mortality/aging
• homozygotes are present at the expected Mendelian frequencies at E17.5 and E18.5, but appear to die perinatally; no homozygotes are obtained at weaning
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• no newborn homozygotes survive beyond the first few hours after birth
(J:93802)
|
skeleton
• homozygotes display a shortened body axis associated with axial skeleton defects in the ventromedial elements of vertebrae that develop around the notochord
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• homozygotes exhibit abnormalities in bones of the basal skull (i.e. basioccipital and basisphenoid) associated with the notochord
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• by E18.5, the mutant basioccipital bone appears significantly misshapen and reduced
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• at E14.5 the number of cells at the midline of the mutant basioccipital bone is significantly decreased
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• by E18.5, the mutant posterior basisphenoid bone is severely reduced
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• at E18.5, homozygotes exhibit a malleus phenotype and lack the predicted malleal/incal fusions due to regulatory changes in genes involved in joint formation
|
• although elements of the malleus, such as the processus brevis and the manubrium appear normal, the width, but not the length, of the malleus is significantly decreased
• however, at E18.5, middle ear ossicle development is relatively normal, with the incus and stapes developing as wild-type with respect to both size and articulation
|
• at E18.5, all homozygotes lack a gonium, an investing bone that lies on the surface of the malleus
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• at E18.5, mutant ribs appear to be tightly spaced and laterally extended but show no other abnormalities such as fusions or disruptions
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• at E18.5, mutant vertebrae appear to be more highly compact along the entire vertebral column, with most vertebrae lacking an ossification center in the ventromedial region
• in contrast, mutant sterna remain unaffected, and the size and number of sternabra are comparable to those observed in wild-type mice
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• at E18.5, the mutant caudal vertebrae are small and lack the anterior processes
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• at E18.5, homozygotes display a midline clefting in the thoracic vertebrae immediately ventral to the region where the centra of vertebral bodies normally form
• in the thoracic region, vertebral bodies exhibit a narrow ventral bridge linking the lateral vertebral elements of the neural arches; only the centra are missing
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• at E18.5, homozygotes exhibit compressed cervical vertebrae relative to wild-type mice
• in the cervical region, all elements at the midline are absent and the neural arches fail to fuse at the midline
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• in the cervical region, all elements at the midline are absent and the neural arches fail to fuse at the midline
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• at E18.5, homozygotes exhibit compressed cervical vertebrae relative to wild-type mice
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• at E18.5, the ventromedial elements of each vertebra, i.e. the vertebral bodies and intervertebral discs, are absent; this phenotype is most prominent in cervical vertebrae
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• at E17.5, homozygotes show a significant reduction or absence of ventro-medial cartilaginous material in cervical vertebrae
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• at E18.5, the ventromedial elements of each vertebra, including the intervertebral discs, are absent
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• at E14.5, homozygotes exhibit reduced numbers of chondrogenic cells in the vicinity of the notochord at the cervical level; this effect is less pronounced at the lumbar level
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• at E14.5, the cells that compose the lateral elements of the neural arches have condensed in both wild-type and mutant embryos; however, mutants exhibit only a few sclerotomal cells organized around the notochord in the cervical and upper thoracic vertebrae
• in the lumbar region, more sclerotomal cells are apparent at the midline near to the notochord, but appear disorganized
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craniofacial
• homozygotes exhibit abnormalities in bones of the basal skull (i.e. basioccipital and basisphenoid) associated with the notochord
|
• by E18.5, the mutant basioccipital bone appears significantly misshapen and reduced
|
• at E14.5 the number of cells at the midline of the mutant basioccipital bone is significantly decreased
|
• by E18.5, the mutant posterior basisphenoid bone is severely reduced
|
• at E18.5, homozygotes exhibit a malleus phenotype and lack the predicted malleal/incal fusions due to regulatory changes in genes involved in joint formation
|
• although elements of the malleus, such as the processus brevis and the manubrium appear normal, the width, but not the length, of the malleus is significantly decreased
• however, at E18.5, middle ear ossicle development is relatively normal, with the incus and stapes developing as wild-type with respect to both size and articulation
|
• at E18.5, all homozygotes lack a gonium, an investing bone that lies on the surface of the malleus
|
limbs/digits/tail
• at E18.5, the mutant caudal vertebrae are small and lack the anterior processes
|
short tail
(
J:57112
)
kinked tail
(
J:79198
)
thick tail
(
J:57112
)
embryo
• homozygotes display regional perturbations of LR asymmetry in the primordial splenopancreatic mesoderm affecting pancreas laterality
|
• at E14.5, homozygotes fail to exhibit a repetitive notochordal pattern of swellings in the posterior region, with swollen nodes being either broadened or absent
• in the cervical region, the thin mutant notochord lacks periodic swellings and shows no organized consensation of cells around it
• by E18.5, only a vestigial notochord is present, and the enlarged notochord-derived nucleus pulposus of each intervertebral disc is absent
|
digestive/alimentary system
• homozygotes exhibit regional perturbations of LR asymmetry in the primordial splenopancreatic mesoderm; as a result, the dorsal pancreas remains at the embryonic midline
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endocrine/exocrine glands
• at E10 and E10.5, the mutant dorsal pancreatic bud fails to grow laterally and remains positioned along the embryonic midline
• at E13.5, the wild-type dorsal pancreas grows along an axis perpendicular to the duodenum whereas the mutant dorsal pancreas grows along the same axis as the stomach
|
growth/size/body
• at E18.5, mutant fetuses appear slightly shorter and broader than wild-type fetuses
|
hematopoietic system
absent spleen
(
J:57112
)
• at E14.5, homozygotes show no evidence of splenic cells in the splanchnic mesoderm-derived tissue near the stomach
|
immune system
absent spleen
(
J:57112
)
• at E14.5, homozygotes show no evidence of splenic cells in the splanchnic mesoderm-derived tissue near the stomach
|
hearing/vestibular/ear
• at E18.5, homozygotes exhibit a malleus phenotype and lack the predicted malleal/incal fusions due to regulatory changes in genes involved in joint formation
|
• although elements of the malleus, such as the processus brevis and the manubrium appear normal, the width, but not the length, of the malleus is significantly decreased
• however, at E18.5, middle ear ossicle development is relatively normal, with the incus and stapes developing as wild-type with respect to both size and articulation
|
• at E18.5, all homozygotes lack a gonium, an investing bone that lies on the surface of the malleus
|
• at E18.5, all homozygotes exhibit a hypoplastic tympanic ring with a portion of the anterior extremity of the ring absent
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• at E18.5
|