Spermatogenesis is a very complex process that involves an array of cellular and biochemical events, collectively culminating in the formation of haploid spermatids from diploid spermatogonia. It is widely accepted that germ cell differentiation requires endocrine regulation by gonadotropins and steroid hormones, a local control through paracrine/autocrine factors, and, importantly, cell-cell interactions via specialized cell junctions. These structures participate in the intercellular communication and coordination of cell metabolism.