Phenotypes Associated with This Genotype

Genotype
MGI:3043792

• Allelic Composition: Runx2^tm1Ldq/Runx2^tm1Ldq
• Genetic Background: involves: C57BL/6J

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

Skeletal abnormalities in Runx2^tm1Ldq/Runx2^tm1Ldq newborn mice

mortality/aging

premature death ( J:89822 )

• almost all homozygotes die by 6 weeks after birth

postnatal lethality, incomplete penetrance ( J:89822 )

• about 80% of homozygotes die in the first week after birth apparently of respiratory failure

craniofacial

abnormal cranium morphology ( J:89822 )

• cranial bones derived from mesenchymal precursors are not affected

large anterior fontanelle ( J:89822 )

• the anterior fontanelle is wider in homozygous mutants compared to wild-type mice

absent occipital bone ( J:89822 )

• the occipital bones are absent in homozygous mutants

absent zygomatic arch ( J:89822 )

• the zygomatic arches are absent in homozygous mutants

abnormal hyoid bone morphology ( J:89822 )

abnormal nasal bone morphology ( J:89822 )

• nasal bone formation is impaired in homozygous mutants

growth/size/body

absent zygomatic arch ( J:89822 )

• the zygomatic arches are absent in homozygous mutants

abnormal hyoid bone morphology ( J:89822 )

abnormal nasal bone morphology ( J:89822 )

• nasal bone formation is impaired in homozygous mutants

decreased birth body size ( J:89822 )

• newborn homozygotes have significantly lower body weights and lengths compared to wild-type littermates

decreased birth weight ( J:89822 )

limbs/digits/tail

abnormal phalanx morphology ( J:89822 )

• ossification centers are absent in phalangeal bones

abnormal tibia morphology ( J:89822 )

• the primary trabeculae in the metaphyseal region are diminished in homozygous mutants compared to wild-type mice

• the cortical bone of the mid-shaft region is thinner and more porous in homozygous mutants compared to wild-type mice

skeleton

abnormal skeleton morphology ( J:89822 )

• homozygotes display severe abnormalities of the intracartilaginous bones, however intramembranous bones and cortical bones derived from mesenchymal precursors are not affected

• the overall skeletal phenotype is less severe than that reported in mice lacking both isoforms of Runx2

abnormal cranium morphology ( J:89822 )

• cranial bones derived from mesenchymal precursors are not affected

large anterior fontanelle ( J:89822 )

• the anterior fontanelle is wider in homozygous mutants compared to wild-type mice

absent occipital bone ( J:89822 )

• the occipital bones are absent in homozygous mutants

absent zygomatic arch ( J:89822 )

• the zygomatic arches are absent in homozygous mutants

abnormal hyoid bone morphology ( J:89822 )

abnormal nasal bone morphology ( J:89822 )

• nasal bone formation is impaired in homozygous mutants

abnormal phalanx morphology ( J:89822 )

• ossification centers are absent in phalangeal bones

abnormal tibia morphology ( J:89822 )

• the primary trabeculae in the metaphyseal region are diminished in homozygous mutants compared to wild-type mice

• the cortical bone of the mid-shaft region is thinner and more porous in homozygous mutants compared to wild-type mice

abnormal clavicle morphology ( J:89822 )

• the distal clavicles are abnormal in homozygous mutants

abnormal long bone epiphysis morphology ( J:89822 )

• the zone of hypertrophic chondrocytes is wider in long bones from homozygous mutants compared to wild-type mice

decreased length of long bones ( J:89822 )

• the long bones are shorter in homozygous mutants compared to wild-type mice

abnormal rib morphology ( J:89822 )

• the distal ribs are abnormal in homozygous mutants

decreased compact bone thickness ( J:89822 )

• the cortical bone of the mid-shaft region is thinner and more porous in homozygous mutants compared to wild-type mice

abnormal trabecular bone morphology ( J:89822 )

• the primary trabeculae in the metaphyseal region are diminished in homozygous mutants compared to wild-type mice

abnormal bone ossification ( J:89822 )

• ossification centers are absent in phalangeal bones

• osteoblast maturation ex vivo is abnormal in cells from homozygous mice

delayed bone ossification ( J:89822 )

• intracartilaginous ossification of the caudal spine is delayed

respiratory system

abnormal nasal bone morphology ( J:89822 )

• nasal bone formation is impaired in homozygous mutants