Fucose in {alpha}(1-6)-linkage regulates proliferation and histogenesis in reaggregated retinal spheroids of the chick embryo

• Published in: Glycobiology
• Main Authors: Stelck, Simone, Robitzki, Andrea, Willbold, Elmar, Layer, Paul G.
• Format: Text
• Language: English
• Published: Oxford University Press 1999
• Subjects: Articles; Anguilla anguilla
• Online Access: http://glycob.oxfordjournals.org/cgi/content/short/9/11/1171; https://doi.org/10.1093/glycob/9.11.1171

We have used the lectin from Aleuria aurantia (AAL) which is highly specific for α(1–6)-linked fucose, to examine its effect on chicken retinogenesis in a reaggregation culture system. When dispersed cells of the embryonic chick retina are reaggregated to form histotypic retinospheroids, AAL elicits strong inhibition of spheroid growth. The action of AAL is specific, since its effect is dose-dependent, saturable, and inhibited by an excess of fucose. Fucosidase treatment entirely abolishes reaggregation. In contrast, Anguilla anguilla agglutinin (AAA) binding to fucose in α(1–2)-linkage does not show any effects. Incubation with CAB4—a specific monoclonal antibody for fucose in α(1–6)-linkage—reduces spheroid size and shape. AAL does not much affect primary aggregation, but rather subsequent processes of cell proliferation and histogenesis. In particular, AAL inhibits uptake of bromo-desoxyuridine (BrdU), most efficiently so during days in vitro 2 (div2) and div3. As a consequence, the histological differentiation is entirely disturbed, as evidenced by vimentin immunostaining; particularly, rosettes are not forming and the radial glia scaffold is disorganized. We conclude that glycoproteins exhibiting fucose in α(1–6)-linkage may play major roles in early processes of retinal tissue formation.