Sertoli cell
Epitheliocytus sustentans
Also known as: sustentacular cell, nurse cell
Tall supporting cells of the seminiferous epithelium that nourish and protect developing germ cells, form the blood–testis barrier, and mediate the effects of FSH and testosterone on spermatogenesis.
Overview
Sertoli cells are columnar cells resting on the basement membrane and extending to the lumen, with an irregular, often triangular nucleus containing a prominent nucleolus. Their lateral and apical cytoplasm forms pockets that cradle the developing germ cells. They stop dividing at puberty, so their number fixes the maximum sperm output of the adult testis (each supports a limited number of germ cells).
Adjacent Sertoli cells are joined near their bases by tight junctions that form the blood–testis barrier. This barrier creates a specialised fluid environment for meiosis and protects post-meiotic germ cells — which express new surface antigens that appear after immune self-tolerance has been established — from autoimmune attack. Preleptotene spermatocytes pass through the barrier by coordinated disassembly and reassembly of junctions.
Germ cells lack FSH and androgen receptors, so the hormonal control of spermatogenesis is exerted through Sertoli cells, which express FSH receptors and androgen receptors.
- Location
Seminiferous tubules, spanning from basement membrane to lumen.
Anatomy
- Development
Differentiate from coelomic-epithelium-derived supporting cells under SRY → SOX9 control (≈week 7); their fetal AMH causes Müllerian duct regression.
Function
- Physical and metabolic support of germ cells (lactate, transferrin, growth factors).
- Form the blood–testis barrier (tight junctions).
- Secrete androgen-binding protein (ABP) to concentrate testosterone in the tubules.
- Secrete inhibin B (negative feedback on FSH) and, in the fetus, anti-Müllerian hormone.
- Phagocytose residual bodies and apoptotic germ cells; release sperm at spermiation.
- Secrete tubular fluid.
- Regulation
FSH (Gs/cAMP) and testosterone (androgen receptor) act on Sertoli cells together to initiate and maintain spermatogenesis.
Clinical significance
Male infertility and contraception research
Low inhibin B with high FSH indicates Sertoli/germ-cell failure. Disruption of the blood–testis barrier (trauma, vasectomy, infection) can expose sperm antigens and produce antisperm antibodies.
Sertoli-cell tumours
Rare sex-cord–stromal tumours; some secrete estrogen and cause gynaecomastia (e.g. large-cell calcifying Sertoli-cell tumour in Peutz–Jeghers or Carney complex).
Test yourself
Which cells form the blood–testis barrier?
- Leydig cells
- Peritubular myoid cells
- Sertoli cells, via tight junctions between adjacent cells
- Endothelial cells of testicular capillaries
Answer: Sertoli cells, via tight junctions between adjacent cells
Tight junctions between neighbouring Sertoli cells divide the seminiferous epithelium into basal and adluminal compartments, protecting meiotic and post-meiotic germ cells (which express novel antigens) from the immune system.
Compiled from standard anatomy and physiology references — see the Reproductive System sources. For education only; not medical advice.