Phenotypes associated with this allele

• Allele Symbol: Sun2⁺
• Allele Name: wild type
• Allele ID: MGI:3583296
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
cx1	Sun1^tm1Mhan/Sun1^tm1Mhan Sun2^tm1Mhan/Sun2^+	involves: 129S6/SvEvTac	MGI:3850093
cx2	Sun1^tm1.1Ktj/Sun1^tm1.1Ktj Sun2^tm1.1Cyh/Sun2^+	involves: 129/Sv * C57BL/6 * C57BL/6N	MGI:5824546

Genotype
MGI:3850093

cx1

• Allelic Composition: Sun1^tm1Mhan/Sun1^tm1Mhan; Sun2^tm1Mhan/Sun2⁺
• Genetic Background: involves: 129S6/SvEvTac

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

muscle

abnormal muscle morphology ( J:150047 )

• 63% of muscle cells have no nuclei beneath neuromuscular junctions unlike in wild-type mice

Genotype
MGI:5824546

cx2

• Allelic Composition: Sun1^tm1.1Ktj/Sun1^tm1.1Ktj; Sun2^tm1.1Cyh/Sun2⁺
• Genetic Background: involves: 129/Sv * C57BL/6 * C57BL/6N

growth/size/body

decreased body weight ( J:224769 )

• at 3-4 months of age, average body weight is only slightly less than that of wild-type controls

behavior/neurological

ataxia ( J:224769 )

• at 5-6 months of age, mice exhibit cerebellar ataxia

impaired coordination ( J:224769 )

• at 3-4 months of age, the time to fall off the rotarod is significantly reduced relative to that in age-matched controls, and mice show a worse motor coordination profile than Sun1^tm1.1Ktj homozygotes

short stride length ( J:224769 )

• at 5-6 months of age, footprint analysis showed that hindlimb stride length is significantly reduced relative to that in age-matched controls

nervous system

abnormal Purkinje cell migration ( J:224769 )

• ~66% of Purkinje cells fail to present at the surface of the internal granule layer (IGL), with lobules IV to VII showing the most severe reductions in Purkinje cell numbe

• however, proliferation and migration of granule neurons are unaffected

reduced cerebellar foliation ( J:224769 )

• at P30, cerebellar foliation is severely reduced

abnormal cerebellum external granule cell layer morphology ( J:224769 )

• an EGL layer is not observed at P30

abnormal Purkinje cell morphology ( J:224769 )

• at P14, only ~14% of Syne2 is localized at the nuclear membrane of Purkinje cells relative to 44% in wild-type cells

abnormal Purkinje cell dendrite morphology ( J:224769 )

• at P30, total dendrite length, segments and branching points in Purkinje cells are reduced by ~20-30%

• at P7, only 46.6% of Purkinje cells show significant extension of primary dendrites versus 92.3% in wild-type cells, indicating retarded primary dendrite specification

ectopic Purkinje cell ( J:224769 )

• at P30, many Purkinje cells are found in the white matter of the cerebellum

• ~66% of Purkinje cells are absent from the surface of the internal granule layer (IGL), with lobules IV to VII showing the most severe reductions

• for those Purkinje cells that are correctly positioned at the surface of the IGL, >50% of the somas show distorted orientation with their cell soma oriented non-perpendicularly (>120 degrees or <60 degrees) to the border of the Purkinje cell layer and the IGL

thin cerebellar molecular layer ( J:224769 )

• at P30, the thickness of the molecular layer is significantly reduced

abnormal cerebellum fissure morphology ( J:224769 )

• at P30, fissuration of the cerebellar cortex is severely reduced

small cerebellum ( J:224769 )

• at P30, mice show a markedly smaller cerebellar size than wild-type controls

• reduced cerebellar volume is due to aberrant positioning and maturation of Purkinje cells

• no differences in apoptosis or cell proliferation are seen in the developing cerebellum at P7

abnormal CNS synapse formation ( J:224769 )

• at P7, the distribution of vesicular glutamate transporter 1 (VgluT1 encoded by the Slc17a7 gene) is amorphous in the developing cerebellum, indicating aberrant synaptic patterning

cellular

abnormal Purkinje cell migration ( J:224769 )

• ~66% of Purkinje cells fail to present at the surface of the internal granule layer (IGL), with lobules IV to VII showing the most severe reductions in Purkinje cell numbe

• however, proliferation and migration of granule neurons are unaffected