Circling (bi-directional), head tilt and head tossing behavior; the mutants are deaf.
Detailed Phenotype Description:
The mutants were identified through head tilt, body leaning and bi-directional circling behavior at wean (average onset at 3.5 +/- 0.6 weeks of age; n=31); they also show head tossing behavior. ABR testing showed the mutants to be deaf at all frequencies (8, 16, 32KHz) tested. Because of phenotypic and genotypic similarities to mutants of Myo7a, complementation tests were performed with B6.Cg-Myo7ash1-8J/J (JR#3184); the results of two heterozygous by homozygous matings (5 affected in a total of 24 progeny) suggest that nmf371 represents an allele of Myo7a. Serial sections of the ears of two mutants (160 days of age) revealed a virtual absence of organ of corti, spiral ganglion cells, hair cells or normal otoconia; whole ear exam also showed defective otoconia. Standard pathology work-up revealed no further abnormalities.
