Abstract: Zinc is a critical factor of sperm maturation. Zinc transfer is mediated by zinc transporters that are composed of two protein families, Zinc transporter (ZnT) and Zrt-, Irt-like protein (ZIP). In testis, Zinc transporters expressed on the membrane of germ cells participate in spermatogenesis and spermiogenesis. In addition, Zinc transporters are also involved in maintaining blood-testis barrier and testosterone biosynthesis. In epididymis, ZnTs expressed highly in epithelial tissues, and ZIP1, ZIP5, ZIP6 and ZIP8 distributed widely on the epididymal sperm surface, are contributed to the zinc absorption by sperm and sperm maturation. In prostatic epithelial cells, zinc is absorbed from blood via ZIP1 in order to maintain a high zinc level in prostate. On the other hand, zinc is reabsorbed from prostatic fluid via ZIP2, ZIP3 and ZIP4 to ensure the normal secretion of citrate, an important anti-oxidant. The role of zinc and zinc transporters in the male reproductive system was reviewed in this paper, which is helpful for us to understand male reproduction and male infertility.

Key words: Zinc, Genitalia, male, Spermatozoa, Zinc transporter, Zrt-, Irt-like protein