Synthesis of retinal gangliosides during chick embryonic development.
Embryonic retina cells incorporated radioactivity from D-[6-3H]glucosamine into gangliosides in vitro. The incorporation was higher in retinas from younger embryos. The pattern of labeling of individual gangliosides of the retina changed gradually from a predominant labeling of gangliosides running chromatographically as GD3 (nomenclature of Svennerholm) and GM3 in retinas from 8-day-old embryos to a predominant labeling of those running as GD1a and GT1 in retinas from 13--18-day-old embryos and newly hatched chicks. The shift in the pattern of labeling correlated with a temporary increase of about sixfold of the activity of UDP-N-acetylgalactosamine:GM3 N-acetylgalactosaminyltransferase occurring between days 8 and 14 of embryonic development and with a regular increase of the activity of the UDP-galactose:GM2 galactosyltransferase occurring from day 8 until hatching. The activities of the CMP-NeuAc:lactosylceramide-, CMP-NeuAc:GM3-, and CMP-NeuAc:GM1-sialosyltransferases in the retinas of newly hatched chicks were 40, 20, and 40% in comparison with the corresponding activities determined in retinas of the 8-day-old embryo.
D000818:Animals; D002642:Chick Embryo; D002855:Chromatography, Thin Layer; D004247:DNA / Q000378:metabolism; D005732:Gangliosides / Q000096:biosynthesis*; D005944:Glucosamine / Q000378:metabolism; D007700:Kinetics; D011506:Proteins / Q000378:metabolism; D012160:Retina / Q000196:embryology / Q000378:metabolism*; D012794:Sialic Acids / Q000032:analysis; D014166:Transferases / Q000378:metabolism
D005732:Gangliosides; D011506:Proteins; D012794:Sialic Acids; D004247:DNA; D014166:Transferases; D005944:Glucosamine