Morphological changes in the boar spermatozoa at different regions of epididymis.

Abstract

In order to obtain the information on the morphological changes occuring in sperm at various regions along the epididymis, forty one boars of Randrace breed were used for the examination of the morphology of sperm in epididymal content from four regions of epididymis. Samples were collected post mortem from the proxi-mal and distal parts of caput and cauda epididymides, respectively.The results obtained are as follows:There was a highly significant decrease in the incidence of abnormal sperm heads (pear-shaped, narrow at the base and narrow) during the passage from the proximal to the distal region of caput epididymidis. The decrease in the incidence of abnormal head with these types may be due to selective resorption or dissolution of sperm in the epithelium of caput epididymidis. Migration of cytoplasmic droplet from the prox-imal to distal position of middle-piece increased progressively during the passage of sperm through the epididymis, and largest migration took place from the proximal to distal region of caput epididymidis. While the incidence of bent tail sperm increased during the passage along the epididymis, it reached maximum in the proximal region of cauda epididymidis. These finding suggest that ability of selective sperm resorption in epididymal epithelium of caput is very active, and it contribute to the improvement semen picture after ejaculation. Studies on morphological characteristics of ejaculated sperm would be important for evaluation of the function at different regions of epididymis.