Tailor made interactions between the uterus and embryo

One of the crucial stages of gestation is implantation of the embryo in the uterus, in contact with a tissue called the endometrium. However, the mechanisms that enable this implantation remain largely unclear. A Franco-American collaboration co-led by INRA research scientists has revealed that intense and fine-tuned crosstalk is established between the embryo and endometrium, allowing them to adapt to each other. Working in cattle, the scientists analysed the expression of genes in the embryo and endometrium at the start of gestation. They showed that many of the biological processes at work in the two tissues are closely correlated. Published in Plos Biology , these findings may help to better understand how defects in reciprocal adaptation processes between the endometrium and embryo may lead to early pregnancy failures in mammals. In cattle, 18 to 20 days after fertilisation, a decisive event for gestation occurs when the embryo enters into contact with the endometrium, the mucous cell layer that covers the internal surface of the uterus.