Academic literature on the topic 'Sex-sorting'
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Journal articles on the topic "Sex-sorting"
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Sakamoto, Y., M. Ueda, S. Toda, and H. Kimura. "20 FACTORS THAT AFFECT PURITY AND YIELD OF BOVINE SEX-SORTED SPERM." Reproduction, Fertility and Development 23, no. 1 (2011): 116. http://dx.doi.org/10.1071/rdv23n1ab20.
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The purposes of these studies were to examine the influence on the yield of sex-sorted sperm by the different size of sorting gate and to evaluate factors that affect the purity of sex-sorted sperm. As the sorting gate was expanded, so the yield of bovine sex-sorted sperm using flow cytometry was increased. At the same time, the purity of sex-sorted sperm became low. In addition, though the sorting gates were the same size, the purity of sex-sorted sperm differed among trials. These observations indicated the existence of factors that affect purity besides the size of sorting gate. To examine the yield of sex-sorted sperm, X-bearing sex-sorted sperm from 4 Holstein bulls were produced repeatedly 34 times by 3 flow cytometers. The sizes of sorting gates were fixed at 40–42%, 44%, and 46%. Each yield of sorting gate at 40–42%, at 44% and at 46% was compared. To evaluate factors that affect purity, X- or Y-bearing sex-sorted sperm were produced by one flow cytometer. These trials were repeated 160 times for the sorting of X-bearing sperm and 45 times for the sorting of Y-bearing sperm. Stepwise multiple regression analysis was used to analyse the relationships between the purity of sex-sorted sperm and the following sorting conditions, the percentage of oriented sperm, the percentage of dead sperm, degree of separation between X-bearing and Y-bearing sperm, the size of sorting gate, event rate, drop drive frequency, drop delay value and drop delay accuracy. The highest yield was acquired by sorting gate at 44%. The number of sex-sorted sperm was increased as sorting gate was expanded, however, the purity became low. The purities of the sperm by some trials using sorting gate at 46% were less than our acceptable lowest purity that was 90%. So that those sperm must be discarded. Therefore the yield of sorting gate at 44% was greater than sorting gate at 46%. Stepwise multiple regression analysis revealed that the factors for increasing purity of X-bearing sex-sorted sperm were the percentage of oriented sperm (P < 0.001), the degree of separation between X-bearing sperm and Y-bearing sperm (P < 0.001), the drop delay accuracy (P < 0.001), the event rate and the drop drive frequency, and the factor for decreasing purity of X-bearing sex-sorted sperm was the size of sorting gate (P < 0.001). On the other hand, the factors for increasing purity of Y-bearing sex-sorted sperm were the percentage of oriented sperm (P < 0.01), the degree of separation between X-bearing sperm and Y-bearing sperm (P < 0.01) and the event rate (P < 0.05), and the factor for decreasing purity of Y-bearing sex-sorted sperm was the size of sorting gate (P < 0.01). From these results, it can be concluded that the purity of sex-sorted sperm was not depend on simply by size of sorting gate but was more completely explained by other sorting conditions.
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Alkmin, Diego V., Inmaculada Parrilla, Tatiana Tarantini, David del Olmo, Juan M. Vazquez, Emilio A. Martinez, and Jordi Roca. "Seminal plasma affects sperm sex sorting in boars." Reproduction, Fertility and Development 28, no. 5 (2016): 556. http://dx.doi.org/10.1071/rd14088.
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Two experiments were conducted in boar semen samples to evaluate how both holding time (24 h) and the presence of seminal plasma (SP) before sorting affect sperm sortability and the ability of sex-sorted spermatozoa to tolerate liquid storage. Whole ejaculate samples were divided into three aliquots immediately after collection: one was diluted (1 : 1, v/v) in Beltsville thawing solution (BTS; 50% SP); the SP of the other two aliquots was removed and the sperm pellets were diluted with BTS + 10% of their own SP (10% SP) or BTS alone (0% SP). The three aliquots of each ejaculate were divided into two portions, one that was processed immediately for sorting and a second that was sorted after 24 h storage at 15–17°C. In the first experiment, the ability to exhibit well-defined X- and Y-chromosome-bearing sperm peaks (split) in the cytometry histogram and the subsequent sorting efficiency were assessed (20 ejaculates). In contrast with holding time, the SP proportion influenced the parameters examined, as evidenced by the higher number of ejaculates exhibiting split and better sorting efficiency (P < 0.05) in semen samples with 0–10% SP compared with those with 50% SP. In a second experiment, the quality (viability, total and progressive motility) and functionality (plasma membrane fluidity and intracellular generation of reactive oxygen species) of sex-sorted spermatozoa were evaluated after 0, 72 and 120 h storage at 15–17°C (10 ejaculates). Holding time and SP proportion did not influence the quality or functionality of stored sex-sorted spermatozoa. In conclusion, a holding time as long as 24 h before sorting did not negatively affect sex sorting efficiency or the ability of sorted boar spermatozoa to tolerate long-term liquid storage. A high proportion of SP (50%) in the semen samples before sorting reduced the number of ejaculates to be sorted and negatively influenced the sorting efficiency, but did not affect the ability of sex-sorted spermatozoa to tolerate liquid storage.
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Garner, D. L., and G. E. Seidel Jr. "Past, present and future perspectives on sexing sperm." Canadian Journal of Animal Science 83, no. 3 (September 1, 2003): 375–84. http://dx.doi.org/10.4141/a03-022.
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Development of flow cytometry for sorting mammalian sperm according to their sex chromosomes began in the late 1970s and early 1980s. This technology, which has recently been commercialized for bovine sperm, is based on the differences in DNA content between X- and Y-chromosome-bearing sperm. Under ideal conditions, 5000 live bovine sperm of each sex can be sorted per second at 90% accuracy. Pregnancy rates of 50% have been achieved routinely in well-managed heifers with sex-sorted, cryopreserved bovine sperm compared to 60–80% with unsexed control sperm. About 90% of offspring have been of the selected sex. Sorting sperm according to sex chromosome content is similarly successful in many other mammals including exotic species, but sorting efficiencies are somewhat less for sperm from some species. Key words: Mammals, sex chromosomes, flow cytometer, cell sorter, DNA content, X and Y sperm, Hoechst 33342
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Burroughs, C. A., J. K. Graham, R. W. Lenz, and G. E. Seidel. "Seminal plasma effects on sex-sorting bovine sperm." Theriogenology 79, no. 3 (February 2013): 551–57. http://dx.doi.org/10.1016/j.theriogenology.2012.10.024.
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Lutrat, Célia, David Giesbrecht, Eric Marois, Steve Whyard, Thierry Baldet, and Jérémy Bouyer. "Sex Sorting for Pest Control: It’s Raining Men!" Trends in Parasitology 35, no. 8 (August 2019): 649–62. http://dx.doi.org/10.1016/j.pt.2019.06.001.
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Steinhauser, C. B., J. K. Graham, R. W. Lenz, and G. E. Seidel. "Removing seminal plasma improves bovine sperm sex-sorting." Andrology 4, no. 6 (August 27, 2016): 1131–37. http://dx.doi.org/10.1111/andr.12245.
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Veuskens, Jacky, Spencer Brown, Dominique Marie, and Loan Negrutiu. "FLOW CYTOMETRIC SEX CHROMOSOMES SORTING OF MELANDRIUM ALBUM." Biology of the Cell 73, no. 2-3 (January 1991): 33a. http://dx.doi.org/10.1016/0248-4900(91)90199-w.
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Das, Siba R., Maciej Maselko, Ambuj Upadhyay, and Michael J. Smanski. "Genetic engineering of sex chromosomes for batch cultivation of non-transgenic, sex-sorted males." PLOS Genetics 16, no. 11 (November 2, 2020): e1009180. http://dx.doi.org/10.1371/journal.pgen.1009180.
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The field performance of Sterile Insect Technique (SIT) is improved by sex-sorting and releasing only sterile males. This can be accomplished by resource-intensive separation of males from females by morphology. Alternatively, sex-ratio biasing genetic constructs can be used to selectively remove one sex without the need for manual or automated sorting, but the resulting genetically engineered (GE) control agents would be subject to additional governmental regulation. Here we describe and demonstrate a genetic method for the batch production of non-GE males. This method could be applied to generate the heterogametic sex (XY, or WZ) in any organism with chromosomal sex determination. We observed up to 100% sex-selection with batch cultures of more than 103 individuals. Using a stringent transgene detection assay, we demonstrate the potential of mass production of transgene free males.
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Evans, G., S. P. De Graaf, and W. M. C. Maxwell. "048. FUNCTIONAL DIFFERENCES BETWEEN SEX-SORTED AND NON-SORTED SPERM." Reproduction, Fertility and Development 21, no. 9 (2009): 13. http://dx.doi.org/10.1071/srb09abs048.
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The development and application of flow cytometric sorting for the pre-selection of sex has progressed at an increasing rate since the first report of live pre-sexed offspring of rabbits (2). The technique has been extended to production of pre-sexed offspring of numerous species and sorted bull semen is now widely available commercially around the world. Due to the stresses involved in the sex-sorting process, sex-sorted sperm may be functionally compromised in terms of reduced motility and viability, and their fertilising lifespan within the female reproductive tract may be reduced. Consequently, fertility in vivo may be compromised. However, improvements to the technology and a greater understanding of its biological impact on the sperm have facilitated recent developments in sheep, and we have demonstrated that sex-sorting is capable of selecting a functionally superior ram sperm population in terms of both in vitro and in vivo function. This has resulted in high fertility after intrauterine insemination of sex-sorted ram sperm (1). Unfortunately, to date, these results have not been matched in other species.
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Hermes, Robert, Britta Behr, Thomas B. Hildebrandt, Steffen Blottner, Birgit Sieg, Antje Frenzel, Andreas Knieriem, Joseph Saragusty, and Detlef Rath. "Sperm sex-sorting in the Asian elephant (Elephas maximus)." Animal Reproduction Science 112, no. 3-4 (June 2009): 390–96. http://dx.doi.org/10.1016/j.anireprosci.2008.05.007.
Full textDissertations / Theses on the topic "Sex-sorting"
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Bathgate, Roslyn Anne. "Studies on the cryopreservation of boar spermatozoa and its integration into assisted reproductive technologies." Thesis, The University of Sydney, 2004. http://hdl.handle.net/2123/1279.
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The aim of this thesis was to investigate the possibility of integrating frozen-thawed boar semen into reproductive technologies and into commercial production of pigs in Australia. This was to be achieved by establishing a semen freezing and AI regime that was of a standard acceptable to industry, and integrating the resultant frozen-thawed sperm into other reproductive technologies, such as flow cytometric sperm sorting and IVF. Initially, a protocol for freezing and thawing boar semen was established, based on the method described by Westendorf et al. (1975) and attempts were made to modify this protocol to improve the post-thaw sperm quality, as determined by in vitro assessment of motility, acrosome integrity and longevity. First, the egg yolk used in the freezing extenders was investigated, and the chicken yolk was replaced with either duck or quail yolk. It was shown that there was no benefit in substituting yolk from duck or quail for the chicken yolk traditionally used in freezing extender. Second, the effect of seminal plasma addition to the freezing extender, or seminal plasma addition to resuspension medium post-thaw was tested. Incorporating whole seminal plasma into the freezing extender at levels above 50% was found to be detrimental to post-thaw sperm quality. Reducing levels to 20% of the final volume improved acrosome integrity, but adversely affected motility of sperm. However, adding 20% seminal plasma to the resuspension medium used after thawing of boar semen had no significant influence on sperm quality compared with resuspension in medium without seminal plasma. The antioxidant catalase, and the iron chelator desferal added to the freezing extender, did not improve post-thaw sperm quality, nor was any benefit seen with addition of these substrates to the resuspension medium post-thaw. However, the bioactive phospholipid PAF and its regulating enzyme PAF:AH appeared to enhance post-thaw motility and acrosome integrity of sperm, respectively, when added to the semen pre-freezing. Unfortunately, due to the restrictions imposed on rPAF:AH as a research drug, it was not possible to test the in vivo effects at this time. After the in vitro experiments were completed, the in vivo fertility of frozen-thawed sperm was tested using the optimal freezing protocol and a novel technology, enabling non-surgical deep intrauterine insemination of sows. The aim was to establish the lowest possible dose of frozen-thawed sperm that could be used, without compromising fertility. Successful pregnancies were achieved with doses as low as 62.5 x 106 frozen-thawed sperm but the farrowing rates were too low to be practicable on a commercial scale. This is the first report of litters born after insemination of such a low dose of frozen-thawed sperm and using the novel DIU insemination technique. However, it was concluded that a double dose of 250 x 106 frozen-thawed sperm was the minimum dose required for maintaining acceptable fertility. Reduction in sperm numbers to such an extent made it possible to consider non-surgical insemination of sex-sorted, frozen-thawed semen. Previously, pregnancies had been achieved only after surgical insemination of sex-sorted boar sperm, or with DIU insemination of unfrozen sperm, immediately after sex-sorting. The low numbers of sex-sorted sperm available restricted the inseminate dose used here to 50 x106 motile sperm. A litter of 5 piglets was born after a low-dose, DIU insemination of sex-sorted, frozen-thawed sperm. This is the first report of piglets born after insemination with sex-sorted frozen-thawed sperm and non-surgical insemination. The low farrowing rate achieved in this experiment prompted the investigation of integrating sex-sorted, frozen-thawed boar sperm into IVF. Morulae were produced after IVF with sex-sorted, frozen-thawed sperm and successfully transferred using non-surgical techniques. This is the first report of pregnancy achieved with non-surgical transfer of embryos produced after IVF and IVC of IVM oocytes with sex-sorted, frozen-thawed boar sperm. Unfortunately, the pregnancy did not hold, and the embryos were lost prior to Day 32, but PCR of non-transferred embryos confirmed successful pre-selection of sex. Overall, this thesis demonstrated that it is still not economically feasible to incorporate frozen-thawed boar semen into the commercial production of pigs although it has considerable application in breeding programmes. However, the development of novel techniques enabling reduction in sperm dose, and for non-surgical transfer of embryos into recipient sows and incorporation of frozen-thawed semen into these technologies means that progress is being made with the integration of reproductive technologies and frozen-thawed semen into the pig industry.
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Bathgate, Roslyn Anne. "Studies on the cryopreservation of boar spermatozoa and its integration into assisted reproductive technologies." Faculty of Veterinary Science, The University of Sydney, 2004. http://hdl.handle.net/2123/1279.
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PhDThe aim of this thesis was to investigate the possibility of integrating frozen-thawed boar semen into reproductive technologies and into commercial production of pigs in Australia. This was to be achieved by establishing a semen freezing and AI regime that was of a standard acceptable to industry, and integrating the resultant frozen-thawed sperm into other reproductive technologies, such as flow cytometric sperm sorting and IVF. Initially, a protocol for freezing and thawing boar semen was established, based on the method described by Westendorf et al. (1975) and attempts were made to modify this protocol to improve the post-thaw sperm quality, as determined by in vitro assessment of motility, acrosome integrity and longevity. First, the egg yolk used in the freezing extenders was investigated, and the chicken yolk was replaced with either duck or quail yolk. It was shown that there was no benefit in substituting yolk from duck or quail for the chicken yolk traditionally used in freezing extender. Second, the effect of seminal plasma addition to the freezing extender, or seminal plasma addition to resuspension medium post-thaw was tested. Incorporating whole seminal plasma into the freezing extender at levels above 50% was found to be detrimental to post-thaw sperm quality. Reducing levels to 20% of the final volume improved acrosome integrity, but adversely affected motility of sperm. However, adding 20% seminal plasma to the resuspension medium used after thawing of boar semen had no significant influence on sperm quality compared with resuspension in medium without seminal plasma. The antioxidant catalase, and the iron chelator desferal added to the freezing extender, did not improve post-thaw sperm quality, nor was any benefit seen with addition of these substrates to the resuspension medium post-thaw. However, the bioactive phospholipid PAF and its regulating enzyme PAF:AH appeared to enhance post-thaw motility and acrosome integrity of sperm, respectively, when added to the semen pre-freezing. Unfortunately, due to the restrictions imposed on rPAF:AH as a research drug, it was not possible to test the in vivo effects at this time. After the in vitro experiments were completed, the in vivo fertility of frozen-thawed sperm was tested using the optimal freezing protocol and a novel technology, enabling non-surgical deep intrauterine insemination of sows. The aim was to establish the lowest possible dose of frozen-thawed sperm that could be used, without compromising fertility. Successful pregnancies were achieved with doses as low as 62.5 x 106 frozen-thawed sperm but the farrowing rates were too low to be practicable on a commercial scale. This is the first report of litters born after insemination of such a low dose of frozen-thawed sperm and using the novel DIU insemination technique. However, it was concluded that a double dose of 250 x 106 frozen-thawed sperm was the minimum dose required for maintaining acceptable fertility. Reduction in sperm numbers to such an extent made it possible to consider non-surgical insemination of sex-sorted, frozen-thawed semen. Previously, pregnancies had been achieved only after surgical insemination of sex-sorted boar sperm, or with DIU insemination of unfrozen sperm, immediately after sex-sorting. The low numbers of sex-sorted sperm available restricted the inseminate dose used here to 50 x106 motile sperm. A litter of 5 piglets was born after a low-dose, DIU insemination of sex-sorted, frozen-thawed sperm. This is the first report of piglets born after insemination with sex-sorted frozen-thawed sperm and non-surgical insemination. The low farrowing rate achieved in this experiment prompted the investigation of integrating sex-sorted, frozen-thawed boar sperm into IVF. Morulae were produced after IVF with sex-sorted, frozen-thawed sperm and successfully transferred using non-surgical techniques. This is the first report of pregnancy achieved with non-surgical transfer of embryos produced after IVF and IVC of IVM oocytes with sex-sorted, frozen-thawed boar sperm. Unfortunately, the pregnancy did not hold, and the embryos were lost prior to Day 32, but PCR of non-transferred embryos confirmed successful pre-selection of sex. Overall, this thesis demonstrated that it is still not economically feasible to incorporate frozen-thawed boar semen into the commercial production of pigs although it has considerable application in breeding programmes. However, the development of novel techniques enabling reduction in sperm dose, and for non-surgical transfer of embryos into recipient sows and incorporation of frozen-thawed semen into these technologies means that progress is being made with the integration of reproductive technologies and frozen-thawed semen into the pig industry.
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Skuratowicz, Eva Michelle. "Sorting women and men into jobs : the mechanisms of sex segregation in an American bank /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2004. http://uclibs.org/PID/11984.
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Ayres, Devin William Philip. "Effect of diet and sex-sorting on growth and gonad development in farmed South African abalone, Haliotis midae." Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1010856.
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Abalone, Haliotis midae, farmers in South Africa that feed formulated diets reported a periodic drop in abalone growth during periods of increased gonad development. A large drop in abalone biomass was noticed after presumed spawning events. This study was aimed to determine the effect of diet and sex-sorting on gonad development in abalone. Experiments were conducted on a commercial abalone farm from July 2012 to the end of June 2013. Isonitrogenous and isoenergetic diets were formulated with two protein sources. A fishmeal and soybean meal (S-diet) diet and a fishmeal only (F-diet) diet were fed to abalone (50 - 70 g abalone⁻¹) over 12 months. Weight and length gain, gonad bulk index (GBI), visceral index (%) and meat mass index (%) were determined monthly and seasonally. A histological study on the female gonads was conducted. This study also included an experiment to test the effect of sex-sorting (70 - 80 g abalone⁻¹) on growth and body composition with treatments including males (M), females (F) and equal numbers of males and females (MF). Weight gain and length gain were faster in S-diet-fed abalone (RM-ANOVA, F ₍₁, ₁₆₎ = 7.77, p = 0.01; F ₍₁, ₆₉₎ = 49.9, p < 0.001, respectively). Gonad development was significantly affected by the inclusion of soybean meal with S-diet-fed abalone showing higher GBI-values than F-diet-fed abalone (RM-ANOVA, F ₍₁, ₃₃)= 16.22, p = 0.0003). Male abalone had higher GBI-values than females (RM-ANOVA, F ₍₁, ₃₃₎ = 39.87, p < 0.0001). There was no significant difference in average feed conversion ratio (FCR) between diets over time (RM-ANOVA, F ₍₁, ₂₁₎ = 0.008, p = 0.97). However, average FCR-values were significantly highest between November 2012 and March 2013, the presumed spawning season. The visceral mass (gut and gonad) as a proportion of whole mass (visceral index, %) was significantly higher in abalone fed the S-diet (RM-ANOVA; F ₍₁, ₆₉₎ = 68.06, p < 0.0001). There was no difference in meat mass index (%) between diets for both male and female abalone (RM-ANOVA; F ₍₇, ₂₄₈₎ = 0.80, p = 0.60; F ₍₇, ₂₄₁₎ = 1.7, p = 0.11,respectively). Meat mass index significantly decreased from September 2012 to February 2013 coinciding with the period of high GBI-values. The distribution of oocyte maturity stages differed between diets. The majority of oocytes within S-diet-fed abalone were fully mature stage 8 oocytes compared to a majority of stage 7 oocytes in F-diet-fed abalone. Histology corroborated peaks in GBI-values for abalone fed both diets. There was no significant difference in growth, GBI, visceral index (%) and meat mass index (%) between abalone sorted into monosex and mixed-sex populations. Thus, the presence of the opposite sex did not have an effect on growth and gonad mass in H. midae. The phytoestrogens daidzin, glycitin, genistin, daidzein, glycitein and genistein were present in soybean meal and only traceable amounts were found in the F-diet. This study provided evidence that soybean meal present in formulated feed affected growth and gonad development in H.midae. The difference in the distribution of the maturity stages of oocytes was affected by diet. Sex-sorting abalone into monosex and mixed-sex populations had no influence on weight and length gain and gonad development.
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Schulz, Benjamin [Verfasser], Detlef [Gutachter] Rath, and Geert [Gutachter] Opsomer. "Investigations into Sperm Sex-Sorting and Reproductive Seasonality in Bottlenose Dolphins / Benjamin Schulz ; Gutachter: Detlef Rath, Geert Opsomer." Hannover : Stiftung Tierärztliche Hochschule Hannover, 2020. http://d-nb.info/1224882938/34.
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Hollinshead, Fiona Kate. "FLOW-CYTOMETRIC SORTING OF RAM SPERMATOZOA: PRODUCTION OF LAMBS OF A PRE-DETERMINED SEX USING IN VIVO AND IN VITRO FERTILISATION." University of Sydney, 2003. http://hdl.handle.net/2123/566.
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Abstract Birth of offspring of a pre-determined sex using flow cytometrically sorted fresh spermatozoa was first achieved in rabbits by Johnson et al. (1989). Since then offspring have been produced using sex-sorted spermatozoa from several different species (reviewed by Johnson, 2000). Initially, efficiency of the sex-sorting technology was poor with only low numbers of spermatozoa sorted per hour. Thus, the offspring derived from flow cytometrically sorted spermatozoa were produced with the use of artificial reproductive technologies (ART) such as in vitro fertilisation (IVF) and culture (IVC), intracytoplasmic sperm injection (ICSI) and deep artificial insemination (AI) which facilitated low dose insemination of potentially compromised spermatozoa. More recently, the development of high-speed sorters (Johnson and Welch, 1999) has facilitated the production of offspring using conventional AI techniques with low dose inseminates (Seidel et al., 1999) and successful cryopreservation of sorted spermatozoa (Schenk et al., 1999; Johnson et al., 2000; Lindsey et al., 2002; Schenk and DeGrofft, 2003). Increased efficiency of sorting bull spermatozoa has evolved through significant instrumentation and biological developments which have enabled the commercialization of the sperm sexing technology in the dairy industry, although conception rates in cows after low dose AI with sexed frozen-thawed spermatozoa are still lower than after standard frozen semen AI (Seidel et al., 1999). Subsequently, over 20 000 calves of pre-determined sex have been produced from commercially available sex-sorted frozen-thawed bull spermatozoa (Seidel, 2003). However, similar developments have not been made in the sheep industry and were examined in this thesis. In this study, successful cryopreservation of sex-sorted ram spermatozoa and production of offspring of the pre-determined sex (X: 94.4 %; Y: 100 %) was achieved after low dose (2-4 x 106 total) insemination using conventional laparoscopic intrauterine (IU) AI. However, the overall pregnancy rate for ewes inseminated with sex-sorted frozen-thawed spermatozoa was low (25 %) compared to ewes inseminated with a commercial dose (140 x 106 total) of non-sorted frozen-thawed spermatozoa (54 %). Cryopreservation has been found to not only reduce the proportion of motile spermatozoa, but cause the remaining spermatozoa to undergo changes that advance membrane maturation thereby shortening their lifespan, especially after in vivo fertilisation (Gillan and Maxwell, 1999). It was found that sorting prior to cryopreservation accelerated the maturation of sperm membranes and after co-incubation with oviducal cells in vitro, sorted frozen-thawed spermatozoa were released more rapidly than non-sorted (control) frozen-thawed spermatozoa. The potentially reduced lifespan of sorted frozen-thawed spermatozoa, and practical constraints on the number of spermatozoa that can be sorted for an insemination dose, makes insemination close to the site of fertilisation and time of ovulation critical for successful fertilisation. After treatment of ewes with GnRH to increase the precision of insemination in respect to the time of ovulation, there was no difference in pregnancy rate between ewes inseminated before, during or after the assumed time of ovulation. Furthermore, there was no difference in pregnancy rate after IU AI with similar doses of sorted frozen-thawed and non-sorted frozen-thawed spermatozoa in GnRH-treated ewes. The minimum dose of sorted frozen-thawed spermatozoa required for commercially acceptable pregnancy rates determined after IU AI was high (20 x 106 motile). Consequently, alternative methods for efficiently producing large numbers of offspring of a pre-determined sex using flow cytometrically sorted ram spermatozoa were investigated. Ram spermatozoa can be stored for short periods of time in a chilled state (liquid storage) or for an indefinite period of time in a frozen state (frozen storage; Salamon and Maxwell, 2000). The fixed location of the sperm sorter requires the need for transport of semen from the point of collection to the site of sorting and processing, but also from the sperm sorter site to the recipient females under artificial conditions. In this study, ram spermatozoa liquid stored for 24 h prior to sorting were efficiently sorted, frozen, thawed and after in vitro fertilisation and culture produced a high proportion of grade 1 blastocysts. Similarly, spermatozoa stored at reduced temperatures after sorting maintained high sperm quality for up to 6 days. Furthermore, frozen-thawed spermatozoa from rams and some non-human primates were successfully prepared for sorting and efficiently sorted producing spermatozoa with high quality in vitro parameters. The quality of frozen-thawed ram spermatozoa after sorting was such that successful re-cryopreservation after sorting was possible. Low numbers of frozen-thawed sorted and re-frozen and thawed spermatozoa were optimal for IVF and a high proportion of grade 1 in vitro embryos of a pre-determined sex were produced. These embryos were either transferred immediately or vitrified prior to transfer, extending the application of the sperm sexing technology further. The birth of lambs of pre-determined sex after transfer of both fresh and vitrified embryos derived from frozen-thawed sorted spermatozoa was achieved. The findings in this thesis suggest that sorted frozen-thawed ram spermatozoa may have more advanced membrane maturation state than non-sorted frozen-thawed spermatozoa, resulting in a decreased fertilizing lifespan in the female reproductive tract. Despite this, the use of sexed ram spermatozoa in a number of physiological states (fresh, liquid, frozen) with several different ARTs is possible in producing significant numbers of offspring of a pre-determined sex. Improved efficiency in both sperm sexing and associated reproductive technologies is required for commercialization to be achieved in the sheep industry.
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Caballero, Posadas Ignacio. "Estudio del plasma seminal y la espermadhesina PSP-I/PSP-II sobre la funcionalidad de los espermatozoides de verraco." Doctoral thesis, Universidad de Murcia, 2007. http://hdl.handle.net/10803/10980.
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En la siguiente tesis se obtuvieron los siguientes resultados. La adición de plasma seminal a los espermatozoides altamente diluidos ejerce un efecto beneficioso variable dependiendo de la fuente de plasma seminal. El heterodímero PSP-I/PSP-II ejerce un efecto beneficioso sobre los espermatozoides altamente diluidos mediante su adhesión al acrosoma. La incubación produce la migración del heterodímero a la región post-acrosomal, siendo eliminado de la superficie espermática. La adición del heterodímero a los medios de cocultivo entre gametos disminuye significativamente la capacidad fecundante de los espermatozoides. La preincubación de los espermatozoides de verraco tanto frescos como congelados preserva la viabilidad y motilidad espermáticas no afecta a la capacidad fecundante de los espermatozoides frescos de verraco y disminuye la capacidad fecundante de los espermatozoides congelados, la cual puede ser restaurada parcialmente mediante un lavado a través de un gradiente de Percoll.The addition of 10% of seminal plasma from certain boars maintains or enhances the viability of largely extended boar spermatozoa in vitro. The protective effect of the PSP-I/PSP-II heterodimer on highly-extended boar spermatozoa could be related to the adhesion of the heterodimer to the acrosome. Exposures of the gametes to the heterodimer during in vitro gamete co-incubation significantly decrease the sperm penetration rates and number of spermatozoa per oocytes in denuded oocytes. The effect could be mediated by exposed ZP receptors. Exposure of fresh or frozen-thawed boar spermatozoa to PSP-I/PSP-II preserves sperm viability and motility. Although there is no obvious influence of the heterodimer on the capability of fresh diluted boar spermatozoa to penetrate homologous oocytes, PSP-I/II exerts a deleterious effect when frozen-thawed spermatozoa are used to penetrate IVM-oocytes. A subsequent washing through a Percoll gradient estored sperm function in some of the cells.
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Parrilla, Riera Inmaculada. "Avances de la técnica de preselección del sexo en el ganado porcino mediante separación de espermatozoides X e Y por citometría de flujo." Doctoral thesis, Universidad de Murcia, 2005. http://hdl.handle.net/10803/10981.
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La separación espermática por citometría de flujo de los espermatozoides X e Y, es actualmente el único método eficaz para la obtención de descendencia de sexo deseado. En porcino, la selección del sexo de las camadas incrementaría notablemente los beneficios productivos de las explotaciones productoras de animales de alto valor genético al poder manejar los esquemas de selección, desviándolos hacia un sexo u otro según las necesidades de cada explotación. Recientemente, se han realizado avances importantes en la separación espermática mediante esta técnica en porcino. Sin embargo, es necesario un mayor conocimiento de diferentes aspectos relacionados con la eficiencia del proceso, con el efecto del procedimiento sobre la viabilidad y la capacidad fecundante de estos espermatozoides, así como del posible efecto perjudicial del propio proceso de separación sobre el ADN de los espermatozoides de verraco. Esta tesis recoge resultados derivados de experiencias destinadas a estudiar estos aspectos.Flow cytometric sorting technology based on differential DNA content between X- and Y- spermatozoa is the only effective procedure for achieving offspring of the desired sex. In swine production the application of this method could improve significantly the productive benefits by planning the insemination to produce a specific sex. A detailed knowledge of aspects related to the efficiency of the sperm sorting technique and to aspects related with effects of sorting procedure on the viability and penetration ability of pig oocytes of flow sorted boar spermatozoa, and of the potential damaging effect of the procedure on sperm DNA is necessary to obtain optimal results. This thesis presents the results of experiences about, the usefulness and efficiency of this technology, followed by the analysis of sorted boar spermatozoa motility, viability, penetration ability. Results of mutagenic effect of Hoechst 33342 staining and sorting on sorted boar spermatozoa are also included.
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Nawaz, Shamaila. "Sex and the city : gender gaps in labor markets and economic geography." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM1074.
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Cette thèse explore la dimension géographique des disparités entre les sexes dans le marché du travail. Les questions étudiées incluent la variation de la prime salariale urbaine entre les sexes (chapitre deux), l'exploration des différents mécanismes derrière les effets importants de la localisation géographique sur les gains du marché du travail des femmes (chapitre trois), et de l'écart entre les sexes sur les rendements d'expérience urbains (chapitre quatre). Le deuxième chapitre entreprend une analyse transversale à l'aide de données françaises pour estimer la prime salariale urbaine et sa variation entre les sexes. Les résultats confirment l'existence d'une prime salariale urbaine nettement supérieure pour les femmes. Un doublement de la densité de l'emploi dans une zone donnée entraîne une réduction de 2,4 pourcent de l'écart salarial entre les sexes, une valeur qui augmente de 4 pourcent lorsqu'on exclut la catégorie professionnelle des ouvriers. Contrairement au reste des professions, l'effet de la densité favorise les hommes dans la catégorie des ouvriers. Le troisième chapitre cherche à trouver les mécanismes à l'origine de l'effet importante de la localisation géographique sur les gains du marché du travail pour les femmes en employant l'approche par l'estimateur « within ». Les résultats suggèrent que la moitié de la prime salariale urbaine est attribuée sur la base d'un tri des travailleurs selon le type de compétences à travers des différentes zones. Cependant, en complément du tri de compétences, d'autres hétérogénéités individuelles contribuent également à l'excès de la prime salariale urbaine pour les femmesThis dissertation explores the geographical dimension of the gender gaps in the labor market. The investigated issues include the variation of urban wage premium across genders (chapter two), exploration of different mechanisms behind stronger location effects for females' labor market gains (chapter three), and the gender gap in the urban returns to experience (chapter four). The second chapter undertakes a cross-sectional analysis by using French data to estimate the urban wage premium and its variation across genders. The findings confirm the existence of an urban wage premium that is significantly higher for women. A twofold increase in employment density of an area results in a 2.4 percent reduction in the gender wage gap, which increases to 4 percent when we exclude manual workers occupational category. Contrary to the rest of the occupations, the density effect favors men in the manual workers category. The third chapter seeks to find the mechanisms behind the stronger location effects on labor market gains for women by employing the within estimate approach. Results suggest that half of the urban wage premium is contributed by the sorting of workers according to skill type across different areas. However, in addition to skill sorting other individual heterogeneities also contribute to the excess urban wage premium for females. Firm level agglomeration effects attribute a minor part to the excess urban wage premium for females. The left over premium is a result of pure urban effects (lower discrimination, better matching, urban amenities)
Books on the topic "Sex-sorting"
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Day, Ian. 'Sorting the men out from the boys': Masculinity, a missing link in the sociology of sport. Sheffield, [South Yorkshire]: PAVIC, 1990.
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Bolt, Prof. Sorting Out Sex: Sex and Lies. Independently Published, 2021.
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Sperino, Sandra F., and Suja A. Thomas. Frameworks. Oxford University Press, 2017. http://dx.doi.org/10.1093/acprof:oso/9780190278380.003.0006.
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This chapter discusses another hurdle workers face: the frameworks that courts use to evaluate employment discrimination cases. When Congress enacted the federal discrimination statutes, it appeared to formulate a simple way to determine whether discrimination happened. The words of the statutes ask the fact-finder to decide whether a particular employment outcome occurred because of a worker’s race, sex, or other protected trait. But since the 1970s, the federal courts have not always used that language to analyze discrimination cases. Instead, the Supreme Court has created a set of frameworks to decide whether discrimination occurred. Each framework introduces new terms and phrases into the discrimination inquiry, often making it harder for courts to adjudicate discrimination claims. The frameworks also reduce discrimination law to a rote sorting process. Ultimately, in many cases, the frameworks distract judges from the fundamental question of whether an employer discriminated against an employee.
Book chapters on the topic "Sex-sorting"
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Garner, Duane L., K. Michael Evans, and George E. Seidel. "Sex-Sorting Sperm Using Flow Cytometry/Cell Sorting." In Methods in Molecular Biology, 279–95. Totowa, NJ: Humana Press, 2012. http://dx.doi.org/10.1007/978-1-62703-038-0_26.
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Johnson, L. A., and G. R. Welch. "Mammalian Sex Preselection: Flow-cytometric Sorting of X and Y Spermatozoa Based on DNA Difference." In Manual on Assisted Reproduction, 289–302. Berlin, Heidelberg: Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/978-3-642-58341-4_10.
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Asquith, Pamela J. "A Woman of Science: Sorting Fact and Illusion in Gender and Primatology." In Primate Life Histories, Sex Roles, and Adaptability, 79–89. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-98285-4_5.
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Schelling, Thomas. "Sorting and Mixing: Race and Sex." In Emergence, 235–48. The MIT Press, 2008. http://dx.doi.org/10.7551/mitpress/9780262026215.003.0015.
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Dahl, Edgar. "Sex selection: sorting sperm as a gateway to the sorting society?" In The Sorting Society, 21–36. Cambridge University Press, 2001. http://dx.doi.org/10.1017/cbo9780511545573.004.
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"Migrant sex work and trafficking: sorting them out." In Introducing the New Sexuality Studies, 678–86. 3rd edition. | New York: Routledge, 2016. | Revised edition of: Routledge, 2016. http://dx.doi.org/10.4324/9781315697215-92.
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Underwood, S. L., C. Vigneault, and P. Blondin. "Flow Cytometric Sorting of Mammalian Sperm for Predetermination of Sex." In Comprehensive Biotechnology, 429–40. Elsevier, 2011. http://dx.doi.org/10.1016/b978-0-08-088504-9.00285-3.
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Underwood, S. L., C. Vigneault, and P. Blondin. "Flow Cytometric Sorting of Mammalian Sperm for Predetermination of Sex." In Comprehensive Biotechnology, 438–49. Elsevier, 2011. http://dx.doi.org/10.1016/b978-0-444-64046-8.00235-4.
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"HIV: prevention." In Oxford Handbook of Genitourinary Medicine, HIV, and Sexual Health, edited by Laura Mitchell, Bridie Howe, D. Ashley Price, Babiker Elawad, and K. Nathan Sankar, 443–48. Oxford University Press, 2019. http://dx.doi.org/10.1093/med/9780198783497.003.0036.
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Tackling the HIV epidemic takes many approaches. Treatment of those with HIV keeps them healthy, with a near-normal life expectancy and reduces onward transmission. The undetectable = untransmissible (U=U) campaign is based on strong evidence that people with sustained undetectable viral load on effective antiretroviral therapy do not pose any risk of transmission within a monogamous relationship. Safer sex using condoms is a mainstay, and sero-sorting and sero-positioning have their role. This chapter details the uses of post-exposure prophylaxis (PEP), how to prescribe and follow up. Pre-exposure prophylaxis (PrEP) is increasingly being recommended and used amongst people at on-going high risk of HIV acquisition. This chapter details benefits, indications and monitoring of people using PrEP
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Hart, D. G. "Americanism Revived." In American Catholic, 160–83. Cornell University Press, 2020. http://dx.doi.org/10.7591/cornell/9781501700576.003.0008.
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This chapter cites conservatives that regard Watergate and Richard Nixon's subsequent resignation as catastrophic. It discusses how the hopes for fusing American ideas of small government and personal liberty with traditional Christianity looked less than promising by 1975. It also refers to the mainline Protestant churches that, in the 1960s, came to terms with the mix of political reform and moral indifference in ways that were more radical than traditional. The chapter emphasizes how Protestants had yet to emerge as an identifiable political constituency as their concerns were generally too pious and moral for the urbane and worldly ethos of movement conservatives. It describes how the Roman Catholic Church was in the midst of sorting out the reforms of the Second Vatican Council while defending the papal teaching on sex and contraception.
Conference papers on the topic "Sex-sorting"
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Manago, S., G. Coppola, M. A. Ferrara, L. Sirleto, I. Rendina, R. Puglisi, D. Balduzzi, A. Galli, P. Ferraro, and A. C. De Luca. "Raman sex sorting of bovine spermatozoa." In 2014 Fotonica AEIT Italian Conference on Photonics Technologies (Fotonica AEIT). IEEE, 2014. http://dx.doi.org/10.1109/fotonica.2014.6843968.
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Giesbrecht, David. "Sex-sorting and sterilization of male Asian tiger mosquitoes (Aedes albopictus) using RNA interference." In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.114932.
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