Phenotypes Associated with This Genotype

Genotype
MGI:2181573

• Allelic Composition: Fgfr1^tm6Jrt/Fgfr1^tm6Jrt
• Genetic Background: involves: 129S1/Sv * 129X1/SvJ * CD-1

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

mortality/aging

neonatal lethality, complete penetrance ( J:49154 )

• homozygotes that survive to term die neonatally

perinatal lethality, incomplete penetrance ( J:49154 )

• not all homozygotes survive to term

embryonic lethality during organogenesis, incomplete penetrance ( J:49154 )

• a number of homozygotes are found dead or resorbed at E8.5-E11.5

craniofacial

abnormal craniofacial bone morphology ( J:49154 )

• homozygotes exhibit defects in craniofacial patterning

fusion of atlas and occipital bones ( J:49154 )

• fusion of the atlas to the occipital bones is common

small second pharyngeal arch ( J:49154 )

• marked reduction in the second branchial arch

limbs/digits/tail

abnormal limb morphology ( J:49154 )

• homozygotes display distal limb defects

broad limb buds ( J:49154 )

• posterior expansion of fore- and hindlimb buds at E9.5 and E10.5

• widened buds split into up to 3 extra buds but these extra buds appear to degenerate leaving only one to developn into a limb

decreased caudal vertebrae number ( J:49154 )

• at P0, 5 +/- 9.4 caudal vertebrae are present compared to 31 +/- 0.9 in wild-type mice

• some remnant vertebrae bodies are seen posterior to the lumbrosacral truncation

skeleton

abnormal axial skeleton morphology ( J:49154 )

abnormal craniofacial bone morphology ( J:49154 )

• homozygotes exhibit defects in craniofacial patterning

fusion of atlas and occipital bones ( J:49154 )

• fusion of the atlas to the occipital bones is common

decreased caudal vertebrae number ( J:49154 )

• at P0, 5 +/- 9.4 caudal vertebrae are present compared to 31 +/- 0.9 in wild-type mice

• some remnant vertebrae bodies are seen posterior to the lumbrosacral truncation

abnormal sternocostal joint morphology ( J:49154 )

• in all mice R1 is not attached to the sternum and in about half of the mice R2 in not attached to the sternum

rib fusion ( J:49154 )

vertebral transformation ( J:49154 )

• at P0, homozygotes display severe vertebral transformations (predominantly in the anterior direction)

thoracic vertebral transformation ( J:49154 )

• occasional posterior transformation of T7 to T8 (loss of attachment to the sternum)

cervical vertebral transformation ( J:49154 )

• penetrance and expressivity of anterior, but not posterior, transformations are enhanced compared to Fgfr1^tm2Jrt homozygotes

• at P0, anterior transformations of C1, C2,C3, and C7 are seen with varying levels of penetrance

embryo

small second pharyngeal arch ( J:49154 )

• marked reduction in the second branchial arch

caudal body truncation ( J:49154 )

• severe posterior deletions extends into the lumbrosacrumlumbrosacral level

• however, hind limbs and occasional remnants of vertebral bodies can be observed

abnormal lateral plate mesoderm morphology ( J:49154 )

• anterior-posterior defects in lateral plate mesoderm patterning

broad limb buds ( J:49154 )

• posterior expansion of fore- and hindlimb buds at E9.5 and E10.5

• widened buds split into up to 3 extra buds but these extra buds appear to degenerate leaving only one to developn into a limb

abnormal neural fold formation ( J:49154 )

• expansion of the posterior neural fold at E8.5

abnormal somite development ( J:49154 )

• at E10.5, somites posterior to the hindlimb buds form but then appear to be degenerating at E10-E11.5

decreased somite size ( J:49154 )

• reduction in the anterior somite size

• however, differentiation of anterior somite is normal