Qualitative and Quantitative Analysis of Lectin Binding on the Epididymal Spermatozoa of Cat (Felis catus)

The variations in the carbohydrate residues present on the surfaces of maturing epididymal spermatozoa of a cat (Felis Catus) have been studied. Spermatozoa recovered from the caput, corpus, and cauda epididymides were labeled with fluorescein isothiocyanate (FITC) linked lectins and examined with a fluorescence microscope and flow cytometer. Seven FITC-linked lectins viz. Canavalia ensiformis or Concanavalin A (Con A), Dolichos biflorus (DBA), Macluvra pomlfera (MPA), Arachis hypogaea or peanut agglutinin (PNA), Glycine max or Soybean agglutinin (SBA), Ulex europaeus (UEA), Triticum vulgaris or Wheatgerm agglutinin (WGA) were used. We find that as the spermatozoa move through the epididymis there is an increase in the lectin binding affinity for Con A and MPA and a decrease in SBA and DBA binding alfa-D-glucose / alfa-D-mannose residues populate the major portion of the cat sperm head and arc present prominently on the plasma membrane covering the acrosome as revealed by Can A labeling. The N-acetyl-galactose specific lectin, MPA exclusively labels the equatorial segment. Flow cytometry indicates no change in the binding intensities of UEA, but microscopic examination reveals a distinct alteration in the labeling sites.