Myelin proteolipid protein (PLP and DM-20) transcripts are deleted in jimpy mutant mice.

The myelin-associated proteolipid protein, PLP, is one of the two major components of the central nervous system (CNS) myelin. We analyze, by using a rat PLP cDNA and S1 nuclease protection experiments, the PLP transcripts in the mouse brain and show that the PLP gene encodes two different but related mRNA transcripts, the PLP and the DM-20 transcripts. On the other hand, we demonstrate that in the jimpy mutant, which is characterized by an abnormal CNS myelination, both these transcripts are partially deleted in the 3' end of their coding region. The deletion is 70 (+/- 5) nucleotides long. Implications of this finding for the synthesis of PLP and DM-20 proteins in the mutant are discussed.