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Phenotypes associated with this allele
Allele Symbol
Allele Name
Allele ID
Arxtm4Kki
targeted mutation 4, Kunio Kitamura
MGI:4359177
Summary 2 genotypes
Jump to Allelic Composition Genetic Background Genotype ID
ot1
Arxtm4Kki/Y involves: 129S/SvEv * C57BL/6J MGI:4359207
ot2
Arxtm4Kki/Y involves: 129S/SvEv * C57BL/6NHsd MGI:6196032


Genotype
MGI:4359207
ot1
Allelic
Composition
Arxtm4Kki/Y
Genetic
Background
involves: 129S/SvEv * C57BL/6J
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Arxtm4Kki mutation (5 available); any Arx mutation (19 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
mortality/aging
• most mice die within 3 months with some surviving for 5 to 6 months

nervous system
• by 1 month, 7 of 10 mice exhibit seizures with one death during status epilepticus
• some mice exhibit hand-washing motion at the end of a seizure
• mice exhibit abnormal activities during ictal electroencephalogram with positive spikes in the hippocampus and negative spikes in the frontal cortex and striatum followed by diffuse spike bursts
• 88% of Arx+ GABAergic cells that migrate in wild-type mice reach the cortical plate by P0
• at P0, tangential migration of SST+ GABAergic neurons is suppressed compared to in wild-type mice
• severe in the cortex and striatum
• at 1 month, cholinergic neurons in the striatum, medial septum, and ventral forebrain nuclei are reduced compared to in wild-type mice

behavior/neurological
• compared to wild-type mice that is worse than in Arxtm3Kki homozygotes
• mice exhibit impaired spatial learning in a win-shift task on the 8-arm radial maze compared with wild-type mice that is worse than in Arxtm3Kki homozygotes
• in a win-stay task, mice exhibit higher unlit-to-lit ratio throughout training compared with wild-type mice
• abnormal spatial learning is independent of hyperactivity and anxiety-like behaviors
• by 1 month, 7 of 10 mice exhibit seizures with one death during status epilepticus
• some mice exhibit hand-washing motion at the end of a seizure
• mice exhibit abnormal activities during ictal electroencephalogram with positive spikes in the hippocampus and negative spikes in the frontal cortex and striatum followed by diffuse spike bursts

cellular
• 88% of Arx+ GABAergic cells that migrate in wild-type mice reach the cortical plate by P0
• at P0, tangential migration of SST+ GABAergic neurons is suppressed compared to in wild-type mice

Mouse Models of Human Disease
DO ID OMIM ID(s) Ref(s)
early infantile epileptic encephalopathy DOID:0050709 OMIM:PS308350
J:197588




Genotype
MGI:6196032
ot2
Allelic
Composition
Arxtm4Kki/Y
Genetic
Background
involves: 129S/SvEv * C57BL/6NHsd
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Arxtm4Kki mutation (5 available); any Arx mutation (19 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
mortality/aging
• 55% of mice survive to P70
• first death occurs at P19, with only 86% of mice being successfully weaned, and with 55% surviving to P70

growth/size/body
• lower body weight throughout development and growth, with weight fluctuations often seen pre- and post-seizure
• mice weight 83% of control at P5, 73% of control at weaning, and 80-90% of control between P35 and P70

behavior/neurological
• mice travel less total distance and spend less time in the inner quadrants of the open field, suggesting decreased exploratory behavior
• mice travel greater distance and spend more time on the open arm of the elevated zero maze indicating increased exploratory behavior
• mice exhibit reduced spatial learning and memory in the Y-maze and Barnes maze, showing no preference for the novel arm in the Y-maze, an increase in time to locate the escape hole in the Barns maze and no preference towards the previously learned (familiar) or rotated (novel) location of the escape hole
• mice travel less total distance and spend less time in the inner quadrants of the open field, suggesting increased anxiety
• mice exhibit decreased fear response in the elevated zero maze, traveling a greater distance and spending more time in the open arm
• 32% of mice show one or more movement phenotypes (such as jumpy or erratic movements when handled or provoked, rapid uncontrolled movement around the cage, twitching ears, straight tail, or increased facial grooming), either singularly or in combination with a myoclonic seizure at 1 month of age which progresses to 91% of mice at P70
• mice show reduced locomotor activity in the open field
• mice show reduced sociability and social novelty, showing reduced interaction time within the chamber, regardless of the occupant
• mice show reduced social novelty, showing reduced interaction time with the novel mouse
• any interaction with a stranger or familiar mouse is at a greater distance
• first myoclonic seizures are seen at P18 during handling of mice
• by P21, 18% of mice exhibit myoclonic seizures
• by P70, 73% of mice exhibit spontaneous seizures

muscle
• first myoclonic seizures are seen at P18 during handling of mice
• by P21, 18% of mice exhibit myoclonic seizures
• by P70, 73% of mice exhibit spontaneous seizures

nervous system
• first myoclonic seizures are seen at P18 during handling of mice
• by P21, 18% of mice exhibit myoclonic seizures
• by P70, 73% of mice exhibit spontaneous seizures

Mouse Models of Human Disease
DO ID OMIM ID(s) Ref(s)
early infantile epileptic encephalopathy DOID:0050709 OMIM:PS308350
J:260340





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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
12/03/2019
MGI 6.14
The Jackson Laboratory