Anatomical, Physiological and Biochemical Studies on the Cerebellum from Mutant Mice. III. Protein Differences Associated with the Weaver, Staggerer and Nervous Mutations

The protein composition of subcellular fractions of the cerebella of normal and weaver, staggerer and nervous mutant mice and of X-irradiated rats are studied by polyacrylamide gel electrophoresis in sodium dodecyl sulphate. The patterns observed are compared with those of granular and Purkinje cells purified from rat cerebella. In particulate fractions from weaver and X-irradiated rat cerebella, several protein bands are missing. These bands are present in purified rat granular cells. The most obvious deficit concerns a nuclear protein of apparent molecular weight 30,000, presumably the F1 histone. In these agranular cerebella the total DNA content is approximately 7 times lower than in the control animals and the DNA to protein ratio decreases approximately by a factor of two. In the cerebella from homozygous staggerer and nervous mutant mice, where the Purkinje cells are either abnormal or absent, a protein of apparent molecular weight 400,000 is markedly reduced. This membrane-bound protein is present in preparations of purified Purkinje cells.