Abstract:

【Objective】The objective of the study was to investigate the differences in expression of mRNAs and proteins for ERα and PR in Yak uterus at different stages of the estrous cycle.【Method】Fluorescent quantitative RT-PCR and streptavidin- perosidase (SP) immunohistochemistry were used to determine the levels of mRNAs and proteins.【Result】The results showed that ERα mRNA and PR mRNA were expressed in both endometrium and myometrium of Yak uterus. ERα and PR immunoreactivity expressed in surface epithelium cells, gland epithelium cells, stromal cells, endometrial blood vessel and myometrial smooth muscle cells. In endometrium, high expression of ERα mRNA and PR mRNA was observed at metestrus, significantly decreased at diestrus (P＜0.05), then re-increased at proestrus. ERα and PR exhibited stronger immunoreactive at estrus compared to that at diestrus. In myometrium, ERα mRNA and PR mRNA were highly expressed at estrus, significantly decreased at metestrus (P＜0.05), lowest at diestrus, and re-increased to its highest at proestrus (P＜0.05); ERα and PR exhibited stronger immunoreactive labeling at estrus compared to that at diestrus, but showed no significant differences (P＞0.05).【Conclusion】In conclusion, mRNAs and proteins for ERα and PR in Yak uterus were differed between endometrium and myometrium at different stages of the estrous cycle. The differences suggested that ERα and PR play important roles in Yak uterus during the estrous cycle.

Key words: Yak uterus, estrogen receptor α, progesterone receptor, mRNA