FACTORS THAT INFLUENCE IN VITRO SPERM CAPACITATION AND THEIR EFFECTS UNDER IN VITRO FERTILIZATION OF EQUINE OOCYTES

• Grant number: 24/03500-9
• Support Opportunities: Scholarships in Brazil - Master
• Start date: August 01, 2024
• End date: March 31, 2026
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Frederico Ozanam Papa
• Grantee: Bruna Merci de Zutter
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

The use of biotechnology in equine reproduction has experienced exponential growth, driven by the search for the genetic improvement of animals with high zootechnical value. The technique of in vitro fertilization (IVF) in horses has been tested, showing persistently low success rates over decades. This complexity is intrinsically related to injuries to equine sperm during the in vitro sperm capacitation process, especially after the freezing process. In this context, this work aims to evaluate factors related to the freezing of equine sperm that may interfere with the success rates of sperm training, and consequently, in IVF. Thus, 2 ejaculates from 15 stallions will be collected and centrifuged with four extenders, based on milk and casein, with and without cholesterol, and then subjected to the freezing process. After thawing, they will be evaluated for sperm kinetics by CASA and plasma membrane integrity and quantification of cholesterol in the plasma membrane by flow cytometry and then subjected to sperm capacitation and reevaluated for the same parameters. The 2 animals that show the best training results, as well as the 2 worst ones, will undergo IVF to evaluate embryo production.