Ultrastructural evidence for resorption of spermatozoa and testicular fluid in the excurrent ducts of the testis of the domestic fowl, Gallus domesticus.

Abstract

Summary. The fate of fowl spermatozoa and testicular fluid retained in the excurrent ducts, and some properties of the epithelial cells lining the ducts, were studied after ligation of the ductus deferens by light and electron microscopy. Striking changes occurred 3 or 4 weeks after ligation. Spermatozoa accumulated cranial to the ligature chiefly in the lumina of the ductuli efferentes. They showed signs of disintegration mainly in the head where there was a disruption of chromatin and loosening of membranes. An increased amount of cell débris of unknown identity was also observed in the lumina of the ducts. The uptake of spermatozoa by epithelial cells lining the male tract was seen in normal males but was much increased after ligation. The process was evident in the low cuboidal cells of the rete testis and in the ciliated and non-ciliated Type I cells lining the ductuli efferentes and narrow connecting ductules, and in the non-ciliated Type II cells lining the wide connecting ductules, ductus epididymidis and ductus deferens. Macrophages, containing spermatozoa, were found in the lumina of the ducts, in the subepithelial tissue and wedged between the basal lamina and the surface epithelia. All of these observations may indicate a route for the disposal of unejaculated spermatozoa in the male fowl. Cytoplasmic vacuoles containing testicular fluid were seen in the apical parts of the ciliated cells and this may represent resorption of the fluid by these cells.