Abstract:

The aim of this study was to investigate the role of Toll-like receptor 4 （TLR4） in pregnancy uterus of goat. Immunochemistry SP method and fluorescent real-time quantitative PCR technology were used to study the distribution of TLR4 and the expression of TLR4 mRNA in Guanzhong dairy goat of early pregnancy (1-30 d), midtrimester of pregnancy (31-120 d) and late pregnancy (121-150 d). The results showed that TLR4 has different distribution in mucous layer, uterine muscle and uterine serosa of guanzhong goat uterus, TLR4 was mostly localized to the luminal and granular epithelium cells, there were less TLR4 positive staining cells in uterine muscle and uterine serosa; With the time of pregnancy increased endometrium epithelium cells staining gradually became lighter, the granular epithelium cells stained strongest in midtrimester of pregnancy, however, in late pregnancy the staining cells decreased; The relative expression of TLR4 exhibited low-high-low regularly change in endometrium, the level of TLR4 expression in midtrimester of pregnancy was significantly higher than that of TLR4 during other periods (P<0.01), the level of TLR4 expression in early pregnancy was lowest, which was significantly lower than that of TLR4 during other periods (P<0.01). TLR4 mRNA expressed in uterus throughout the whole pregnancy cycle, the expression level of TLR4 mRNA was consistent with the relative expression of TLR4. These results indicated that the distribution and expression in pregnancy uterus of Guanzhong dairy goat have certain rules, and that TLR4 may plays a role in regulating the immune and secretion of uterus.