Changes in WGA-lectin binding sites on sperm during epididymal transit in the Chacma baboon (Papio ursinus) and the vervet monkey (Cercopithecus aethiops).

Abstract

Epididymal maturation of sperm entails molecular changes to the sperm plasma membrane. These changes are reflected by changes in lectin binding. The wheat germ agglutinin (WGA) lectin was used, since it binds to acetylglucosamine and sialic acid, which are involved in sperm function. The objective was to study changes in WGA-lectin binding during epididymal passage and in the ejaculate of the Chacma baboon and vervet monkey. The intensity and location of lectin binding on sperm from the ejaculate and the caput, corpus, and cauda epididymidis of 5 adult males from each species were studied. In both baboon and monkey sperm, the acrosomal region had the highest intensity stain and the equatorial region had the lowest intensity. Significant differences in staining of the different regions of sperm were found for the different epididymal sites and the ejaculate of both species. It was concluded that changes in the molecular composition of the sperm membrane, taking place during epididymal maturation, can at least in part be monitored by studying WGA-lectin binding on sperm. The changes noted are probably important for the organization of a membrane of the correct molecular conformation and mandatory for complete sperm function.