Maturation of spermatozoa in the epididymis of the Chinese hamster

Abstract

Chinese hamster spermatozoa gain their ability to move when they descend from the testis to the distal part of the caput epididymis, but it is not until they enter the corpus epididymis that they become capable of fertilizing eggs. The maturation of the spermatozoa proceeds as they further descend the tract and perhaps continues even in the vas deferens. During transit between the distal caput and proximal cauda epididymides, small membrane-limited vesicles (and tubules) appear on the plasma membrane over the acrosomes of the spermatozoa. The number of vesicles appearing on the sperm brane reaches a maximum when the spermatozoa are in the proximal cauda epididymis. It declines sharply in the distal cauda epididymis. Spermatozoa in the vas deferens are free of the vesicles. The origin, chemical nature, and functional role of the vesicles that appear on the sperm surface during epididymal transit must be the subject of further investigation.

The Epididymis: Embryology, Structure, Function And Its Role In Fertilization And Infertility

“…Conversely, the luminal diameter and the thickness of the peritubular smooth muscle increases from the proximal to the distal regions (Lasserre et al, 2001;Toshimori, 2003). Few sperm are found in the initial segment, but a large mass of sperm aggregates are located in the cauda (Yanagimachi et al, 1985;Cornwall, 2009). In all of these segments, the epididymal duct is lined with an epithelium composed of principal and basal cells.…”

“…Each region consists of a lumen and a polarized epithelium composed mostly of principal and basal cells (Lasserre et al, 2001;Dacheux et al, 2005). Although these four anatomical regions of the epididymis are easily identified in most adult male mammals (Yanagimachi et al, 1985;Smithwick & Young, 2001), histological and ultrastructural segmentation of this organ varies among the different phylogenies of mammals. The rat epididymis is most commonly adopted as an experimental model of study (Figure 1).…”

Membrane transfer from oocyte to sperm occurs in two CD9-independent ways that do not supply the fertilising ability of Cd9-deleted oocytes

“…Indeed, sperm acquire their fertilising ability during epididymal transit. Particularly, they acquire proteins from membranous vesicles called epididymosomes released in the epididymal intraluminal compartment (Yanagimachi et al 1985, Fornes et al 1995, Frenette & Sullivan 2001. Epididymosomes could be considered as 'exosome-like' vesicles insuring a way of communication between the epididymis epithelium and the maturing sperm.…”

“…Sperm are able to achieve membrane exchanges with other cell types than oocytes Along their journey from the testis to the oocytes, sperm have multiple interactions essential for their maturation process in the epididymis (Yanagimachi et al 1985, Fornes et al 1995, Frenette & Sullivan 2001, with seminal fluid (Ronquist et al 1978, Breitbart & Rubinstein 1982 and while transiting in the female genital tract (Suarez 1987, Baillie et al 1997. As sperm can exchange with different cell types, we wondered whether there were membrane exchanges between K/K males (lane 2).…”

Epididymosomes, prostasomes, and liposomes: their roles in mammalian male reproductive physiology

“…First described by Jones et al (1978) in boar andDavis (1980) in rabbit, they were thought to be an artifact due to poor tissue fixation (Aumuller et al 1999). Yanagimachi et al (1985) have nicely revisited the association of small membrane vesicles with epididymal spermatozoa in Chinese hamsters. In this species, 20-100 nm vesicles appear on the sperm surface in the distal caput epididymidis and start to decrease in number in the cauda epididymidis.…”