Oocyte lipid accumulation in cattle: effects of variations in the in vitro maturation system

• Grant number: 21/09123-4
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: January 01, 2022
• End date: March 31, 2023
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Felipe Perecin
• Grantee: Luana Alves
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil

Abstract

Reproductive success, which ranges from oocyte fertilization to pregnancy maintenance, depends on oocyte competence. Oocyte competence can be damaged when these gametes are subjected to an in vitro environment. One of the commonly observed adverse effects is the excessive accumulation of lipids during maturation, resulting in loss of quality, metabolism changes, lower tolerance to cryopreservation and pregnancy rate reduction. The components of in vitro maturation medium (IMV) and the transport of biomolecules between cumulus-oocyte cells via transzonal projections (TZPs) and small extracellular vesicles (EVs) are shown to play a crucial role in this mechanism. Thus, our hypothesis is that the composition of the IVM medium and the communication between cumulus and oocyte cells modulate intraoocyte lipid accumulation, as well as the expression of related genes and proteins in bovine cumulus-oocyte complexes (COCs). To test this hypothesis, 3 experiments were designed with aims of: 1) To investigate the effects of the presence or absence of small fetal bovine serum EVs (FBS) in the IVM medium on intraoocyte lipid accumulation in bovine COCs; 2) To analyze the influence of the communication period between cumulus cells and oocyte via TZPs on the intraoocyte lipid accumulation in bovine COCs during IVM, validating the pre-IVM system as an experimental model for this purpose; 3) To evaluate the intraoocyte lipid accumulation in bovine COCs that will undergo pre-IVM and will be matured in conventional maturation medium and in modified maturation medium. With this project results we hope to bring advances in understanding the mechanisms associated with lipid metabolism in COC and improve protocols for IVM in cattle.

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

ALVES, Luana. Oocyte lipid accumulation in cattle: effects of in vitro maturation variations. 2024. Doctoral Thesis - Universidade de São Paulo (USP). Faculdade de Zootecnica e Engenharia de Alimentos (FZE/BT) Pirassununga.