Articles de revues : « Reproductive cell »

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Vidane, Atanásio S., Helena D. Zomer, Bruna M. M. Oliveira, Carina F. Guimarães, Cláudia B. Fernandes, Felipe Perecin, Luciano A. Silva, Maria A. Miglino, Flávio V. Meirelles et Carlos E. Ambrósio. « Reproductive Stem Cell Differentiation ». Reproductive Sciences 20, n^o 10 (18 février 2013) : 1137–43. http://dx.doi.org/10.1177/1933719113477484.

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Zadrag-Tecza, Renata, Magdalena Kwolek-Mirek, Małgorzata Alabrudzińska et Adrianna Skoneczna. « Cell Size Influences the Reproductive Potential and Total Lifespan of theSaccharomyces cerevisiaeYeast as Revealed by the Analysis of Polyploid Strains ». Oxidative Medicine and Cellular Longevity 2018 (2018) : 1–17. http://dx.doi.org/10.1155/2018/1898421.

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The total lifespan of the yeastSaccharomyces cerevisiaemay be divided into two phases: the reproductive phase, during which the cell undergoes mitosis cycles to produce successive buds, and the postreproductive phase, which extends from the last division to cell death. These phases may be regulated by a common mechanism or by distinct ones. In this paper, we proposed a more comprehensive approach to reveal the mechanisms that regulate both reproductive potential and total lifespan in cell size context. Our study was based on yeast cells, whose size was determined by increased genome copy number, ranging from haploid to tetraploid. Such experiments enabled us to test the hypertrophy hypothesis, which postulates that excessive size achieved by the cell—the hypertrophy state—is the reason preventing the cell from further proliferation. This hypothesis defines the reproductive potential value as the difference between the maximal size that a cell can reach and the threshold value, which allows a cell to undergo its first cell cycle and the rate of the cell size to increase per generation. Here, we showed that cell size has an important impact on not only the reproductive potential but also the total lifespan of this cell. Moreover, the maximal cell size value, which limits its reproduction capacity, can be regulated by different factors and differs depending on the strain ploidy. The achievement of excessive size by the cell (hypertrophic state) may lead to two distinct phenomena: the cessation of reproduction without “mother” cell death and the cessation of reproduction with cell death by bursting, which has not been shown before.

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Kustan, Jacqueline M., Karen P. Maruska et Russell D. Fernald. « Subordinate male cichlids retain reproductive competence during social suppression ». Proceedings of the Royal Society B : Biological Sciences 279, n^o 1728 (6 juillet 2011) : 434–43. http://dx.doi.org/10.1098/rspb.2011.0997.

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Subordinate males, which are excluded from reproduction often save energy by reducing their investment in sperm production. However, if their position in a dominance hierarchy changes suddenly they should also rapidly attain fertilization capability. Here, we asked how social suppression and ascension to dominance influences sperm quality, spermatogenesis and reproductive competence in the cichlid Astatotilapia burtoni , where reproduction is tightly coupled to social status. Dominant territorial (T) males are reproductively active while subordinate non-territorial (NT) males are suppressed, but given the opportunity, NT males will perform dominance behaviours within minutes and attain T male testes size within days. Using the thymidine analogue 5-bromo-2-deoxyuridine (BrdU) to label germ cell proliferation, we found that the spermatogenic cycle takes approximately 11–12 days, and social status had no effect on proliferation, suggesting that spermatogenesis continues during reproductive suppression. Although sperm velocity did not differ among social states, NT males had reduced sperm motility. Remarkably, males ascending in status showed sperm motility equivalent to T males within 24 h. Males also successfully reproduced within hours of social opportunity, despite four to five weeks of suppression and reduced testis size. Our data suggest that NT males maintain reproductive potential during suppression possibly as a strategy to rapidly improve reproductive fitness upon social opportunity.

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Lie, Merete. « Reproductive Images : The Autonomous Cell ». Science as Culture 21, n^o 4 (décembre 2012) : 475–96. http://dx.doi.org/10.1080/09505431.2012.679728.

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Boddy, Amy M., Hanna Kokko, Felix Breden, Gerald S. Wilkinson et C. Athena Aktipis. « Cancer susceptibility and reproductive trade-offs : a model of the evolution of cancer defences ». Philosophical Transactions of the Royal Society B : Biological Sciences 370, n^o 1673 (19 juillet 2015) : 20140220. http://dx.doi.org/10.1098/rstb.2014.0220.

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The factors influencing cancer susceptibility and why it varies across species are major open questions in the field of cancer biology. One underexplored source of variation in cancer susceptibility may arise from trade-offs between reproductive competitiveness (e.g. sexually selected traits, earlier reproduction and higher fertility) and cancer defence. We build a model that contrasts the probabilistic onset of cancer with other, extrinsic causes of mortality and use it to predict that intense reproductive competition will lower cancer defences and increase cancer incidence. We explore the trade-off between cancer defences and intraspecific competition across different extrinsic mortality conditions and different levels of trade-off intensity, and find the largest effect of competition on cancer in species where low extrinsic mortality combines with strong trade-offs. In such species, selection to delay cancer and selection to outcompete conspecifics are both strong, and the latter conflicts with the former. We discuss evidence for the assumed trade-off between reproductive competitiveness and cancer susceptibility. Sexually selected traits such as ornaments or large body size require high levels of cell proliferation and appear to be associated with greater cancer susceptibility. Similar associations exist for female traits such as continuous egg-laying in domestic hens and earlier reproductive maturity. Trade-offs between reproduction and cancer defences may be instantiated by a variety of mechanisms, including higher levels of growth factors and hormones, less efficient cell-cycle control and less DNA repair, or simply a larger number of cell divisions (relevant when reproductive success requires large body size or rapid reproductive cycles). These mechanisms can affect intra- and interspecific variation in cancer susceptibility arising from rapid cell proliferation during reproductive maturation, intrasexual competition and reproduction.

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Templeman, Nicole M., et Coleen T. Murphy. « Regulation of reproduction and longevity by nutrient-sensing pathways ». Journal of Cell Biology 217, n^o 1 (26 octobre 2017) : 93–106. http://dx.doi.org/10.1083/jcb.201707168.

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Nutrients are necessary for life, as they are a crucial requirement for biological processes including reproduction, somatic growth, and tissue maintenance. Therefore, signaling systems involved in detecting and interpreting nutrient or energy levels—most notably, the insulin/insulin-like growth factor 1 (IGF-1) signaling pathway, mechanistic target of rapamycin (mTOR), and adenosine monophosphate-activated protein kinase (AMPK)—play important roles in regulating physiological decisions to reproduce, grow, and age. In this review, we discuss the connections between reproductive senescence and somatic aging and give an overview of the involvement of nutrient-sensing pathways in controlling both reproductive function and lifespan. Although the molecular mechanisms that affect these processes can be influenced by distinct tissue-, temporal-, and pathway-specific signaling events, the progression of reproductive aging and somatic aging is systemically coordinated by integrated nutrient-sensing signaling pathways regulating somatic tissue maintenance in conjunction with reproductive capacity.

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Liu, Hong-Bo, Pei-Ru Lv, Ruo-Gang He, Xiao-Gan Yang, Xiao-E. Qin, Tian-Biao Pan, Guang-Yun Huang et al. « Cloned Guangxi Bama Minipig (Sus scrofa) and Its Offspring Have Normal Reproductive Performance ». Cellular Reprogramming 12, n^o 5 (octobre 2010) : 543–50. http://dx.doi.org/10.1089/cell.2009.0094.

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Renfree, Marilyn B. « WOMEN IN REPRODUCTIVE SCIENCE : Reproduction down under ». Reproduction 158, n^o 6 (décembre 2019) : F127—F137. http://dx.doi.org/10.1530/rep-19-0230.

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Australia is home to a unique assembly of mammals – the marsupials and monotremes. Despite this uniqueness, they have been largely ignored by the biomedical scientific community, and yet study of marsupials has contributed to modern research on reproduction, development, evolution, conservation, molecular and comparative genomics. My lifetime passion for these long-neglected Australian fauna has led to unexpected discoveries and insights that challenged assumptions and opened up new areas of international research. I used a range of disciplinary expertise to pursue the study of these unique mammals. My main experimental species has been the tammar wallaby that I have used as a model species to investigate and understand not only biomedical problems but also to provide knowledge that is critical for the continued conservation and management of Australia’s dwindling native mammals. This model provided more than a few surprises for me and my wonderful team of students, post-docs and collaborators about how hormones, genes and signalling molecules control reproductive biology and development in a wider context as well as how the interactions of the environment with mother and conceptus, with mother and fetus and mother and young ultimately control most aspects of successful reproduction in mammals.

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Wocławek-Potocka, Izabela, Paulina Rawińska, Ilona Kowalczyk-Zieba, Dorota Boruszewska, Emilia Sinderewicz, Tomasz Waśniewski et Dariusz Jan Skarzynski. « Lysophosphatidic Acid (LPA) Signaling in Human and Ruminant Reproductive Tract ». Mediators of Inflammation 2014 (2014) : 1–14. http://dx.doi.org/10.1155/2014/649702.

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Lysophosphatidic acid (LPA) through activating its G protein-coupled receptors (LPAR 1–6) exerts diverse cellular effects that in turn influence several physiological processes including reproductive function of the female. Studies in various species of animals and also in humans have identified important roles for the receptor-mediated LPA signaling in multiple aspects of human and animal reproductive tract function. These aspects range from ovarian and uterine function, estrous cycle regulation, early embryo development, embryo implantation, decidualization to pregnancy maintenance and parturition. LPA signaling can also have pathological consequences, influencing aspects of endometriosis and reproductive tissue associated tumors. The review describes recent progress in LPA signaling research relevant to human and ruminant reproduction, pointing at the cow as a relevant model to study LPA influence on the human reproductive performance.

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Li, Lin, Risako Yang, Chenghong Yin et Kehkooi Kee. « Studying human reproductive biology through single-cell analysis and in vitro differentiation of stem cells into germ cell-like cells ». Human Reproduction Update 26, n^o 5 (28 mai 2020) : 670–88. http://dx.doi.org/10.1093/humupd/dmaa021.

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Abstract BACKGROUND Understanding the molecular and cellular mechanisms of human reproductive development has been limited by the scarcity of human samples and ethical constraints. Recently, in vitro differentiation of human pluripotent stem cells into germ cells and single-cell analyses have opened new avenues to directly study human germ cells and identify unique mechanisms in human reproductive development. OBJECTIVE AND RATIONALE The goal of this review is to collate novel findings and insightful discoveries with these new methodologies, aiming at introducing researchers and clinicians to the use of these tools to study human reproductive biology and develop treatments for infertility. SEARCH METHODS PubMed was used to search articles and reviews with the following main keywords: in vitro differentiation, human stem cells, single-cell analysis, spermatogenesis, oogenesis, germ cells and other key terms related to these subjects. The search period included all publications from 2000 until now. OUTCOMES Single-cell analyses of human gonads have identified many important gene markers at different developmental stages and in subpopulations of cells. To validate the functional roles of these gene markers, researchers have used the in vitro differentiation of human pluripotent cells into germ cells and confirmed that some genetic requirements are unique in human germ cells and are not conserved in mouse models. Moreover, transcriptional regulatory networks and the interaction of germ and somatic cells in gonads were elucidated in these studies. WIDER IMPLICATIONS Single-cell analyses allow researchers to identify gene markers and potential regulatory networks using limited clinical samples. On the other hand, in vitro differentiation methods provide clinical researchers with tools to examine these newly identify gene markers and study the causative effects of mutations previously associated with infertility. Combining these two methodologies, researchers can identify gene markers and networks which are essential and unique in human reproductive development, thereby producing more accurate diagnostic tools for assessing reproductive disorders and developing treatments for infertility.

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Pei, Jie, Lin Xiong, Shaoke Guo, Xingdong Wang, Yongfu La, Min Chu, Chunnian Liang, Ping Yan et Xian Guo. « Single-Cell Transcriptomics Analysis Reveals a Cell Atlas and Cell Communication in Yak Ovary ». International Journal of Molecular Sciences 24, n^o 3 (17 janvier 2023) : 1839. http://dx.doi.org/10.3390/ijms24031839.

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Yaks (Bos grunniens) are the only bovine species that adapt well to the harsh high-altitude environment in the Qinghai-Tibetan plateau. However, the reproductive adaptation to the climate of the high elevation remains to be elucidated. Cell composition and molecular characteristics are the foundation of normal ovary function which determines reproductive performance. So, delineating ovarian characteristics at a cellular molecular level is conducive to elucidating the mechanism underlying the reproductive adaption of yaks. Here, the single-cell RNA-sequencing (scRNA-seq) was employed to depict an atlas containing different cell types with specific molecular signatures in the yak ovary. The cell types were identified on the basis of their specifically expressed genes and biological functions. As a result, a cellular atlas of yak ovary was established successfully containing theca cells, stromal cells, endothelial cells, smooth muscle cells, natural killer cells, macrophages, and proliferating cells. A cell-to-cell communication network between the distinct cell types was constructed. The theca cells were clustered into five subtypes based on their biological functions. Further, CYP11A1 was confirmed as a marker gene for the theca cells by immunofluorescence staining. Our work reveals an ovarian atlas at the cellular molecular level and contributes to providing insights into reproductive adaption in yaks.

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Smith-Whitley, Kim. « Reproductive issues in sickle cell disease ». Blood 124, n^o 24 (4 décembre 2014) : 3538–43. http://dx.doi.org/10.1182/blood-2014-07-577619.

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Abstract As medical advances improve survival, reduce disease-related morbidity, and improve quality of life, reproductive issues will take higher priority in the sickle cell disease (SCD) community. A wide variety of topics are addressed in this chapter, including fertility, gonadal failure, erectile dysfunction, and menstrual issues in SCD. Etiologies of impaired male fertility are multifactorial and include hypogonadism, erectile dysfunction, sperm abnormalities, and complications of medical therapies. Much less is known about the prevalence and etiology of infertility in women with SCD. Other reproductive issues in women included in this review are pain and the menstrual cycle, contraception, and preconception counseling. Finally, long-term therapies for SCD and their impact on fertility are presented. Transfusional iron overload and gonadal failure are addressed, followed by options for fertility preservation after stem cell transplantation. Focus is placed on hydroxyurea therapy given its benefits and increasing use in SCD. The impact of this agent on spermatogenesis, azoospermia, and the developing fetus is discussed.

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Smith-Whitley, Kim. « Reproductive issues in sickle cell disease ». Hematology 2014, n^o 1 (5 décembre 2014) : 418–24. http://dx.doi.org/10.1182/asheducation-2014.1.418.

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Abstract As medical advances improve survival, reduce disease-related morbidity, and improve quality of life, reproductive issues will take higher priority in the sickle cell disease (SCD) community. A wide variety of topics are addressed in this chapter, including fertility, gonadal failure, erectile dysfunction, and menstrual issues in SCD. Etiologies of impaired male fertility are multifactorial and include hypogonadism, erectile dysfunction, sperm abnormalities, and complications of medical therapies. Much less is known about the prevalence and etiology of infertility in women with SCD. Other reproductive issues in women included in this review are pain and the menstrual cycle, contraception, and preconception counseling. Finally, long-term therapies for SCD and their impact on fertility are presented. Transfusional iron overload and gonadal failure are addressed, followed by options for fertility preservation after stem cell transplantation. Focus is placed on hydroxyurea therapy given its benefits and increasing use in SCD. The impact of this agent on spermatogenesis, azoospermia, and the developing fetus is discussed.

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Soygur, Bikem, et Leyla Sati. « The role of syncytins in human reproduction and reproductive organ cancers ». Reproduction 152, n^o 5 (novembre 2016) : R167—R178. http://dx.doi.org/10.1530/rep-16-0031.

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Human life begins with sperm and oocyte fusion. After fertilization, various fusion events occur during human embryogenesis and morphogenesis. For example, the fusion of trophoblastic cells constitutes a key process for normal placental development. Fusion in the placenta is facilitated by syncytin 1 and syncytin 2. These syncytins arose from retroviral sequences that entered the primate genome 25 million and more than 40 million years ago respectively. About 8% of the human genome consists of similar human endogenous retroviral (HERVs) sequences. Many are inactive because of mutations or deletions. However, the role of the few that remain transcriptionally active has not been fully elucidated. Syncytin proteins maintain cell–cell fusogenic activity based onenvgene-mediated viral cell entry. In this review, we summarize how syncytins and their receptors are involved in fusion events during human reproduction. The significance of syncytins in tumorigenesis is also discussed.

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Tucker, Emily K., Megan E. Zurliene, Cory D. Suski et Romana A. Nowak. « Gonad development and reproductive hormones of invasive silver carp (Hypophthalmichthys molitrix) in the Illinois River ». Biology of Reproduction 102, n^o 3 (11 novembre 2019) : 647–59. http://dx.doi.org/10.1093/biolre/ioz207.

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Abstract Reproduction is a major component of an animal’s life history strategy. Species with plasticity in their reproductive biology are likely to be successful as an invasive species, as they can adapt their reproductive effort during various phases of a biological invasion. Silver carp (Hypophthalmicthys molitrix), an invasive cyprinid in North America, display wide variation in reproductive strategies across both their native and introduced ranges, though the specifics of silver carp reproduction in the Illinois River have not been established. We assessed reproductive status using histological and endocrinological methods in silver carp between April and October 2018, with additional histological data from August to October 2017. Here, we show that female silver carp are batch spawners with asynchronous, indeterminate oocyte recruitment, while male silver carp utilize a determinate pattern of spermatogenesis which ceases in the early summer. High plasma testosterone levels in females could be responsible for regulating oocyte development. Our results suggest that silver carp have high spawning activity in the early summer (May–June), but outside of the peak spawning period, female silver carp can maintain spawning-capable status by adjusting rates of gametogenesis and atresia in response to environmental conditions, while males regress their gonads as early as July. The results of this study are compared to reports of silver carp reproduction in other North American rivers as well as in Asia.

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Moreno, Inmaculada, et Carlos Simon. « Deciphering the effect of reproductive tract microbiota on human reproduction ». Reproductive Medicine and Biology 18, n^o 1 (1 novembre 2018) : 40–50. http://dx.doi.org/10.1002/rmb2.12249.

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Bachelot, Anne, et Nadine Binart. « Reproductive role of prolactin ». Reproduction 133, n^o 2 (février 2007) : 361–69. http://dx.doi.org/10.1530/rep-06-0299.

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The biological actions of prolactin (PRL), a polypeptide hormone, are mostly related to lactation and reproduction. These actions have been clarified by studies of PRL and PRL-deficient receptor mice, which have a clear phenotype of reproductive failure at multiple sites. This review aims to summarize current knowledge about PRL and its receptor, role in reproductive axis and presents information of hyperprolactinemia in reproductive medicine. Our understanding of the physiology and transduction pathway of PRL has largely increased in the past 20 years with the cloning of PRL and its receptor gene.

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Wen, Lixin, Rongfang Li, Ji Wang et Jine Yi. « The reproductive stress hypothesis ». Reproduction 158, n^o 6 (décembre 2019) : R209—R218. http://dx.doi.org/10.1530/rep-18-0592.

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In this paper, we propose the reproductive stress hypothesis that describes the pregnant females response to reproductive events based upon the activation of the hypothalamic–pituitary–adrenal axis and sympathetic adrenomedullary system. The main components of the reproductive stress hypothesis can be summarized as follows: (1) events unique to reproduction including empathema, pregnancy, parturition and lactation cause non-specific responses in females, called active reproductive stress; (2) the fetus is a special stressor for pregnant females where endocrine hormones, including corticotropin-releasing hormones and fetal glucocorticoids secreted by the fetus and placenta, enter the maternal circulatory system, leading to another stress response referred to as passive reproductive stress and (3) response to uterine tension and intrauterine infection is the third type of stress, called fetal intrauterine stress. Appropriate reproductive stress is a crucial prerequisite in normal reproductive processes. By contrast, excessive or inappropriate reproductive stress may result in dysfunctions of the reproductive system, such as compromised immune function, leading to susceptibility to disease. The novel insights of the reproductive stress hypothesis have important implications for deciphering the pathogenesis of certain diseases in pregnant animals, including humans, which in turn may be applied to preventing and treating their occurrence.

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Pertiwi, Putu Dewi Diah, Ida Arimurti Sanjiwani et Ni Kadek Ayu Suarningsih. « A, Adolescent The Relations between Parenting Styles with Adolescent Reproductive Health Knowledge in Junior High School “X” in Gianyar Regency ». Journal of A Sustainable Global South 6, n^o 2 (24 août 2022) : 32. http://dx.doi.org/10.24843/jsgs.2022.v06.i02.p03.

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Adolescence are changes both physically and psychologically. The occurrence of physical changes characterized by changes in reproductive functions and systems causes sexual motivation that makes adolescents vulnerable to diseases and reproductive health problems. Adolescents are expected to have good reproductive health knowledge to avoid various reproductive health problems. Knowledge of reproductive health is influenced by several factors, such as parenting styles. Parents have a big role in providing supervision and nurturing of teenagers in a family environment. This study aims to determine the relations between parenting styles and adolescent reproductive health knowledge. This research was conducted on April - May 2019. This research was cross sectional approach. Respondents numbered are 198 adolescents, obtained through proportional random sampling techniques. Parenting styles and health reproduction knowledge were measured using a questionnaire which has been tested for validity and reliability. Data analysis using chi-square test. The results showed there is a relationship between parenting styles and adolescent reproductive health knowledge (p <0.05). The parenting styles are necessary in providing about reproductive health knowledge to provide information by providing correct information from reliable sources.

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M, Hitit. « Putative Role of Micro - RNA s i n Female Reproductive Tract ». Open Access Journal of Veterinary Science & ; Research 2, n^o 2 (2017) : 1–5. http://dx.doi.org/10.23880/oajvsr-16000131.

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Female reproductive tract is composed of ovarium, oviduct, cervix and uterus. Development and function of reproductive tract is dispens a ble for maintenance and achievement of reproduction. Reproductive tract responses to cyclic changes and ovarium hormones which provide optimum conditions for gam e t e movement and development. While the potential influence of pitu i tary and gonadal hormones on reproductive function is clearly understood, the molecular mechanism regulating reproductive tract remains elusive. Although, post - transcriptional gene regulation has critical role in cell differ e ntiation and proliferation, little information is ava i lable in post - transcriptional gene regulation in reproductive tract. Post - transcriptional g ene regulation includes splicing, processing, transport and translation of mRNA. In addition, role of RNA binding proteins and recently discovered miRNAs were also implicated in reproductive tract.

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Chong, L. D., et L. B. Ray. « Reproductive Biology ». Science Signaling 2002, n^o 138 (25 juin 2002) : eg9-eg9. http://dx.doi.org/10.1126/stke.2002.138.eg9.

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Issigonis, Melanie, Akshada B. Redkar, Tania Rozario, Umair W. Khan, Rosa Mejia-Sanchez, Sylvain W. Lapan, Peter W. Reddien et Phillip A. Newmark. « A Krüppel-like factor is required for development and regeneration of germline and yolk cells from somatic stem cells in planarians ». PLOS Biology 20, n^o 7 (15 juillet 2022) : e3001472. http://dx.doi.org/10.1371/journal.pbio.3001472.

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Sexually reproducing animals segregate their germline from their soma. In addition to gamete-producing gonads, planarian and parasitic flatworm reproduction relies on yolk cell–generating accessory reproductive organs (vitellaria) supporting development of yolkless oocytes. Despite the importance of vitellaria for flatworm reproduction (and parasite transmission), little is known about this unique evolutionary innovation. Here, we examine reproductive system development in the planarian Schmidtea mediterranea, in which pluripotent stem cells generate both somatic and germ cell lineages. We show that a homolog of the pluripotency factor Klf4 is expressed in primordial germ cells (PGCs), presumptive germline stem cells (GSCs), and yolk cell progenitors. Knockdown of this klf4-like (klf4l) gene results in animals that fail to specify or maintain germ cells; surprisingly, they also fail to maintain yolk cells. We find that yolk cells display germ cell–like attributes and that vitellaria are structurally analogous to gonads. In addition to identifying a new proliferative cell population in planarians (yolk cell progenitors) and defining its niche, our work provides evidence supporting the hypothesis that flatworm germ cells and yolk cells share a common evolutionary origin.

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Comizzoli, Pierre, et William V. Holt. « Breakthroughs and new horizons in reproductive biology of rare and endangered animal species ». Biology of Reproduction 101, n^o 3 (17 février 2019) : 514–25. http://dx.doi.org/10.1093/biolre/ioz031.

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Abstract Because of higher extinction rates due to human and natural factors, more basic and applied research in reproductive biology is required to preserve wild species and design proper strategies leading to sustainable populations. The objective of the review is to highlight recent, inspiring breakthroughs in wildlife reproduction science that will set directions for future research and lead to more successes in conservation biology. Despite new tools and approaches allowing a better and faster understanding of key mechanisms, we still know little about reproduction in endangered species. Recently, the most striking advances have been obtained in nonmammalian species (fish, birds, amphibians, or corals) with the development of alternative solutions to preserve fertility or new information about parental nutritional influence on embryo development. A novel way has also been explored to consider the impact of environmental changes on reproduction—the allostatic load—in a vast array of species (from primates to fish). On the horizon, genomic tools are expected to considerably change the way we study wildlife reproduction and develop a concept of “precision conservation breeding.” When basic studies in organismal physiology are conducted in parallel, new approaches using stem cells to create artificial gametes and gonads, innovations in germplasm storage, and more research on reproductive microbiomes will help to make a difference. Lastly, multiple challenges (for instance, poor integration of new tools in conservation programs, limited access to study animals, or few publication options) will have to be addressed if we want reproductive biology to positively impact conservation of biodiversity.

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Winship, Amy, Ellen Menkhorst, Michelle Van Sinderen et Evdokia Dimitriadis. « Interleukin 11 : similar or opposite roles in female reproduction and reproductive cancer ? » Reproduction, Fertility and Development 28, n^o 4 (2016) : 395. http://dx.doi.org/10.1071/rd14128.

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During placental development and carcinogenesis, cell invasion and migration are critical events in establishing a self-supporting vascular supply. Interleukin (IL)-11 is a pleiotropic cytokine that affects the invasive and migratory capabilities of trophoblast cells that form the placenta during pregnancy, as well as various malignant cell types. The endometrium is the site of embryo implantation during pregnancy; conversely, endometrial carcinoma is the most common gynaecological malignancy. Here, we review what is known about the role of IL-11 in trophoblast function and in gynaecological malignancies, focusing primarily on the context of the uterine environment.

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Bidne, K. L., M. J. Dickson, J. W. Ross, L. H. Baumgard et A. F. Keating. « Disruption of female reproductive function by endotoxins ». Reproduction 155, n^o 4 (avril 2018) : R169—R181. http://dx.doi.org/10.1530/rep-17-0406.

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Endotoxemia can be caused by obesity, environmental chemical exposure, abiotic stressors and bacterial infection. Circumstances that deleteriously impact intestinal barrier integrity can induce endotoxemia, and controlled experiments have identified negative impacts of lipopolysaccharide (LPS; an endotoxin mimetic) on folliculogenesis, puberty onset, estrus behavior, ovulation, meiotic competence, luteal function and ovarian steroidogenesis. In addition, neonatal LPS exposures have transgenerational female reproductive impacts, raising concern about early life contacts to this endogenous reproductive toxicant. Aims of this review are to identify physiological stressors causing endotoxemia, to highlight potential mechanism(s) by which LPS compromises female reproduction and identify knowledge gaps regarding how acute and/or metabolic endotoxemia influence(s) female reproduction.

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Zhang, Tongqian, Junling Wang, Yi Song et Zhichao Jiang. « Dynamical Analysis of a Delayed HIV Virus Dynamic Model with Cell-to-Cell Transmission and Apoptosis of Bystander Cells ». Complexity 2020 (17 août 2020) : 1–12. http://dx.doi.org/10.1155/2020/2313102.

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In this paper, a delayed viral dynamical model that considers two different transmission methods of the virus and apoptosis of bystander cells is proposed and investigated. The basic reproductive number R0 of the model is derived. Based on the basic reproductive number, we prove that the disease-free equilibrium E0 is globally asymptotically stable for R0<1 by constructing suitable Lyapunov functional. For R0>1, by regarding the time delay as bifurcation parameter, the existence of local Hopf bifurcation is investigated. The results show that time delay can change the stability of endemic equilibrium and cause periodic oscillations. Finally, we give some numerical simulations to illustrate the theoretical findings.

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Huala, Eva, et Ian M. Sussex. « Determination and Cell Interactions in Reproductive Meristems ». Plant Cell 5, n^o 10 (octobre 1993) : 1157. http://dx.doi.org/10.2307/3869769.

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Gosden, R., et N. Spears. « Programmed cell death in the reproductive system ». British Medical Bulletin 53, n^o 3 (1 janvier 1997) : 644–61. http://dx.doi.org/10.1093/oxfordjournals.bmb.a011636.

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Ransick, Andrew. « Reproductive cell specification during Volvox obversus development ». Developmental Biology 143, n^o 1 (janvier 1991) : 185–98. http://dx.doi.org/10.1016/0012-1606(91)90065-b.

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Kresovich, Jacob K., Christine G. Parks, Dale P. Sandler et Jack A. Taylor. « Reproductive history and blood cell telomere length ». Aging 10, n^o 9 (19 septembre 2018) : 2383–93. http://dx.doi.org/10.18632/aging.101558.

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Ionov, Ilya D. « The mast cell system in reproductive toxicology ». Reproductive Toxicology 4, n^o 4 (janvier 1990) : 251–55. http://dx.doi.org/10.1016/0890-6238(90)90036-u.

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Santos, E. M., V. L. Workman, G. C. Paull, A. L. Filby, K. J. W. Van Look, P. Kille et C. R. Tyler. « Molecular basis of sex and reproductive status in breeding zebrafish ». Physiological Genomics 30, n^o 2 (juillet 2007) : 111–22. http://dx.doi.org/10.1152/physiolgenomics.00284.2006.

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The zebrafish ( Danio rerio) is used extensively as a model species for studies on vertebrate development and for assessing chemical effects on reproduction. Despite this, the molecular mechanisms controlling zebrafish reproduction are poorly understood. We analyzed the transcriptomic profiles of the gonads of individual zebrafish, using a 17k oligonucleotide microarray, to define the molecular basis of sex and reproductive status in sexually mature fish. The gonadal transcriptome differed substantially between sexes. Among the genes overexpressed in females, 11 biological processes were overrepresented including mitochondrion organization and biogenesis, and cell growth and/or maintenance. Among the genes overexpressed in males, six biological processes were overrepresented including protein biosynthesis and protein metabolism. Analysis of the expression of gene families known to be involved in reproduction identified a number of genes differentially expressed between ovaries and testes including a number of sox genes and genes belonging to the insulin-like growth factor and the activin-inhibin pathways. Real-time quantitative PCR confirmed the expression profiles for nine of the most differentially expressed genes and indicated that many transcripts are likely to be switched off in one of the sexes in the gonads of adult fish. Significant differences were seen between the gonad transcriptomes of individual reproductively active females reflecting their stage of maturation, whereas the testis transcriptomes were remarkably similar between individuals. In summary, we have identified molecular processes associated with (gonadal) sex specificity in breeding zebrafish and established a strong relationship between individual ovarian transcriptomes and reproductive status in females.

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Bagchi, D., N. S. Deshmukh, F. C. Lau et M. Bagchi. « Reproductive ». Experimental and Toxicologic Pathology 61, n^o 4 (juillet 2009) : 405. http://dx.doi.org/10.1016/j.etp.2009.02.093.

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Shimasaki, Shunichi, R. Kelly Moore, Fumio Otsuka et Gregory F. Erickson. « The Bone Morphogenetic Protein System In Mammalian Reproduction ». Endocrine Reviews 25, n^o 1 (1 février 2004) : 72–101. http://dx.doi.org/10.1210/er.2003-0007.

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Using molecular, cellular, and genetic approaches, recent studies examining the role of the bone morphogenetic protein (BMP) family of growth factors in the reproductive system have led to significant breakthroughs in our understanding of mammalian reproduction and fertility. Gene expression studies have revealed that key components of the BMP system (ligands, receptors, signaling molecules, and binding proteins) exhibit coordinated spatial and temporal expression patterns in fundamental cell types throughout the reproductive system. Availability of recombinant BMPs has enabled functional studies that have demonstrated important biological activities of BMPs in controlling cellular proliferation, differentiation, and apoptosis in reproductive tissues. The physiological importance of the BMP system for mammalian reproduction has been further highlighted by the elucidation of the aberrant reproductive phenotypes of animals with naturally occurring mutations or targeted deletions of certain BMP family genes. Collectively, these studies have established the concept that the BMP system plays a crucial role in fertility in female and male mammals. The purpose of this article is to review the evidence underpinning the importance of the BMP system in mammalian reproduction.

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Dong, Shucan, Biwei Hou, Chuang Yang, Yaokun Li, Baoli Sun, Yongqing Guo, Ming Deng, Dewu Liu et Guangbin Liu. « Comparative Hypothalamic Transcriptome Analysis Reveals Crucial mRNAs, lncRNAs, and circRNAs Affecting Litter Size in Goats ». Genes 14, n^o 2 (9 février 2023) : 444. http://dx.doi.org/10.3390/genes14020444.

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Litter size is an important indicator to measure the reproductive performance of goats, which is affected by the reproductive function of animals. The hypothalamus, as the regulatory center of the endocrine system, plays an important role in the reproduction of female animals. Here, we performed high-throughput RNA sequencing using hypothalamic tissue from high-fecundity and low-fecundity Leizhou goats to explore critical functional genes associated with litter size. Differentially expressed mRNA, lncRNA, and circRNAs were screened using DESeq and were enriched, and then analyzed by Gene Ontology and Kyoto Encyclopedia of Gene and Genome. Results showed that some of these differentially expressed mRNAs could be enriched in reproductive processes, jak-STAT, prolactin signaling pathway, and other signaling pathways related to reproduction, such as SOCS3. Furthermore, the central proteins POSTN, MFAP5, and DCN from protein–protein interaction may regulate animal reproductive activity by affecting cell proliferation and apoptosis. lncRNA MSTRG.33887.2 as well as circRNAs chicirc_098002, chicirc_072583, and chicirc_053531 may be able to influence animal reproduction by participating in folate metabolism and energy metabolism homeostasis through their respective target genes. Our results expand the molecular mechanism of hypothalamic regulation on animal reproduction.

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Wyffels, Jennifer T., Robert George, Lance Adams, Cayman Adams, Tonya Clauss, Alisa Newton, Michael W. Hyatt, Christopher Yach et Linda M. Penfold. « Testosterone and semen seasonality for the sand tiger shark Carcharias taurus† ». Biology of Reproduction 102, n^o 4 (13 décembre 2019) : 876–87. http://dx.doi.org/10.1093/biolre/ioz221.

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Abstract Understanding the fundamental reproductive biology of a species is the first step toward identifying parameters that are critical for reproduction and for the development of assisted reproductive techniques. Ejaculates were collected from aquarium (n = 24) and in situ (n = 34) sand tiger sharks Carcharias taurus. Volume, pH, osmolarity, sperm concentration, motility, status, morphology, and plasma membrane integrity were assessed for each ejaculate. Semen with the highest proportion of motile sperm was collected between April and June for both in situ and aquarium sand tiger sharks indicating a seasonal reproductive cycle. Overall, 17 of 30 semen samples collected from aquarium sharks from April through June contained motile sperm compared to 29 of 29 of in situ sharks, demonstrating semen quality differences between aquarium and in situ sharks. Sperm motility, status, morphology, and plasma membrane integrity were significantly higher (P < 0.05) for in situ compared to aquarium sand tiger sharks. Testosterone was measured by an enzyme immunoassay validated for the species. Testosterone concentration was seasonal for both aquarium and in situ sharks with highest concentrations measured in spring and lowest in summer. In situ sharks had higher (P < 0.05) testosterone concentration in spring than aquarium sharks. This study demonstrated annual reproduction with spring seasonality for male sand tiger sharks through marked seasonal differences in testosterone and semen production. Lower testosterone and poorer semen quality was observed in aquarium sharks likely contributing to the species’ limited reproductive success in aquariums.

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Markova, E., L. Lyulkova, R. Melnik et V. Popova. « Cultural properties of swine reproductive and respiratory syndrome virus isolate ». Agrarian Bulletin of the 195, n^o 4 (13 mai 2020) : 71–77. http://dx.doi.org/10.32417/1997-4868-2020-195-4-71-77.

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Abstract. This article summarizes the results of a study of the cultural properties of the swine reproductive and respiratory syndrome virus isolate in transferable cultures of MA-104, PK-15, MARC-145 and Vero cells. The purpose of our research was to determine the sensitivity of cell culture lines to the swine reproductive and respiratory syndrome virus isolate, which is necessary for obtaining a highly active antigen as the main component of diagnostic and vaccine biologics. An isolate of the virus was isolated from a Piglet in the LPH of the Moscow region of the Kolomenskoye district. The isolated isolate of an infectious disease of pigs by the method of molecular biological analysis is characterized in the established order for this pathogen. Novelty. The possibility of reproduction in MARC-145 cell culture has been demonstrated. Results. It was shown that during reproduction of the virus isolate in cell culture for 96 ± 6 hours at a dose of 0.1 TCD50 / cell infection, an antigen with high biological activity was obtained. Infectious activity of the virus on the MARC-145 culture averaged 5.51 ± 0.45 lg TCD50/cm3 after the first three passages (after adaptation). Real-time PCR confirmed the presence of the virus genome in the test samples. Detection of the virus antigen in an infected cell culture was determined by the manifestation of a specific glow in the indirect immunofluorescence (RNIF) reaction in the cell culture monolayer fixed with acetone. It was found that FITZ-conjugate of rabbit polyclonal antibodies to pig immunoglobulins detected antigen-containing cells due to intense illumination.

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Evans, Janice P., et Phyllis C. Leppert. « “Feeling the force” in reproduction : Mechanotransduction in reproductive processes ». Connective Tissue Research 57, n^o 3 (12 avril 2016) : 236–44. http://dx.doi.org/10.3109/03008207.2016.1146715.

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Sedivy, John M. « Reproductive cloning conserves cellular senescence ». Nature Cell Biology 5, n^o 6 (juin 2003) : 495–96. http://dx.doi.org/10.1038/ncb0603-495.

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Baker, F. L., L. J. Sanger, R. W. Rodgers, K. Jabboury et O. R. Mangini. « Cell proliferation kinetics of normal and tumour tissue in vitro : quiescent reproductive cells and the cycling reproductive fraction ». Cell Proliferation 28, n^o 1 (janvier 1995) : 1–15. http://dx.doi.org/10.1111/j.1365-2184.1995.tb00035.x.

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Hashem, Nesrein M., Antonio Gonzalez-Bulnes et Jesus Simal-Gandara. « Polyphenols in Farm Animals : Source of Reproductive Gain or Waste ? » Antioxidants 9, n^o 10 (21 octobre 2020) : 1023. http://dx.doi.org/10.3390/antiox9101023.

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Reproduction is a complex process that is substantially affected by environmental cues, specifically feed/diet and its components. Farm animals as herbivorous animals are exposed to a large amount of polyphenols present in their natural feeding system, in alternative feed resources (shrubs, trees, and agro-industrial byproducts), and in polyphenol-enriched additives. Such exposure has increased because of the well-known antioxidant properties of polyphenols. However, to date, the argumentation around the impacts of polyphenols on reproductive events is debatable. Accordingly, the intensive inclusion of polyphenols in the diets of breeding animals and in media for assisted reproductive techniques needs further investigation, avoiding any source of reproductive waste and achieving maximum benefits. This review illustrates recent findings connecting dietary polyphenols consumption from different sources (conventional and unconventional feeds) with the reproductive performance of farm animals, underpinned by the findings of in vitro studies in this field. This update will help in formulating proper diets, optimizing the introduction of new plant species, and feed additives for improving reproductive function, avoiding possible reproductive wastes and maximizing possible benefits.

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Chronowska, Ewa. « High-Throughput Analysis of Ovarian Granulosa Cell Transcriptome ». BioMed Research International 2014 (2014) : 1–7. http://dx.doi.org/10.1155/2014/213570.

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The quality of follicular oocytes depends on interactions with surrounding granulosa cells. Development of molecular techniques and methods enables better understanding of processes underlying mammalian reproduction on cellular level. The success in reproductive biology and medicine in different species depends on reliable assessment of oocyte and embryo viability which presently mainly bases on embryo morphology. Although successful pregnancies have been achieved using this approach, its precision still should be improved and completed with other, more objective, and accurate assessment strategies. Global profiling of gene expression in follicular cumulus cells using microarrays is continuously leading to the establishment of new biomarkers which can be used to select oocytes with highest developmental potential. Even more potential applications and greater precision could be achieved using next generation sequencing (NGS) of granulosa and cumulus cell RNA (RNA-seq). However, due to the high cost, this method is not used as frequently as microarrays at the moment. In any case, high-throughput technologies offer the possibilities and advantages in ovarian somatic cell analysis on scale that has not been noted so far. The aim of this work is to present current directions and examples of global molecular profiling of granulosa cells and underline its impact on reproductive biology and medicine.

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Ryan, Calen P., Meaghan J. Jones, Rachel D. Edgar, Nanette R. Lee, Michael S. Kobor, Thomas W. McDade et Christopher W. Kuzawa. « Immune cell type and DNA methylation vary with reproductive status in women : possible pathways for costs of reproduction ». Evolution, Medicine, and Public Health 10, n^o 1 (1 janvier 2022) : 47–58. http://dx.doi.org/10.1093/emph/eoac003.

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Abstract Background Consistent with evolutionarily theorized costs of reproduction (CoR), reproductive history in women is associated with life expectancy and susceptibility to certain cancers, autoimmune disorders and metabolic disease. Immunological changes originating during reproduction may help explain some of these relationships. Methodology To explore the potential role of the immune system in female CoR, we characterized leukocyte composition and regulatory processes using DNA methylation (DNAm) in a cross-sectional cohort of young (20–22 years old) women differing in reproductive status. Results Compared to nulliparity, pregnancy was characterized by differential methylation at 828 sites, 96% of which were hypomethylated and enriched for genes associated with T-cell activation, innate immunity, pre-eclampsia and neoplasia. Breastfeeding was associated with differential methylation at 1107 sites (71% hypermethylated), enriched for genes involved in metabolism, immune self-recognition and neurogenesis. There were no significant differences in DNAm between nulliparous and parous women. However, compared to nullipara, pregnant women had lower proportions of B, CD4T, CD8T and natural killer (NK) cells, and higher proportions of granulocytes and monocytes. Monocyte counts were lower and NK counts higher among breastfeeding women, and remained so among parous women. Implications Our findings point to widespread differences in DNAm during pregnancy and lactation. These effects appear largely transient, but may accumulate with gravidity become detectable as women age. Nulliparous and parous women differed in leukocyte composition, consistent with more persistent effects of reproduction on cell type. These findings support transient (leukocyte DNAm) and persistent (cell composition) changes associated with reproduction in women, illuminating potential pathways contributing to CoR. Lay Summary: Evolutionary theory and epidemiology support costs of reproduction (CoR) to women’s health that may involve changes in immune function. We report differences in immune cell composition and gene regulation during pregnancy and breastfeeding. While many of these differences appear transient, immune cell composition may remain, suggesting mechanisms for female CoR.

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Keane, Kevin N., Vinicius F. Cruzat, Emily K. Calton, Prue H. Hart, Mario J. Soares, Philip Newsholme et John L. Yovich. « Molecular actions of vitamin D in reproductive cell biology ». Reproduction 153, n^o 1 (janvier 2017) : R29—R42. http://dx.doi.org/10.1530/rep-16-0386.

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Vitamin D (VitD) is an important secosteroid and has attracted attention in several areas of research due to common VitD deficiency in the population, and its potential to regulate molecular pathways related to chronic and inflammatory diseases. VitD metabolites and the VitD receptor (VDR) influence many tissues including those of the reproductive system. VDR expression has been demonstrated in various cell types of the male reproductive tract, including spermatozoa and germ cells, and in female reproductive tissues including the ovaries, placenta and endometrium. However, the molecular role of VitD signalling and metabolism in reproductive function have not been fully established. Consequently, the aim of this work is to review current metabolic and molecular aspects of the VitD–VDR axis in reproductive medicine and to propose the direction of future research. Specifically, the influence of VitD on sperm motility, calcium handling, capacitation, acrosin reaction and lipid metabolism is examined. In addition, we will also discuss the effect of VitD on sex hormone secretion and receptor expression in primary granulosa cells, along with the impact on cytokine production in trophoblast cells. The review concludes with a discussion of the recent developments in VitD–VDR signalling specifically related to altered cellular bioenergetics, which is an emerging concept in the field of reproductive medicine.

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Yang, Xue, Yongmei Su, Huijia Li et Xinjian Zhuo. « Optimal Control of a Cell-to-Cell Fractional-Order Model with Periodic Immune Response for HCV ». Symmetry 13, n^o 11 (8 novembre 2021) : 2121. http://dx.doi.org/10.3390/sym13112121.

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In this paper, a Caputo fractional-order HCV Periodic immune response model with saturation incidence, cell-to-cell and drug control was proposed. We derive two different basic reproductive numbers and their relation with infection-free equilibrium and the immune-exhausted equilibrium. Moreover, there exists some symmetry in the relationship between the two equilibria and the basic reproduction numbers. We obtain the global stability of the infection-free equilibrium by using Lyapunov function and the local stability of the immune-exhausted equilibrium. The optimal control problem is also considered and two control strategies are given; one is for ITX5061 monotherapy, the other is for ITX5061 and DAAs combination therapy. Matlab numerical simulation shows that combination therapy has lower objective function value; therefore, it is worth trying to use combination therapy to treat HCV infection.

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TCHUENCHE, JEAN M. « REALISTIC PATTERNS OF INHERITANCE OF SICKLE-CELL ANEMIA GENE : A THEORETICAL APPROACH ». Journal of Biological Systems 13, n^o 01 (mars 2005) : 13–22. http://dx.doi.org/10.1142/s0218339005001379.

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We derive equations which describe the reproductive interactions of human individuals in a population governed by their genotype structure. The model assumes reproduction within a specified age interval and the approach is basically theoretical. Some fundamental properties of the renewal equations as well as the interaction function are listed. It is significant that genetic screening prior to marriage still remains the principal preventive measure in order to avoid an increase in the population of those suffering from genetic defects.

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Schmidt, Christina M., Sandra Arbi et Nigel C. Bennett. « Ovulation mitigates fatty liver associated with reproductive suppression and oxidative stress in Damaraland mole-rats (Fukomys damarensis) ». Reproduction, Fertility and Development 32, n^o 10 (2020) : 923. http://dx.doi.org/10.1071/rd20049.

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Oxidative damage is often linked to reproduction; however, reproducing female Damaraland mole-rats (Fukomys damarensis) exhibit a reduction in oxidative damage relative to their non-reproductive, anovulatory, cohorts. Specifically, liver concentrations of malondialdehyde, a biomarker for lipid peroxidation, are significantly lower in reproducing females. We examined liver histology in reproductive, anovulatory and recently ovulating non-reproductive females, demonstrating an accumulation of lipid droplets only in the livers of anovulatory females and no fibrosis, cell death or inflammatory infiltrates in any group. Our observations suggest that anovulatory females experience a form of non-alcoholic fatty liver disease, which is reversed once they commence ovulation. We propose hormonal interactions that may underlie our observations.

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Nikogosyan, Seda O., T. Sh Tagibova, V. V. Kuznetsov et O. A. Anurova. « Female reproductive system tumors with Merkel cell phenotype ». Russian Journal of Oncology 21, n^o 4 (15 août 2016) : 172–74. http://dx.doi.org/10.18821/1028-9984-2016-21-4-172-174.

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Diagnostics and treatment of female reproductive system tumors with Merkel cell phenotype, rare aggressive tumors with dismal prognosis, is under consideration in this article. Only 20 cases of Merkel cell vulvar carcinoma and 1 case of Merkel cell vagina cancer were described in the literature. Diagnostics must include immunohistochemical analysis, as expression of cytokeratine 20 proves to be the most typical factor. Polyomavirus infection is believed to be associated with the disease pathogenesis. No treatment standards were accepted due to the rarity of the disease. Considering the data on tumor radiosensitivity, the treatment must include radio- or chemoradiotherapy.

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Harris, Elizabeth A., Oscar J. Fletcher, Kenneth E. Anderson, James N. Petitte, Levy Kopelovich et Paul E. Mozdziak. « Epithelial Cell Tumors of the Hen Reproductive Tract ». Avian Diseases 58, n^o 1 (mars 2014) : 95–101. http://dx.doi.org/10.1637/10643-082313-reg.1.

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FUJIWARA, HIROHI, KIMITOSHI IMAI, TAKUYA INOUE, MICHIYUKI MAEDA et SHINGO FUJII. « Membrane-Bound Cell Surface Peptidases in Reproductive Organs. » Endocrine Journal 46, n^o 1 (1999) : 11–25. http://dx.doi.org/10.1507/endocrj.46.11.

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