A Sertoli cell (a kind of sustentacular cell) is a "nurse" cell of the testicles that is part of a seminiferous tubule.

It is activated by follicle-stimulating hormone (FSH) and has FSH-receptor on its membranes. It is specifically located in the convoluted seminiferous tubules (since this is the only place in the testes where the spermatozoa are produced). Development of Sertoli cells is directed by the testis-determining factor protein.

Because its main function is to nourish the developing sperm cells through the stages of spermatogenesis, the Sertoli cell has also been called the "mother" or "nurse" cell. Sertoli cells also act as phagocytes, consuming the residual cytoplasm during spermatogenesis. Translocation of germ cells from the base to the lumen of the seminiferous tubules occurs by conformational changes in the lateral margins of the Sertoli cells.

Sertoli cells secrete the following substances:

The tight junctions of Sertoli cells form the blood-testis barrier, a structure that partitions the interstitial blood compartment of the testis from the adluminal compartment of the seminiferous tubules. Because of the apical progression of the spermatogonia, the tight junctions must be dynamically reformed and broken to allow the immunoidentical spermatogonia to cross through the blood-testis barrier so they can become immunologically unique. Sertoli cells control the entry and exit of nutrients, hormones and other chemicals into the tubules of the testis as well as make the adluminal compartment an immune-privileged site.

The cell is also responsible for establishing and maintaining the spermatogonial stem cell niche, which ensures the renewal of stem cells and the differentiation of spermatogonia into mature germ cells that progress stepwise through the long process of spermatogenesis, ending in the release of spermatozoa. Sertoli cells bind to spermatogonial cells via N-cadherins and galctosyltransferase (via carbohydrate residues).

During the maturation phase of spermiogenesis, the Sertoli cells consume the unneeded portions of the spermatozoa.

Sertoli cells are required for male sexual development. During male development, the gene SRY activates SOX9, which then activates and forms a feedforward loop with FGF9. Sertoli cell proliferation and differentiation is mainly activated by FGF9.[2] The absence of FGF9 tends to cause a female to develop [3]

Once fully differentiated, the Sertoli cell is unable to proliferate. Therefore, once spermatogenesis has begun, no more Sertoli cells are created.

Recently however, some scientists have found a way to grow these cells outside of the body. This gives rise to the possibility of repairing some defects that cause male infertility.

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Sertoli cell - Wikipedia, the free encyclopedia

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