CONICET | Buscador de Institutos y Recursos Humanos

Previously, we showed that paternal alcohol intake partially inhibits sperm capacitation, increases nuclear decondensation rate and deregulates the dynamics of pronucleus formation and fertilization1,2,3. Aim: To evaluate the effect of paternal alcohol consumption and its consequences on mouse early embryo development focusing on trophoblast (TB) differentiation and inner cell mass (ICM) as critical embryo stages invading maternal decidua. Methods: CF-1 fertile males were exposed (treated group, T) or not (control group, C) to 15% (v/v) ethanol in drinking water ad libitum for 15 days. They were mated with a fertile nontreated CF-1 female (1:1). Positive mating females were sacrificed at day 2 of gestation to obtain 2 cell embryos which, then, were cultured for 7 days. Embryo differentiation, growth and morphology were evaluated during pre- and peri-implantation phases in vitro. Then, embryos were classified as type A (ICM: protruding aggregates of compact cells; TB: symmetric monolayer of flat and elongated cells) or type B (ICM: disaggregated, few scattered or no cells, TB: asymmetric trophoblast outgrowth). Frequency differences between C and T were tested by Fisher´s exact test. Results: Male alcohol consumption for 15 days delayed the embryo differentiation and growth by detention/fragmentation and altered the embryo morphology. Differences between type A and B distribution in C and T were statistically significant for ICM and TB in both groups. For ICM: Type A 53% C vs 10% T (p<0.0001), for TB: 60% C vs 26% T (p<0.01). When we evaluated the trophoblast growth area at day 7 of culture there were no significant differences between both groups. Conclusion:Paternal alcohol consumption impairs early mouse embryo peri-implantation, affecting ICM and TB development. These effects might be crucial for further embryo survival, considering that ICM participates in the embryo formation and TB plays a relevant role in placental development.