GLYCOSIDASES INTERACT DIFFERENTLY WITH EPIDIDYMAL SPERM

AGUILERA, ANDREA CAROLINA; BOSCHIN, V.; SARTOR, TIRSO; MICHAUT, MARCELA A.; SOSA, MIGUEL A.

Buenos Aires

Congreso; Primer Congreso de la Sociedad Latinoamericana de Reproducción Animal; 2015

Sociedad Latinoamericana de Reproducción Animal

The mammalian spermatozoa undergo modifications during maturation in the epididymis to  acquire their fertilizing capacity. In bulls, as in other mammals, many glycosidases (GLY) are secreted into the epididymal fluid. In this work we describe and characterize the interaction of  some epididymal GLY with bull spermatozoa. We found that β-galactosidase (β-Gal) is weekly associated to sperm since it is released with low ionic strength, whereas the interaction of N- acetyl-β-D-glucosaminidase (β-NAG) and β-glucuronidase (β-Glu) with gametes seem to be  stronger. In addition, part of these enzymes can also be released by mannose-6-phosphate. On  the other hand, α-mannosidase (α-Man) and α-fucosidase (α-Fuc) are mostly anchored to the  plasmalemma. From these results, we explored the presence of mannose-6-phosphate receptors (MPRs) and found that both, the cation-independent (CI-MPR) and the cation-dependent MPR (CD-MPR) are present in the gamete and they are differently distributed on the sperm surface. In addition, β-NAG and β-Glu from epididymal fluid interact mostly with CI-MPR,  while β-Gal is recognized by both receptors. We concluded that GLY might become associated to the gametes during epididymal transit, as part of maturation process in bull epididymis, either for activation of these enzymes or to be transported into the female reproductive tract and their participation in fertilization.