Effects of the maternal mRNA on the maturation of the oocyte and early embryonic development in mammals. Review

Abstract

Get in vitro matured oocytes that could be competent for in vitro fertilization with a result of 50 % viableblastocysts, is one of the main problems in the in vitro development of bovine embryos. For these reason, isnecessary to understand the cellular processes that lead to the maturation of the oocyte during folliculogenesis andsubsequent transition to the embryo. The transition from oocyte to embryo is a complex process that involvesgenomic inactivation of the oocyte and embryonic genome activation. This process occurs in cattle in thestage of 8 to 16 cells where there are a selective degradation of maternal mRNA, which were stored duringoogenesis and are the source of protein in the early stages of embryonic development. The action ofmaternal mRNA is a key for that embryonic genome activation takes place in form and time. Understandingthe involvement of these transcripts in embryonic genome activation is essential to elucidate the cellularprocesses falling in oocyte maturation in vitro protocols. The aim of this review was to gather informationfrom maternal genes that have been isolated both in the murine model and cattle, this in order toincorporate knowledge related to genomic processes that enable the development of the embryo in cattle,and to design also new strategies to improve in vitro fertilization protocols.