SEQUENTIAL HISTOLOGY OF THE ADULT CHIMPANZEE EPIDIDYMIS

The chimpanzee epididymis consists of three gross anatomical regions: caput (Cp), corpus (Cr), and cauda (Cd). During epididymal transit, ch impanzee sperm undergo maturational changes (affecting motility, capac itation, and the acrosome reaction), which enable fertilization. Eluci dation of the sequential histology of the chimpanzee epididymis is pre liminary to determining the role of each region of epididymal duct in the process of sperm maturation. We report the histology, in the adult male chimpanzee, of sequential segments of epididymis from the proxim al efferent ductules through the Cp, Cr, and Cd regions of the epididy mis proper to the proximal ductus deferens. These data illustrate the gross architecture of the tissue and reveal the histology characterist ic of the diverse epithelia composing the epididymal ducts at each lev el. The tubules composing the epididymis of the adult male chimpanzee present at least 16 histologically-distinct epithelia and their transi tional forms. Such diversity of epithelia suggests a corresponding div ersity of function. Although there are some clear differences, the his tological appearance of the ducts, and of the component epithelia of t he chimpanzee epididymis, is remarkably similar to that reported for t he human.