Production of Energy and Determination of Competence: Past Knowledge, Present Research, and Future Opportunities in Oocyte and Embryo Metabolism

Oocytes and embryos undergo multiple physiological changes like completion of meiosis, fertilization, and activation of the embryonic genomes in three very different environments such as the follicle, the oviduct, and the uterus as they progress from the immature (germinal vesicle) oocyte to the hatched blastocyst. During this time, oocytes and embryos exhibit a unique combination of metabolic plasticity and sensitivity. This chapter discusses two techniques, radiolabeled substrates and microfluorescence, to measure metabolism, as well as the shortcomings of these approaches. It examines oocyte and embryo metabolism and describes the current understanding of metabolism in the oocytes and embryos from a variety of species. The chapter discusses the current knowledge about the impact of maternal status on oocytes and embryos and potential therapeutic approaches. Currently, the use of oocyte in vitro maturation (IVM) to treat human infertility is limited, making treatment during embryo culture the most feasible approach.