Effect of the coculture of porcine luteal cells with porcine cumulus oocyte complexes on the in vitro maturation rate.

TEPLITZ, G.; LORENZO, MS.; CRUZANS, PR.; LOMBARDO, DM.

Ciudad Autónoma de Buenos Aires

Otro; Reunión Conjunta de Sociedades de Biociencias; 2017

Sociedad Argentina de Biología - Sociedad Argentina de Investigación Clínica

Nuclear and cytoplasmic maturation have not been well described in porcine until the moment. The establishment and maintenance of a suitable microenvironment play an essential role in maturation and subsequent fertilization. The choice of porcine luteal cells (PLC) for coculture with cumulus oocyte complexes (COC) is based on the production of progesterone, a hormone with an antiapoptotic and antioxidant effect. The aim of this study was to evaluate the effect of the coculture with PLC on the in vitro maturation rates of porcine oocytes. Slaughterhouse ovaries were used for the PLC culture and COC aspiration. COC were matured in vitro for 44 h in 100 µL drops of supplemented TCM199 and with human menopausal gonadotropin (hMG) (control) and over a monolayer of PLC without the addition of hormones. Nuclear maturation rates were assessed with Hoechst 33342 stain (displaying the metaphase plate). After in vitro fertilization (IVF) with fresh sperm with proof fertility, the suspected zygotes were dyed with Hoechst 33342, and sperm penetration, monospermic penetration, male pronuclear formation, and IVF efficiency were evaluated. The Fischer test was used and it was considered as significant a p ˂ 0.05. No significant differences were observed in nuclear maturation rates between coculture treatment (72%, n = 104) and control (78%, n = 139). The coculture treatment significantly increased the monospermic penetration (60.47%, n = 96) and IVF efficiency (27.08%) in compare with the control (35.85% n = 137; 13.87%). No significant differences were observed in sperm penetration and male pronuclear formation. We conclude that nuclear maturation in coculture is similar than nuclear maturation with hormones and that monospermic penetration and IVF efficiency are improved with this treatment. Therefore, we could replace the conventional maturation with hormones using this coculture system, having a lower rate of polyspermic penetration, a key issue in the in vitro embryo production in pigs.