Histological Investigation of Cyclic Variation in Secretory Activity of Seminal Vesicles in Emballonurid Bat, Taphozous kacchensis (Dobson)

Abstract

The present study describes the cyclical changes in the secretory activity of the seminal vesicle in the emballonurid bat, Taphozous kacchensis. The secretory activity in the seminal vesicles during the quiescence cycle was not well marked in T. kacchensis. During the sexually quiescent period (May to August), seminal vesicles were regressed, the tubules were lined by cuboidal to low columnar epithelial cells with round to elongated darkly stained basally to centrally placed nuclei. Cytoplasm was basophilic containing fine or coarse secretory granules in the cytoplasm. The lumina of the tubules were devoid of secretion. During the pre-breeding (September to January) period, the tubules were enlarged and were lined by tall columnar epithelial cells with large spherical basally situated nucleus. The secretory blebs were seen arising from the apical surface of the cells and were seen releasing into the lumen. Lumina of the tubules were filled with homogenous eosinophilic secretion. During the breeding period (February to March), the seminal vesicle showed hypertrophy resulting in the increase in the tubular diameter as compared to that of quiescent period. The epithelial lining of the tubules was cuboidal with centrally placed nuclei. The tubular lumina were full of homogenous secretion during active pre-breeding and breeding period as the secretory material released into the lumen by both apocrine and merocrine modes. Regressive changes in the seminal vesicle were evident from April. The tubules showed gradual hypotrophy as the quiescent period approaches in May.