Male Reproductive System: Testis Development and Spermatogenesis

Abstract

The determination of gonadal sex establishes the basic structure of the testis. This results in the formation of seminiferous cords containing immature Sertoli cells and gonocytes, with the testosterone-secreting Leydig cells lying within the intertubular region. Gonadotrophic stimulation of the testis and the resultant testosterone secretion stimulates spermatogenesis, which involves mitosis, meiosis, and the production of spermatozoa. Germ cell function is crucially dependent on the Sertoli cells that control the intratubular environment, partly by forming the blood–testis barrier. The biochemical nature of the signals that regulate somatic cell function and germ cell maturation is now partially understood, though the complexities of the regulatory pathways and their complete significance are yet to be clarified. This brief overview of the current state of knowledge regarding the controlling signals presents some aspects of their impact on the target cells, both somatic and germinal.