title: The histological changes in the testis, epididymis and prostate gland of the red-bellied tree squirrel, Callosciurus erythraeus, during the growth and reproductive cycle.
abstract: The male reproductive glands of the red-bellied tree squirrel, Callosciurus erythraeus, in the infantile, and prepubertal males, as well as sexually functional, degenerating and redeveloping adults were studied histologically. In the infant, testes are characterized with solid seminiferous tubules filled with primordial germ cells and Sertoli cells. Interstitial cells are sparse. The prostate is composed of condensed cell cords grouped into lobules dispersed with interlobular tissues rich in fibroblasts. In the epididymis the highly convoluted tubule is lined with a simple cuboidal or columnar epithelium and thin smooth musculature without. In the prepubertal male, germ cells are engaged actively in mitosis. Primary spermatocytes are readily recognized. Leydig cells appear in groups in the interstitial tissue. In the prostate, cell cords become highly branched and collecting tubules make their appearance. The tubules in the epididymis are enlarged in diameter but their peripheral musculature becomes thinner. In functional males, meiosis is active and bundles of spermatozoa are scattered along the central lumen. Leydig cells have their cytoplasm highly enriched. The prostate is in the secretory phase. The tubule in the epididymis is filled with sperm. In the degenerating adult, meiosis is interrupted and necrotic germ cells are detached from germinal epithelium. In the prostate, secretory and collecting ducts are eventually reduced to condensed lobules separated by interlobular fibrous tissue. The tubule in the epididymis often fills with necrotic germ cells but no sperm. In the redeveloping adult, the histology of the testes, prostate and epididymis is similar to that of the prepubertal male. However, there is more fibrous tissue in the interlobular septa in the prostate gland and thick musculature at the periphery of the tubule in the epididymis.
mesh_terms: D000375:Aging; D000818:Animals; D001835:Body Weight; D004822:Epididymis / Q000166:cytology / Q000254:growth & development* / Q000502:physiology; D008297:Male; D009929:Organ Size; D011467:Prostate / Q000166:cytology / Q000254:growth & development* / Q000502:physiology; D012098:Reproduction; D012589:Sciuridae / Q000254:growth & development*; D012741:Sexual Maturation; D013737:Testis / Q000166:cytology / Q000254:growth & development* / Q000502:physiology