Building the mammalian testis: origins, differentiation, and assembly of the component cell populations

Abstract

Development of testes in the mammalian embryo requires the formation and assembly of several cell types that allow these organs to achieve their roles in male reproduction and endocrine regulation. Testis development is unusual in that several cell types such as Sertoli, Leydig, and spermatogonial cells arise from bipotential precursors present in the precursor tissue, the genital ridge. These cell types do not differentiate independently but depend on signals from Sertoli cells that differentiate under the influence of transcription factors SRY and SOX9. While these steps are becoming better understood, the origins and roles of many testicular cell types and structures—including peritubular myoid cells, the tunica albuginea, the arterial and venous blood vasculature, lymphatic vessels, macrophages, and nerve cells—have remained unclear. This review synthesizes current knowledge of how the architecture of the testis unfolds and highlights the questions that remain to be explored, thus providing a roadmap for future studies that may help illuminate the causes of XY disorders of sex development, infertility, and testicular cancers.

Gonadotrope-specific Deletion of Dicer Results in Severely Suppressed Gonadotropins and Fertility Defects

“…5G). The transcription factor SOX9 is expressed downstream of SRY, the testis determining factor, and defines the Sertoli cell lineage in the testis (81)(82)(83). The expression of SOX9 did not change irrespective of whether the male fertility was moderately or severely affected in Dicer cKO mutant mice (Fig.…”

R-spondin1, WNT4, and the CTNNB1 signaling pathway: strict control over ovarian differentiation

“…1). Initially, the morphogenesis of the gonadal primordium appears to be similar between male and female embryos, although the transcriptomic signature is different between both sexes in mice (Jameson et al 2012a), in which the genital ridges are formed at w9.5 dpc (reviewed by Svingen & Koopman (2013)). Proliferation of coelomic epithelial cells, combined with the recruitment of precursor cells from the mesonephroi, leads to the outgrowth of future gonads.…”

Cell‐specific ablation in the testis: what have we learned?

“…The important role that these cells play in orchestrating testicular differentiation (promotion of foetal Leydig cell and peritubular myoid cell development) and subsequent masculinisation of the foetus is well established (Svingen & Koopman, 2013). During foetal and early postnatal life there is a period of intensive Sertoli cell proliferation which ceases at puberty as the cells undergo a fundamental change in activity (Sharpe et al ., 2003) (O'Shaughnessy, 2015).…”