Phenotypes Associated with This Genotype

Genotype
MGI:2181775

• Allelic Composition: Ank2^tm1Bnt/Ank2^tm1Bnt
• Genetic Background: involves: 129X1/SvJ * C57BL/6

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

Small body size in Ank2^tm1Bnt/Ank2^tm1Bnt mouse compared to wild type

mortality/aging

postnatal lethality, complete penetrance ( J:52124 )

• 95% of remaining homozygotes die by P8; only a few (4 out of 8) survive to P20

neonatal lethality, incomplete penetrance ( J:52124 )

• over half of homozygotes are moribund (and therefore killed) at P1

behavior/neurological

impaired balance ( J:52124 )

• homozygotes that survive to 2 weeks of age exhibit impaired balance

abnormal locomotor behavior ( J:52124 )

• homozygotes that survive to 2 weeks of age exhibit abnormal locomotor activity

growth/size/body

decreased body weight ( J:52124 )

• homozygotes that survive to 2 weeks of age exhibit a 75% reduction in body weight relative to wild-type littermates

vision/eye

optic nerve degeneration ( J:52124 )

• at P9, many mutant optic nerve axons become dilated with diameters up to 8-fold greater than normal, and contain multivescicular bodies

• axon fasciculation is also impaired with frequent loss of direct axon-axon contacts

• a nearly complete degeneration of the optic nerve is noted by P21

disorganized secondary lens fibers ( J:52124 , J:70385 )

• disruption of secondary lens fiber organization at anterior pole (J:52124)

• organization of secondary lens fibers at the anterior pole was severely disturbed at postnatal day 1 (J:70385)

nervous system

enlarged lateral ventricles ( J:52124 )

• at P1, homozygotes show a 7-fold enlargement of the lateral ventricles

• enlargement of lateral ventricles is not associated with occlusion of the cerebral aqueduct

decreased corpus callosum size ( J:52124 )

• at P1-P5, ~61.5% homozygotes display a size reduction or absence of the corpus callosum; a nearly complete absence of the anterior portion is observed

• the corpus callosum cannot be visualized in parasagittal sections and appears greatly reduced in coronal sections of mutant brain

decreased brain internal capsule size ( J:52124 )

• at P1, homozygotes exhibit a size reduction or absence of the internal capsule

abnormal anterior corticospinal tract morphology ( J:52124 )

• at P1, homozygotes exhibit hypoplasia or absence of the pyramidal tracts

abnormal lateral corticospinal tract morphology ( J:52124 )

• at P1, homozygotes exhibit hypoplasia or absence of the pyramidal tracts

abnormal axon morphology ( J:52124 )

• homozygotes display decreased L1 staining in premyelinated axons of long fiber tracts, including the corpus callosum, fimbria, and internal capsule in the brain, and pyramidal tracts and lateral columns of the spinal cord

• L1 staining is unreduced in the mutant optic nerve at P1-P3 but disappears by P7, although the optic nerve itself is still present

optic nerve degeneration ( J:52124 )

• at P9, many mutant optic nerve axons become dilated with diameters up to 8-fold greater than normal, and contain multivescicular bodies

• axon fasciculation is also impaired with frequent loss of direct axon-axon contacts

• a nearly complete degeneration of the optic nerve is noted by P21