Gangliosides and proteins in developing chicken brain myelin.

Ganglioside and protein content of chicken brain myelin have been studied as a function of development and maturation. Ganglioside concentration remained relatively constant at approximately 225-266 micrograms sialic acid per 100 mg myelin, from 17-day-old embryos to 540-day-old adults. The ganglioside distributional pattern was also constant, GM1 and GM4 each accounting for approximately one-third of total sialic acid. These properties are contrasted with those of mouse and rat brain myelin which previously showed enrichment of GM1 at early stages of myelination and appearance of GM4 at a later stage of maturation. In an earlier study of the mouse total myelin gangliosides doubled in concentration between 3 and 5 weeks of age and full maturity. Myelin proteins of the chicken also remained relatively constant in concentration and distributional pattern during development, although the percentage of basic protein increased somewhat during the first few weeks after hatching. Correlations were observed between molar concentrations of basic protein and various gangliosides, particularly the monosialo types.