Sertoli cells of fetus testis secretes –
**Core Concept**
Sertoli cells in the fetal testis play a crucial role in the development and maintenance of spermatogenesis. They produce hormones and growth factors essential for the maturation of spermatogonia into mature sperm cells.
**Why the Correct Answer is Right**
The correct answer is Mullerian inhibiting substance (MIS), also known as anti-Mullerian hormone (AMH). Sertoli cells secrete MIS during fetal development, which causes the regression of the Mullerian ducts in male embryos, preventing the formation of female reproductive organs. This hormone is crucial for the development of the male reproductive system. The action of MIS is mediated by the AMH receptor type II, which is expressed on the surface of cells in the Mullerian ducts.
**Why Each Wrong Option is Incorrect**
**Option A:** Inhibin - This hormone is also produced by Sertoli cells, but it is involved in regulating the production of follicle-stimulating hormone (FSH) in the pituitary gland, rather than promoting testicular development.
**Option B:** Testosterone - While Sertoli cells do produce testosterone, it is not the primary hormone secreted by these cells in the fetal testis. Testosterone production increases significantly during puberty.
**Option C:** Estrogen - Sertoli cells do produce small amounts of estrogen, but this is not their primary function.
**Clinical Pearl / High-Yield Fact**
The presence of anti-Mullerian hormone (AMH) in a male patient can be used as an indicator of testicular function and fertility potential.
**Correct Answer:** D. Mullerian inhibiting substance (MIS)