Histochemical analysis of glycoconjugates in the domestic cat testis

Abstract

The localization and characterization of oligosaccharide sequences in the cat testis was investigated using 12 lectins in combination with the ßelimination reaction, N-Glycosidase F and sialidase digestion. Leydig cells expressed O-linked glycans with terminal aGalNAc (HPA reactivity) and N-glycans with terminal/internal aMan (Con A affinity). The basement membrane showed terminal Neu5Aca2,6Gal/GalNAc, Galß1,3GalNAc, a/ßGalNAc, and GlcNAc (SNA, PNA, HPA, SBA, GSA II reactivity) in O-linked oligosaccharides, terminal Galß1,4GlcNAc (RCA120 staining) and aMan in N-linked oligosaccharides; in addition, terminal Neu5Aca2,3Galß1,4GlcNac, Forssman pentasaccharide, aGal, aL-Fuc and internal GlcNAc (MAL II, DBA, GSA I-B4, UEA I, KOH-sialidase-WGA affinity) formed both O- and N-linked oligosaccharides. The Sertoli cells cytoplasm contained terminal Neu5Ac- Galß1,4GlcNAc, Neu5Ac-ßGalNAc as well as internal GlcNAc in O-linked glycans, aMan in N-linked glycoproteins and terminal Neu5Aca2,6Gal/ GalNAc in both O- and N-linked oligosaccharides. Spermatogonia exhibited cytoplasmic N-linked glycoproteins with aMan residues. The spermatocytes cytoplasm expressed terminal Neu5Aca2,3Galß1,4 GlcNAc and Galß1,3GalNAc in O-linked oligosaccharides, terminal Galß1,4GlcNAc and a/ßGalNAc in N-linked glycoconjugates. The Golgi region showed terminal Neu5aca2,3Galß1,4GlcNac, Galß1,4GlcNAc, Forssman pentasaccharide, and aGalNAc in O-linked oligosaccharides, aMan and terminal ßGal in N-linked oligosaccharides. The acrosomes of Golgi-phase spermatids expressed terminal Galß1,3GalNAc, Galß1,4GlcNAc, Forssmann pentasaccharide, a/ßGalNAc, aGal and internal GlcNAc in O-linked oligosaccharides, terminal a/ßGalNAc, aGal and terminal/internal aMan in N-linked glycoproteins. The acrosomes of cap-phase spermatids lacked internal Forssman pentasaccharide and aGal, while having increased a/ßGalNAc. The acrosomes of elongated spermatids did not show terminal Galß1,3GalNAc, displayed terminal Galß1,4GlcNAc and a/ßGalNAc in N-glycans and Neu5Ac-Galß1,3GalNAc in O-linked oligosaccharides.