DYSTROPHIN AND ITS ISOFORMS IN A SYMPATHETIC-GANGLION OF NORMAL AND DYSTROPHIC MDX MICE - IMMUNOLOCALIZATION BY ELECTRON-MICROSCOPY AND BIOCHEMICAL-CHARACTERIZATION

In normal mouse superior cervical ganglion, dystrophin immunoreactivit y is present in ganglionic neurons, satellite cells and Schwann cells. It is associated with several cytoplasmic organelles and specialized plasma membrane domains, including two types of structurally and funct ionally different intercellular junctions: synapses, where if is locat ed at postsynaptic densities, and adherens junctions. Dystrophin immun ostaining can be ascribed to the 427,000 moi. wt full-length dystrophi n, as well as to the several dystrophin isoforms present in superior c ervical ganglion, as revealed by western immunoblots. In mdx mouse sup erior cervical ganglion, which lacks the 427,000 mel. wt dystrophin, t he unchanged pattern of dystrophin immunolabelling observed at several subcellular structures indicates the presence of dystrophin isoforms at these sites. Moreover, the absence of labelled adherens junctions i ndicates the presence of full-length dystrophin at this type of juncti on in the normal mouse superior cervical ganglion. The lower number of immunopositive postsynaptic densities in mdx mouse superior cervical ganglion than in normal mouse ganglion suggests the presence, in the l atter, of postsynaptic densities with differently organized dystrophin cytoskeleton: some containing dystrophin isoforms alone or together w ith 427,000 mel. wt dystrophin, and others containing 427,000 mel, wt dystrophin alone. (C) 1997 IBRO. Published by Elsevier Science Ltd.