N-ACETYLGLUCOSAMINE CONTENT CHANGES IN BULL SPERM DURING EPIDIDYMAL MATURATION

AGUILERA AC,; LEIVA N,; ALVAREZ P; DIANA, A; SOSA MA

Congreso; Cuyo Biology Society XXXVII; 2019

Sociedad de Biología de Cuyo

After leaving the testis, spermatozoa undergo several molecular changes up to reach the female genital tract. Most of thesemodifications occur during epididymal transit as a direct result of exposure to, and interaction with, epididymal luminal environment.Among these modifications, addition, removal, and/or modification of external sugars on glycolipids or glycoproteins have beendescribed in different species. The aim of this study was to evaluate changes in N-acetyl-glucosamine (NAG) content of the plasmamembrane glycoproteins in bull spermatozoa during their epididymal maturation. For this purpose, fresh epididymides from bulls(Aberdeen Angus) were used. Organs were dissected into caput, corpus, and cauda, and the sperm were obtained by slicing of thetissue and centrifugation. Ejaculated spermatozoa were obtained from cryopreserved samples. NAG and galactose (GAL) wereevaluated in sperm glycoproteins by using respectively WGA and BS-I lectins conjugated with either FITC for flow cytometry orwith biotin for blotting assay. By flow cytometry, we observed that NAG detection increased progressively from caput to ejaculatedsperm. By blotting sperm glycoproteins onto nitrocellulose membranes, and subsequent detection with biotinylated lectins, weobserved a decrease in the NAG content of some glycoproteins, while the signal increased in a 60 kDa protein of caudaspermatozoa. No major changes were observed in the GAL content between sperm from caput to cauda. We also observed that β-Nacetyl-glucosaminidase activity increased from caput to cauda and the enzyme is redistributed to the epididymal fluid. These changescould provide new insights about carbohydrate rearrangement that can be used as parameters for sperm maturation.