Morphological and histological changes in the genital ducts of the male Atlantic stingray, Dasyatis sabina, during the seasonal reproductive cycle
Abbreviated Journal Title
Fish Physiol. Biochem.
seminal vesicle; epididymis; PCNA; Dasyatis sabina; PORT-JACKSON SHARK; MACROPUS-EUGENII MACROPODIDAE; ESTROGEN-RECEPTOR-ALPHA; ST JOHNS RIVER; HETERODONTUS-PORTUSJACKSONI; TAMMAR WALLABY; EPITHELIUM PROLIFERATION; EURYHALINE ELASMOBRANCH; CALLORHYNCHUS-MILII; EFFERENT DUCTULES; Biochemistry & Molecular Biology; Fisheries; Physiology
Changes in the morphology and histology of the epididymis and seminal vesicle in male Atlantic stingrays (Dasyatis sabina) were examined in relation to the seasonal reproductive cycle. Observations on the size and structure of these organs were accompanied by analysis of cell proliferation in genital duct epithelia using proliferating cell nuclear antigen ( PCNA) as a marker for mitotic activity. No signs of reproductive tract growth or histological alteration were apparent during the initial stages of spermatogenesis. However, increased PCNA expression in the seminal vesicle epithelium was observed during this period, suggesting that this organ begins to undergo preparatory changes at an early stage in the reproductive cycle. During late spermatogenesis, heightened expression of PCNA in epithelial cells of the epididymis and seminal vesicle was observed in conjunction with dramatic increases in size and semen content of these organs. Extensive changes in the histological architecture of the genital ducts also were evident at this time, including regression of the stroma and an increase in size and secretory activity of the epithelium. Although the epididymis regressed in size and structure shortly after sperm production was completed, the seminal vesicle retained its appearance and activity for the duration of the 7-month copulatory period. Afterwards, immune cell content increased considerably in both ducts, likely reflecting clearance of residual spermatozoa in preparation for the subsequent reproductive season. The present study provides a basis for future reports on the physiological regulation of reproductive tract function in elasmobranchs, and establishes PCNA immunocytochemistry as a novel tool for such investigations.
Fish Physiology and Biochemistry
"Morphological and histological changes in the genital ducts of the male Atlantic stingray, Dasyatis sabina, during the seasonal reproductive cycle" (2003). Faculty Bibliography 2000s. 3963.