Phenotypes associated with this allele

• Allele Symbol: Nfix^tm1.1Rmg
• Allele Name: targeted mutation 1.1, Richard M Gronostajski
• Allele ID: MGI:3802571
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Nfix^tm1.1Rmg/Nfix^tm1.1Rmg	involves: 129S4/SvJae * C57BL/6 * C57BL/6J	MGI:3804638
ht2	Nfix^tm1.1Rmg/Nfix^+	involves: 129S4/SvJae * C57BL/6J	MGI:6467327

Genotype
MGI:3804638

hm1

• Allelic Composition: Nfix^tm1.1Rmg/Nfix^tm1.1Rmg
• Genetic Background: involves: 129S4/SvJae * C57BL/6 * C57BL/6J

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

nervous system

abnormal brain morphology ( J:137651 )

• brain shape is elongated in the anterior to posterior direction resulting in less cerebellum exposure

increased brain weight ( J:137651 )

• brains weigh 11% to 24% more than normal and this weight increases with age

enlarged lateral ventricles ( J:137651 )

• unlike in wild-type mice, the lateral ventricles are expanded and filled with cells of unknown origin that appear at P0 and persist through at least P69

abnormal corpus callosum morphology ( J:137651 )

• more U-shaped

abnormal hippocampus morphology ( J:137651 )

• the angle of junction between the fimbria and hippocampus is more oblique than in wild-type mice

• in some brains the CA3/CA4 fields have a wavy appearance

abnormal hippocampus CA1 region morphology ( J:137651 )

• dorsal enlargement

abnormal dentate gyrus morphology ( J:137651 )

• the dentate gyrus is shorter and the angle of the arrowhead of the gyrus is larger than in wild-type mice

abnormal cerebral cortex morphology ( J:137651 )

• from P22 to P69, mice exhibit a 17% to 20% dorsal-ventral expansion of cortex and septum

growth/size/body

slow postnatal weight gain ( J:137651 )

• beginning at P8

weight loss ( J:137651 )

• at P14, mice exhibit weight loss

• however, supplementing diet with soft dough from P10 improves weight gain and survival

vision/eye

delayed eyelid opening ( J:137651 )

hearing/vestibular/ear

abnormal inner ear canal morphology ( J:137651 )

• mice exhibit a delay in the opening of the ear canal

craniofacial

craniofacial phenotype ( J:137651 )

N • mice exhibit normal tooth morphology

Genotype
MGI:6467327

ht2

• Allelic Composition: Nfix^tm1.1Rmg/Nfix⁺
• Genetic Background: involves: 129S4/SvJae * C57BL/6J

behavior/neurological

impaired active avoidance behavior ( J:295051 )

• mice can learn facets of the active place avoidance task but their performance is reduced compared to wild-type mice indicating learning and memory deficits

impaired spatial learning ( J:295051 )

• mice show learning deficits in the active place avoidance task

abnormal long-term spatial reference memory ( J:295051 )

• in the active place avoidance task, mice receive more shocks on days 3, 4, and 5 and receive their first shock earlier on days 4 and 5, indicating poor long-term memory

abnormal short-term spatial reference memory ( J:295051 )

• in the active place avoidance task, mice show a shorter latency to the second entry to the shock zone on days 4 and 5, and show a shorter maximum time of avoiding the shock zone indicating impaired short-term memory

abnormal social investigation ( J:295051 )

• in the 3-chambered sociability task, mutant mice show no differences in the time spent between the first conspecific mouse and the empty chamber compared to wild-type mice which spend more time with the first conspecific mouse, indicating no overall social preference for the unfamiliar mouse over an empty chamber

abnormal response to social novelty ( J:295051 )

• in the second trial of the 3-chambered sociability task, mice show no preference for either the novel or first conspecific mouse in the first minute of the test while wild-type mice spend more time with the novel mouse

nervous system

abnormal cortical plate morphology ( J:295051 )

• increase in thickness of the cortical plate

increased brain size ( J:295051 )

• mice exhibit increased brain volume (megalencephaly), with the cerebral cortex showing the highest increase

• the three largest volume increases in the brain include the corpus callosum (25.46%), neocortex (23.11%) and anterior commissure (17.52%)

abnormal brain commissure morphology ( J:295051 )

• adults show aberrant microstructure of major forebrain commissure tracts (the corpus callosum, the hippocampal commissure and the anterior commissure)

• commissures show reduced fractional anisotropy and reduced radial diffusivity indicating loss of microstructural integrity and reduced directional coherence and abnormal fanning and bending of white matter tracts

• fiber tracts of the major forebrain commissures are aberrantly dispersed

abnormal hippocampal commissure morphology ( J:295051 )

• the tract density intensity of the hippocampal commissure is decreased indicating that axonal tracts are less densely packed

abnormal anterior commissure morphology ( J:295051 )

• fiber tracts of the major forebrain commissures are aberrantly dispersed, most prominently in the anterior commissure which shows an abnormally high number of tracts in the dorsal-ventral direction compared to wild-type mice

• the tract density intensity of the anterior commissure is decreased indicating that axonal tracts are less densely packed

abnormal retrosplenial region morphology ( J:295051 )

• the retrosplenial cortex is increased by 27.79%

• the retrosplenial cortex shows an increase in Satb2+ upper layer neurons, Olig2+ oligodendrocytes, and PDGFRalpha+ oligodendrocytes

increased cingulate cortex size ( J:295051 )

• the cingulate cortex is increased by 25.02%

abnormal neocortex morphology ( J:295051 )

• expansion of cortical layers within the neocortex

• mice show elevated neural and glial cell number within the neocortex

increased neocortex size ( J:295051 )

• thickness of the neocortex is increased

• expansion of cortical thickness is due to an increase in overall cell number while maintaining a normal cellular distribution

abnormal somatosensory cortex morphology ( J:295051 )

• the rostral somatosensory cortex is increased by 19.02%

• caudal somatosensory cortex is increased by 29.49%

• the somatosensory cortex shows an increase in Satb2+ upper layer neurons, Olig2+ oligodendrocytes, PDGFRalpha+ oligodendrocytes, and S100Beta+ astrocytes

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
Sotos syndrome 2		DOID:0112102	OMIM:614753	J:295051