Phenotypes associated with this allele

• Allele Symbol: Mixl1^tm1Robb
• Allele Name: targeted mutation 1, Lorraine Robb
• Allele ID: MGI:2387828
• Summary: 1 genotype

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Mixl1^tm1Robb/Mixl1^tm1Robb	either: (involves: 129/Sv * 129S1/Sv) or (involves: 129S1/Sv * C57BL/6)	MGI:3696565

Genotype
MGI:3696565

hm1

• Allelic Composition: Mixl1^tm1Robb/Mixl1^tm1Robb
• Genetic Background: either: (involves: 129/Sv * 129S1/Sv) or (involves: 129S1/Sv * C57BL/6)

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

mortality/aging

embryonic lethality during organogenesis, complete penetrance ( J:77443 )

• homozygous embryos are present in normal numbers at E7.5, but are absent after E10.5

• embryos with severely disorganized head folds are only rarely recovered at E9-9.5; such embryos have failed to turn or form a heart tube

embryo

abnormal embryo development ( J:77443 )

• at E8.5, embryos adopt a flattened disc morphology instead of a lordotic shape

abnormal rostral-caudal axis patterning ( J:77443 )

• at E9.5, axial tissue mass present at E8.5 has grown and developed into huge mass of tail bud-like tissue protruding dorsally from caudal region of embryo, giving impression that the axis is bifurcated

short rostral-caudal axis ( J:77443 )

• at E8.5, AP axis is markedly foreshortened

abnormal embryonic tissue morphology ( J:77443 )

• definitive endoderm is specified, but gut morphogenesis is defective in mutants

decreased paraxial mesoderm size ( J:77443 )

• deficient paraxial mesoderm

abnormal head mesenchyme morphology ( J:77443 )

• at E8.5, little head mesenchyme is found beneath the head folds

abnormal neural fold morphology ( J:77443 )

• at E8.5, neural folds are small and disorganized

abnormal neural fold elevation formation ( J:77443 )

• in early-neural plate stage (E7.75), elevation of neural folds is retarded and a shallow anterior intestinal portal develops

abnormal notochord morphology ( J:77443 )

• notochord is replaced by a thick axial mass of flattened neuroectoderm overlying a condensed core of mesodermal tissues

• at E9.5, mutants have a poorly organized structure resembling the notochordal plate and a notochord-like structure that ends caudally either in an ectopic protrusion or in a bulbous mass

abnormal primitive streak morphology ( J:77443 )

• by E7, mutants display a thickened primitive streak

• an excess of mesoderm-like cells accumulates in anterior streak and in region lateral to streak at E7

abnormal anterior primitive streak morphology ( J:77443 )

• an excess of mesoderm-like cells accumulates in anterior streak at E7

absent primitive node ( J:77443 )

• homozygotes lack a recognizable node at E7

abnormal somite development ( J:77443 )

• from two to five somite pairs form in the paraxial mesoderm flanking a thick axial mass of flattened neuroectoderm overlying a condensed core of mesodermal tissues

enlarged allantois ( J:77443 )

• compared to wild-type, allantois is disproportionately large

abnormal amnion morphology ( J:77443 )

• fusion of the posterior and anterior amniotic folds is delayed, leading to persistence of the proamniotic canal as late as the late bud/early head fold stage

cardiovascular system

absent heart tube ( J:77443 )

• heart tube is absent at E8.25

digestive/alimentary system

abnormal foregut morphology ( J:77443 )

• foregut invagination is rudimentary

absent hindgut ( J:77443 )

• no hindgut portal is formed by E8.25

growth/size/body

abnormal head mesenchyme morphology ( J:77443 )

• at E8.5, little head mesenchyme is found beneath the head folds