Seasonal Variation of the Intraepithelial Gland in Camel Epididymis with Special Reference to Autophagosome

Abstract

AbstractThe key role of the epididymis is contributing to sperm storage, maturation, and survival. The epididymis of camel has a unique structure called the intraepithelial gland. The present work aimed to investigate the structure of the epididymal intraepithelial gland with special references to the seasonal variation. The samples were collected from the distal part of the corpus epididymes of completely healthy mature camels (Camelus dromedarius) in the breeding and nonbreeding seasons. Tomato lectin-positive material had been demonstrated within the epididymal spermatozoa. Here, we provide the first transmission electron microscopic study for the intraepithelial gland of camel epididymis detecting the autophagy during the nonbreeding season. The autophagosomes originated from the endoplasmic reticulum, surrounding mitochondria, and located mainly next to the basement membrane. This location is probably valuable for subsequent passing of their contents into the interstitium for possible recycling. The histochemical and ultrastructural characteristics of the gland in the breeding season indicated a hyperactive secretory microenvironment enriched with the glycoprotein-producing machinery, which could be controlled by androgens. The present data suggest that the camel intraepithelial gland has a significant impact on the reproductive activity through their secretory microenvironment during the breeding season. Moreover, it recycles the unused organelles or proteins for reuse or to supply energy under stress conditions in the nonbreeding season.