Myelin Gangliosides: An Unusual Pattern in the Avian Central Nervous System

Abstract

Gangliosides were isolated from purified myelin obtained from brain and spinal cord of mature chickens and pigeons. Total concentrations were approximately 2- to 5-fold greater than for previously reported mammalian species and their patterns also differed in containing significantly more sialosylgalactosylceramide (GM4). The latter comprised 1/3-1/4 of total myelin ganglioside, approximately equivalent to GM1 (II3NeuNAc-GgOse4Cer). As in mammals, GM4 of avian CNS appeared to be localized in myelin. Fatty acids of this ganglioside included both the hydroxy- and unsubstituted types and long-chain bases were almost entirely C18. Ganglioside GM1 split into 2 closely migrating bands on TLC, the slower of which resembled mammalian GM1 in having stearate as the main fatty acid with a measurable amount (10%) of C20-sphingosine; the faster band had predominantly longer-chain fatty acids and very little C20-sphingosine.