About   Help   FAQ
Phenotypes associated with this allele
Allele Symbol
Allele Name
Allele ID
Kif21a+
wild type
MGI:2434266
Summary 4 genotypes
Jump to Allelic Composition Genetic Background Genotype ID
ht1
Kif21atm1b(EUCOMM)Hmgu/Kif21a+ C57BL/6N-Kif21atm1b(EUCOMM)Hmgu/J MGI:6262749
ht2
Kif21atm3Ece/Kif21a+ involves: 129S1/Sv MGI:6241438
ht3
Kif21atm1.1Ece/Kif21a+ involves: 129S1/Sv * 129S4/SvJae MGI:6241434
cx4
Kif21atm1.1Ece/Kif21a+
Map1btm1Prop/Map1b+
Tg(Isl1-EGFP*)1Slp/0
involves: 129S1/Sv * 129S4/SvJae * 129X1/SvJ * BALB/c * C57BL/6 MGI:6241441


Genotype
MGI:6262749
ht1
Allelic
Composition
Kif21atm1b(EUCOMM)Hmgu/Kif21a+
Genetic
Background
C57BL/6N-Kif21atm1b(EUCOMM)Hmgu/J
Cell Lines HEPD0697_4_H11
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Kif21atm1b(EUCOMM)Hmgu mutation (1 available); any Kif21a mutation (80 available)
Data Sources
phenotype observed in females
phenotype observed in males
N normal phenotype
homeostasis/metabolism




Genotype
MGI:6241438
ht2
Allelic
Composition
Kif21atm3Ece/Kif21a+
Genetic
Background
involves: 129S1/Sv
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Kif21atm3Ece mutation (0 available); any Kif21a mutation (80 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
normal phenotype
• mice are viable and appear phenotypically normal, with no external congenital fibrosis of the extraocular muscles phenotype




Genotype
MGI:6241434
ht3
Allelic
Composition
Kif21atm1.1Ece/Kif21a+
Genetic
Background
involves: 129S1/Sv * 129S4/SvJae
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Kif21atm1.1Ece mutation (0 available); any Kif21a mutation (80 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
vision/eye
• mice exhibit unilateral or bilateral ptosis and/or globe retraction that is 43% penetrant and primarily unilateral
• mice exhibit unilateral or bilateral ptosis and/or globe retraction that is 43% penetrant and primarily unilateral

nervous system
• about 50% of distal oculomotor nerves have only mild proximal thickening and distal thinning compared to wild-type, the other 50% have proximal bulbs and significant distal nerve hypoplasia and branching defects

Mouse Models of Human Disease
DO ID OMIM ID(s) Ref(s)
congenital fibrosis of the extraocular muscles DOID:0080143 OMIM:PS135700
J:213171




Genotype
MGI:6241441
cx4
Allelic
Composition
Kif21atm1.1Ece/Kif21a+
Map1btm1Prop/Map1b+
Tg(Isl1-EGFP*)1Slp/0
Genetic
Background
involves: 129S1/Sv * 129S4/SvJae * 129X1/SvJ * BALB/c * C57BL/6
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Kif21atm1.1Ece mutation (0 available); any Kif21a mutation (80 available)
Map1btm1Prop mutation (0 available); any Map1b mutation (85 available)
Tg(Isl1-EGFP*)1Slp mutation (1 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
nervous system
• approximately 90% penetrance of abducens nerve hypoplasia
• oculomotor nerve superior branch axons terminate prematurely within a bulb with a penetrance of 90%





Contributing Projects:
Mouse Genome Database (MGD), Gene Expression Database (GXD), Mouse Models of Human Cancer database (MMHCdb) (formerly Mouse Tumor Biology (MTB)), Gene Ontology (GO)
Citing These Resources
Funding Information
Warranty Disclaimer, Privacy Notice, Licensing, & Copyright
Send questions and comments to User Support.
last database update
12/30/2025
MGI 6.24
The Jackson Laboratory