Phenotypes Associated with This Genotype

Genotype
MGI:3694699

• Allelic Composition: Pax2^tm1Pgr/Pax2^tm1Pgr
• Genetic Background: involves: 129S1/Sv * 129X1/SvJ * C57BL/6

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

hearing/vestibular/ear

abnormal inner ear morphology ( J:92326 )

• at E15.5, homozygotes exhibit mild to severe inner ear defects

• notably, inner ears are more severely affected in mutants with exencephaly

abnormal cochlea morphology ( J:92326 )

• at E12, the cochlear region is wider than normal and displays a stunted ventral extension

• at E11.5, cochlear outgrowth is arrested due to increased apoptosis of cells in the cochlear anlage; however, apoptosis within the otic epithelia is greatly reduced by E12.5

• a rudimentary cochlea is always present in all mutant inner ears

• Background Sensitivity: the cochlear phenotype is more severe on a 129/Sv genetic background (cochlear agenesis) than on a mixed 129/Sv x C57BL/6 background

abnormal cochlear sensory epithelium morphology ( J:92326 )

abnormal scala media morphology ( J:92326 )

• at E15.5, the cochlear duct is medially displaced in 15 of 17 cases due to the exencephaly

abnormal organ of Corti morphology ( J:92326 )

• at E15.5, only a rudimentary organ of Corti is observed

abnormal stria vascularis morphology ( J:92326 )

• homozygotes exhibit aberrant locations of neural crest-derived melanocytes, suggesting impaired cell fate specification

decreased cochlea coiling ( J:92326 )

• at E15.5, the cochlear duct shows less than a signle turn

abnormal semicircular canal morphology ( J:92326 )

• at E15.5, 15 of 17 homozygotes display misoriented inner ears with laterally displaced ampullae and SCCs as a result of exencephaly

• the diameter of SCCs is sometimes smaller or slightly larger than normal

abnormal common crus morphology ( J:92326 )

• at E15.5, the endolymphatic duct is invariably fused with the common crus

abnormal semicircular canal ampulla morphology ( J:92326 )

• the size of ampullae are sometimes smaller or slightly larger than normal

abnormal vestibular saccular macula morphology ( J:92326 )

• at E15.5, 8 of 12 mutant inner ears show a distinct but smaller macula sacculi

• in contrast, the macula utriculi remains unaffected

absent vestibular saccule ( J:92326 )

• at E15.5, most mutant inner ears lack a well-defined saccule

abnormal endolymphatic duct morphology ( J:92326 )

• at E12, the endolymphatic duct is either shorter and broader or smaller than normal

• at E15.5, the endolymphatic duct is invariably fused with the common crus

small endolymphatic duct ( J:92326 )

short endolymphatic duct ( J:92326 )

nervous system

exencephaly ( J:92326 )

absent cochlear ganglion ( J:92326 )

• at E15.5, most homozygotes lack a spiral ganglion

small vestibular ganglion ( J:92326 )

• at E15.5, 5 of 8 homozygotes display a reduced vestibular ganglion

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
renal coloboma syndrome		DOID:0090006	OMIM:120330	J:92326