Macro, micro, and molecular research on spermatogenesis: The quest to understand its control

Abstract

Synchronous maturation of the germ cells in the seminiferous epithelium has long been recognized by microscopy, and is believed to be a consequence of a complex interaction between the germ cells and the Sertoli cells, largely driven by testosterone and its synergistic action with follicle-stimulating hormone. Overall coordination of the cycle of the seminiferous epithelium is reviewed with regard to the known and possible actions of testosterone upon the Sertoli cells and the germ cells. With gradual refinements of optical instrumentation and development of a wide range of histological, morphometric, biochemical, and molecular techniques, coupled with selective alterations of hormonal stimulation and the cellular composition of the testis, new approaches to the question of how sperm production is regulated are becoming available. Germ cell and Sertoli cell functions are intimately related to each other via local, intratesticular or paracrine signals which are suppressed or triggered at certain defined steps in the spermatogenic process. The coordination of germ cell proliferation and maturation is discussed in terms of the contributions made by microscopical techniques.

PTEN 2, a Golgi-associated Testis-specific Homologue of the PTEN Tumor Suppressor Lipid Phosphatase

“…The cell type, which shows predominant expression of PTEN 2, was the secondary spermatocyte, a stage of spermatogenesis that occurs just before the large morphological changes that accompany the production of mature sperm (27). A potential role for PTEN 2 in terminal sperm differentiation is also supported by our finding that the transcript for the enzyme appears simultaneously with the development of mature sperm and sexual maturity (Fig.…”

“…3). Because testis contains a diversity of cell types, some of which (spermatocytes) pass through a number of developmental stages (27), we decided to analyze this tissue using in situ hybridization. Isotopic in situ hybridization was performed on adult testis, as well as on testes representing various stages of adolescence.…”

Review Article: Evaluation of Testicular Toxicity in Safety Evaluation Studies: The Appropriate Use of Spermatogenic Staging

“…1) (40). The same principle has been applied to classify the stages of the spermatogenic cycle in other species (49 (27), Kerr (37), and Sharpe (52) (Fig. 3).…”

Identification of differentially expressed genes of primary spermatocyte against round spermatid isolated from human testis using the laser capture microdissection technique

“…The development of one generation of spermatogonia, spermatocytes, and spermatids is closely integrated with other generations presented in the same region of the tubule. Spermatogenesis is acknowledged to be a process encompassing both time and space [2]; whereby genes are expressed under stringent temporal and spatial regulations. Thus identifying the differentially expressed genes will be of immense value in delineating the regulatory mechanism of spermatogenesis.…”