title: Concanavalin A binding to amphibian embryo and effect on morphogenesis.
abstract: The effect of Concanavalin A (Con A) on morphogenesis in Pleurodeles waltlii has been studied. Embryos were incubated with various concentrations of the lectin for a period of 6 days. Three stages of development were examined, late blastula, young gastrula and late gastrula. In the presence of the lectin at a concentration of 200, 150 or 100 micrograms/ml morphogenic movements were delayed, altered and finally blocked. At lower concentrations, 50 or 25 microgram/ml, there was a slight delay in gastrulation, but in some cases development was normal. These findings indicate that Con A exerted an inhibitory effect on amphibian morphogenesis and there is evidence that the lectin effect was concentration dependent. The effects of Con A were specific since they were totally inhibited by alpha-methyl-D-mannopyranoside (0.05 M). The viability of the 24 h lectin-treated embryos was demonstrated by washing experiments. Labelled Con A binding to the embryos was investigated before and after discarding the vitelline membrane. The results suggest a direct interaction between Con A and the cell surface and this was confirmed by using fluorescein isothiocyanate Con A.
mesh_terms: D000818:Animals; D003208:Concanavalin A / Q000378:metabolism / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D008766:Methylmannosides / Q000494:pharmacology; D008856:Microscopy, Fluorescence; D008858:Microscopy, Phase-Contrast; D009024:Morphogenesis / Q000187:drug effects; D011952:Receptors, Concanavalin A / Q000378:metabolism; D012455:Salamandridae / Q000196:embryology*; D014562:Caudata / Q000196:embryology*
chemical_list: D008766:Methylmannosides; D011952:Receptors, Concanavalin A; D003208:Concanavalin A