Maduración in-vitro de ovocitos bovinos en cultivo de células oviductales

Abstract

In vitro maturation (IVM) of bovine oocytes in culture systems represents a promising strategy for improving meiotic competence and embryonic development in assisted reproduction. This study aimed to evaluate the effect of culturing bovine cumulus-oocyte complexes (COCs) with a monolayer of bovine oviduct epithelial cells cultured in TCM-19 medium. The COCs were classified according to morphological criteria established by the IETS into grades 1 to 4 and assigned to two experimental groups: a control group and a group with oviduct epithelial cells. The degree of cumulus expansion was evaluated on a scale of 0–4, together with the nuclear maturation rate (MII). The data were analyzed using a chi-square test (p > 0.005). The results showed that the control group exhibited a greater degree of cumulus expansion compared to the oviductal cell group, with a statistically significant difference (χ² = 8.00; df = 3; p-value = 0.046). In contrast, no significant difference (p < 0.005) was observed in the nuclear maturation rate between the two treatments, indicating a functional dissociation between cumulus expansion and the resumption of meiosis in the oocyte. The results of this study underscore that the supportive capacity of a monolayer of oviduct epithelial cells for oocytes depends on the functional status and prior hormonal conditioning of the oviductal cells, and that the physical presence of the monolayer alone is not sufficient to ensure complete cumulus expansion during in vitro oocyte maturation. Keywords.

Oocytes, epithelial cells, maturation, in vitro, oviduct.