Histochemical analysis of rat testicular glycoconjugates. 3. Non-reducing terminal residues in seminiferous tubules.

Lectins of Helix pomatia (HPA), Glycine max (SBA), Vicia villosa (VVA), Dolichos biflorus (DBA), Ulex europaeus (UEA-1), Tetragonolobus purpureus (LTA), Griffonia simplicifolia (BSA-1B4), Maclura pomifera (MPA), Sambucus nigra (SNA) and Maackia amurensis (MAA) were used to explore the distribution of saccharides characteristic of non-reducing termini of O- and N-linked glycoprotein glycans in the seminiferous tubules of rat testis. Sialyl residues (both alpha 2,3- and alpha 2,6-linked, as shown by MAA and SNA respectively) and alpha-L-fucosyl residues (shown by UEA-1 and LTA) were expressed on spermatogonia, spermatocytes and spermatozoa, but not on spermatids. In contrast, 2-deoxy-2-acetamido-alpha-D-galactosyl termini were abundant on spermatozoa, but not on any of their precursors (as shown by HPA, SBA and VVA). All occurred on both O- and N-linked glycans. Sertoli cells expressed small amounts of fucose and alpha 2,3-linked sialic acid, and abundant alpha 2,6 sialyl residues, largely on N-glycans. alpha-Galactosyl residues were readily detected on the tubular basement membrane, but not elsewhere.