Changes in ganglioside profile in chick embryo retina: Studies on tissue and cell cultures.

The developmental profile of gangliosides in the neural retina of the chick embryo is characterized by a progressive decrease in the concentration of GD3 complex from a high level on day 6; by a continuous increase in GD1a concentration; and by less striking increases in GD1b and GT1b concentrations during the growth phase; GM1 increases in the post-mitotic retina. Gangliosides were analyzed by thin layer chromatography and by densitometry of the TLC plates. (Ganglioside nomenclature is according to Svennerholm.(37)) We have examined comparatively ganglioside changes in organ cultures of retina tissue from 6 day embryos (R(36)), in cell aggregates and in primary monolayer cultures of R(26) cells, all maintained for 6 days in vitro. In all cases, the pattern of ganglioside changes was qualitatively similar to that in the retina in vivo. These results suggest that, unlike some other aspects of retina differentiation, the progression of ganglioside changes in the 6-12 day embryonic retina is not critically dependent on histotypic cell organization or on specific contact-dependent cell interactions; these changes appear to be largely preprogrammed in the cells at some earlier phase of development.