C-PATHWAY POLYSIALOGANGLIOSIDES IN THE NERVOUS-TISSUE OF VERTEBRATES, REACTING WITH THE MONOCLONAL-ANTIBODY Q211

The mouse monoclonal antibody Q211, previously shown to recognize a common epitope of chicken brain GP1c and of two other polysialogangliosides containing 4 and 6 sialic acid residues respectively, is demonstrated to bind to gangliosides with identical thin-layer chromatography (TLC) migration in the brain of representatives of boney fish, rays, reptiles and mammals, including man. In the boney fish brains, the Q211 binding gangliosides were found to be alkali-labile, the Q211 epitope, however, is alkali-stable. After alkaline treatment, the cichlid fish contained at least 4 Q211-binding gangliosides, migrating as GT1c, GQ1c, GP1c and 'GH'. In the trout brain only one Q211 antigenic fraction was found, migrating as GQ1c. In the brains of ray, turtle and embryonic chicken an identical pattern of Q211-binding gangliosides (GQ1c, GP1c, 'GH') occurred. In the embryonic rat and human brain, the content of Q211-binding gangliosides was much lower as compared to the other vertebrate species. The epitope was found in two fractions, migrating like GQ1c (human and rat) and GP1c (rat). The presence of Q211 epitope in all species was confirmed by immunohistochemistry. These data confirm that the Q211-epitope contains a complete c-ganglio-tetraose structure, carrying 3 sialic residues at the inner galactose. They furthermore demonstrate that the expression of c-pathway polysialogangliosides is a general feature of the vertebrate nervous tissue, either during whole life (fish, reptiles) or more or less transient during embryonic development (birds, mammals). © 1990.