Circling and head tossing behavior observed by weaning age; mutants are deaf.
Detailed Phenotype Description:
The mutants exhibit circling and head tossing behavior by weaning age (average date of onset 3.7 weeks of age +/- 0.66; n=20), and two animals tested for Auditory brainstem response at 6 weeks of age were found to be deaf. Male or female mutants have been produced and a colony can be maintained through heterozygote or mutant breeding (though heterozygotes breed better than mutants). Standard pathology work-up on four mutants (29, 36 or 111 days of age) revealed abnormal development of the ears of three mutants. Serial sections of the ears of a 29 and a 111 day old mutant showed a lack of organization, no properly formed hair cells were observed in the older mouse; the semicircular canals also appeared very small. However, whole ear histology performed on an additional mutant (29 days of age) revealed no abnormalities. In the 36 day old mutant, macrophages were present in spinal and trigeminal nerve roots, as well as in the white matter of the CNS. No other abnormalities were observed.
