Phenotypes associated with this allele

• Allele Symbol: Hoxb2^tm3.2Fmr
• Allele Name: targeted mutation 3.2, Filippo M Rijli
• Allele ID: MGI:5490994
• Summary: 1 genotype

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Hoxb2^tm3.2Fmr/Hoxb2^tm3.2Fmr	involves: 129S2/SvPas * C57BL/6	MGI:5491193

Genotype
MGI:5491193

hm1

• Allelic Composition: Hoxb2^tm3.2Fmr/Hoxb2^tm3.2Fmr
• Genetic Background: involves: 129S2/SvPas * C57BL/6

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

hearing/vestibular/ear

abnormal organ of Corti morphology ( J:197162 )

• very few crossing medial olivocochlear (MOC) terminals are observed contacting outer hair cells in adult mice

abnormal cochlear outer hair cell morphology ( J:197162 )

• at P8, no difference in shape or organization of outer hair cells (OHCs) is observed at the apical and basal turns relative to wild-type

• morphological defects of OHCs in adults are less severe than observed in constitutive Hoxb1-deficient (Hoxb1^tm1.2Fmr) mice but statistically significant loss of OHCs and moderate OHC ciliar malformations are observed

increased or absent threshold for auditory brainstem response ( J:197162 )

• at 3 months, threshold is pathologically elevated compared to the normal 40dB, but not as significantly as in Hoxb1^tm1.2Fmr (null) mice

nervous system

abnormal cochlear outer hair cell morphology ( J:197162 )

• at P8, no difference in shape or organization of outer hair cells (OHCs) is observed at the apical and basal turns relative to wild-type

• morphological defects of OHCs in adults are less severe than observed in constitutive Hoxb1-deficient (Hoxb1^tm1.2Fmr) mice but statistically significant loss of OHCs and moderate OHC ciliar malformations are observed

abnormal brainstem morphology ( J:197162 )

• area of the ventral nucleus of the lateral lemniscus is reduced by about 40% compared to wild-type controls at P8

abnormal pons morphology ( J:197162 )

• specification and innervation of olivocochlear neurons is abnormal, no medial olivocochlear neurons (MOC) cross the midline at P8

• the cholinergic population of lateral olivocochlear (LOC) neurons is very small indicating defective specification

abnormal cochlear VIII nucleus morphology ( J:197162 )

• axon pathfinding defects are observed, with ectopic projections to the contralateral medial nucleus of the trapezoid body (cMNTB) from the posterior ventral cochlear nucleus (PVCN)