Submitted to: Reproduction of Domestic Animals
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 1, 2000
Publication Date: N/A
Interpretive Summary: The utilization of sex preselection for swine reproduction worldwide would have a dramatic impact on breeding schemes and reproductive efficiency. The Beltsville Sperm Sexing Technology applied to boar sperm is capable of producing sexed sperm for use in in vitro fertilization (IVF) with embryo transfer and for surgical insemination. This study shows that the system is scapable of producing females at the rate of 97% of the litter versus the normal 50% when the embryos are produced from sexed sperm. The application of this technology in swine in specific market situations would be useful in advancing genetic improvement at a faster rate. The utilization of the current technology will allow the production of sexed sperm at the rate of 6 million sperm of each sex per hour of sorting. This will ultimately allow the use of sexed swine sperm for deep uterine insemination in the pig. However, advances are required in that technique prior to its utilization.
Technical Abstract: The Beltsville Sperm Sexing Technology has been proven as the only effective means of altering the sex ratio of offspring in livestock and humans. The application in humans is being done by MicroSort, GIVF Institute, Fairfax, VA. The method is based on the flow cytometric separation of X- and Y-chromosome bearing sperm based on X/Y DNA difference. It has been proven an effective means of producing progeny of predetermined sex in cattle, swine, horses, sheep and laboratory animals. The method involves treating sperm with a DNA binding fluorochrome, Hoechst 33342 and flow cytometrically sorting them into separate X and Y populations that can subsequently be used for surgical intra-tubal or intrauterine insemination, deep-uterine and regular artificial insemination and with in vitro fertilization to produce sexed embryos for transfer. Sorted X and Y sperm have also been used for intracytoplasmic sperm injection of ova. Skewed sex ratios of 85 to 100% of one sex or the other have been repeatably achieved in most species. The method has been used worldwide to produce hundreds of morphologically normal animal offspring of the predicted sex. It has also been validated in the laboratory using DNA re-analysis of the sorted sperm populations and by fluorescence in situ hybridization and PCR of individual sperm. Significant improvements in the original method have been made in the past two years. Sperm have been used for artificially inseminating cattle, horses and other species. Calves have been born from IVF-ET and from artificial insemination using deep-uterine or conventional techniques. Pigs of the desired and predicted (90+%) sex have been born after surgical insemination and after transfer of sexed embryos produced from IVM-ET.