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Submitted to: Journal of Reproduction and Fertility
Publication Type: Book / Chapter Publication Acceptance Date: 9/5/1997 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Gender preselection using isolated populations of X- and Y-chromosome bearing spermatozoa that have been separated based on DNA content is currently possible in swine, and other farm animals as well as in humans. Semen from most livestock species can now be successfully separated into predominantly X or Y sperm populations prior to their use for intra-tubal insemination, deep-uterine insemination or for in vitro fertilization (IVF to produce sexed offspring. Birth of progeny of the desired sex in cattle, sheep, and swine under semi-practical conditions has successfully validated the sexing technology. Spermatozoa are separated based on the inherent difference of DNA content in the X-and Y-chromosome bearing sperm population using modified flow cytometry/cell sorting technology. Sperm are stained with Hoechst 33342 which binds to the DNA in an amount proportional to the amount of DNA present in the individual sperm. Over 300 animals from mvarious species at several locations have been born using the USDA- Beltsville Sperm Sexing Technology for separating X and Y sperm. Sex ratios are shifted from the normal 50:50 to 85 to 90% of one sex or the other. In swine, offspring have been born as the result of surgical intratubal insemination of separated sperm and also from IVF and embryo transfer. At the present time, standard swine artificial insemination techniques are not optimized to use with the low numbers of flow cytometrically separated X or Y sperm populations. Numerous improvements have been made in the sexing technology since it was first reported in 1989. Increasing the speed of the sexing process so as to make the application of the technology available to a larger segment of the livestock industry is paramount, even with low sperm number insemination technology. |
