Mouse Genome Informatics
hm
    Tomtm1Btlr/Tomtm1Btlr
C57BL/6J-Tomtm1Btlr
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
       
behavior/neurological
• homozygous mutant male mice caged together exhibit heightened inter-male aggression, fighting with and inflicting wounds on each other
• at 8 weeks of age, mutant mice exhibit no acoustic startle response to a 120 dB sound
• mutant mice perform poorly in the lateral beam test
• this behavior is suppressed when the mice are sleeping or nursing
• evident by three weeks of age
• this behavior is suppressed when the mice are sleeping or nursing
• mutant mice exhibit repetitive brief backward bending of the neck so that the head's long axis is vertical ("stargazing")
• this behavior is suppressed when the mice are sleeping or nursing
• evident by three weeks of age

hearing/vestibular/ear
• revealed by scanning electron microscopy in four day old mice
• progressive loss of inner hair cells (IHC)
• progressive loss of outer hair cells
• mutant mice exhibit progressive degeneration of the organ of Corti
• in five day old mice the inner ear appears histologically normal by light microscopy, but by 8 weeks severe degenerative changes are evident
• 8 week old mutant mice exhibit no acoustic brainstem response (ABR) at 90 dB, vs. an ABR threshold of ~40 dB in wild-type control mice
• the DPOAE of 8 week old mutant mice in response to stimuli at 0-70 dB and 6-28 kHz is within noise level

nervous system
N
• the cerebra of mutant mice appear histologically normal by light microscopy (J:137493)
• revealed by scanning electron microscopy in four day old mice
• progressive loss of inner hair cells (IHC)
• progressive loss of outer hair cells
• the density of spiral ganglion neurons appears normal in four day old mice, but has decreased by 8 weeks

growth/size
• homozygous mutant mice are leaner than their unaffected littermates; this may be due to their higher activity level

Mouse Models of Human Disease
OMIM IDRef(s)
Deafness, Autosomal Recessive 63; DFNB63 611451 J:137493