A preparatory technique for semen selection

Abstract

OBJECTIVE: The desire to control the gender is apparent across time and culture. From nobility of medieval Europe striving for male heirs, to modern day dairy farmers seeking female calves to increase productivity in their herds, there are many motivations driving people to discover a practical technique to control sex. Previous research has sought a technique that will not only allow for the determination of the offspring preconceived but that also is robust and practical in a wide variety of settings. To date, Flow Cytometry, is the only technique capable of producing a semen sample with a 90% concentration of either X or Y bearing spermatozoa. However, flow cytometry is costly in both time and equipment, has safety concerns, and results in a small inseminatable sample. The current study reports of a new, proprietary methodology for inexpensive semen selection.DESIGN: Laboratory based study on semen separation using a animal model.MATERIALS AND METHODS: Semen samples from 14 bulls were obtained and prepared in extender before being exposed to 4 proprietary chemical solutions (A-D) using the new proprietary Semen Selection Chamber (SSC). Samples were monitored for changes in motility and concentration measurements at 1, 3 and 6 hours. Samples were then collected and processed for Fluorescent in situ Hybridization analysis.RESULTS: As expected, there were differences in both cell concentration and motility in each of the 4 chemical solutions (P < .001), with solutions, B and C, the solutions closest to normal body physiology, having the highest concentration of motile cells. Further, there were shifts in the sex ratios in at least three of the solutions. Solution D showed statistically higher ratios (P < .001) of Y bearing sperm averaging a 35:65 ratio (X:Y). Solutions A and B showed a trend toward higher X bearing ratios with an average of 56:44.CONCLUSIONS: While sex selection with the SSC yielded significantly lower ratios of X:Y sperm than that reported in the literature for flow cytometry (reported as high as 90%), the data from the present study suggests that the SSC can significantly shift the sex ratios of semen samples during processing. Further, given the average expense of a flow cytometry sorted sample ($500 for animals and $1500 or more in humans) verses the <$10/sample cost of the SSC sorting, further work with the SSC is justified to determine if it can increase birth rates of the selected sex. OBJECTIVE: The desire to control the gender is apparent across time and culture. From nobility of medieval Europe striving for male heirs, to modern day dairy farmers seeking female calves to increase productivity in their herds, there are many motivations driving people to discover a practical technique to control sex. Previous research has sought a technique that will not only allow for the determination of the offspring preconceived but that also is robust and practical in a wide variety of settings. To date, Flow Cytometry, is the only technique capable of producing a semen sample with a 90% concentration of either X or Y bearing spermatozoa. However, flow cytometry is costly in both time and equipment, has safety concerns, and results in a small inseminatable sample. The current study reports of a new, proprietary methodology for inexpensive semen selection. DESIGN: Laboratory based study on semen separation using a animal model. MATERIALS AND METHODS: Semen samples from 14 bulls were obtained and prepared in extender before being exposed to 4 proprietary chemical solutions (A-D) using the new proprietary Semen Selection Chamber (SSC). Samples were monitored for changes in motility and concentration measurements at 1, 3 and 6 hours. Samples were then collected and processed for Fluorescent in situ Hybridization analysis. RESULTS: As expected, there were differences in both cell concentration and motility in each of the 4 chemical solutions (P < .001), with solutions, B and C, the solutions closest to normal body physiology, having the highest concentration of motile cells. Further, there were shifts in the sex ratios in at least three of the solutions. Solution D showed statistically higher ratios (P < .001) of Y bearing sperm averaging a 35:65 ratio (X:Y). Solutions A and B showed a trend toward higher X bearing ratios with an average of 56:44. CONCLUSIONS: While sex selection with the SSC yielded significantly lower ratios of X:Y sperm than that reported in the literature for flow cytometry (reported as high as 90%), the data from the present study suggests that the SSC can significantly shift the sex ratios of semen samples during processing. Further, given the average expense of a flow cytometry sorted sample ($500 for animals and $1500 or more in humans) verses the <$10/sample cost of the SSC sorting, further work with the SSC is justified to determine if it can increase birth rates of the selected sex.