Phenotypes Associated with This Genotype

Genotype
MGI:2674285

• Allelic Composition: Meox1^tm1Bmk/Meox1^tm1Bmk; Meox2^tm1Vpa/Meox2^tm1Vpa
• Genetic Background: involves: 129P2/OlaHsd * C57BL/6

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

mortality/aging

neonatal lethality, complete penetrance ( J:84754 )

• mice are born in Mendelian ratios but die shortly after birth

embryo

abnormal somite development ( J:84754 )

• disrupted somite development, patterning, and differentiation

• absence of ventral (ribs and vertebrae) and dorsal (skeletal muscle) somite derivatives

abnormal dorsal-ventral polarity of the somites ( J:84754 )

• patterning and specification of the posterior and anterior halves of somites are defective

abnormal somite shape ( J:84754 )

• newly formed somites are irregular in shape and fail to epithelialize

abnormal somite size ( J:84754 )

• newly formed somites are irregularly sized

growth/size/body

decreased body length ( J:84754 )

• newborn pups present with drastically reduced trunk length

limbs/digits/tail

absent caudal vertebrae ( J:84754 )

• tail vertebrae are completely absent

vestigial tail ( J:84754 )

• rudimentary stump lacking skeletal elements

muscle

abnormal myotome development ( J:84754 )

• myotomes of anterior somites are fused ventrally but separated dorsally, a defect in epithelialization

abnormal dermomyotome development ( J:84754 )

• epithelial dermomyotome is absent at E10.5

abnormal skeletal muscle morphology ( J:84754 )

• most skeletal muscles are absent or reduced in size in the mutant, including prevertebral muscles of the neck, the epaxial muscles of the trunk, the hypaxial muscles of the trunk including those of the abdominal wall and intercostal muscles

abnormal epaxial muscle morphology ( J:84754 )

• the epaxial muscles of the trunk are severely depleted

abnormal hypaxial muscle morphology ( J:84754 )

• the hypaxial muscles of the trunk including those of the abdominal wall and intercostal muscles are severely depleted

skeleton

abnormal axial skeleton morphology ( J:84754 )

• mutants lack an axial skeleton

occipital bone hypoplasia ( J:84754 )

• occipital skull bones are hypoplastic

abnormal sternum morphology ( J:84754 )

• sternum develops abnormally

absent ribs ( J:84754 )

• although centers of ossification are seen at the cervical and thoracic levels, normal ribs are not observed

abnormal vertebral column morphology ( J:84754 )

• vertebral column is absent and largely replaced by two strips of fused cartilage, in a position corresponding to the neural arches

abnormal vertebrae morphology ( J:84754 )

• ossified, deformed vertebrae are formed at the cervical and thoracic level but more posterior lumbar vertebrae are present only as cartilage condensations at the position expected of the neural arches

absent caudal vertebrae ( J:84754 )

• tail vertebrae are completely absent

abnormal sclerotome morphology ( J:84754 )

• segmented organization of the ventral sclerotome is lost and instead a uniform unsegmented mesenchyme is observed

• marker analysis indicates perturbed sclerotome differentiation but not specification

adipose tissue

decreased brown adipose tissue amount ( J:84754 )

• brown fat overlying the shoulders muscles is absent

craniofacial

occipital bone hypoplasia ( J:84754 )

• occipital skull bones are hypoplastic

homeostasis/metabolism

cyanosis ( J:84754 )

nervous system

abnormal dorsal root ganglion morphology ( J:84754 )

• dorsal root ganglia are irregular in shape and size and fused together

fused dorsal root ganglion ( J:84754 )

abnormal spinal nerve morphology ( J:84754 )

• spinal nerves are irregular in spacing and direction

integument

loose skin ( J:84754 )