Effect of mTOR pathway inhibition during embryonic culture on trophectoderm differentiation in bovine embryos

• Grant number: 24/04778-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: December 01, 2024
• End date: November 30, 2026
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Marcelo Demarchi Goissis
• Grantee: Viviane Beatriz de Godoi Bacaro
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 23/06051-8 - Effects of metabolic modulations on the initial cell differentiation of bovine embryos, AP.R

Abstract

The in vitro production of bovine embryos (IVP) has brought significant advances in animal reproduction, allowing the emergence of genetically superior offspring in a short period. However, despite these advances, IVP faces challenges such as low pregnancy rates when compared to in vivo produced embryos. These limitations may be related to the quality of the produced embryos, affecting their implantation capacity due to failures in the phases of adhesion and fixation of the trophectoderm (TE). Cell differentiation during embryonic development involves different factors from cell polarity to transcription of specific genes. Glucose metabolism plays a key role in regulating the expression of genes involved in the formation of TE in mouse embryos, via the biosynthetic pathway of hexosamines and pentose phosphate pathway. The mTOR (mammalian target of rapamycin) pathway is also involved, coordinating cell growth and metabolism. Lack of nutrients or inhibition of mTOR can negatively affect the differentiation and proliferation capacity of TE cells. Thus, we propose the hypothesis that the mTOR pathway has a positive effect on the differentiation of TE in bovine embryos produced in vitro. To achieve this, we will inhibit the mTOR pathway with specific inhibitor Torin2. We will evaluate gene expression by q-RT-PCR and immunofluorescence, aiming to assess genes and proteins related to TE differentiation. It is expected that inhibition of the mTOR pathway inhibits the differentiation of trophectoderm, reflecting in a decrease of TE cell number. This project can assist in the development of strategies for modulating the allocation of TE cells in IVP in cattle.