Bovine Sperm Sexing Alters Sperm Morphokinetics and Subsequent Early Embryonic Development

Steele, H.; Makri, D.; Maalouf, W. E.; Reese, S.; K�lle, S.

Abstract

In artificial insemination the use of sex-sorted bovine sperm results in reduced conception, the causes of which are only partly understood. Therefore, we set out to investigate the effects of sexing on bovine sperm function and early embryonic development. Computer-assisted semen analysis (CASA) of sperm of the same bulls (n = 5), before and after sexing, demonstrated significantly reduced fast (A) and slow (B) progressively motile sperm (p [less than] 0.05) after sexing. Sexed-sperm also revealed significantly less hyperactivated sperm (p [less than] 0.05). As shown by time-lapse videomicroscopy of in vitro produced embryos (n = 360), embryos derived from sexed-sperm displayed significantly increased incidences of arrest at the 4-cell stage (p [less than] 0.05). The relative risk for shrinkage/fusion of blastomeres with subsequent lysis was 1.71 times higher in the embryos derived from sexed-sperm as compared to conventional embryos (p [less than] 0.05) resulting in significantly reduced blastocyst rates (p [less than] 0.001). The relative risk for cleavage was 2.36 times lower in the embryos derived from sex-sorted sperm (p [less than] 0.001). Additionally, sexed-sperm-derived embryos showed reduced survival times (hazard ratio HR = 1.54, p [less than] 0.001) which were bull dependent (p [less than] 0.001). However, the percentage of apoptotic cells was similar to conventional embryos. Furthermore, embryos derived from sexed-sperm were found to reach developmental stages at similar timings as conventional embryos. Our results suggest that reduced conception rates after sexing are due to altered sperm morphokinetics, decreasing the chance of sperm to reach and fertilise the oocyte, and aberrant early embryonic development.

Citation

Steele, H., Makri, D., Maalouf, W. E., Reese, S., & Kölle, S. (2020). Bovine Sperm Sexing Alters Sperm Morphokinetics and Subsequent Early Embryonic Development. Scientific Reports, 10(1), Article 6255. https://doi.org/10.1038/s41598-020-63077-6

• Journal Article Type: Article
• Acceptance Date: Mar 20, 2020
• Online Publication Date: Apr 10, 2020
• Publication Date: 2020
• Deposit Date: Apr 29, 2020
• Publicly Available Date: Apr 29, 2020
• Journal: Scientific reports
• Electronic ISSN: 2045-2322
• Publisher: Nature Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 10
• Issue: 1
• Article Number: 6255
• DOI: https://doi.org/10.1038/s41598-020-63077-6
• Public URL: https://nottingham-repository.worktribe.com/output/4359678
• Publisher URL: https://www.nature.com/articles/s41598-020-63077-6