Phenotypes associated with this allele

• Allele Symbol: Lrp8^tm4Her
• Allele Name: targeted mutation 4, Joachim Herz
• Allele ID: MGI:3619603
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Lrp8^tm4Her/Lrp8^tm4Her	Not Specified	MGI:3621443
cx2	Lrp8^tm4Her/Lrp8^tm4Her Vldlr^tm1Her/Vldlr^tm1Her	involves: 129S7/SvEvBrd	MGI:3621444

Genotype
MGI:3621443

hm1

• Allelic Composition: Lrp8^tm4Her/Lrp8^tm4Her
• Genetic Background: Not Specified

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

behavior/neurological

abnormal contextual conditioning behavior ( J:105699 )

• mutants show a reduction in freezing after reintroduction to the context compared to wild-type in a fear conditioned learning test

abnormal spatial reference memory ( J:105699 )

• mutants show a profound learning deficit in that in a Morris water maze test, for all days after the first day of training, animals require much more time and a longer swimming distance to find the platform compared to wild-type or Lrp8^tm1Her animals

nervous system

abnormal neuronal migration ( J:117956 )

• corticospinal neurons are mislocalized to layers 4 and 6 of cerebral cortex

abnormal dentate gyrus morphology ( J:105699 )

• mutants have many calbindin-positive cells in the polymorph layer, with the granule cell layers appearing more dispersed than in Lrp8^tm1Her brains

abnormal hippocampus layer morphology ( J:105699 )

• mutants display a splitting of neuronal layering in region CA1 with a pronounced dispersion of neurons in CA3 and dentate gyrus

abnormal cerebral cortex morphology ( J:105699 )

• cortical lamination in the brain is abnormal

• at P21, markers for cortical layer 6 and subplate neurons have broadened expression, indicating that neurons are infiltrating layers closer to the cortical surface

• majority of layer 5 neurons is shifted to layer 4 with a smaller population in layer 6

reproductive system

reduced male fertility ( J:105699 )

♂ • males exhibit reduced fertility

cellular

abnormal neuronal migration ( J:117956 )

• corticospinal neurons are mislocalized to layers 4 and 6 of cerebral cortex

Genotype
MGI:3621444

cx2

• Allelic Composition: Lrp8^tm4Her/Lrp8^tm4Her; Vldlr^tm1Her/Vldlr^tm1Her
• Genetic Background: involves: 129S7/SvEvBrd

mortality/aging

postnatal lethality, complete penetrance ( J:105699 )

• animals usually die between 2 and 3 weeks of age due to severe motor abnormalities

growth/size/body

decreased body size ( J:105699 )

nervous system

abnormal cortical marginal zone morphology ( J:105699 )

• at P21, the normally cell-free layer 1 or marginal zone shows infiltration

abnormal hippocampus morphology ( J:105699 )

• at P21, mice display a striking disorganization of the entire hippocampal region with a more prominent splitting of CA1, CA3 and dentate gyrus regions

abnormal dentate gyrus morphology ( J:105699 )

• at P21, granule cells do not form a tightly packed layer, and calbindin-labelled cells are scattered throughout the granule-cell population

delaminated cerebral cortex ( J:105699 )

• mice display a complete disruption of cortical layering at P21

abnormal cerebellar Purkinje cell layer ( J:105699 )

• ectopic Purkinje cells are located below an outer layer of granule cells

small cerebellum ( J:105699 )

• cerebellum is severely reduced in size

behavior/neurological

tremors ( J:105699 )

• mice exhibit tremors by 2 weeks of age

ataxia ( J:105699 )

• ataxia develops by 2 weeks of age

impaired balance ( J:105699 )

• mice display impaired balance by 2 weeks of age

abnormal gait ( J:105699 )

• mice have an abnormal gait by 2 weeks of age