Differential lectin binding patterns in the oviductal ampulla of the horse during oestrus

We investigated the oligosaccharide sequence of glycoconjugates,
mainly sialoglycoconjugates, in the horse oviductal
ampulla during oestrus by means of lectin and pre-lectin
methods such as the KOH-neuraminidase procedure to
remove sialic acid residues and incubation withN-glycosidase
F to cleaveN-linked glycans. Ciliated cells displayedN-linked
oligosaccharides throughout the cytoplasm. The cilia
glycocalyx expressed bothN- andO-linked (mucin-type)
oligosaccharides, both showing a high variety of terminal
sequences. In the most non-ciliated cells, the whole cytoplasm
containedN-linked oligosaccharides with terminal
αGal as well as mucin-type glycans with terminal Forssman
pentasaccharides. In a few scattered non-ciliated cells, the
whole cytoplasm displayed sialylatedN-linked oligosaccharides
with terminal Neu5Ac-GalNAc andO-linked glycans terminating
with neutral and/or αGalNAc, Neu5Acα2,6Gal/
GalNAc, Neu5AcGalβ1,3GalNAc. Supra-nuclear granules,
probably Golgi zones, of non-ciliated cells showed mainlyO-linked
glycans rich in sialic acid residues. The luminal surface
of non-ciliated cells showedN-linked oligosaccharides,
containing terminal/internal αMan/αGlc, βGlcNAc and terminal
αGal, as well as mucin-type oligosaccharides terminating
with a large variety of either neutral saccharides or
sialylated sequences. Apical protrusions containingO-linked
oligosaccharides with terminal Forssman pentasaccharide,
Neu5Ac-Galβ1,4GlcNAc, Neu5Ac-GalNAc were seen in nonciliated
cells scattered along the epithelium. These findings
show the presence of sialoglycoconjugates in the oviductal
ampulla epithelium of the mare and the existence of different
lectin binding profiles between ciliated and non-ciliated
(secretory) cells, as well as the presence of non-ciliated cell
sub-types which might determine functional differences
along the ampullary epithelium of mare oviduct.