What is the name of the cell found between Sertoli cells and what does it differentiate into?

• A. Primary spermatocyte; differentiates into two secondary spermatocytes by meiosis
• B. Sertoli cell; differentiates into spermatozoa
• C. Spermatid; differentiates into mature sperm in the epididymis
• D. Spermatogonium; differentiates into a primary spermatocyte and another spermatogonium by mitosis

Answer: (D)

Spermatogonia sit in the basal portion of the seminiferous tubules between Sertoli cells. They act as the germline stem cells, dividing by mitosis to renew themselves and to produce the cell that will enter meiosis. From a single spermatogonium, mitosis yields one daughter spermatogonium and one primary spermatocyte, which then proceeds through meiosis to form sperm. So the cell found between Sertoli cells is a spermatogonium, and it differentiates into a primary spermatocyte while also renewing another spermatogonium through mitosis.