Society for Reproductive Biology Founders' Lecture 2005. Control of metabolic cooperativity between oocytes and their companion granulosa cells by mouse oocytes

Oocytes orchestrate the rate of follicular development and expression of genes in the surrounding granulosa cells. Oocytes are deficient in their ability to carry out some metabolic processes, such as glycolysis and amino acid uptake, and depend on the cooperation of granulosa cells to carry out these processes. In this dependency, the oocyte was previously considered a passive recipient of the nutritional support from granulosa cells. However, recent studies indicate an active role for the oocyte in controlling metabolic activity in granulosa cells. The ability of oocytes to control granulosa cell metabolism is achieved, at least in part, by regulating granulosa cell expression of genes encoding proteins involved in the metabolic processes. This review summarises current knowledge of intercellular communication between oocytes and granulosa cells from the perspective of oocyte control of gene expression in granulosa cells and metabolic cooperativity between the two cell types. The oocyte probably controls metabolism in granulosa cells to provide metabolites for its own development. In addition, we hypothesise that oocytes use their ability to regulate metabolic pathways in granulosa cells to orchestrate the rate of follicular development.