Hgsnat (Heparin-alfa-glucosaminide N-acetyltransferase) gene inactivation affects the morphology of spermatozoa and their fertilization capacity in adult mice

HERMO L; PSHEZHETSKY AV; MORALES CR; O´FLAHERTY C; OKO R; CARVELLI L

Villa de Merlo, San Luis

Congreso; XXXV Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2017

Sociedad de Biología de Cuyo

The epididymal epithelium provides a proper environment for sperm maturation, controlled in part by the secretion of proteins into the lumen and endocytosis of substances from the lumen and basal compartment. Heparan sulphate (HS) is a component of basal membranes and the apical surface of cells. HS is degraded after endocytosis by the action of several enzymes, including heparin-alfa-glucosaminide N-acetyltransferase (HGSNAT). In adult male mice, inactivation of the Hgsnat gene shows severe morphological alterations in the epididymal epithelial cells, consistent with a phenotype of a lysosomal storage disorder. In addition to this, the fact that these animals have shown reduced litter size suggests that sperm maturation may be affected. The objectives of this investigation were to determine the effect of Hgsnat gene inactivation on the mice epididymal spermatozoa morphology (by electron and scanning microscopy), on sperm motility (by CASA) and in vitro fertilization. In the cauda epididymal lumen of Hgsnat-deficient mice, a significant number of spermatozoa presented abnormal tail and head shapes. Moreover, in these animals, some sperm motility parameters were affected, and their fertilization capacity was significantly decreased compared to wild types. Our results provide the first evidence that abnormal glycan catabolism, upon Hgsnat gene inactivation, could affect sperm quality.