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Phenotypes associated with this allele
Allele Symbol
Allele Name
Allele ID
Six3+
wild type
MGI:2432992
Summary 2 genotypes
Jump to Allelic Composition Genetic Background Genotype ID
ht1
Six3tm4(cre/ERT2)Gco/Six3+ involves: 129S1/Sv * C57BL/6 MGI:3814906
cx2
Six3tm3.1Gco/Six3+
Shhtm1Chg/Shh+
involves: 129S1/Sv * 129X1/SvJ * C57BL/6 MGI:3814907


Genotype
MGI:3814906
ht1
Allelic
Composition
Six3tm4(cre/ERT2)Gco/Six3+
Genetic
Background
involves: 129S1/Sv * C57BL/6
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Six3tm4(cre/ERT2)Gco mutation (0 available); any Six3 mutation (13 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
nervous system
• Background Sensitivity: 16% display a phenotype typical of holoprosencephaly after one backcross to C57BL/6
• Background Sensitivity: after two additional backcrosses to C57BL/6, 85% show a holoprosencephaly phenotype

Mouse Models of Human Disease
DO ID OMIM ID(s) Ref(s)
holoprosencephaly 2 DOID:0110872 OMIM:157170
J:140315




Genotype
MGI:3814907
cx2
Allelic
Composition
Six3tm3.1Gco/Six3+
Shhtm1Chg/Shh+
Genetic
Background
involves: 129S1/Sv * 129X1/SvJ * C57BL/6
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Shhtm1Chg mutation (2 available); any Shh mutation (48 available)
Six3tm3.1Gco mutation (0 available); any Six3 mutation (13 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
nervous system
• 75% display a phenotype typical of holoprosencephaly after one backcross to C57BL/6
• after five backcrosses to C57BL/6, 100% show a holoprosencephaly phenotype
• a single ganglionic eminence
• telencephalon is smaller at E10.5 than in controls
• reduced apoptosis in the ventral midline at E10.5
• increased apoptosis in the lateral dorsal telencephalon
• cerebral hemispheres fused rostrally

craniofacial
• defective separation of the medial nasal prominence at E11.5
• fusion defects in the secondary palate
• absence of philtrum at E17.5
• no cartilaginous nasal septum at E17.5

respiratory system
• no cartilaginous nasal septum at E17.5

vision/eye
• reduced apoptosis at E10.5
• shorter distance between the eyes at E11.5

digestive/alimentary system
• fusion defects in the secondary palate

growth/size/body
• fusion defects in the secondary palate
• absence of philtrum at E17.5
• no cartilaginous nasal septum at E17.5
• at E11.5

Mouse Models of Human Disease
DO ID OMIM ID(s) Ref(s)
holoprosencephaly 2 DOID:0110872 OMIM:157170
J:140315





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Mouse Genome Database (MGD), Gene Expression Database (GXD), Mouse Models of Human Cancer database (MMHCdb) (formerly Mouse Tumor Biology (MTB)), Gene Ontology (GO)
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last database update
03/18/2025
MGI 6.24
The Jackson Laboratory