seminifer

Seminifer is an adjective rooted in Latin, meaning relating to seed or seed-bearing. In biology and anatomy, it is most commonly encountered in reference to semen production, especially in the term seminiferous, as in seminiferous tubules of the testes, where sperm production takes place.

In male mammals, the testes house tightly coiled seminiferous tubules. Each tubule is lined by a germinal epithelium containing Sertoli cells and developing germ cells at various stages of maturation. Spermatogonia reside near the basement membrane, giving rise to primary and secondary spermatocytes, then spermatids, which are eventually transformed into mature spermatozoa that are released into the tubule lumen. Surrounding the tubules is interstitial tissue containing Leydig cells that produce testosterone, a hormone essential for normal spermatogenesis. The seminiferous tubules drain into the rete testis, then through efferent ducts to the epididymis where sperm mature further.

Spermatogenesis is regulated by endocrine signals. Follicle-stimulating hormone (FSH) acts on Sertoli cells to support germ cell development, while luteinizing hormone (LH) stimulates Leydig cells to produce testosterone. Adequate temperature, nutrition, and overall health are important for tubule function and sperm production.

Clinically, damage to or disease affecting the seminiferous tubules can cause male infertility, including effects from infections, trauma, chemotherapy, or hormonal imbalances. Germ-cell tumors, such as seminomas, arise from cells within the seminiferous tubules and are a major category of testicular cancer.

Etymology-wise, the term derives from seminis meaning seed and ferre meaning to bear.