The testis is a highly dynamic organ not only in the fetal stage but also during postnatal development and in adult life. It is composed of two major compartments: the interstitium with the steroidogenic Leydig cells, and the seminiferous tubules. The seminiferous tubules are surrounded by...

Spermatogenesis is a highly complicated process in which functional spermatozoa (haploid, 1n) are generated from primitive mitotic spermatogonia (diploid, 2n). This process involves the differentiation and transformation of several types of germ cells as spermatocytes and spermatids undergo...

Two anatomically distinct compartments, respectively, the interstitium where Leydig cells reside and the seminiferous tubules contribute the major functions of the testis, testosterone secretion and sperm production. This structural partitioning is achieved by peritubular myoid cells, which...

The term “blood-testis barrier” appears to have been first used by Chiquoine in an article on effects of cadmium on the testis, but evidence for such a barrier already existed, dating back to the early years of the twentieth century (see ref. 2 for early references). In a number of studies,...

Spermatogenesis takes place in the seminiferous tubules in adult testes such as rats, in which developing germ cells must traverse the seminiferous epithelium while spermatogonia (2n, diploid) undergo mitotic and meiotic divisions, and differentiate into elongated spermatids (1n, haploid). It is...

Spermatogenesis is a highly coordinated process in which diploid spermatogonia (2n) differentiate into mature haploid (1n) spermatozoa in the seminiferous epithelium. In this process, spermatogonia undergo several mitotic divisions and either enter a stem cell renewal pathway, or commit...

For many years androgens were thought to be the primary hormones required for proper functioning of the male reproductive system, and testes were shown to be the major producers of the hormone. In the 1970s it was recognized that in addition to androgens testes were also a source of estrogens,...

Spermatogenesis is a highly complicated process in which functional spermatozoa (haploid, 1n) are generated from primitive mitotic spermatogonia (diploid, 2n). This process involves the differentiation and transformation of several types of germ cells as spermatocytes and spermatids undergo...

Spermatogenesis is a complex, organized process involving intimate interactions between the developing germ cells and supporting Sertoli cells. The process is also highly regulated. Studies suggest that regulation in the seminiferous epithelium involves molecules normally associated with either...

Spermatogenesis is a complex biological process of cellular transformation that produces male haploid germ cells from diploid spermatogonial stem cells. This process has been simplified morphologically by recognizing cellular associations or ‘stages’ and ‘phases’ of spermatogenesis, which...

In adult mammalian testes, such as rats, Sertoli and germ cells at different stages of their development in the seminiferous epithelium are in close contact with the basement membrane, a modified form of extracellular matrix (ECM). In essence, Sertoli and germ cells in particular spermatogonia...

Spermatogenesis is an extremely active replicative process capable of generating approximately 1,000 sperm a second. The high rates of cell division inherent in this process imply correspondingly high rates of mitochondrial oxygen consumption by the germinal epithelium. However, the poor...

Selenium is essential for normal spermatogenesis of mammals and its critical role is mainly mediated by two selenoproteins, namely phospholipid hydroperoxide glutathione peroxidase (PHGPx/GPx4) and Selenoprotein P. PHGPx/GPx4 is the major selenoprotein expressed by germ cells in the testis,...

Spermatogenesis is a sophisticated process facilitating transmission of the genetic patrimony and, thus, perpetuation of the species. Mammalian spermatogenesis is classically divided into three 3 phases. In the first—the proliferative or mitotic phase—primitive germ cells or spermatogonia...