Distribution of zinc and zinc transporters in the mouse ovarian follicles and corpus luteum.

Zinc is essential for female reproduction and it plays a role in sexual development, ovulation, menstruation and estrous cycles. Zinc deficiency may lead to female reproductive system dysfunction. The present study aimed to investigate the expression and distribution patterns of free zinc and the members of zinc transporter (ZnT) family, with zinc autometallographic (AMG), immunohistochemistry and real-time PCR, to explore the relationship of zinc homeostasis in the development and function of the ovary in the mouse. Our data revealed that the free zinc ions and ZnTs are predominantly distributed in the mouse ovarian follicles and corpus luteum. Specifically, AMG staining presented in various stages of the ovarian follicles and corpus luteum. ZnT1-9 mRNA was variously expressed, whereas ZnT10 mRNA was almost undetectable in the ovary. Moreover, the immunoreactivity of all the tested ZnTs, except for ZnT10, was detected with various intensity in the mouse primordial follicles, primary follicles, secondary follicles and antral follicles. In the corpus luteum, the immunoreactivity of ZnT1-5, 7, 8, 10, was abundantly observed in the granular and theca lutein cells and interstitial cells. Collectively, our results suggest that ZnT family proteins are differently distributed and might exert different biological functions in controlling cellular zinc levels, which regulate ovarian development and function in the mouse ovary.