Melatonin on in vitro oocyte maturation and embryo development in bovine

• Grant number: 19/25964-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2020
• End date: May 31, 2021
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Cláudia Lima Verde Leal
• Grantee: Sophia Silva Carrijo
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil

Abstract

Melatonin (MEL) is an indoleamine that can act on reproductive competence, has antioxidant and antiapoptotic activities and influences different cell signaling pathways. In vitro studies have shown contradictory effects of MEL on in vitro maturation (IVM) and culture (IVC) of oocytes and embryos, respectively, in several species. In this study, we propose to investigate the effect of MEL on the development and quality of bovine embryos produced in vitro. In experiment 1, MEL will be supplemented to the IVM medium for 24 h in association with gonadotropins: 1) FSH; 2) FSH+LH; 3) MEL; 4) FSH+MEL and 5) FSH+LH+MEL. Oocytes will be evaluated for meiosis progression (% MII) and cortical granule (CG) migration and respective cumulus cells (CC) by PCR for transcript abundance of antioxidant enzymes (SOD1 and SOD2). The best combination of MEL and gonadotropins (highest % MII and CG migration) will be used in experiment 2 in which matured COCs will be submitted to in vitro fertilization (IVF) followed by IVC with MEL (0, 10-11, 10-9 and 10-7 M). The embryos will be evaluated for cleavage and blastocysts rates, and quality analysis by TUNEL. The study will contribute to investigate to potential of MEL use during embryo IVP aiming to improve embryo quality in cattle. (AU)