain declined at the peak lactation when maternal energy intake was limited. Body temperature rose sharply after parturition. Body temperature during the day considerably increased. Consequently, lactating mice faced a constantly high body temperature through the day despite lower activity levels. There were no trends that litter size and litter mass stimulated maternal body temperature and physical activity on average through lactation. Body temperature during suckling inside the nest increased towards the end of suckling. However, no significant increase in body temperature was found between 20 and 1 minutes before terminating suckling bouts. Dams that raised larger litters encountered higher body temperature while suckling inside the nest, suggesting that suckling offspring considerably contributed to heat retention in mothers. Suckling offspring appeared to prevent mothers from releasing cumulative heat, although the significance of suckling behaviour on overheating was smaller than that of metabolic heat generation.
7
Jackson, Claire. "Studies of the environmental and endocrine control of reproduction in the four striped field mouse, Rhabdomys pumilio". Thesis, Rhodes University, 2003. http://hdl.handle.net/10962/d1005465.
Testo completoAbstract (sommario):
Previous studies of the control of reproduction in Rhabdomys pumilio have shown that day length alone does not inhibit spermatogenesis, that a reduction in food availability and ambient temperature results in an inhibition of gametogenesis, that females are more susceptible to inhibition than are males, and that mice that are able to maintain a body fat store in the face of an energetic challenge, are less likely to show reproductive inhibition than those that lose their fat store. In the present study, field and laboratory experiments were conducted to examine the effects of winter food supplementation on reproduction and population dynamics, and the effects of exogenous GnRH, leptin and mercaptoacetate (MA) on reproductive activity of Rhabdomys pumilio exposed to an energetic challenge. In the field food supplementation experiments in Thomas Baines Nature Reserve (2000, 2001), there was no winter inhibition of reproduction and provision of supplementary food had little effect. While at Mountain Zebra National Park (2002) winter was harsher, females became reproductively inactive, spermatogenesis continued and the provision of extra food resulted in higher rates of individual growth and larger reproductive organs. Treatment of mice that had been exposed to a prolonged energetic challenge, with exogenous GnRH (1µg/mouse/treatment) resulted in an increase in the masses of the testes and epididymides, and in the activity of the reproductive organs. Treatment with exogenous leptin (40µg/mouse/treatment), concurrently with an energetic challenge, countered the negative effects of the energetic challenge, and treated males had larger reproductive organs. MA (600µmol/kg body mass), given concurrently with an energetic challenge, did not inhibit fat metabolism, although the high-fat diet countered the effects of the energetic challenge. Results suggest that the first response of male Rhabdomys pumilio to an energetic challenge is a reduction in the size of the reproductive organs, without an inhibition of spermatogenesis. It is likely that this effect is mediated via white fat and leptin, and leptin’s influence on the hypothalamic-pituitary-gonad axis. Results of the study support the suggestion that females are more sensitive to reproductive inhibition than males and that reproduction in Rhabdomys pumilio is truly opportunistic.
8
Bander, S. A. A. "Pre-zygotic interactions in mice : A genetic analysis". Thesis, University of Essex, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380568.
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9
Shukri, N. M. "Genetic studies of male reproductive characteristics in mice". Thesis, University of Essex, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383426.
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10
Gray, Janine. "The effect of photoperiod on some aspects of reproduction in a Southern African rodent : the pouched mouse (Saccostomus Campestris)". Thesis, Rhodes University, 2001. http://hdl.handle.net/10962/d1005361.
Testo completoAbstract (sommario):
The pouched mouse, Saccostomus campestris is widely distributed south of the Sahara, inhabiting both subtropical and tropical latitudes and a number of different biotic zones, where it breeds seasonally. In North temperate latitudes, reproduction in small mammals is controlled by photoperiod however this cue becomes less influential as latitude decreases towards the equator. The aim of the present study is to establish the role of photoperiod in the environmental control of reproduction in a seasonally breeding small mammal at low latitudes in a highly unpredictable environment. Spermatogenesis of domesticated and Fl-generation pouched mice was not inhibited by short daylength while decreasing daylength significantly affected the oestrous cycle of adult domesticated female pouched mice. Photoperiod had little effect on the oestrous cycle of F I-generation females while a possible inherent circannual endogenous rhythm controlled inhibition of reproduction in these females. Body mass of male and female juvenile pouched mice was consistently lower in short daylength and in juvenile female pouched mice the onset of fertility may be weight-dependent. The attainment of sexual maturity of domesticated and FIlF2-generation females was retarded but not halted in short daylength and females in long daylength reached puberty 7.8 - 10.2 days earlier. Short daylength also lengthened the interval between vaginal perforation and first oestrus. Puberty in juvenile females was age-dependent as both domesticated and FIlF2-generation males attained puberty at 50 days of age, although fewer males were fertile in long daylength than short daylength. Although litter size of pouched mice was smaller in short daylength for both domesticated and wildcaught females this was not due to a reduction in the ovulation rate. Domesticated females had significantly larger litters than wild-caught females. Male and female pouched mice have evolved different reproductive strategies as males become sexually mature at the same age irrespective of photoperiod and remain fertile throughout the year. In contrast, females tend to be more complex as juveniles delay reproductive maturity and adults become nonreproductive in short daylength. However, in the presence of a fertile male and if environmental conditions are favourable, in short daylength, females can become reproductively active within approximately 3 days. Thus, although the pouched mouse has adopted a purely opportunistic reproductive strategy, vestiges of photoresponsiveness are still present in the female. The seasonality exhibited in the wild is therefore due to the female. Pouched mice live in a highly unpredictable environment so the sole use of photoperiod to regulate reproduction would be disadvantageous.
11
SALGADO, ANDREIA R. "Transferencia ovariana como alternativa para a restauracao das funcoes reprodutivas em femeas de camundongos irradiadas com radiacao gama de Co-60". reponame:Repositório Institucional do IPEN, 2010. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11530.
Testo completoAbstract (sommario):
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
12
Widin, Abigail Grace. "Regulation of ion channels in the unfertilised mouse egg". Thesis, The University of Sydney, 1998. https://hdl.handle.net/2123/27594.
Testo completoAbstract (sommario):
This thesis describes the use of the patch-clamp technique to study the large conductance K" channel and the T-type calcium current in unfertilised mouse eggs. In addition, this thesis also describes studies that examined cytokinesis of
one-cell mouse zygotes.
13
Sekulovski, Nikola. "TISSUE-SPECIFIC ABLATION OF INSULIN RECEPTOR SIGNALING RESULTS IN INFERTILITY IN FEMALE MICE". OpenSIUC, 2020. https://opensiuc.lib.siu.edu/dissertations/1833.
Testo completoAbstract (sommario):
IGF1 and its receptor IGF1R have been correlated with the proliferation of granulosa cells as well as steroid synthesis. Studies have shown that conditional ablation of Igf1r in granulosa cells leads to follicular arrest at a secondary stage, absence of ovulation and infertility. With a high homology between IGF1R and INSR, the full effects of insulin signaling could be masked by just a single receptor knockout. Therefore, utilizing Esr2-iCre we generated a granulosa specific double knockout mouse model. These mice have severely disrupted follicular development, with a block at a primary stage. Granulosa cells do not proliferate, while the oocytes appear activated resulting in reduction of ovarian size, absence of estrous cyclicity and infertility. Since an early granulosa cell knockout leads to block in follicular development, it masks the receptor function during ovulation, and CL formation. With the use of Pgr-Cre, the follicular development goes undisturbed until the periovulatory stages. Pgr-Cre knockout of Insr and Igf1r results in reduced ovulation, and progesterone synthesis. Few oocytes, that do escape, get fertilized but fail to thrive, and do not implant. Pgr-Cre is also active in the uterine endometrium. Ablation of Insr and Igf1r in the uterus results in reduced endometrial proliferation during the preimplantation period, complete absence of implantation and decidualization. Collectively, these results indicate the importance of INSR and IGF1R during follicular development, and ovulation, as well as in uterine proliferation, implantation, and decidualization.
14
Wagner, Catherine Ann Robertson. "Reproduction and Enzyme Detoxification Activities in Mouse Lines Selected for Response to Fescue Toxicosis". Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/9783.
Testo completoAbstract (sommario):
In previous work, mouse lines were selected for resistance (R) or for susceptibility (S) to fescue toxicosis based upon reductions in post-weaning growth rate caused by an endophyte-infected diet. The first objective of the current experiment was to determine whether long term reproduction of S mice was more severely depressed than that of R mice by the toxic diet. The second objective was to quantify glutathione-S-epoxytransferase (GST) and uridine diphosphate glucuronosyl-transferase (UDPGT) activities in R and S dams form the experiment and to determine whether reproduction during continuous cohabitation and liver detoxification enzyme activities were correlated within line x diet groups. Effects of the toxic diet were detectable within the first litters produced. Reproduction was more seriously influenced by the toxic diet within the S line than within the R line when these measures were compared within four equal time phases. The effects of the toxic diet on reproduction were greatest early in the experiment; by the fourth time phase differences among line x diet groups, with the exception of litter weight, were not significant. Percentage differences in total reproduction were greater between S mice fed the non-toxic diet and S mice fed the toxic diet than those between the R mice fed the non-toxic and toxic diets. Averaged across diets, GST activities were higher in R mice, but UDPGT activities were not significant. Within R line mice, GST was correlated with three reproductive measures, but UDPGT activity was not correlated with reproduction within any line x diet group.Master of Science
15
Suzuki, Taichi A. "Speciation and Reduced Hybrid Female Fertility in House Mice". Thesis, The University of Arizona, 2011. http://hdl.handle.net/10150/202701.
Testo completoAbstract (sommario):
I asked whether there is female sterility in hybrid offspring of Mus musculus domesticus and M. m. musculus using two wild derived inbred strains representing each subspecies. I evaluated F1 hybrid female fertility by crossing F1 females to a tester male and comparing multiple reproductive parameters between intra-subspecific controls and inter-subspecific hybrids. Hybrid females had smaller litter size, reduced embryo survival, fewer ovulations, and fewer small follicles relative to controls. Significant variation in reproductive parameters was seen among different genotypes. Genes contributing to hybrid female infertility are polymorphic within subspecies. Differences in reproductive phenotypes in F1's of reciprocal crosses suggest that female subfertility may be due to either cyto-nuclear incompatibility or to imprinting. These findings suggest a greater complexity in hybrid sterility than has been previously appreciated and highlight the potential importance of hybrid female sterility in the early stages of speciation.
16
Shi, Mingxin. "EFFECTS OF BISPHENOL A ANALOGUES (BISPHENOL E AND BISPHENOL S) ON REPRODUCTIVE FUNCTION IN MICE". OpenSIUC, 2019. https://opensiuc.lib.siu.edu/dissertations/1724.
Testo completoAbstract (sommario):
Bisphenol (BP) A is a common manufacturing chemical in polycarbonate plastics and has been widely used in plastics, epoxy resin liners of canned foods, dental materials, and thermal receipts. Human exposure to BPA is associated with a negative impact on human health including the development and function of the reproductive system due to its action as an endocrine-disrupting chemical (EDC). Numerous experimental studies have demonstrated that BPA impairs both male and female reproductive function, despite the variation in study paradigms such as dose, exposure route, timing, and outcomes measured. Due to the toxicological effects of BPA, BPA analogues such as BPS have been used as alternatives for BPA. However, recent evidence has suggested these BPA analogues can induce similar or even more severe toxic effects as BPA, and health risks of exposure to replacement bisphenols need to be considered. Therefore, my study was designed to examine whether prenatal exposure to BPE and BPS negatively impacts on male and female reproductive function in mice. Pregnant females were orally administrated corn oil (control), BPA, BPE, and BPS (0.5, 20, or 50mg/kg/day) from gestational day 11 (the presence of vaginal plug=1) to birth, and reproductive tissues in F1 mice were collected and analyzed in both neonatal and adult mice. In males, I observed reduced sperm counts and quality, disrupted stages of spermatogenesis in adults and increased germ cell apoptosis in neonatal testis following prenatal BPA, BPE or BPS exposure. Particularly, I found the expression of methyltransferases for DNA methylation and histone modification was also affected by prenatal exposure to BPA, BPE, or BPS in neonatal testis, suggesting a potential of epigenetic alterations in F1 males. In females, prenatal exposure to BPE and BPS accelerated the onset of puberty, disrupted estrous cyclicity, and caused several fertility problems especially in aged mice. In the neonatal ovaries, I also observed that BPE and BPS inhibit germ cell nest breakdown comparable to BPA. These results suggest that prenatal exposure to BPE and BPS with physiologically relevant doses affects male and female reproductive function probably due to germ cell development defects in the developing gonads. Finally, to understand their complete impact on male and female fertility, a study of transgenerational effects of BPE and BPS is performed to examine the transgenerational effects of prenatal exposure to BPA, BPE and BPS on reproductive function in F3 offspring. To be called transgenerational, expression of the specific phenotype will be continued at least across three generations. As described in previous studies, the direct exposure of a pregnant female (F0 generation) results in the exposure of the embryos (F1 generation) and the germline that will generate the next generation (F2 generation). Thus, I orally exposed to control treatment (corn oil), BPA, BPE or BPS (0.5 or 50 μg/kg/day) from gestational day 7 to birth in pregnant females (F0). Mice from F1 and F2 offspring were used to generate the F3 generation. In F3 males, prenatal exposure to BPA, BPE, and BPS induces persistence and even more severe phenotypes in sperm counts and motility in the F3 generation than in the F1 offspring. The expression of DNA and histone methyltransferases were transgenerationally increased by BPA, BPE and BPS exposure in both neonatal and adult testis. In F3 females, prenatal exposure to BPA, BPE, and BPS accelerated the onset of puberty and exhibited abnormal estrous cyclicity, and those females exhibited similar fertility problems as those in the F1 generation. However, BPA, BPE and BPS exposure did not affect neonatal follicular development such as germ cell nest breakdown or follicle numbers in the ovary on postnatal day 4. Taken together, our results suggest that prenatal exposure to BPA analogues, BPE and BPS, have transgenerational effects on male and female reproductive function in mice. Our findings suggest the hypothesis that transgenerational epigenetic alterations in germ cells may lead to reproductive disorders/dysfunction in the F3 generation.
17
Wang, Oulu. "Glucocorticoids Regulate Kisspeptin Neurons during Stress and Contribute to Infertility and Obesity in Leptin-Deficient Mice". Thesis, Harvard University, 2012. http://dissertations.umi.com/gsas.harvard:10169.
Testo completoAbstract (sommario):
Stressors generate adaptive responses, including transient suppression of reproductive function. Natural selection depends on successful reproduction, but inhibition of reproduction to survive famine or escape predation allows animals to survive to reproduce at a later time. The cellular locations and mechanisms responsible for inhibiting and reactivating the reproductive axis during and after stress, respectively, are not well understood. We demonstrated that stress-induced elevation in glucocorticoids affects hypothalamic neurons that secrete kisspeptin (KISS1), an important reproductive hormone. Stressors that stimulated glucocorticoid secretion, as well as glucocorticoid administration itself, inhibited Kiss1 mRNA expression, while conditions that did not change glucocorticoid secretion did not alter Kiss1 mRNA expression. In mice lacking glucocorticoid receptor specifically in kisspeptin-containing neurons, Kiss1 mRNA expression was no longer inhibited during restraint stress despite a rise in corticosterone, and both testosterone and copulatory behaviors showed accelerated recovery in the post-traumatic period. We also demonstrated that increased glucocorticoid secretion contributed to infertility and obesity in leptin-deficient mice. Leptin deficiency creates a chronic state of perceived starvation, and leptin-deficient mice exhibit elevated plasma glucocorticoid concentrations, morbid obesity, and infertility. Leptin-deficient, glucocorticoid-deficient mice exhibited decreased body weight and fat composition, decreased hyperphagia, and normal fertility. When supplemented with glucocorticoids back to the initial levels present in leptin deficiency, these mice gained weight and became infertile. Thus, leptin is not required for fertility as previously believed, and glucocorticoids can contribute to obesity and suppress fertility independently of leptin signaling. Together, these findings implicate glucocorticoids in the regulation of obesity and reproductive inhibition during stress, including perceived starvation caused by leptin deficiency. These studies may provide novel mechanisms and molecular targets in the reproductive and metabolic aspects of disorders characterized by glucocorticoid dysregulation, including post-traumatic stress disorder, anorexia nervosa, and mood disorders.
18
Qin, Kun, e 秦堃. "Role of a distinct PA gene for the pathogenicity and replication properties of avian H5N1 influenza virus in mice". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B43278462.
Testo completo
19
Rehmeier, Ryan L. "Factors influencing nightly activity of deer mice (Peromyscus maniculatus) in tallgrass prairie". Diss., Manhattan, Kan. : Kansas State University, 2005. http://hdl.handle.net/2097/139.
Testo completo
20
Yaeram, Jakrit. "The effect of whole body heating on testis morphology and fertility of male mice". Title page, table of contents and summary only, 2002. http://web4.library.adelaide.edu.au/theses/09PH/09phj259.pdf.
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21
Firman, Renee C. "The evolutionary implications of polyandry in house mice (Mus domesticus)". University of Western Australia. School of Animal Biology, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0162.
Testo completoAbstract (sommario):
[Truncated abstract] Despite the costs associated with mating, females of many taxa solicit multiple mates during a single reproductive event (polyandry). Polyandry is clearly adaptive when females gain direct benefits from males at mating. However, polyandry has also been shown to increase female fitness in the absence of direct benefits. Thus, a number of genetic benefit hypotheses have been developed to account for the origin of this behaviour. Although not mutually exclusive, a distinction lays between genetic benefits that propose defense against reproductive failure (nonadditive genetic effects), and those that propose benefits from intrinsic sire effects (additive genetic effects). Nonadditive genetic benefits of polyandry have been documented in a number of species; by soliciting multiple mates females can avoid inbreeding and other forms of incompatibility between parental genotypes. Polyandry may also increase female reproductive success when genetically superior males have greater success in sperm competition, and produce better quality offspring. An inevitable consequence of polyandry is that sperm from rival males will overlap in the female reproductive tract and compete to fertilise the ova. The outcome of sperm competition is typically determined by bias in sperm use by the females, interactions between parental genotypes, and ejaculate characteristics that provide a fertilisation advantage. Thus, sperm competition is recognised as a persuasive force in the evolution of male reproductive traits. Comparative analyses across species, and competitive mating trials within species have suggested that sperm competition can influence the evolution of testis size and sperm production, and both sperm form and sperm function. ... After six generations of selection I observed phenotypic divergence in litter size - litter size increased in the polyandrous lines but not in the monandrous lines. This result was not attributable to inbreeding depression, or environmental/maternal effects associated with mating regime. Genetic benefits associated with polyandry could account for this result if increased litter size were attributable to increased embryo survival. However, males from the polyandrous lineages were subject to sperm competition, and evolved ejaculates with more sperm, suggesting that evolutionary increases in litter size may in part be due to improved male fertility. Finally, Chapter Five is an investigation of the natural variation in levels of polyandry in the wild, and the potential for sperm competition to drive macroevolutionary changes in male reproductive traits among geographically isolated island populations of house mice. I sampled seven island populations of house mice along the coast of Western Australia and, by genotyping pregnant females and their offspring, determined the frequency of multiply sired litters within each population. I applied the frequency of multiple paternity as an index of the risk of sperm competition, and looked for selective responses in testis size and ejaculate traits. I found that the risk of sperm competition predicted testis size across the seven island populations. However, variation in sperm traits was not explained by the risk of sperm competition. I discuss these results in relation to sperm competition theory, and extrinsic factors that influence ejaculate quality.
22
Bianco, Juares Ednaldo Romero. "O modelo de pseudogestação em camundongos para o estudo 'in situ' das celulas Natural Killer uterinas". [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/316845.
Testo completoAbstract (sommario):
Orientador: Aureo Tatsumi YamadaDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-06T17:18:35Z (GMT). No. of bitstreams: 1 Bianco_JuaresEdnaldoRomero_M.pdf: 23225852 bytes, checksum: 523781fa325c40e61fa0fe33c59406a1 (MD5) Previous issue date: 2006
Resumo: Durante o período peri-implantacional na gestação de humanos e roedores, ocorre no estroma da mucosa uterina um conjunto de fenômenos que envolvem modificações dos componentes celulares e da matriz extracelular. Este conjunto de modificações é conhecido como decidualização ou reação decidual. Concomitante a este processo ocorre a migração de leucócitos provenientes de órgão hematopoéticos para este estroma. Dentre estes leucócitos predominam as subpopulações de linfócitos denominados de células ¿uterine Natural Killer¿ (uNK), que atuam na gestação reconhecendo o embrião alogeneico, modulando a reação decidual e o crescimento placentário. Porém, a sua participação nos casos de aborto e o possível desencadeamento do potencial lítico e citotóxico relacionado com a resposta imune inata, não foi ainda totalmente elucidado. O presente trabalho buscou desenvolver estratégias para o estudo in situ das células uNK, sem a influência de fatores oriundos do embrião, empregando o modelo da pseudogestação em camundongos. Foram utilizados fêmeas pseudogestantes obtidos através do acasalamento com machos vasectomizados e inoculação intraluminal do óleo vegetal (arachis) ou mineral (nujol) no útero de 4° dia de pseudogestação (dpg). Estes animais pseudogestantes foram subdivididos em grupos submetidos ou não a ovarectomia e com suplementação hormonal de estrógeno e/ou progesterona ou hormônio gonadotrófico coriônico (hCG). Foram coletados o útero e ovário e processados para análise em microscopia de luz e eletrônica de transmissão no 9°, 12° e 14° dpg. Fêmeas em gestação normal foram utilizados como grupo controle. As análises histológicas, citoquímicas e ultra-estruturais efetuadas demonstraram que a indução da pseudogestação com emprego tanto de óleo vegetal (arachis) quanto de óleo mineral resultam na reação decidual e presença de células uNK lectina DBA (Dolichos biflorus) positivas. A reação decidual resultante e mais exuberante com o óleo de arachis, porém, o período de manutenção do deciduoma é menor, mesmo com a suplementação hormonal de progesterona, se comparado ao grupo de animais induzidos com o óleo mineral e suplementada com HCG. As características morfológicas das células uNK foram melhor preservadas nos animais pseudogestantes induzidos com o óleo mineral, não ovarectomizados e suplementados com o HCG.Nestes, as células uNK foram encontradas aém do 12° dpg em meio ao endométrio que mantinha o deciduoma, enquanto nos demais grupos o deciduoma era destituído antes do 12º dpg. Porém, , à semelhança dos demais grupos experimentais, houve predominância de formas menos diferenciadas de células uNK (subtipos I e II), sendo raras as formas plenamente diferenciadas (subtipo III). Em nenhum dos grupos foi encontrado o subtipo IV, correspondentes à forma de degeneração destas células. Estes resultados demonstram que as características do endométrio e o comportamento das células uNK na pseudogestação, apresentam diferenças influenciadas pelos meios de indução utilizados e regimes hormonais adotados.Além disso, a ausência do concepto parece ser o fator limitante na continuidade da manutenção do utero seudogestante. Por conseguinte, a pseudogestação induzida com óleo mineral e mantida sob a regência ovariana supra-controlado pelo HCG poderia ser adotada como modelo experimental para estudo das células uNK sem a interferência do embrião. Este modelo deverá permitir novas estratégias para investigação dos diversos fatores de origem embrionário/fetal que possam afetar as atividades destas e/ou outras células de forma controlada in situ no ambiente uterino que simule a gestação
Abstract: During the period of pre-implantation in humans and rodents gestations, a set of phenomenon, involving, modifications of cellular components and extracellular matrix occur in the stroma of the uterus. These modifications, are known as decidualization or decidual reaction. During this processes a migration of leukocytes that came from the heamatopoetic organs occur into the uterine stroma. Among these leukocytes, there is a predominance of a subpopulation of leukocytes known as uterine Natural Killers (uNK) that play important roles during gestation by recognizing the allogeneic embryos and modulating the decidual reaction and the placental growth. However, the uNK participations in miss carriage and triggering of lytic and citotoxic potential related to innate immune response during pregnancy have not elucidated yet. The present work aimed to develop a strategy for uNK study without the influence of embryonaryfactors by using the pseudopregnancy model in mice. It was used the pseudopregnant females mice obtained by matting with vasectomized males and intra-luminal injection of arachis or mineral oil in the uterus on 4th day of pseudopregnancy (dpp). These animals were grouped according to treatment submitted of ovarectomy or not and with exogenous supplement of progesterone and/or estradiol or chorionic gonadotrophin hormone (HCG). The uteri and ovary were collected and processes for light and electron microscope on the 9th, 12thand 14thdpp. Normal pregnant females were used as controls. Histological analysis, cytochemistry and ultrastructure demonstrated that the induction of pseudopregnancy by using both arachis oil and mineral oil resulted in decidual reaction and presence of the DBA (Dolichos biflorus) lectin positive uNK cells. The decidual reactions induced by arachis oil were more intensive and exuberant, but the deciduomas were not sustained longer even under progesterone treatment, if compared to those, in the uterus induced with mineral oil, and supplemented with HCG. The morphological characteristics of the uNK cells were better preserved in the pseudopregnant animals induced with mineral oils, not ovarectomized and supplement with HCG. In these animals, the uNK cells were found over the 12th dpp in the endometrium preserving the deciduoma while it failed before 12th dpp in the other groups However, similarly to other experimental groups, there was predominance immature forms of uNK cells (subtypes I and II), being rare the fully differentiated forms (subtype III). No groups did not show the uNK sub type IV, corresponding to the degeneration form of this cell
Mestrado
Histologia
Mestre em Biologia Celular e Estrutural
23
Silva, Raquel Frenedoso 1988. "Ação protetora da N-acetilcisteína sobre efeitos persistentes do trióxido de arsênio no sistema genital de camundongos Swiss". [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/316179.
Testo completoAbstract (sommario):
Orientador: Wilma De Grava KempinasTexto em português e inglês
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-24T16:12:27Z (GMT). No. of bitstreams: 1 Silva_RaquelFrenedoso_M.pdf: 3492189 bytes, checksum: 66cf94f64336b7c79f7b1cf8981d8d60 (MD5) Previous issue date: 2014
Resumo: O trióxido de arsênio (As2O3) tem se mostrado altamente eficaz e muito utilizado no tratamento para diminuir ou eliminar a leucemia promielocítica aguda. Estudos mostram relação entre exposição a este composto e inibição da espermatogênese ou desenvolvimento do espermatozoide, uma vez que exerce efeito inibitório nos testículos. Diante da crescente utilização do As2O3 no tratamento da leucemia e da escassez de resultados sobre os seus efeitos adversos na reprodução masculina, justifica-se a realização do presente estudo, pelo qual se avaliou os efeitos imediatos e tardios do tratamento com As2O3 sobre fisiologia reprodutiva de camundongos Swiss adultos e se a co-administração de N-acetilcisteína (NAC), previne esses efeitos. Em um primeiro experimento, camundongos Swiss adultos foram tratados com veículo, 0,3 ou 3,0 mg/Kg/dia de As2O3, via subcutânea, em 25 aplicações. No final do tratamento, metade dos animais foram eutanasiados para avaliação dos efeitos pós-tratamento e a outra metade foi mantida sem a droga por período de 50 dias, até que se procedeu a eutanasia para avaliação da possível reversibilidade dos efeitos. Foram investigados: peso dos órgãos vitais, reprodutores e glândulas sexuais acessórias, quantidade e qualidade espermáticas, dosagem de testosterona e dosagem de arsênio no sangue. Os animais tratados com 3,0 mg/kg de As2O3 e eutanasiados logo após o fim do tratamento mostraram diminuição no peso da vesícula seminal, número de espermatozoides móveis e produção espermática diária. Após período de suspensão do tratamento, os animais tratados com a mesma dose continuaram apresentando redução nos mesmos parâmetros. Em um segundo experimento, foi avaliada a contratilidade do ducto epididimário isolado tanto frente ao tratamento in vivo dos animais (tratados com o veículo ou com a dose de 3,0 mg/kg/dia de As2O3) quanto ao tratamento in vitro do tecido. Essa análise revelou que a contração máxima do ducto epididimário estava significativamente aumentada nos animais tratados com As2O3 in vivo. E em uma terceira etapa os animais foram divididos em Controle, As2O3 (3,0 mg/Kg/dia), NAC na água de beber (40mM) e As2O3 + NAC, tratados por 5 semanas. Após o final do tratamento, os animais foram avaliados quanto aos parâmetros que se apresentaram prejudicados com o tratamento anterior, descrito na etapa um. Quando a NAC foi oferecida aos animais, houve uma melhora significativa nos parâmetros espermáticos antes prejudicados pela administração da droga, i.e., o peso de vesícula seminal, número de espermatozoides móveis e produção espermática diária do grupo As2O3 + NAC foram similares ao grupo controle. Podemos concluir que o As2O3 exerce efeitos tóxicos sobre o sistema genital de camundongos machos, e que esses efeitos podem ser persistentes mesmo após o término do tratamento. Os resultados mostraram, também, que a administração de um antioxidante pode prevenir os efeitos deletérios dessa droga sobre os parâmetros avaliados
Abstract: Arsenic trioxide (As2O3), a trivalent arsenic form has proven highly effective and widely used in the treatment to reduce or eliminate acute promyelocytic leukemia. Studies show a relationship between exposure to this compound and inhibition of spermatogenesis and sperm development since it exerts an inhibitory effect on the testis. Given the growing use of As2O3 on treatment of leukemia and the lack of results about the side effects on male reproduction, it is justified to carry out this study, which evaluated the immediate and late effects of treatment with As2O3 on the structure and reproductive physiology of adult Swiss mice and whether the co-administration of N-acetylcysteine (NAC) prevents these effects. In a first experiment, adult Swiss mice were treated with vehicle, 0.3 or 3.0 mg/Kg/day of As2O3, subcutaneously in 25 applications. At the end of treatment, half of the animals were euthanized for evaluation of the post- treatment effects and the other half was maintained without the drug for 50 days until the euthanasia to evaluate the potential reversibility of the effects. It was evaluated: the vital, reproductive and accessories organ weights, analyzes of sperm quantity and quality, testosterone and arsenic measurements in blood. Animals treated with 3.0 mg/Kg of As2O3 and euthanized immediately after the end of treatment showed a decrease of seminal vesicle weight, in number of motile spermatozoa and daily sperm production. After suspension of treatment, animals treated with this same dose continued to show reduction in these same parameters. In a second experiment, the contractility of the epididymal duct was evaluated both in vivo treatment of animals (treated with vehicle or a 3.0 mg/Kg/day of As2O3) and in vitro treatment of the tissues. This analysis revealed that the maximum contraction of the epididymal duct was significantly increased in in vivo treated animals. And in a third step animals were divided into Control, As2O3 (3.0 mg/Kg/day) NAC in tap water (40 mM) and As2O3 + NAC, treated for 5 weeks. After the end of treatment, animals were assessed for previously impaired parameters described in step one. When NAC was given to the animals, there was a significant improvement in sperm parameters before harmed by the drug administration, i.e. seminal vesicle weight, number of motile sperm and daily sperm production in As2O3 + NAC group were similar to the control group. We conclude that As2O3 exerts toxic effects on the male mice genital system, and that these effects may be persistent even after the end of treatment. Also, the results showed that administration of an antioxidant can prevent the deleterious effects of this drug on the parameters evaluated
Mestrado
Biologia Celular
Mestra em Biologia Celular e Estrutural
24
Mjihdi, Abdelkarim. "Capacité de reproduction de la souris et infection aiguë par Trypanosoma cruzi". Doctoral thesis, Universite Libre de Bruxelles, 2004. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/211065.
Testo completoAbstract (sommario):
Trypanosoma cruzi est un parasite protozoaire à multiplication intracellulaire, agent de la maladie de Chagas, infectant 16 à 18 millions de personnes en Amérique latine. Il peut être transmis de la mère infectée au fœtus dans 2 à 10 % des cas, mais ses autres effets sur la gestation ont été peu étudiés. Par ailleurs, les cytokines ont des effets sur la gestation. Certaines d’entre elles, comme l’interleukine-1, l’IL-4, l’IL-5, l’IL-10, le GM-CSF et le TGF-b2, sont bénéfiques pour la gestation, tandis que d’autres, comme l’IL-2, l’IL-12, l’IFN-g et le TNF-a ont des effets nocifs sur celle-ci. L’impact de l’infection à T. cruzi, stimulant la production de TNF-a et d’IFN-g, sur l'implantation et la croissance fœtale n’a pas été étudié.Le but de notre travail était d’étudier les effets de l’infection aiguë à T. cruzi sur la capacité de reproduction de la souris. Nous avons ainsi évalué les effets de cette infection sur la fertilité, le développement et la viabilité des fœtus de souris et le rôle de l’IFN-g et du TNF produits au cours de l’infection sur le développement de la gestation.
Nous avons montré que l’infection aiguë à T. cruzi :i) diminue la capacité de reproduction de la souris ;ii) provoque une mortalité fœtale massive précoce (résorptions), tardive et néonatale associée à un retard de croissance intra-utérin, et ce, iii) en dehors de toute transmission congénitale du parasite.
Par ailleurs nos travaux montrent que la mortalité fœtale/néonatale est associée à une invasion parasitaire massive du placenta qui présente d’importantes lésions à type d’infiltrats inflammatoires, de nécrose ischémique, de dépôts de fibrine et de thromboses vasculaires. Nous avons noté qu’il existe une relation inverse entre la charge parasitaire des unités utéro-placentaires et la viabilité du conceptus, suggérant que ces lésions placentaires contribuent à la mortalité fœtale en limitant les échanges materno-fœtaux.
Enfin, nous avons également étudié le rôle de cytokines abortogènes comme le TNF et l’IFN-g, produites abondamment pendant l’infection aiguë de la souris par T. cruzi. Les taux sanguins maternels d’IFN-g étaient augmentés au 9ième mais pas aux 17ième et 19ième jours de gestation, alors que les taux de TNF sanguin et la production placentaire de cette cytokine augmentaient aux 17ième et 19ième jours de gestation. Afin d’évaluer le rôle de ces deux cytokines dans la mortalité fœtale, des souris ont été traitées par la pentoxifylline, pour inhiber la transcription du gène de TNF-a et diminuer la production d’IFN-g. Ces souris montraient une réduction de la mortalité fœtale à mi-gestation, associée à une diminution de la production du TNF placentaire, sans modifications des taux systémiques et sans effets sur l’IFN-g, suggérant la contribution du TNF dans la mortalité fœtale associée à l’infection aiguë par T. cruzi.
En conclusion, notre travail montre que l’infection aiguë à Trypanosoma cruzi exerce un effet particulièrement néfaste sur la capacité de reproduction et le développement de la gestation chez la souris et que les lésions placentaires liées à l’infection et la production de TNF par le placenta infecté contribuent à cet effet.
Doctorat en sciences biomédicales
info:eu-repo/semantics/nonPublished
25
Consonni, Sílvio Roberto 1986. "Avaliação morfológica, bioquímica e molecular da elastogênese em tecidos adultos no modelo da sínfise púbica de camundongos durante e após a prenhez". [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317879.
Testo completoAbstract (sommario):
Orientadores: Paulo Pinto Joazeiro, Cláudio Chrysostomo WerneckDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-18T04:27:14Z (GMT). No. of bitstreams: 1 Consonni_SilvioRoberto_M.pdf: 3398352 bytes, checksum: 7a1238aba907982b903dec23fbc0470d (MD5) Previous issue date: 2011
Resumo: A organização das fibras elásticas envolve a síntese e a deposição de moléculas em uma sequência altamente regulada para assegurar as características elásticas nos estágios iniciais do desenvolvimento. Durante e prenhez, os tecidos pélvicos ricos em fibras elásticas se alteram para permitir um parto seguro e essa remodelação é essencial para o parto normal. A sínfise púbica de camundongos também remodela em um processo controlado por hormônios. Este fenômeno compreende a "transformação" da fibrocartilagem em um ligamento interpúbico (LIp) seguido por seu relaxamento antes do parto. Após o primeiro parto, o processo de retorno ocorre e assegura a homeostase dos tecidos pélvicos. Ainda, alterações no suporte dos órgãos pélvicos foram descritas em animais geneticamente modificados para proteínas envolvidas na elastogênese como a lysyl oxidase-like 1 (LOXL1), fibulina-3 e 5. Como ligamentos são as principais estruturas de suporte dos órgãos pélvicos, o objetivo deste estudo foi avaliar a elastogênse no desenvolvimento do LIp durante a prenhez de camundongos. Assim, camundongos selvagens C57Bl/06 e deficientes em fibrilina-1 virgens, prênhes e no pós-parto foram estudados usando microscopia de luz convencional, microscopia confocal a laser, microscopia eletrônica de transmissão, western blotting e real-time PCR. Ambos os animais selvagens e deficientes em fibrilina-1 apresentaram classicamente a separação dos ossos púbicos, a formação e relaxamento do LIp e a involução deste no pós-parto. Esses processos sugeriram um padrão no qual as células controlam a remodelação da matriz extracelular sob sinalização hormonal e molecular. A ultra-estrutura dos tecidos fibrocartilaginosos apresentou delgadas microfibrilas aleatoriamente distribuídas entre os fibrocondrócitos. Na formação do LIp, foram observadas fibras elásticas com conglomerados de material amorfo distribuídos entre as microfibrilas. O LIp mostrou fibras elásticas e todos os componentes teciduais alinhados na direção da abertura da articulação interpúbica antes do parto. O estudo imuno-histoquímico e de expressão gênica relativa quantitativa indicou que durante o desenvolvimento do LIp em camundongos selvagens, elastina/tropoelastina, fibrilina-1 e 2, LOXL1, fibulina-5 e TGF-? foram regulados espacial e temporalmente, e estas moléculas poderiam contribuir para a síntese de novas fibras elásticas que asseguram a elasticidade necessária para a cintura pélvica durante o preparo para o parto e também no fechamento da articulação no pós-parto. Entretanto, se comparados com o animal selvagem, a análise indicou alteração na expressão gênica relativa da tropoelastina, fibrilina-1, LOXL1, fibulina-5 e TGF-?, diferentemente da morfologia muito similar observada em camundongos selvagens. Neste estudo, o camundongo deficiente em fibrilina-1 não apresentou prolapso de órgãos pélvicos após o primeiro parto como o deficiente em LOXL1 (Liu et al., 2004), nem modificações morfológicas que poderiam ser relacionadas ao enfraquecimento dos tecidos pélvicos. No entanto, este é o primeiro estudo que relata disfunções pélvicas nos camundongos deficientes em fibrilina-1 multíparos, usados como matrizes reprodutivas. Em conclusão, a formação das fibras elásticas que ocorreu na sínfise púbica de camundongos durante a vida adulta possui características únicas de um modelo que pode ser usado para compreensão dos processos normais e patológicos, principalmente aqueles relacionados aos animais geneticamente modificados para proteínas envolvidas na elastogênese. Assim, este trabalho traz à luz as evidências das profundas modificações que a sínfise púbica de camundongos passa durante a prenhez com a síntese de novas fibras elásticas, o que pode contribuir na compreensão dos mecanismos biológicos para formação das fibras elásticas
Abstract: The organization of elastic fibers involves the synthesis and the deposition of molecules in a high regulated sequence to ensure the elastic characteristics in the early stages of development. During pregnancy, elastic fibers-enriched pelvic tissues change to allow safe delivery and this remodeling is essential to the vaginal delivery. The mouse pubic symphysis articulation also remodels in a controlled hormonal process. This phenomenon comprises the "transformation" of the fibrocartilage into an interpubic ligament (IpL) followed by its relaxation before parturition. After the first parturition, recovery process occurs to ensure the pelvic tissue homeostasis. Adding to that, pelvic organ support impairment had been described in genetically modified mouse for the proteins involved in the elastogenesis such as lysyl oxidase-like 1 (LOXL-1), fibulin-3 and -5. Since, ligaments are the main supportive structures of pelvic organs, the aim of this study was to evaluate the elastogenesis in the IpL development during mouse pregnancy. Thus virgin, pregnant and postpartum C57Bl/06 wild-type and fibrillin-1mg?/+ female mice were studied using light, confocal, transmission electron microscopy, western blotting and real-time PCR. Both, wild-type and fibrillin-1mg?/+ female mice showed classically the separation of the pubic bones, the formation and relaxation of the IpL and the recovery at postpartum. These processes suggested a pattern which cells control the extracellular matrix remodeling under hormonal and molecular signaling. The ultra-structure of the fibrocartilaginous tissue had slender bundles of microfibrils randomly distributed among the fibrochondrocytes. By the time IpL is formed, there were seen elastic fibers, which consist of small conglomerates of amorphous material, distributed among the bundles of microfibrils. The IpL showed elastic fibers and all tissue compounds aligned to the opening axis of the articulation before parturition. The immunohistochemical study and quantitative gene expression indicated that during IpL development in wild-type mice, tropoelastin/elastin, fibrillin-1, fibrillin-2, LOXL-1, fibulin-5 and TGF-? were spatial and temporal regulated, and these molecules might contribute to the synthesis of new elastic fibers that assure the elasticity that is needed to the pelvic girdle during preparation for parturition and also the recovery at postpartum. However, compared to wild-type mice, alterations were found in the quantitative gene expression of elastin, fibrillin-1, LOXL-1, fibulin-5 and TGF- ?, different from the morphology that was very similar to the one that was observed in wild-type mice. In this study, the fibrillinmg?/+ mice did not show pelvic organ prolapse after the first parturition as LOXL1-/- did (Liu et al., 2004), neither morphological modifications that could be related to the weakness of pelvic tissue. However, this is the first work about pelvic dysfunctions in multiparous fibrillin-1mg?/+ mice used as reproductive matrices. In conclusion, the elastic fiber assembly that occurred in the mouse pubic symphysis during the adult life has characteristics of a model that could be used to understand normal and pathological processes, mainly those related to genetically modified mice for the proteins involved in the elastogenesis. Then, this work may bring readers up-to-date with accumulating evidence that the mouse pubic symphysis undergoes remarkable modifications during pregnancy with new synthesized elastic fibers and may contribute to our understanding of the biological mechanisms about elastic fiber assembly
Mestrado
Histologia
Mestre em Biologia Celular e Estrutural
26
Christou-Kent, Marie. "Caractérisation de l'arrêt de la gamétogenèse chez l'homme du gène à la protéine Échec de maturation ovocytaire: Un rôle essentiel pour la protéine PATL2 dans l’ovogenèse PATL2 is a key actor of oocyte maturation whose invalidation causes infertility in women and mice". Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAV071.
Testo completoAbstract (sommario):
L’infertilité est considérée comme une préoccupation majeure de santé, touchant à plus de 50 millions de couples mondialement. Les techniques actuelles d’Assistance Médicale à la Procréation (AMP) ont comme prérequis des gamètes aptes à la fécondation et au développement embryonnaire. Dans les rares cas où des anomalies génétiques mène à un arrêt de la gamétogenèse et donc à la production de gamètes immatures, défectueux ou dégradés, un traitement n’est pas possible. Afin d’envisager de nouvelles stratégies de traitement, il est nécessaire de comprendre les bases moléculaires de ce type d’infertilité. De plus, ces patients représentent une opportunité unique nous permettant de découvrir de nouveaux acteurs de l’ovogenèse et de la spermatogenèse ainsi que de déchiffrer les voies moléculaires impliquées dans la production de gamètes compétentes.L’analyse génétiques de cohortes de patients consanguins peut permettre l’identification de variants génétiques héritées comme causes possibles de la pathologie. Nous avons identifié, par séquençage exomique, un variant pathogène du gène PATL2 dans les patientes atteintes d’un échec de maturation ovocytaire. Cette pathologie, que nous avons appelé la Déficience Méiotique Ovocytaire (DMO), consiste en l’ovulation récurrent d’ovocytes immatures et non-fécondables. Le gène PATL2 code une ribonucléoprotéine ovocytaire qui a été impliqué dans la régulation de la traduction des ARNm maternelles chez l’amphibien. Sa fonction chez les mammifères était jusqu’à présent mal caractérisé. Nous avons aussi identifié un variant pathogène du gène SPINK2, codant un inhibiteur de protéases qui est important pour la neutralisation de l’acrosine pendant le développement de l’acrosome.Par la génération de lignées de souris déficientes (KO) pour les gènes Patl2 et Spink2, et d’une lignée PATL2 « étiquetée » par la méthode CRISPR-Cas9, nous avons montrés que les deux protéines correspondantes jouent des rôles indispensables dans leur gamétogénèses respectives. Nous avons démontré que Patl2 est fortement exprimé dans l’ovocyte murin en cours de croissance, et que son absence entraîne une dérégulation de nombreux transcrits essentiels pendant la phase de croissance, de maturation méiotique ou de développement pré-implantatoire. Les femelles PATL2 KO sont subfertiles par accouplement naturel, et lors de la stimulation hormonale produisent une grande proportion d’ovocytes sans globule polaire (immatures) et/ou avec des défauts au niveau du fuseau méiotique, mis en évidence par immunomarquage. Suite à la fécondation in vitro, un grand nombre d’ovocytes PATL2 KO ont répondu de manière aberrante à la fécondation. Concernant les mâles SPINK2 KO, nous avons montré que l’absence de la protéine SPINK2, qui se localise dans l’acrosome, entraîne un arrêt de la spermiogenèse et une azoospermie à cause d’une autophagie au stade spermatide-ronde. Cet effet est vraisemblablement dû à une activité aberrante de l’acrosine en absence de son inhibiteur, une hypothèse soutenue par la fragmentation de l’appareil de Golgi et l’absence de l’acrosome, événements observés par immunofluorescence.Nous avons, donc, caractérisé deux sous-types génétiques d’infertilité humaine associés à la mutation de ces deux gènes. Ce faisant, nous avons approfondi notre compréhension des fonctions respectives de ces acteurs clés de la gamétogenèse chez les mammifères, ce qui pourrait ouvrir la voie vers une amélioration des techniques d’AMP actuelles ainsi que le développement de thérapies alternatives et personnaliséesInfertility is considered a global public health issue since it affects more than 50 million couples worldwide. Current assisted reproductive technologies (ARTs) have minimal requirements for gametes that are competent for fertilisation and subsequent embryo development. In cases where genetic abnormalities lead to arrested gametogenesis and the production of immature, defective or degraded gametes, treatment is not usually possible. Identifying the molecular causes of these types of infertility is crucial for developing new strategies to treat affected couples. Moreover, these patients represent a unique opportunity to discover new actors of oogenesis and spermatogenesis and to decipher the molecular pathways involved in the production of competent gametes.Genetic analysis of cohorts of infertile patients with shared ancestry can allow the identification of inherited genetic variants as possible causal factors. Using whole exome sequencing, we identified a homozygous pathogenic variant of the gene PATL2 in a cohort of patients with a phenotype of arrested oogenesis due to oocyte meiotic deficiency (OMD). OMD is a rare pathology characterised by the recurrent ovulation of immature oocytes. PATL2 encodes an oocyte ribonucleoprotein whose amphibian orthologue had been shown to be involved in oocyte translational control and whose function in mammals was poorly characterised. We also identified a pathogenic variant of the gene SPINK2 in a familial case of azoospermia. SPINK2 encodes a serine protease inhibitor essential for the neutralisation of acrosin activity during sperm acrosome formation.We showed, through generation of Patl2 and Spink2 knockout (KO) mice and Patl2 tagged mice (the latter using CRISPR-Cas9), that both corresponding proteins play essential respective roles in gametogenesis. We demonstrated that Patl2 is strongly expressed in growing mouse oocytes and that its absence leads to the dysregulation of numerous transcripts necessary for oocyte growth, meiotic maturation and preimplantation embryo development. This was accompanied by a phenotype of subfertility in KO females in natural mating, a large proportion of ovulated oocytes lacking a polar body (immature) and/or displaying spindle assembly defects in immunostaining, and high rate of oocytes with an aberrant response to fertilisation in IVF experiments. In Spink2 KO mice, we demonstrated that absence of Spink2 protein, which is located in the acrosome of maturing and mature spermatozoa, leads to arrested spermiogenesis and azoospermia due to autophagy at the round-spermatid stage. This is plausibly due to aberrant acrosin activity in the absence of its inhibitor, corroborated by fragmentation of the Golgi and absence of the acrosome in immunostaining.We have thus characterised two genetic subtypes of human infertility associated with mutation of these two genes. In doing so, we have furthered our understanding of the respective roles of these crucial actors of mammalian gametogenesis, potentially paving the way for improvement of current ARTs and development of new, personalised therapies
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Ogliari, Karolyn Sassi. "Efeitos intra-uterinos e pós-natais da exposição crônica ao combustível diesel sobre o aparelho reprodutor humano". Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/5/5144/tde-27102011-103611/.
Testo completoAbstract (sommario):
INTRODUÇÃO. Os efeitos da poluição atmosférica sobre a saúde humana são cada vez mais reconhecidos. A exposição ao combustível diesel, que contribui significativamente para a poluição em zonas de tráfego veicular intenso, pode ser ao menos parcialmente, responsável por estes efeitos. Estudos epidemiológicos demonstram maior incidência de pré-eclampsia, prematuridade e baixo peso ao nascer. Maiores taxas de falha de implantação e alterações da morfologia placentária são demonstrados em estudos experimentais. OBJETIVO. Análise morfológica do ovário e do útero de camundongos após exposição crônica ao combustível diesel durante a fase intra-uterina e pós-natal. MÉTODO. Estudo experimental prospectivo com crossover. Camundongos foram expostos durante uma hora a doses de combustão do diesel que correspondem a média diária de material particulado fino (MP2.5) recomendado pela Organização Mundial da Saúde (WHO) e a doses acima da média anual recomendada pela mesma. A dose de exposição a MP2.5 foi abaixo da dose recomendada pela Comissão Nacional do Meio Ambiente (CONAMA). Quatro grupos foram formados: animais expostos a ar filtrado no período intra-uterino e no período pós-natal (CC); animais expostos a diesel apenas no período intra-uterino, sendo que no período pós-natal foram expostos a ar filtrado (EC); animais expostos a ar filtrado no período intra-uterino e a diesel no pós-natal (CE), e animais expostos a diesel nos períodos intra-uterino e pós-natal (EE). A análise morfométrica do ovário e do útero foi realizada para definir a área relativa ocupada por cada tipo de folículo, pelo corpo lúteo e pelo estroma, e a proporção de área ocupada por glândulas, estroma e epitélio no endométrio. RESULTADOS. Uma redução significativa de folículos primordiais foi observada em animais expostos a diesel durante o período intra-uterino (p=0,035) e durante o período pós-natal (p=0,015), assim como em animais expostos a diesel nos dois períodos (p=0.004). Houve redução significativa de folículos primários quando os animais foram expostos no período intra-uterino (p=0.04). Não foram demonstradas alterações significativas no útero. CONCLUSÃO. A exposição a níveis considerados aceitáveis de combustão do diesel é prejudicial ao potencial reprodutivo de camundongos fêmeas, diminuindo sua reserva ovariana ao atingir a maturidade sexual, sugerindo o envolvimento de alterações epigenéticas. Tal efeito aumenta o risco de menopausa precoce. Estes resultados sugerem que diretrizes ambientais sejam revisadas, já que a exposição prejudica gerações futuras, diminuindo a janela reprodutiva, já comprometida pelo desejo de grande parte das mulheres de adiar a maternidadeBACKGROUND. There is growing awareness that ambient air pollution compromises human health. Exposure to diesel exhaust, which significantly contributes to pollution in heavy traffic areas, may be at least partially responsible for the observed effects of pollution on human health. Poor reproductive outcomes, such as preeclampsia, preterm deliveries and low birth weight, are described in epidemiological studies. Moreover, experimental evidence shows increased implantation failure rates and placental morphology alterations in exposed mice. OBJECTIVE. The purpose of this study was to analyse ovarian and uterine morphological changes resulting from chronic intrauterine and postnatal exposure to diesel exhaust in mice. METHODS. A experimental prospective crossover study. Mice were exposed to diesel exhaust with doses that correspond to the daily average PM2.5 levels reported by the World Health Organization (WHO) and above the annual average PM2.5 levels. The diesel exhaust exposure doses were also below daily and annual levels recommended by the National Council of Environment (CONAMA). Four groups were examined: intrauterine and postnatal clean, filtered air exposure; intrauterine exposure to diesel only; postnatal exposure to diesel only; and intrauterine and postnatal exposure to diesel. Morphometric analyses of the ovaries and uterus were performed to define the relative area occupied by follicles, corpus luteum and stroma. These analyses also aimed to determine the proportionate area of glands, the epithelial layer and stroma within the uterine endometrium. RESULTS: A significant reduction in primordial follicles was observed in intra-uterine-exposed animals (p=0.035), those exposed during the postnatal period (p=0.015) and in animals exposed during both phases (p=0.004). Primary follicles were reduced in animals exposed during pregnancy (p=0.04). No significant changes were detected in uterine morphology. CONCLUSIONS: Intrauterine exposure to currently acceptable levels of diesel exhaust compromises the reproductive potential of female mice, diminishing ovarian reserve when sexual maturity is achieved suggesting involvement of epigenetic changes. This effect in turn increases the risk of premature menopause. These findings suggest that environmental guidelines should be reviewed because diesel exposure affects future generations. Premature menopause reduces the span of the reproductive window, which is already shortening due to womens desire to bear children later in life
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Pereira, Paulo Augusto Amador. "Estudo das alterações no sistema reprodutor de camundongos expostos a contaminação ambiental". Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/5/5144/tde-16122008-155830/.
Testo completoAbstract (sommario):
O Laboratório de Poluição Atmosférica Experimental da Faculdade de Medicina da Universidade de São Paulo desenvolve várias linhas de pesquisa sobre os efeitos da poluição nos organismos vivos. O objetivo deste trabalho foi estudar as alterações no sistema reprodutor de camundongos balb-c machos expostos a água de manancial localizado próximo a depósito de resíduos químicos. Oitenta camundongos balb-c foram divididos em quatro grupos: Grupo A (controle) recebeu água mineral, grupo B recebeu água de nascente na região do depósito, grupo C recebeu água de cidade abastecida por água originada na região do depósito e grupo D recebeu água de rio que passa ao lado do depósito. A exposição foi do desmame até a idade adulta. Ao atingir a idade reprodutiva eles foram acasalados e posteriormente sacrificados. Os parâmetros avaliados foram: peso das gônadas, espermograma, taxa de gravidez, proporção de machos na prole e contagem de células de Sertoli. A análise da água do grupo A e C não mostrou presença de poluentes, a do grupo B mostrou presença de cádmio nas concentrações de 3,58 ± 0,50 microgramas/L e de 2,92 ± 0,10 microgramas/L, a do grupo D mostrou a presença de hidrocarbonetos aromáticos policíclicos, de chumbo nas concentrações de 113 ± 11 microgramas/L e de 221 ± 16 microgramas/L, cádmio nas concentrações de 11,33 ± 0,50 microgramas/L, 12,6 ± 1,2 microgramas/L e 3,78 ± 0,35 microgramas/L e de mercúrio nas concentrações de 4,58 ± 0,92 microgramas/L e 5,3 ± 1,1 microgramas/L. Foram utilizados os testes de Levene e Kolmogorov-Smirnov para se verificar a homogeneidade das variâncias e a aderência a curva normal, respectivamente. Para as variáveis que apresentaram esses dois princípios satisfeitos foram utilizados testes paramétricos (ANOVA- analise de variância), caso contrario foram utilizados testes não paramétricos (Teste de Kruskall-Wallis). Quando diferenças foram observadas foi utilizado o teste de comparações múltiplas de Tukey (KLEIBAUM). Os resultados mostraram que houve redução significativa da proporção de machos na prole dos animais do grupo B e uma redução marginalmente significante nos animais do grupo D. Os outros parâmetros avaliados não mostraram diferenças entre os grupos. A alteração verificada na proporção de machos do grupo B não pode ser explicada pela presença de cádmio na água, pois o grupo D foi exposto a doses muito maiores e não apresentou a mesma alteração. No presente trabalho não identificamos diferenças que permitam afirmar que a exposição à água da região do depósito de lixo químico cause alterações no sistema reprodutivo de camundongosThe Atmospheric Pollution Laboratory of The Sao Paulo University Medical College develops research on the effects of environmental pollution in health. This study investigated the effects on the reproductive system of balb-c mice exposed to water from a river near a deactivated waste depositary. Eighty male mice were separated in four groups: Group A (mineral water); Group B (water from the water treatment station); Group C (water from Cubatao city); Group D (water from the waste depositary region). They were exposed to water since they were weaned until they reached sexual maturity. They were coupled with females in reproductive age and after this mating time they were sacrificed. The evaluated parameters had been testicle weight, sperm analysis, pregnancy rate, sex ratio of the offspring and Sertoli cell count. The analysis of the water did not show presence of pollutants in the group a and group c water. Group b showed low levels of cadmium, 3,58 ± 0,50 g/L and 2,92 ± 0,10g/L. Group d showed the presence of PAHs and high levels of lead (113 ± 11 g/L and 221 ± 16 g/L), cadmiun (11,33 ± 0,50 g/L and 12,6 ± 1,2 g/L) and mercury (4,58 ± 0,92 g/L and 5,3 ± 1,1 g/L . The tests of Levene and Kolmogorov-Smirnov had been used to verify the homogeneity of the variances and the tack to the normal curve, respectively. The parametric tests used ANOVA and the non parametric tests used Kruskall-Wallis test and the test of multiple comparisons of Tukey (Kleibaun). Results: There were no differences between groups in testicle weight, sperm analysis, pregnancy rate and Sertoli cell count. There was a significant reduction in sex-ratio of the offspring in group b. This alteration cannot be explained by the cadmium levels in group b water. In the present work we cannot associate the exposition to water from the waste depositary and reproductive alterations
29
Singh, Umashankar. "New Functions for Old Genes in the Mouse Placenta". Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Universitetsbiblioteket [distributör], 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6882.
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Cheong, Wan-yee Ana. "Regulation and characterization of microsomal epoxide hydrolase (Ephx1) in the female reproductive tract /". View the Table of Contents & Abstract, 2007. http://sunzi.lib.hku.hk/hkuto/record/B38284182.
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31
Davies, S. "Oocyte maturation in mice". Thesis, University of Essex, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377928.
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32
Robertson, Kirsten 1975. "The reproductive phenotype of the male aromatase knockout mouse". Monash University, Dept. of Biochemistry and Molecular Biology, 2001. http://arrow.monash.edu.au/hdl/1959.1/8444.
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33
Serpedin, Nesrin. "Abnormal reproductive function in female homozygous leaner mice". Texas A&M University, 2003. http://hdl.handle.net/1969.1/559.
Testo completoAbstract (sommario):
The leaner mouse carries an autosomal recessive mutation in the α1A subunit of neuronal P/Q-type voltage gated calcium ion channels. Due to this mutation, the leaner mouse exhibits severe ataxia, absence seizures and paroxysmal dyskinesia. Mutations in this same gene in humans cause: episodic ataxia type 2, familial hemiplegic migraine, spinocerebellar ataxia type 6 and probably the newly recognized form of human inherited epilepsy.
Decreased amplitude of calcium current in cerebellar Purkinje cells and decreased calcium buffering capacity suggest that failure of calcium homeostasis may lead to the neurodegeneration observed in these mutant mice. Both sexes are affected. Despite their neurological dysfunction, homozygous leaner mice are able to breed and produce viable offspring. The survival rate for these pups is highly correlated with early fostering to normal lactating dams.
This thesis studies the reproductive dysfunction observed in female homozygous leaner mice and is divided into four parts: onset of puberty, estrous cycle, pregnancy and litter assessment, and hormone levels. We have discovered that the onset of puberty is precocious in leaner females compared to age-matched wild type females, and leaner mice spend more time in estrous than age-matched wild type females. Also, we have observed that leaner mice became pregnant less readily than wild type mice, but once pregnant, female leaner mice produced more pups per litter compared with wild type mice. The number of corpora lutea observed in leaner mice is greater than in wild type mice. In leaner mice, the number of corpora lutea in the ovary corresponding to the uterine horn with the highest number of offspring is larger than the number of corpora lutea found in the ovary corresponding to the other uterine horn. Radioimmunoassays of estradiol hormone levels at postnatal day 28 shows higher levels in leaner compared to age-matched wild type mice. However, at postnatal day 28, the luteinizing hormone levels are similar in both categories of mice.
This study of reproductive dysfunction in leaner mice was performed to gain further understanding about the role of intracellular calcium ion signaling in neuronal regulation of reproductive processes in females.
34
Turner, Leslie McCue. "Evolution of reproductive proteins in deer mice (Peromyscus)". Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2007. http://wwwlib.umi.com/cr/ucsd/fullcit?p3268583.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--University of California, San Diego, 2007.Title from first page of PDF file (viewed August 8, 2007). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
35
Cheong, Wan-yee Ana, e 張韻怡. "Regulation and characterization of microsomal epoxide hydrolase (Ephx1) in the female reproductive tract". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B4501114X.
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36
Bergman, Mark. "Estrogen receptor dynamics and reproductive aging in female mice". Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=75942.
Testo completoAbstract (sommario):
The effects of aging on estrogen receptor (ER) levels and dynamics were assessed in hypothalamus (HYPO), pituitary (PIT), and uterus (UT) of female mice, 0-24 h following a bolus of estradiol. Nuclear ER levels were reduced and dynamics were altered in all tissues of aged mice. Age-related reductions of nuclear ER were associated with both losses of ER and reduced ability of cell nuclei to bind ER. Irrespective of age, ER dynamics differed among tissues. The duration of elevated nuclear ER was longest, and the rate of replenishment of cytosolic ER was fastest, in HYPO. Transient loss of ER was observed in UT and PIT, but not HYPO. In separate experiments involving chronic E2 exposure, tissue differences in the duration of elevated nuclear ER persisted, but all tissues exhibited ER loss. This thesis reveals age and tissue differences in ER dynamics. These differences may contribute to altered responsiveness to estrogens during aging and among tissues.
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Garratt, Michael Glenn. "Oxidative stress, reproductive investment and sexual signalling in house mice". Thesis, University of Liverpool, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.539731.
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Dermyer, Lindsey Jane, Noëlle Bittner, Polly Campbell e Michael Nachman. "BRCA1: A Candidate Gene for Reproductive Isolation in House Mice". Thesis, The University of Arizona, 2011. http://hdl.handle.net/10150/144334.
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39
Rightler, Michelle E. "The Energetics of Seasonal Reproductive Inhibition in White-Footed Mice". W&M ScholarWorks, 2001. https://scholarworks.wm.edu/etd/1539626307.
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40
Clouse, Angela K. "Development of a gene expression screen to assess effects of endocrine disrupting agents in female mouse reproductive tissues". Click here for download, 2008. http://proquest.umi.com/pqdweb?did=1564017131&sid=1&Fmt=2&clientId=3260&RQT=309&VName=PQD.
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Jones, Maren Bell. "Effects and interactions of endocrine disrupting chemicals and diet on the mouse reproductive system". Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/5006.
Testo completoAbstract (sommario):
Thesis (M.A.)--University of Missouri-Columbia, 2007.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on October 29, 2007) Vita. Includes bibliographical references.
42
Good, Jeffrey. "The Genetic Basis of Reproductive Isolation Between Two Species of House Mice". Diss., The University of Arizona, 2007. http://hdl.handle.net/10150/195901.
Testo completoAbstract (sommario):
Determining the genetic basis of reproductive isolation is a fundamental goal in evolutionary biology. Intrinsic reproductive isolation often arises due to epistasis between divergent interacting genes. The rapid evolution of hybrid male sterility is known to have several causes, including the exposure of recessive X-linked incompatibilities in males and the rapid evolution of male reproductive traits. Despite these insights, little is known about the genetics of reproductive isolation during the early stages of speciation. This deficiency inspired parallel studies on the molecular evolution of male reproduction in house mice and the genetic basis of hybrid male sterility between two mouse species, Mus domesticus and M. musculus. Evolutionary analysis of 946 genes showed that the intensity of positive selection varies across sperm development and acts primarily on phenotypes that develop late in spermatogenesis (Appendix A). Several reciprocal crosses between wild-derived strains of M. musculus and M. domesticus were used to examine F1 hybrid male sterility (Appendix B). These crosses revealed hybrid male sterility linked to the M. musculus X chromosome and a novel sterility polymorphism within M. musculus. A large introgression experiment was used to further dissect the genetic basis of X-linked incompatibilities between M. musculus and M. domesticus (Appendix C). Introgression of the M. musculus X chromosome into a M. domesticus genetic background produced male sterility and involved a minimum of four factors. No sterility factors were uncovered on the M. domesticus X chromosome. These data demonstrate the complex genetic basis of hybrid sterility in mice and provide numerous X-linked candidate sterility genes. The molecular evolution of five rapidly evolving candidate genes was examined using population and phylogenetic sampling in Mus (Appendix D). Four of these loci showed evidence of positive natural selection. One locus, 4933436I01Rik, showed divergent protein evolution between M. domesticus and M. musculus and was one of a handful of testis-expressed genes within a narrow interval involved in hybrid male sterility. In summary, these data demonstrate that hybrid male sterility has a complex genetic basis between two closely related species of house mice and provide a foundation for the identification of specific mutations that isolate these species.
43
Widelka, Malgorzata. "Neonatal Exposure To Bisphenol Analogues Disrupts Reproductive Organ Development Of Male Mice". OpenSIUC, 2016. https://opensiuc.lib.siu.edu/theses/2079.
Testo completoAbstract (sommario):
Bisphenol A (BPA) is one of the highest volume chemicals produced worldwide and, as a result, is universally found in environmental and human matrixes. Bisphenol A is a known endocrine disruptor that acts as an estrogen agonist and an androgen antagonist. Due to health concerns, BPA is being phased out and replaced by other bisphenol analogues structurally similar to BPA. To date, there have been little to no studies showing the effects of BP analogues on the reproductive organ development of male mice. Thus, this study aimed to compare the effects of BPA and selected analogues (including BPB, BPE, and BPS) on the reproductive organ development in male mice, and determine preliminary toxicity threshold levels, such as the lowest-observed-effect-dose (LOED) and no-observed-effect-dose (NOED). Exposure to BPA, BPB and BPE via subcutaneous injection at a dose of 10 μg/g body weight (bw)/day each significantly caused a decrease in anogenital distance and glans penis length in male mice. Testis weight was also significantly reduced by BPA and BPE. Although BPS did not cause an effect on the glans penis length, anogenital distance or testis weight, histology work indicated that the spines on the glans penis were at a different developmental stage than the control. A similar result was seen with BPA on the glans penis spines. The LOED and NOED of BPA affecting anogenital distance, penis length, or testis weight were determined to be 10 and 5 μg/g bw/day, respectively. These LOED and NOED values are preliminary for BPA, because only five dose levels are used. Further research is needed to estimate more accurate threshold levels for the studied endpoints for BPA as well as other bisphenol analogues. The results indicated that some bisphenol analogues (BPB and BPE) showed comparable effects to BPA on the reproductive organ development of male mice, including anogenital distance and penis length. This could be indicative of more severe reproductive issues later in life and raised a concern on the safety of using these analogues to replace BPA in consumer products. More research is needed to investigate the mechanisms of the observed effects on genetic or molecular levels, determine what the long-term adverse effects of bisphenol analogues are to the reproductive system of male mice, and determine whether similar effects will be seen at dose levels comparable to human exposure rates.
44
Turnock, Margaret Elizabeth. "Effects of stress and intra-uterine position on reproductive function in female mice". Thesis, Keele University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385556.
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Thomas, Alysia D. "Endocrine mechanisms for reproductive failure and transgene transmission in oMt1a-oGH transgenic mice /". For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2003. http://uclibs.org/PID/11984.
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Lavergne, Christopher Leon Joseph. "Peri-Ovulatory Supplementation of L-Ornithine to Increase Reproductive Success in Aged Mice". Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/38341.
Testo completoAbstract (sommario):
In all mammalian species examined thus far, the ovaries produce a burst of ornithine decarboxylase (ODC) and putrescine during ovulation or after application of a bolus of human chorionic gonadotropin (hCG). Aged mice are deficient in this peri-ovulatory ODC and putrescine burst. Moreover, peri-ovulatory putrescine supplementation in aged mice increases egg quality and reduces miscarriage rates. These studies suggest that peri-ovulatory putrescine supplementation may be a simple and effective therapy for reproductive aging for women. However, putrescine has never been used in humans and, currently no pure source of putrescine is suitable for human trials. Given that ODC is highly expressed in the ovaries during ovulation but otherwise exhibits low activity in most tissues, we hypothesized that L-ornithine, the substrate of ODC, might be a better alternative. In this study, we have demonstrated that systemic application of L-ornithine increased ovarian putrescine levels; the increase was restricted to animals that had been injected with hCG. Furthermore, L-ornithine specifically increased ovarian putrescine levels without affecting putrescine levels in most other tissues. Unfortunately, thus far peri-ovulatory L-ornithine supplementation in mouse drinking water produced mixed effects on reproductive outcome in aged mice. Therefore, our studies demonstrated the potential of L-ornithine supplementation as a possible therapy for aging-related infertility, but further work is required to produce an effective application method.
47
Mabry, Michelle Lee. "Social Influences on Reproductive Maturation in Female White-Footed Mice (Peromyscus leucopus noveboracensis)". W&M ScholarWorks, 1994. https://scholarworks.wm.edu/etd/1539625878.
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Jacobs-Palmer, Emily. "The Genetics of Sexually Selected Male Reproductive Traits in Mice (Mus and Peromyscus Species)". Thesis, Harvard University, 2015. http://nrs.harvard.edu/urn-3:HUL.InstRepos:17463151.
Testo completoAbstract (sommario):
Sexual selection is rampant in Nature, and has produced some of the most beautiful and bizarre traits on Earth. Because females are often promiscuous, sexual selection can continue even after mating, as the sperm of multiple males race to fertilize a limited number of eggs. Though post-copulatory sexual selection is ubiquitous and drives both rapid adaptation and divergence between lineages, we know little about the genetic basis of phenotypes subject to this force. To illuminate one of the important mechanisms by which evolution produces a remarkable diversity of traits, we must identify the genetic loci targeted by post-copulatory sexual selection.
Here we determine the genes or genomic regions underlying particular male reproductive traits—sperm development and morphology, age to male sexual maturity, and segregation distortion—that were likely shaped by post-copulatory sexual selection in the ancestors of mice from the genera Peromyscus and Mus. We measure phenotype at the organismal and cellular levels, and then employ quantitative trait locus mapping, RNA sequencing, and bulk DNA sequencing to pinpoint loci influencing the aforementioned traits.
We first identify a single locus of large effect controlling sperm midpiece length, a trait relevant to sperm competition success that differs between promiscuous and monogamous sister species of Peromyscus mice. We then show that regions of the genome underlying polymorphism in sperm morphology within species are entirely distinct from those determining divergence in the same traits between species. Next, we determine differences in age to male sexual maturity in closely related species with disparate mating systems, and characterize the role of cis-regulatory evolution in the timing of male reproductive development. Additionally, we develop a novel method to identify segregation distortion systems that may have been shaped by historical selection at multiple levels, but find none in hybrids of Mus musculus. Finally, we characterize the role of a non-coding RNA locus in male fertility, discovering that it mediates separation of spermatids from collective cytoplasm. In sum, we reveal links between particular genes or genomic regions and male reproductive phenotypes that may influence success in post-copulatory competition, thereby clarifying the mechanistic basis of evolution by sexual selection.Biology, Organismic and Evolutionary
49
Howdeshell, Kembra L. "Effects of exposure to environmentally-relevant levels of bisphenol A on mouse reproductive physiology and maternal behavior /". free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3060107.
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50
Sundberg, Sebastian. "The ecological significance of sexual reproduction in peat mosses (Sphagnum)". Doctoral thesis, Uppsala University, Department of Evolutionary Biology, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-526.
Testo completoAbstract (sommario):
Peat mosses (Sphagnum) are widely distributed and are a major component of mire vegetation and peat throughout the boreal and temperate regions. Most boreal Sphagnum species regularly produce sporophytes, but the ecological role of the spore has been questioned. This study shows that the spores can form a spore bank and have the ability to germinate and contribute to moss establishment whenever suitable conditions occur. The results suggest that spore production is important for explaining the wide distribution and omnipresence of Sphagnum in nutrient-poor wetlands. The results further imply that initial recruitment from spores predominates in Sphagnum after disturbance or formation of suitable habitats.
A series of experiments showed that addition of phosphorus-containing substrates, such as fresh plant litter or moose dung, resulted in spore establishment on bare, moist peat. A field experiment indicated establishment rates of about 1% of sown, germinable spores on peat with added substrates. Plant litter on moist soil, without a closed cover of bryophytes, is an important safe site for the establishment of Sphagnum spores. The results fit the observed pattern of colonisation by Sphagnum beneath Eriophorum vaginatum tussocks in mires severely disturbed by peat extraction. Successful long-distance dispersal was indicated by the occurrence of several regionally new or rare Sphagnum species in disturbed mires.
Spore number per sporophyte ranged among Sphagnum species from 18 500 to 240 000, with a trade-off between spore number and spore size. Annual spore production was estimated at 15 million spores per square metre on two investigated mires. Sporophyte production showed a large interannual variation. Sporophyte production was positively related to the amount of precipitation the preceding summer. This was probably because a high water level promoted gametangium formation. Spore dispersal occurred in July and August. The earlier timing of spore dispersal in the more drought-sensitive, hollow-inhabiting sphagna should reduce the risk of sporophytes drying out prematurely during summer droughts.
Spores kept refrigerated up to 13 years retained high germinability. A field experiment showed that Sphagnum can form a persistent spore bank, with a potential longevity of several decades.