Chimeric analysis of the pathogenesis of dysmyelination of shiverer mutant mice. Presence of patches of MBP-positive and negative sites in white matter indicating the absence of humoral factors for dysmyelination.

Shiverer is an autosomal recessive mutant mouse characterized by abnormal and poor myelin formation of the central nervous system. Chimera mice were produced from wild-type control (C57BL/6N) and the shiverer mutant mice (BALB/C) by the aggregation technique in order to analyze the pathogenesis of the shiverer mutation. The coat color was a mosaic of both strains. Immunohistochemically we have examined sections of cerebellar white matter of the chimera using antiserum against myelin basic protein (MBP), since MBP is absent in the myelin of the shiverer. Patches of MBP-negative and positive sites were observed in cerebellar white matter. The myelin sheaths, both positive and negative to MBP staining, were well mixed in the white matter but each stained myelin sheath was clearly visible, even in the mixed part. The possibility that humoral factors caused dysmyelination could be eliminated, and it is suggested that the shiverer mutation occurs intrinsic to the cells themselves.