抄録
Several mutant alleles for ataxic animals have been identified to date and some of them are genetically characterized. Some strains (e.g., pcd) are considered as models for the neuronal degeneration or hereditary spinocerebellar ataxia. We found ataxic Syrian hamsters in our breeding colony, and have maintained them by sibling mating. The hereditary mode of the mutation was autosomal recessive. Homozygotes showed a moderate ataxia beginning at seven to eight weeks of age. They were fertile and showed normal life span. Histological observation revealed that the affected hamsters exhibited an adult-onset degeneration of cerebellar Purkinje neurons, followed by a slow, mild reduction in the density of granule cells. Northern hybridization demonstrated that the expression of Nna1 transcript, the gene responsible for the Purkinje cell degeneration (pcd) phenotype, was almost negligible in the brain of homozygous hamsters. On the other hand, four ataxia-related genes (weaver/Kcnj6, lurcher/Grid2, reeler/Rln, and staggerer/Rora) were expressed comparably in the brain of wild-types and the mutants. These results strongly suggest that pcd-type mutation is involved in the ataxic phenotype of mutant hamsters. Although further studies are necessary to confirm how the mutated allele affects its phenotype, mutant hamsters would be a new tool for the study of neurodegenerative diseases. [J Physiol Sci. 2007;57 Suppl:S246]
