Effects of duct ligation on the fertilzing ability of spermatozoa from different regions of the rabbit epididymis

Abstract

Abstract In the normal rabbit, fertile spermatozoa first appear in the lower half of the corpus epididymidis. If sperm passage is impeded in the low corpus region, the capacity to fertilize and initiate normal ovum development can ultimately arise in sperm withheld in any part of the ductus epididymidis, distal to the caput flexure. Sperm released from the initial part of the epididymis proximal to the caput flexure did not fertilize, even though many showed apparently normal progressive motility twelve and one‐half to fifteen days after low corporeal ligation. Since these infertile, motile sperm did not show the normal head–head agglutination reaction of mature rabbit sperm in a medium containing serum, it appears that the dichotomy between motility and fertilizing ability may have been at least partly due to the persistence in an immature state of the sperm plasma membrane. Many caput sperm which displayed normal sustained motility had retained the cytoplasmic droplet in the neck region, whereas, in others showing comparable motility, the droplet had moved along the midpiece or had been lost. It, therefore, seems unlikely that movement and loss of the droplet can be of importance in development of the capacity for motility in maturing spermatozoa.