About   Help   FAQ
Due to maintenance, access to MGI may be intermittent 8:00 AM ET Wed, September 18.
Phenotypes Associated with This Genotype
Genotype
MGI:2675280
Allelic
Composition
Hoxb1tm1Mrc/Hoxb1tm1Mrc
Genetic
Background
involves: 129S1/Sv * 129X1/SvJ * C57BL/6J
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Hoxb1tm1Mrc mutation (0 available); any Hoxb1 mutation (21 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
respiratory system
• two-fold reduction in the size of the caudal digastric muscle

skeleton
• lower teeth are longer and more rounded than in wild-type mice

mortality/aging
• 1 of 20 mice died at 15 days after birth

nervous system
N
• rhombomere structure, neural crest cell production and neural crest migration are normal
• neurons that are present along the medial margin of r4 and r5 are either absent or reduced in number with anteriorly directed axons fibers not detected and dispersed neuronal cell bodies and fibers of r4 exiting the hindbrain without forming tightly bound fasciculation as observed in wild-type mice
• the caudal and ventrolateral migration of medial neurons around the parasympathetic neurons in r5 is absent
• 3 of five mice have undetectable facial motor nuclei
• 2 of five mice have small facial motor nuclei compared to in wild-type mice
• mice exhibit variable defects in branching of the CN-VII including a 2- to 3-fold reduction in nerve branch diameter and missing branches including the orbicularis oris, the mandibular branch and buccal branch
• the nerve that innervates the stapes and stapedius muscle is reduced in size and dissociated from the muscle
• however, despite defects in the motor component of the facial nerve, the sensory component of the facial nerve is normal

craniofacial
• lower teeth are longer and more rounded than in wild-type mice
• some mice exhibit a narrow face
• two-fold reduction in the size of the buccinator muscle
• two-fold reduction in the size of the depressor anguli oris muscle
• mice exhibit abnormal mass and shape of the masseter muscles
• mice exhibit abnormal mass and shape of the temporalis muscle
• two-fold reduction in the size of the zygomatic muscles
• absence of the nasolabialis and labii maxillaries muscle
• mice exhibit degeneration of facial muscles including a two-fold reduction in the size of the zygomatic, buccinator, depressor anguli oris and caudal digastric muscles and an absence of the nasolabialis and labii maxillaris muscle
• some mice exhibit a receded lower lip

muscle
• two-fold reduction in the size of the buccinator muscle
• two-fold reduction in the size of the depressor anguli oris muscle
• mice exhibit abnormal mass and shape of the masseter muscles
• mice exhibit abnormal mass and shape of the temporalis muscle
• two-fold reduction in the size of the zygomatic muscles
• absence of the nasolabialis and labii maxillaries muscle
• mice exhibit degeneration of facial muscles including a two-fold reduction in the size of the zygomatic, buccinator, depressor anguli oris and caudal digastric muscles and an absence of the nasolabialis and labii maxillaris muscle
• two-fold reduction in the size of the caudal digastric muscle

behavior/neurological
• mice exhibit facial paralysis including the inability to move whiskers or nose, to close eye lids in response to touch or to move ears in response to sound or touch

growth/size/body
• lower teeth are longer and more rounded than in wild-type mice
• some mice exhibit a narrow face
• two-fold reduction in the size of the buccinator muscle
• two-fold reduction in the size of the depressor anguli oris muscle
• mice exhibit abnormal mass and shape of the masseter muscles
• mice exhibit abnormal mass and shape of the temporalis muscle
• two-fold reduction in the size of the zygomatic muscles
• absence of the nasolabialis and labii maxillaries muscle
• mice exhibit degeneration of facial muscles including a two-fold reduction in the size of the zygomatic, buccinator, depressor anguli oris and caudal digastric muscles and an absence of the nasolabialis and labii maxillaris muscle
• some mice exhibit a receded lower lip
• some mice exhibit runting

cellular
• neurons that are present along the medial margin of r4 and r5 are either absent or reduced in number with anteriorly directed axons fibers not detected and dispersed neuronal cell bodies and fibers of r4 exiting the hindbrain without forming tightly bound fasciculation as observed in wild-type mice
• the caudal and ventrolateral migration of medial neurons around the parasympathetic neurons in r5 is absent


Contributing Projects:
Mouse Genome Database (MGD), Gene Expression Database (GXD), Mouse Models of Human Cancer database (MMHCdb) (formerly Mouse Tumor Biology (MTB), Gene Ontology (GO)
Citing These Resources
Funding Information
Warranty Disclaimer & Copyright Notice
Send questions and comments to User Support.
last database update
09/10/2019
MGI 6.14
The Jackson Laboratory