Sperm Capacitation and Its Relationship with the Sperm Proteomic Profile and Fertility in Nellore Bulls

• Grant number: 25/12589-6
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: January 01, 2026
• End date: December 31, 2027
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Eneiva Carla Carvalho Celeghini
• Grantee: Laura Nataly Garcia Oliveros
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 23/01059-0 - Relationship between sperm capacitation and fertility in cryopreserved semen of Nellore bulls: emphasis on sperm microRNA profile and metabolomics, AP.R

Abstract

The present project aims to investigate the molecular mechanisms associated with sperm capacitation in Nellore bulls, with an emphasis on identifying functional proteomic biomarkers related to the ability of spermatozoa to respond to capacitation, as well as to their fertilizing potential and cryotolerance. Capacitation is an essential process for fertilization, involving complex biochemical modifications modulated by specific proteins from both the spermatozoa and the reproductive environment. The study will be conducted in two experiments, using samples previously obtained from earlier projects. In Experiment 1, an untargeted proteomic analysis by UPLC-MS/MS will be carried out on fresh and cryopreserved semen from bulls previously classified according to their responsiveness to capacitation, aiming to correlate proteomic profiles with functional capacitation events. In Experiment 2, samples from bulls with high fertility and high responsiveness will be compared with those from bulls with low fertility and low responsiveness to identify differentially expressed proteins associated with sperm competence. The proteomic data will be integrated with functional variables already obtained from metabolomic, lipidomic, and microRNAs data. This study is expected to identify key proteins and molecular pathways involved in capacitation and fertilization success, providing insights for bull reproductive selection and the improvement of semen cryopreservation protocols. (AU)