Biology of Reproduction, Vol 6, 13-22, Copyright © 1972 by Society for the Study of Reproduction

Immunofluorescent Evaluation of the Male Rabbit Reproductive Tract for Sites of Secretion and Absorption of Seminal Antigens

¹ Department of Animal Science, University of Minnesota, St. Paul, Minnesota 55101

A fluorescent antibody technique was used to determine the distribution in the rabbit genital tract of antigens present in seminal plasma, and washed, ejaculated spermatozoa. Sperm-specific antigens became detectable at the spermatid stage of spermatogenesis. These antigens, associated primarily with the acrosome and the cytoplasmic droplet, and to a lesser degree with the midpiece and tail, were also associated in an amorphous mass which disappeared after transport from the testis to the caput epididymis. The gradual loss of immunofluorescence by the cytoplasmic droplet during passage through the epididymis was paralleled by the appearance of similarly detectable antigens in the epithelia of the epididymis, especially in the cauda epididymides. This was more pronounced in sexually rested bucks than in sexually active bucks, suggesting loss of antigens from the spermatozoa and absorption by the epididymal epithelia.