Localisation of the lectin reactive sites in adult and prepubertal horse testes

The testes of prepubertal and adult horses were investigated using 10 horse radish peroxidase conjugated lectins combined with sialidase digestion and potassium hydroxide treatment. to localise the oligosaccharide sequences of glycoconjugates during spermatid maturation. In adult animals. the lectins showed a variable affinity for spermatids and Sertoli cell apical extensio ns. Soybean agglutinin (SBA), peanut agglutinin (PNA), Ricinus communis agg lutinin (RCA-I) and wheat germ agglutinin (WGA) bound to the acrosomal stru ctures of spermatids, whereas Griffonia simplicifolia agglutinin (GSA-II) l abelled these structures only during Golgi and cap phases. These results su ggested that glycoproteins of mature acrosomes contain both N- and O-linked oligosaccharides and that these carbohydrate chains undergo modifications during spermiogenesis. Sialic acid residues were not detected throughout th e acrosomal development. The lectin binding pattern of Sertoli cells was ve ry similar to that of acrosome of spermatids during the maturation phase. I n sexually immature horses, only the degenerated germinal cells and the Ley dig cells showed reactivity towards lectins. The first cells reacted with S BA and Dolichos biflorus agglutinin (DBA), the latter with SBA, PNA, WGA, G SA-II, Canavalia ensiformis agglutinin (ConA), Lens culinaris agglutinin (L CA) and also with DBA after sialidase digestion. (C) 2000 Harcourt Publishe rs Ltd.