Phenotypes associated with this allele

• Allele Symbol: Isl1^tm1Tmj
• Allele Name: targeted mutation 1, Thomas M Jessell
• Allele ID: MGI:2182246
• Summary: 3 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Isl1^tm1Tmj/Isl1^tm1Tmj	either: 129S1/Sv-Isl1^tm1Tmj or (involves: 129S1/Sv * C57BL/6J)	MGI:3688254
hm2	Isl1^tm1Tmj/Isl1^tm1Tmj	involves: 129S1/Sv	MGI:3688257
cx3	Isl1^tm1Tmj/Isl1^tm1Tmj Pou4f1^tm1Et/Pou4f1^tm1Et	involves: 129 * C57BL/6	MGI:3817489

Genotype
MGI:3688254

hm1

• Allelic Composition: Isl1^tm1Tmj/Isl1^tm1Tmj
• Genetic Background: either: 129S1/Sv-Isl1^tm1Tmj or (involves: 129S1/Sv * C57BL/6J)

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

mortality/aging

embryonic lethality during organogenesis, complete penetrance ( J:31131 )

• die by E11.5

growth/size/body

decreased embryo size ( J:31131 )

• embryos are smaller by E9-9.5

embryo

embryonic growth arrest ( J:31131 )

• E10.5 embryos show no advance in development compared with E9.5, indicating arrested development soon after E9.5

decreased embryo size ( J:31131 )

• embryos are smaller by E9-9.5

decreased embryonic neuroepithelium thickness ( J:31131 )

• exhibit marked thinning of the neuroepithelium in the ventral neural tube

embryo tissue necrosis ( J:31131 )

• embryos are necrotic at E11.5

nervous system

decreased embryonic neuroepithelium thickness ( J:31131 )

• exhibit marked thinning of the neuroepithelium in the ventral neural tube

abnormal motor neuron morphology ( J:31131 )

• motor neuron differentiation does not occur at E9.5 in the hindbrain and spinal cord, however notochord, floorplate and neural tube differentiation appear normal

• isolated neural tube segments do not generate motor neurons in culture, indicating an inability, not a delay, of neural progenitors to generate motor neurons

• exhibit a marked increase in the incidence of apoptotic cell death in the ventral neural tube, the region in which motor neurons normally are generated

• exhibit an approximately 73% decrease in mitotic cells in the ventral neural tube, indicating decreased cell proliferation of cells that give rise to motor neurons

abnormal spinal cord interneuron morphology ( J:31131 )

• engrailed1 positive interneurons are absent in the neural tube of 25 somite stage embryos

• cultured cervical neural tube explants to not form interneurons, indicating a failure, and not a delay, of interneuron differentiation

cardiovascular system

abnormal dorsal aorta morphology ( J:31131 )

• dorsal aorta formation is disrupted at E9.5-10.5

abnormal vascular endothelial cell morphology ( J:31131 )

• exhibit abnormalities in the organization of the vascular endothelium and its surrounding mesenchyme at E9.5-10.5

Genotype
MGI:3688257

hm2

• Allelic Composition: Isl1^tm1Tmj/Isl1^tm1Tmj
• Genetic Background: involves: 129S1/Sv

mortality/aging

embryonic lethality during organogenesis, complete penetrance ( J:95093 )

• die around E10.5

embryo

abnormal pharyngeal arch morphology ( J:95093 )

• exhibit decreased cell proliferation in pharyngeal endoderm

embryonic growth arrest ( J:95093 )

• growth retardation at about E9.5

abnormal splanchnic mesoderm morphology ( J:95093 )

• exhibit decreased cell proliferation and increased apoptosis of splanchnic mesodermal cells that are immediately adjacent to pharyngeal endoderm at E8.75 or E9.5

cardiovascular system

absent cardiac outflow tract ( J:95093 )

• lack an outflow tract as indicated by marker analysis

abnormal heart development ( J:95093 )

• cardiac primorida at E8.75 resembles cardiac primordia seen in wild-type at E8.25, suggesting an interruption in heart development

failure of heart looping ( J:95093 )

• hearts are unlooped at E9-9.5

abnormal heart atrium morphology ( J:95093 )

• exhibit significant reduction in the amount of atrial tissue

abnormal heart shape ( J:95093 )

• hearts are misshapen at E9-9.5

absent heart right ventricle ( J:95093 )

• lack the right ventricle, although cells with left ventricular, A/V canal and atrial identities are present

digestive/alimentary system

abnormal pancreatic acinar cell morphology ( J:37641 )

• exhibit failure of exocrine cell differentiation in the dorsal but not the ventral pancreas

endocrine/exocrine glands

abnormal Rathke's pouch development ( J:50517 )

• rudimentary pouch forms at E9.5, small and primitive

• pouch cells are aberrant and fail to differentiate

small Rathke's pouch ( J:50517 )

• at E9.5

abnormal pancreas morphology ( J:37641 )

abnormal pancreatic acinar cell morphology ( J:37641 )

• exhibit failure of exocrine cell differentiation in the dorsal but not the ventral pancreas

abnormal pancreatic islet morphology ( J:37641 )

• cultured gut explants do not generate differentiated islet cells

absent pancreatic alpha cells ( J:37641 )

• exhibit complete absence of islet (glucogon+) cells in E9.5 embryos

abnormal pancreas mesenchyme morphology ( J:37641 )

• dorsal pancreatic mesenchyme does not form

craniofacial

abnormal pharyngeal arch morphology ( J:95093 )

• exhibit decreased cell proliferation in pharyngeal endoderm

nervous system

abnormal Rathke's pouch development ( J:50517 )

• rudimentary pouch forms at E9.5, small and primitive

• pouch cells are aberrant and fail to differentiate

small Rathke's pouch ( J:50517 )

• at E9.5

Genotype
MGI:3817489

cx3

• Allelic Composition: Isl1^tm1Tmj/Isl1^tm1Tmj; Pou4f1^tm1Et/Pou4f1^tm1Et
• Genetic Background: involves: 129 * C57BL/6

mortality/aging

embryonic lethality during organogenesis, complete penetrance ( J:141110 )

• embryonic lethality occurs at E10.5

embryo

embryonic growth arrest ( J:141110 )

• growth arrest occurs about E9.5

nervous system

abnormal brain development ( J:141110 )

• dorsal fore-brain and midbrain are lost due to necrosis at E10.5