In vivo and in vitro matured bovine oocytes present a distinct pattern of single-cell gene expression.

Oocyte gene expression is a well controlled event that promotes gamete competence to undergo maturation, fertilization, and to support early embryo development, directly affecting reproductive outcomes. Considering that controlled ovarian stimulation or maturation (IVM) for the acquisition of mature oocytes has distinct implications for gene expression, we sought to evaluate the effects of these procedures on the expression of competence-related genes in single-cell oocytes. Healthy Nelore cows of reproductive age were synchronized to harvest matured oocytes; ovaries from slaughtered animals were used to obtain cumulus-oocyte complexes that were matured. Single-cell gene expression was performed using TaqMan Low-Density Arrays and 42 genes were evaluated. analysis of protein interactions and Gene Ontology (GO) analysis was performed. Reduced gene expression was observed for 24 targets in IVM oocytes when compared with those of matured oocytes ( < 0.05). Differences ranged from 1.5-fold to 4.8-fold higher in oocytes and the (5.28), (6.23), (7.25), (7.85) and (11.00) showed the greatest fold increases. The strongest score of functional interactions was observed between the and , with the differentially expressed gene being the main marker behind GO enrichment. IVM negatively affected the expression of important genes related to oocyte competency, and showed higher expression levels in matured oocytes. controlled ovarian stimulation may be a better strategy to achieve proper oocyte competence and increase the success of assisted reproductive technologies.