Mutant ICR mouse, kuru2, manifests hearing impairment and abnormal behavior.

BACKGROUND

Establishment of mutant animals presents valuable information on corresponding human diseases. We established a mutant mouse, kuru2, from the previously reported Ascites ICR Mouse.

MATERIALS AND

METHODS

Epileptic individuals of Ascites ICR Mouse were mated and maintained with sibling mating. This mouse was characterized by hearing impairment and abnormal behavior such as ataxic gait, disturbance of positional sense, hyperirritability, head-tossing and circling movement.

RESULTS

No detectable auditory brain stem response was evoked from an early stage of life. Abnormal behavior started from 4 to 12 weeks of age. Microscopic examination revealed no major abnormalities in the central nervous system. In the inner ear, the vestibule and cochlea were well developed, however degeneration of the spiral ganglions was observed at a late age. The genetic mode was autosomal recessive.

DISCUSSION: Since this mouse has a distinctive phenotype, the animal may provide an understanding of hereditary hearing impairment and abnormal behavior.