MYELIN GLYCOPROTEIN P-0 IS EXPRESSED AT EARLY STAGES OF CHICKEN AND RAT EMBRYOGENESIS

Although previous studies suggest that P-0 is expressed only in myelin ating Schwann cells, monoclonal antibody 1E8 reacts with P-0, yet also stains early Schwann cell precursors and non-myelinating Schwann cell s (Bhattacharyya et al.: Neuron 7:831-844, 1991). We therefore charact erized the 1E8 epitope and analyzed P-0 mRNA expression during develop ment. Immunoblot analyses of P-0 fusion proteins and of deglycosylated P-0 indicated that the 1E8 epitope is polypeptide. Northern blot and polymerase chain reaction (PCR) analyses revealed that P-0 is encoded by a single mRNA that is expressed in chicken embryos as early as E4 a nd in rat embryos as early as E14. These data indicate that the antige n recognized by 1E8 in early chicken embryos is P-0 and that, during d evelopment of both chickens and rats, P-0 mRNA is expressed long befor e myelination. (C) 1995 Wiley-Liss, Inc.