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Disproportional Expression of Proteolipid Protein and DM‐20 in the X‐Linked, Dysmyelinating Shaking Pup Mutant
Author(s) -
Yanagisawa Katsuhiko,
Moller Johanna R.,
D. Duncan Ian,
Quarles Richard H.
Publication year - 1987
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1987.tb02454.x
Subject(s) - mutant , proteolipid protein 1 , antiserum , spinal cord , myelin , microbiology and biotechnology , blot , immunostaining , biology , chemistry , biochemistry , central nervous system , myelin basic protein , antibody , endocrinology , gene , immunohistochemistry , immunology , neuroscience
The shaking pup is an X‐linked canine mutant with a severe hypomyelination of the CNS. Proteolipid protein (PLP) and the related DM‐20 protein were examined in this mutant by densitometric scanning of Western blots stained with PLP antiserum. In the spinal cord of 4‐week‐old mutants, PLP was reduced to less than 1 % of the control level, which is a greater deficiency than was found for other myelin proteins. On Western blots of control spinal cord, PLP stained much more intensely than DM‐20. However, on Western blots of the mutant spinal cord, a component with the electrophoretic mobility of DM‐20 stained slightly more intensely with PLP antiserum than PLP itself. This component was shown to be DM‐20 by its lack of reactivity with an antiserum raised to a synthetic peptide corresponding to part of the PLP sequence that is missing in DM‐20. Thus PLP and DM‐20 are expressed in approximately equal and greatly reduced amounts in the mutant spinal cord. Although PLP or DM‐20 could not be detected in brain from the 4‐week‐old mutant, similar disproportional expression of these two proteins was demonstrated in both spinal cord and brain from a 10‐week‐old mutant pup. Immunostaining of tissue sections showed that the small amounts of PLP and/or DM‐20 synthesized in the mutant are present in the thin myelin sheaths. The results suggest that the shaking pup could have a primary defect in the PLP gene leading to a severe deficiency of PLP and DM‐20 as well as disproportional expression of these two proteins.