Severe hearing loss in Dlxl mutant mice.
The Dlx homeobox gene family participates in regulating middle and inner ear development. A significant role for Dlxl, in particular,has been demonstrated in the development of the middle ear ossicles, but the functional consequences of Dlx.l gene mutation on hearing thresholds has not been assessed. The present study characterizes auditory brainstem responses to click and tonal stimuli in a non-lethal variant of a Dlxl gene knockout. We found that peripheral hearing thresholds for click and tonal stimuli were significantly elevated in homozygous Dlxl knockout (Dlxl-/ ) compared to both heterozygous (Dlxl+/ ) and wild type (Dlxl+/+) mice. Thus, abnormal mor-phogenesis of the incus and stapes that has been documented previously with histological measures is now known to result in a severe peripheral hearing deficit.
Polley
Daniel B
DB
Coleman Memorial Laboratory, Department of Otolaryngology, University of California, San Francisco, CA 94143, USA. daniel.polley@vanderbilt. edu
Cobos
Inma
I
Merzenich
Michael M
MM
Rubenstein
John L R
JL
D000818:Animals; D004429:Ear Ossicles / Q000473:pathology* / Q000503:physiopathology; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D006319:Hearing Loss, Sensorineural / Q000235:genetics* / Q000473:pathology* / Q000503:physiopathology; D018398:Homeodomain Proteins / Q000235:genetics*; D051379:Mice; D009154:Mutation; D012720:Severity of Illness Index; D014157:Transcription Factors
C088334:Distal-less homeobox proteins; D018398:Homeodomain Proteins; D014157:Transcription Factors