Expression of a P0-like glycoprotein in central nervous system myelin of amphibians (Ambystoma mexicanus, Xenopus laevis and Rana catesbeiana).

1. The myelin protein profiles in the CNS and PNS of three species of amphibians were analyzed by biochemical and immunohistochemical methods. 2. The CNS myelin of the African clawed frog (Xenopus) and the Mexican salamander (axolotl) contained, in addition to proteolipid protein, a unique protein zero (P0)-like protein, whereas the adult bullfrog did not. 3. A strong expression of the P0-like protein in the bullfrog CNS myelin was found transiently at ontogenetically early phases including at the time of metamorphosis. 4. The CNS P0-like protein and the PNS P0 protein showed a difference in reactivity with lectins and anti-L2/HNK-1 antibodies, suggesting that the two proteins differ in some aspects of their carbohydrate structures.