Phenotypes Associated with This Genotype

Genotype
MGI:3044921

• Allelic Composition: Tbx18^tm1.1Akis/Tbx18^tm1.1Akis
• Genetic Background: involves: 129S1/SvImJ * NMRI

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

mortality/aging

neonatal lethality, complete penetrance ( J:90513 )

• homozygous mice die shortly after birth from respiratory failure

craniofacial

fusion of atlas and occipital bones ( J:90513 )

• partial or complete fusion of the occipital bone and the atlas occurs in some homozygous mice

embryo

abnormal dorsal-ventral polarity of the somites ( J:90513 )

• marker expression patterns indicate that anterior-posterior polarity is not maintained within the lateral sclerotome

• at E10.5 cell density differences and cellular prolifration differences between the anterior and posterior lateral sclerotome are absent in homozygous mutants

• apoptosis is increased in the anterior portion of the lateral sclerotome in homozygous mutants compared to wild-type mice

growth/size/body

decreased birth body size ( J:90513 )

• mutant pups are born with a shortened body

skeleton

abnormal rib morphology ( J:90513 )

• the segmental organization of the attached ribs is impaired in the cervical and thoracic regions

rib fusion ( J:90513 )

• fusion of the distal ribs is occasionally seen

small intervertebral disk ( J:90513 )

• intervertebral disc are reduced and delocalized

abnormal vertebrae morphology ( J:90513 )

fusion of atlas and occipital bones ( J:90513 )

• partial or complete fusion of the occipital bone and the atlas occurs in some homozygous mice

abnormal thoracic vertebrae morphology ( J:90513 )

• expansion of the ossification centers of vertebral bodies in the thoracic region is occasionally seen

abnormal lumbar vertebrae morphology ( J:90513 )

• the pedicles within the lumbar region are symmetrical rather than polarized in shape as in wild-type mice

abnormal vertebrae development ( J:90513 )

• the segmental organization of the vertebrae is impaired in the cervical and thoracic regions

abnormal vertebral arch morphology ( J:90513 )

• the pedicles of the neural arches with their transverse processes and the proximal regions of the ribs are expanded to form contiguous bony bands

• at E14.5 the pedicles in the cervical and thoracic regions and proximal ribs are expanded to form contiguous bands

nervous system

fused dorsal root ganglion ( J:90513 )

• from E10.5 on partial fusion of the dorsal root ganglia can be seen

abnormal spinal nerve morphology ( J:90513 )

• at E10.5 spinal nerve projections are partially lost or deflected from their path

• spinal nerves transversing anterior somite halves appear thinner