Ultrastructure of epithelial cells in the epididymal region of the turkey (Meleagris gallopavo).

Abstract

SUMMARY The epithelial cells in the epididymal region of the turkey were classified ultra­structurally by electron microscopy. Six cell types were described: squamous and low cuboidal cells of the rete testis, non-ciliated Type I and ciliated cells of the ductuli efferentes and connecting ductules, non-ciliated Type II cells of the ductus epididymidis, and basal cells occasionally found in all the ducts except the rete. The squamous cells were more electron-dense and contained fewer organelles than the cuboidal cells. The Type I cells secreted blebs of material into the ductal lumen and contained numerous mitochondria, extensive rough and smooth endo­plasmic reticulum and well developed Golgi complexes, indicating active apocrine secretion. The Type I cells also contained large zymogen-like granules and numerous rod-shaped bodies which were considered to be lysosomes associated with an absorptive function. The Type II cells had small Golgi complexes and numerous lipid vesicles. Ciliated cells presumably concerned in the transport of spermatozoa contained numerous mitochondria in the apical cytoplasm, lobulated nuclei and perinuclear fibrillar bundles. Lysosomal-like bodies and large cytoplasmic vacuoles indicated an absorptive function. The basal cells were smaller and more electron­dense than other cell types, and rested directly on the basal lamina. This study has shown that the epithelial cells of the ductuli efferentes appear to be the most active cells of the turkey epididymal region. They apparently function in the transportation of spermatozoa, resorption of luminal fluids, and the secretion of proteinaceous material.