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Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only Publication Acceptance Date: 5/15/1998 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: The USDA-Beltsville Sperm Sexing Technology has been proven conclusively as the only effective means of altering the sex ratio of offspring in livestock. Progress in methods development has extended the usefulness of the technology for use in broader management situations. The method is based on the flow cytometric separation of X and Y chromosome bearing sperm mbased on X/Y DNA difference and is an effective means of producing progeny of predetermined sex in cattle, swine, sheep and laboratory animals. Sperm are treated with a DNA binding fluorochrome, Hoechst 33342 and flow cytometrically sorted into separate X and Y populations that can be used for surgical insemination, deep-uterine insemination and AI in cattle, IVF to produce sexed embryos for transfer, or ICSI of ova. Skewed sex ratios of 90 to 95% of one sex or the other have been repeatably achieved. The method has been used worldwide to produce several hundred normal offspring of the predicted sex. The method represents the only fully validated sexin method for man and animals. Recent improvements to the technology take two forms. Firstly, the development of a new orienting nozzle that we have fitted to standard and high speed cell sorters that have been modified for sperm. The addition of the nozzle to Coulter Epics sperm sorters has increased the utilization of the starting population of sperm by two to three fold. We have also adapted the orienting nozzle to a Cytomation MoFlo high speed cell sorter modified for sperm. This adaptation has increased the overall production rate of sorted X and Y sperm from about 0.4 million per hour to 4 to 5 million per hour. The Sperm Sexing Technology continues to show significant promise for application to the livestock industry. |
