Seminiferous Epithelium

Abstract

Mammalian testes form the focal point of the male reproductive system. Their development and differentiation occur during foetal life (Guraya 1980). During the postnatal period, the testes mature to perform two functions, one hormonal (e.g. production of testosterone and other sex steroids, which are also well known to be secreted by the foetal testis) and the other production of spermatozoa (spermatogenesis) in the adult. These processes are localized in two distinct morphological compartments, the vascularized Leydig cells of the interstitium and the avascular seminiferous tubules (Fig. 1). Morphological, histochemical, biochemical, immunological, physiological and endocrinological aspects of development, differentiation and maturation of these two testicular compartments are discussed in a previous monographic review (Guraya 1980). Several other interesting reviews also deal with (1) differentiation and development of the testes (Wartenberg 1981, Ramaswami 1983), (2) endocrinology of the foetal testis (Faiman et al. 1981), and (3) endocrine control of testicular function from birth to puberty (Swerdloff and Heber 1981). The earliest morphological feature by which the foetal testes can be distinguished is the formation of the seminiferous cords. Differentiation of primordial germ-cells in the testes begins at later stages of development, usually after birth. The male-specific antigen, histocompatibility-Y (H-Y) antigen, has been proposed as a testis-determining factor. This hypothesis is based on the finding that the development of testes is related closely with the presence of male-specific antigen regardless of the karyotyped sex.