This seminar will explore data produced in cattle on roles of oocyte and cumulus-derived peptides (e.g. fibroblast growth factors, bone morphogenetic protein 15, Kit ligand and natriuretic peptide C) in the regulation of cumulus metabolism and oocyte developmental competence. The interaction of follicular steroids and peptides in the control of meiosis progression, as well as the importance of chromatin configuration for in vitro oocyte maturation will also be discussed.