Metaboepigenetic: Modulation of Glutamine Metabolism as a New Perspective for the Maintenance of DNA Methylation Profile in In Vitro Produced Bovine Embryos

• Grant number: 24/20178-3
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: April 01, 2025
• End date: January 31, 2027
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Marcella Pecora Milazzotto
• Grantee: João Vitor Alcantara da Silva
• Host Institution: Centro de Ciências Naturais e Humanas (CCNH). Universidade Federal do ABC (UFABC). Ministério da Educação (Brasil). Santo André , SP, Brazil
• Associated research grant: 21/11747-6 - Remote or presential: the importance of communication in the reproductive processes, AP.TEM

Abstract

The development of technologies for improving the in vitro embryo production (IVP) system has been widely investigated due to the impacts this environment has on embryonic development. Recently, the epigenetic profile of the embryo has become a focus of research, following studies that show that IVP embryos exhibit different levels of DNA methylation compared to embryos produced in vivo-a system that still yields higher pregnancy rates. During embryonic development, the embryo undergoes epigenetic mechanisms that promote cellular differentiation. Among these processes is DNA demethylation, which is associated with the activation of the embryonic genome and occurs through the activity of ten eleven translocation (TET) enzymes. Studies have shown an important relationship between glutamine metabolism and the functioning of TET enzymes. Although glutamine is found in high concentrations in follicular fluid and plays an important metabolic role in the early stages of bovine embryonic development, there are still no investigations into the relationship between this amino acid and the DNA methylation profile of bovine embryos. Thus, the hypothesis of this study is that the formulation of a culture medium supplemented with glutamine induces changes in embryonic mitochondrial metabolism, altering the pattern of metabolite generation related to DNA methylation events. These changes consequently induce different DNA methylation profiles in embryos, altering the activity of gene groups silenced during embryonic development and causing drastic transformations in the metabolism and molecular control of IVP bovine embryos. This study aims to provide information for the use of glutamine as a target molecule for the formulation of a culture medium that produces IVP embryos with DNA methylation levels similar to those of embryos produced in vivo. To achieve this, glutamine supplementation in in vitro culture is proposed. Assays will be conducted to assess metabolic parameters (mitochondrial activity, production of reactive oxygen species, and metabolite consumption and production) in cleaved embryos, morulae, and blastocysts. Additionally, molecular parameters will be analyzed (nuclear DNA methylation pattern, mitochondrial DNA methylation pattern, and transcriptional profile of mitochondrial genes related to methylation) in IVP cleaved embryos, morula, and blastocysts, as well as in blastocysts produced in vivo.