Embryo-maternal communication: signalling before and during placentation in cattle and pig

The maternal recognition of pregnancy and establishment of the placenta are the key events essential for successful reproduction and full-term development. These are controlled by interactions among transcriptional, epigenetic and environmental factors both between and within the conceptus(es) and the mother. Coming from the species-specific differences in placentation and prenatal development, our review addresses several aspects involved in recognition of pregnancy and initial placentation in cattle and pig. Furthermore, we address morphological and mainly transcriptional changes in the endometrium accompanying placentation as well as several epigenetic regulation mechanisms directing placentation in these species.