Phenotypes associated with this allele

• Allele Symbol: Dhx9^tm1Ehl
• Allele Name: targeted mutation 1, Elizabeth Lacy
• Allele ID: MGI:3663380
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Dhx9^tm1Ehl/Dhx9^tm1Ehl	involves: 129S1/Sv * Black Swiss	MGI:3664034
hm2	Dhx9^tm1Ehl/Dhx9^tm1Ehl	involves: 129S1/Sv * C57BL/6	MGI:3664031

Genotype
MGI:3664034

hm1

• Allelic Composition: Dhx9^tm1Ehl/Dhx9^tm1Ehl
• Genetic Background: involves: 129S1/Sv * Black Swiss

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

mortality/aging

embryonic lethality between implantation and somite formation, complete penetrance ( J:50931 )

cellular

increased ectoderm apoptosis ( J:50931 )

• at E7.5 abundant apoptotic cells are observed

embryo

abnormal embryo development ( J:50931 )

• Background Sensitivity: severity of observed phenotype is greater on mixed 129S1/Sv * Black Swiss background than on 129S1/Sv * C57BL/6 genetic background

• by E8.5 only the extraembryonic portion of the conceptus remains and exhibited some differentiation

• although embryonic mesodermal layer is observed, extraembryonic mesoderm is generated, forming the allantois, exocoelomic lining and some yolk sac blood island-like structures

abnormal ectoderm development ( J:50931 )

• at E7.5 embryonic ectoderm is almost completely absent with only a few dying cells remaining

increased ectoderm apoptosis ( J:50931 )

• at E7.5 abundant apoptotic cells are observed

abnormal ectoplacental cone morphology ( J:50931 )

• at E7.5 ectoplacental cone remains undifferentiated

Genotype
MGI:3664031

hm2

• Allelic Composition: Dhx9^tm1Ehl/Dhx9^tm1Ehl
• Genetic Background: involves: 129S1/Sv * C57BL/6

mortality/aging

embryonic lethality between implantation and somite formation, complete penetrance ( J:50931 )

• mutant phenotype is first observed at E7.5; at E7.5 and E8.5, mutant embryos resemble E6.5 and E7.5 control embryos respectively

• defective formation of embryonic tissue layers are observed, accompanied by extensive apoptosis

• at E9.5 and E10.5, homozygous embryos are found as small embryonic masses exhibiting complete resorption

embryo

embryo phenotype ( J:50931 )

N • Background Sensitivity: severity of observed phenotype is less on mixed 129S1/Sv * C57BL/6 background than on 129S1/Sv * Black Swiss genetic background

N • a distinct ectoplacental cone formed from the extraembryonic ectoderm is seen at E7.5 while some embryos show thickening of the embryonic endoderm; on a mixed Black Swiss background, the cone does not form

increased embryonic tissue cell apoptosis ( J:50931 )

• at E7.5, mutants show numerous apoptotic bodies compared few dying cells in control embryos; apoptotic bodies are frequently clustered, and are also present in the proamniotic cavity

abnormal embryo development ( J:50931 )

• Background Sensitivity: severity of observed phenotype is less on mixed 129S1/Sv * C57BL/6 background than on 129S1/Sv * Black Swiss genetic background

abnormal gastrulation ( J:50931 )

• gastrulation fails to progress beyond the early stages

increased ectoderm apoptosis ( J:50931 )

• at E8.5, a high level of apoptotic cell death is observed in cells constituting the embryonic ectoderm

delayed gastrulation ( J:50931 )

• gastrulation is initiated in mutants but delayed

absent mesoderm ( J:50931 )

• no mesodermal layer can be distinguished in E7.5 embryos

• at E8.5, the embryonic ectoderm is pseudostratified but no mesoderm is detected

abnormal primitive streak formation ( J:50931 )

• at E7.5 primitive streak formation in homozygotes is abnormal

absent amnion ( J:50931 )

abnormal parietal endoderm morphology ( J:50931 )

• parietal endodermal cells are rounded

abnormal visceral endoderm morphology ( J:50931 )

• a cuboidal layer of visceral endoderm surrounds the entire conceptus

• at E8.5 the embryonic portion of the visceral endoderm appears flattened

cellular

increased embryonic tissue cell apoptosis ( J:50931 )

• at E7.5, mutants show numerous apoptotic bodies compared few dying cells in control embryos; apoptotic bodies are frequently clustered, and are also present in the proamniotic cavity

increased ectoderm apoptosis ( J:50931 )

• at E8.5, a high level of apoptotic cell death is observed in cells constituting the embryonic ectoderm