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Phenotypes associated with this allele
Allele Symbol
Allele Name
Allele ID
Fgfr1tm6Jrt
targeted mutation 6, Janet Rossant
MGI:2153351
Summary 3 genotypes
Jump to Allelic Composition Genetic Background Genotype ID
hm1
Fgfr1tm6Jrt/Fgfr1tm6Jrt involves: 129S1/Sv * 129X1/SvJ MGI:3702767
hm2
Fgfr1tm6Jrt/Fgfr1tm6Jrt involves: 129S1/Sv * 129X1/SvJ * CD-1 MGI:2181573
hm3
Fgfr1tm6Jrt/Fgfr1tm6Jrt involves: 129S1/Sv * 129X1/SvJ * ICR MGI:3702996


Genotype
MGI:3702767
hm1
Allelic
Composition
Fgfr1tm6Jrt/Fgfr1tm6Jrt
Genetic
Background
involves: 129S1/Sv * 129X1/SvJ
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Fgfr1tm6Jrt mutation (0 available); any Fgfr1 mutation (221 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
nervous system
• partial deletions of the inferior colliculi of the midbrain are seen in newborns
• defects in the midline vermis are seen in newborns




Genotype
MGI:2181573
hm2
Allelic
Composition
Fgfr1tm6Jrt/Fgfr1tm6Jrt
Genetic
Background
involves: 129S1/Sv * 129X1/SvJ * CD-1
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Fgfr1tm6Jrt mutation (0 available); any Fgfr1 mutation (221 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
mortality/aging
• homozygotes that survive to term die neonatally
• not all homozygotes survive to term
• a number of homozygotes are found dead or resorbed at E8.5-E11.5

craniofacial
• homozygotes exhibit defects in craniofacial patterning
• fusion of the atlas to the occipital bones is common
• marked reduction in the second branchial arch

limbs/digits/tail
• homozygotes display distal limb defects
• 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
• 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
• homozygotes exhibit defects in craniofacial patterning
• fusion of the atlas to the occipital bones is common
• 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
• in all mice R1 is not attached to the sternum and in about half of the mice R2 in not attached to the sternum
• at P0, homozygotes display severe vertebral transformations (predominantly in the anterior direction)
• occasional posterior transformation of T7 to T8 (loss of attachment to the sternum)
• penetrance and expressivity of anterior, but not posterior, transformations are enhanced compared to Fgfr1tm2Jrt homozygotes
• at P0, anterior transformations of C1, C2,C3, and C7 are seen with varying levels of penetrance

embryo
• marked reduction in the second branchial arch
• severe posterior deletions extends into the lumbrosacrumlumbrosacral level
• however, hind limbs and occasional remnants of vertebral bodies can be observed
• anterior-posterior defects in lateral plate mesoderm patterning
• 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
• expansion of the posterior neural fold at E8.5
• at E10.5, somites posterior to the hindlimb buds form but then appear to be degenerating at E10-E11.5
• reduction in the anterior somite size
• however, differentiation of anterior somite is normal




Genotype
MGI:3702996
hm3
Allelic
Composition
Fgfr1tm6Jrt/Fgfr1tm6Jrt
Genetic
Background
involves: 129S1/Sv * 129X1/SvJ * ICR
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Fgfr1tm6Jrt mutation (0 available); any Fgfr1 mutation (221 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
mortality/aging
• homozygotes die within 24 hrs after birth

hearing/vestibular/ear
• at birth, the three rows of OHCs are disrupted in the lower half of the cochlea, while the sensory epithelium of the upper cochlear half is arranged in patches of variable size rather than as continuous rows
• in the upper cochlear half, the gaps between sensory patches show no signs of differentiation of hair cells or supporting cells
• in contrast, the vestibular sensory epithelium remains unchanged
• at E18.5, homozygotes display variable numbers of OHCs and frequently doublet IHCs, with many HCs appearing shorter than normal
• at E16.5, homozygotes display no molecular signs of HC specification or differentiation in the gap regions found between sensory patches
• however, the remaining HCs in the sensory patches undergo normal differentiation
• at birth, the third OHC row is absent in the lower half of the cochlea
• in the upper cochlear half, the gaps between the sensory patches display no signs of OHC differentiation
• at birth, the sensory patches found in the upper cochlear half frequently show doublet IHCs instead of a single continuous IHC row
• at birth, the sensory patches found in the upper cochlear half frequently show an accumulation of disorientated IHCs at the edges
• at birth, the sensory patches found in the upper cochlear half frequently show no signs of differentiation of supporting cells

nervous system
• at E18.5, homozygotes display variable numbers of OHCs and frequently doublet IHCs, with many HCs appearing shorter than normal
• at E16.5, homozygotes display no molecular signs of HC specification or differentiation in the gap regions found between sensory patches
• however, the remaining HCs in the sensory patches undergo normal differentiation
• at birth, the third OHC row is absent in the lower half of the cochlea
• in the upper cochlear half, the gaps between the sensory patches display no signs of OHC differentiation
• at birth, the sensory patches found in the upper cochlear half frequently show doublet IHCs instead of a single continuous IHC row
• at birth, the sensory patches found in the upper cochlear half frequently show an accumulation of disorientated IHCs at the edges





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last database update
04/23/2024
MGI 6.23
The Jackson Laboratory