MOLECULAR-CLONING OF CDNAS THAT ENCODE THE CHICKEN PO PROTEIN - EVIDENCE FOR EARLY EXPRESSION IN AVIANS

As the major transbilayer glycoprotein of peripheral myelin, Po is believed to play a prominent role in the formation of this structure by Schwann cells. The amino acid sequence of the chicken Po molecule, deduced from the nucleotide sequence of cDNA clones, is reported here. Comparison with the mammalian molecule reveals an extensive overall homology, thus underlining the importance both of the cytoplasmic and of the extracellular domains of this protein in the stablishment and preservation of peripheral myelin structure. Unexpectedly, an avian Po cDNA probe was found to hybridise with several mRNA species, in exclusively in peripheral nerve and in proportions that varied according to the developmental stag. The expression of these transcripts was detected significantly earlier than that of po mRNA in nammals. Copyright © 1990 Wiley‐Liss, Inc.