The study of endometrium at gestational days 5 and 15 in dairy goats (Capra hircus)

Abstract

Endometrium receptivity, an absolutely necessary part of successful embryo implantation, and several morphological and biochemical endometrial receptivity biomarkers have already been studied and proposed in some animals. However, to our knowledge, no such a study has as yet been undertaken in dairy goat. In the present study, the serum and uterus of dairy goat were studied at gestational days 5 and 15, the estrogen (E2) and progesterone (P4) concentrations in serum were determined by electrochemiluminescence immunoassay, the surface topography of endometrium was observed by scanning electron microscopy. Furthermore, the estrogen receptors (ER), prolactin (PRL), some marker genes of receptive endometrium, and cell proliferation and apoptosis in the uterus were also detected. Well-formed pinopodes were found on the surface of endometrium at day 15 with higher E2 and P4 concentrations in the serum and higher estrogen receptors ERα and ERβ expression levels and a lower PRL level in the endometrium. Moreover, some expression levels of marker genes of receptive endometrium (OPN, VEGF, LIF, PRLR) were increased at day 15 compared to day 5, but no significant differences were observed in the cell proliferation and apoptosis in the uterus. The results showed that the endometrium reached the receptive state at gestational day 15 in dairy goats.