ABSTRACT. Mogollon-Waltero E.M., Calixto C., Vale D.F., Pereira J.L., Curcio A.G., Logullo C., Dias A.J.B. & Gomes H.F. [Insulin signaling during in vitro maturation of bovine oocytes]. Sinalizacao por insulina durante a maturacao in vitro de oocitos bovinos. Revista Brasileira de Medicina Veterinaria, 35(Supl. 1):12-20, 2013. Curso de Pos-graduacao em Ciencia Animal, CCTA, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Lamego, 2000, Parque California, Campos dos Goytacazes, RJ 28013-602, Brasil. E-mail: mao5_2000@yahoo.com The oocyte maturation is a process tightly regulated by a cascade of enzymatic events based on several ways of phosphorylation and dephosphorylation as a means to activity control of many enzymes involved in this pathway. In general, the results of the research has shown that there is an influence of insulin-signaling pathway in the maturation of bovine oocytes and that the deepening of this study may contribute significantly to the improvement of in vitro production of bovine embryos. It has been shown that the phosphatidylinositol 3 kinase (PI3K) participates in this process regulating the activity of important reactions related to the resumption of meiosis. The inhibition of PI3K could affect events of actin microfilaments polarization and depolarization leading to produce changes in the movement patterns of leading cellular organelles. Taken together the evidences demonstrated until now reinforce the hypothesis about involvement of insulin on oocyte maturation in bovines.