About   Help   FAQ
Phenotypes Associated with This Genotype
Genotype
MGI:6241436
Allelic
Composition
Kif21atm1.1Ece/Kif21atm1.1Ece
Tg(Isl1-EGFP*)1Slp/0
Genetic
Background
involves: 129S1/Sv * 129S4/SvJae * BALB/c * C57BL/6
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Kif21atm1.1Ece mutation (0 available); any Kif21a mutation (57 available)
Tg(Isl1-EGFP*)1Slp mutation (1 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
vision/eye
• extraocular muscle hypoplasia begins after P0, several days after extraocular muscle innervation is reduced, with normal position and size of the superior rectus and superior rectus muscles at E14.5

nervous system
• oculomotor nerve neurons show increased apoptosis from E12.5-E15.5
• oculomotor nerve neurons show failure of axon elongation to the orbit; this nerve growth failure precedes motor neuron apoptosis
• developing axons of the oculomotor nerves superior division stall in the proximal nerve, and the growth cones enlarge, extend excessive filopodia, and assume random trajectories while inferior division axons reach the orbit but branch ectopically
• oculomotor explant axons have normal growth but enlarged growth cones and increased filopodia
• the distal abducens nerves appear thin at E12.5 and are thinner at E15.5
• oculomotor nerve superior branch axons terminate prematurely within a bulb; the bulb contains misdirected axons with enlarged growth cones and increased number of filopodia and degenerating axons
• the developing distal oculomotor nerve superior division is hypoplastic while the inferior division develops aberrant branches
• the oculomotor nerve distal sections contain 55% fewer axons than proximal sections, and the proximal sections contain 18% fewer axons than wild-type proximal sections
• oculomotor nerve pathology does not arise from a primary defect in extraocular muscle development, axon retraction, or motor neuron cell death
• thinning of distal oculomotor nerves at E11.5
• the developing oculomotor nerves superior division is thinner than that of wild-type mice, while the oculomotor nerves inferior division appears moderately thinner, with premature fasciculation into transient aberrant branches

muscle
• extraocular muscle hypoplasia begins after P0, several days after extraocular muscle innervation is reduced, with normal position and size of the superior rectus and superior rectus muscles at E14.5

cellular
• oculomotor nerve neurons show increased apoptosis from E12.5-E15.5
• oculomotor nerve neurons show failure of axon elongation to the orbit; this nerve growth failure precedes motor neuron apoptosis
• developing axons of the oculomotor nerves superior division stall in the proximal nerve, and the growth cones enlarge, extend excessive filopodia, and assume random trajectories while inferior division axons reach the orbit but branch ectopically

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


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 & Copyright Notice
Send questions and comments to User Support.
last database update
06/28/2022
MGI 6.20
The Jackson Laboratory