Phenotypes associated with this allele

• Allele Symbol: Ppm1l^tm1Tkoba
• Allele Name: targeted mutation 1, Takayasu Kobayashi
• Allele ID: MGI:6117305
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Ppm1l^tm1Tkoba/Ppm1l^tm1Tkoba	B6.Cg-Ppm1l^tm1Tkoba	MGI:6117424
hm2	Ppm1l^tm1Tkoba/Ppm1l^tm1Tkoba	CBA.Cg-Ppm1l^tm1Tkoba	MGI:6117427

Genotype
MGI:6117424

hm1

• Allelic Composition: Ppm1l^tm1Tkoba/Ppm1l^tm1Tkoba
• Genetic Background: B6.Cg-Ppm1l^tm1Tkoba

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

mortality/aging

postnatal lethality, complete penetrance ( J:238086 )

• homozygotes are born but die immediately after birth, with none surviving past weaning

• Background Sensitivity: on a CBA congenic background, ~50% of homozygotes survive into adulthood

Genotype
MGI:6117427

hm2

• Allelic Composition: Ppm1l^tm1Tkoba/Ppm1l^tm1Tkoba
• Genetic Background: CBA.Cg-Ppm1l^tm1Tkoba

mortality/aging

decreased survivor rate ( J:238086 )

• only ~50% of homozygotes survive into adulthood

postnatal lethality, incomplete penetrance ( J:238086 )

• although homozygotes are born at approximately normal Mendelian ratios, only ~50% survive to P28

behavior/neurological

limb grasping ( J:238086 )

• homozygotes exhibit foot clasping when suspended by the tail

impaired coordination ( J:238086 )

• homozygotes take a significantly longer time to cross the balance beam relative to wild-type controls

• however, no differences in the latency to fall are noted in the hanging wire test or in spontaneous alternations and the number of arm entries in the Y-maze test

impaired limb coordination ( J:238086 )

• in the balance beam test, homozygotes show a hind limb drag behavior with their abdomen pressed against the surface of the beam and the hind limbs laterally wrapped around the beam

nervous system

abnormal anterior commissure morphology ( J:238086 )

• the number of axons passing through the anterior commissure is significantly reduced

• EM analysis of the anterior commissure revealed a significantly decreased number of myelinated axons and hypomyelination

• however, the thickness of layers II/III of the cerebral cortex and the density of neurons in these layers is normal

decreased anterior commissure size ( J:238086 )

• at P0, the anterior commissure is markedly reduced

abnormal forebrain morphology ( J:238086 )

enlarged lateral ventricles ( J:238086 )

• at P0, the lateral ventricles are markedly enlarged

decreased corpus callosum size ( J:238086 )

• at P0, the corpus callosum is present at rostral levels but does not extend as far caudally as in wild-type controls

abnormal dorsal striatum morphology ( J:238086 )

• at P0, the caudate putamen is significantly reduced

decreased striatum size ( J:238086 )

• at P0, the caudate putamen is significantly reduced

decreased myelin sheath thickness ( J:238086 )

• G-ratio analysis [the ratio between the diameter of the axon and the total fiber (axon + myelin sheath)] revealed a significant reduction in myelin thickness of nerve fibers in the anterior commissure

dysmyelination ( J:238086 )

• at P28, a reduction in myelin basic protein (MBP)-positive nerve fibers is observed in the corpus callosum, anterior commissure, and the internal capsule

• the density of myelinated axons in the anterior commissure is significantly reduced

• in contrast, nerve fibers in other brain regions such as cerebellum and medulla appear unaffected