Phenotypes associated with this allele

• Allele Symbol: Bdnf^tm1Krj
• Allele Name: targeted mutation 1, Kevin R Jones
• Allele ID: MGI:3582638
• Summary: 4 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Bdnf^tm1Krj/Bdnf^tm1Krj	involves: 129S2/SvPas * C57BL/6	MGI:5427383
cn2	Bdnf^tm1Krj/Bdnf^tm1Lfr H2az2^Tg(Wnt1-cre)11Rth/H2az2^+	involves: 129S2/SvPas * C57BL/6 * CBA	MGI:3584263
cn3	Bdnf^tm1Krj/Bdnf^tm1Lfr Emx1^tm1(cre)Krj/Emx1^+	involves: 129S2/SvPas * C57BL/6J	MGI:3584256
cn4	Bdnf^tm1Krj/Bdnf^+ Emx1^tm1(cre)Krj/Emx1^+	involves: 129S2/SvPas * C57BL/6J	MGI:3584257

Genotype
MGI:5427383

hm1

• Allelic Composition: Bdnf^tm1Krj/Bdnf^tm1Krj
• Genetic Background: involves: 129S2/SvPas * C57BL/6

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

nervous system

nervous system phenotype ( J:184139 )

N • dendritic arborization of layer 2/3 pyramidal neurons in the visual cortex is normal at 3 weeks and at 4 months

N • basal response properties of the visual cortex are normal

abnormal GABAergic neuron morphology ( J:184139 )

• GABAergic innervation of the visual cortex is deficient

abnormal dendrite morphology ( J:184139 )

• distal segment density of both basal and apical dendrites is elevated at 4 months of age

• spine length and head diameter are not altered at 4 months as they are in controls

abnormal nervous system physiology ( J:184139 )

• recovery from monocular deprivation in the visual cortex fails to occur as expected

• maintenance of cortical responsiveness is impaired

abnormal nervous system electrophysiology ( J:184139 )

• spontaneous firing rate deviates from controls

Genotype
MGI:3584263

cn2

• Allelic Composition: Bdnf^tm1Krj/Bdnf^tm1Lfr; H2az2^{Tg(Wnt1-cre)11Rth}/H2az2⁺
• Genetic Background: involves: 129S2/SvPas * C57BL/6 * CBA

behavior/neurological

limb grasping ( J:99291 )

• at 1 month of age 78% of mutants clutch compared to 8% of wild-type mice and by 6 months all mutants clutch compared to 16% of wild-type

impaired coordination ( J:99291 )

• at 4 - 5 weeks of age performance on the rotarod test is impaired

nervous system

abnormal substantia nigra morphology ( J:99291 )

• tyrosine hydroxylase-positive neurons are reduced by about 27% and 23% at postnatal day 0 and 120, respectively and appear disorganized

abnormal substantia nigra pars compacta morphology ( J:99291 )

• the extent of the substantia nigra pars compacta appears reduced in coronal sections but the density of calbindin-positive neurons appears increased

Genotype
MGI:3584256

cn3

• Allelic Composition: Bdnf^tm1Krj/Bdnf^tm1Lfr; Emx1^tm1(cre)Krj/Emx1⁺
• Genetic Background: involves: 129S2/SvPas * C57BL/6J

mortality/aging

premature death ( J:84683 )

nervous system

abnormal medium spiny neuron morphology ( J:96903 )

• the cross-sectional area of medium spiny neuron soma is reduced by 25% and the diameter of all portions of the dendritic tree is reduced by about 40% compared to wild-type mice with spine density reduced by 30-40% at every order of dendrite

decreased striatum size ( J:96903 )

• the striatal volume is reduced by 15% at P14 and by 33% and P35 and P120

abnormal hippocampus morphology ( J:96903 )

• hippocampal volume is reduced by 12% at 14 days of age however by 120 days of age no significant reduction in hippocampal volume is seen

abnormal cerebral cortex morphology ( J:96903 )

• cortical volume is reduced by 16% at P14, by about 25% at P35, and by 30% at P120

abnormal visual cortex morphology ( J:84683 )

• in layer II/III of the visual cortex soma area is normal at 2 weeks of age but reduced by 28% and 29% at 3 and 5 weeks of age, respectively; however the number of neurons is not significantly different compared to wild-type mice

• in layer II/III of the visual cortex basal dendrite branching is normal at 2 weeks of age, but reduced by 29% at 5 weeks of age with distal branches more severely affected than proximal branches

• in layer II/III of the visual cortex the number of primary dendrites is normal at 2 weeks of age but reduced by 19% and 36% at 3 and 5 weeks of age, respectively, compared to wild-type mice

thin cerebral cortex ( J:84683 )

• at 5 weeks of age the thickness of the somatosensory and visual cortex are reduced by 12% and 17%, respectively and a 22% increase in neuron density is seen in layer II/III of the visual cortex compared to wild-type mice

behavior/neurological

increased aggression ( J:84683 )

limb grasping ( J:96903 )

• all mutants display limb clasping by 120 days of age and clasping progresses with age from only hindlimbs to include hind and forlimbs; however no impairment od motor function is seen in the rotarod test

abnormal nest building behavior ( J:84683 )

growth/size/body

decreased body weight ( J:84683 )

• body weight is reduced at 3 and 5 weeks of age

obese ( J:84683 )

• a 35% increase in body mass is seen at 16 weeks of age

reproductive system

reduced fertility ( J:84683 )

vision/eye

delayed eyelid opening ( J:84683 )

• mutants open their eyes 1 day later

Genotype
MGI:3584257

cn4

• Allelic Composition: Bdnf^tm1Krj/Bdnf⁺; Emx1^tm1(cre)Krj/Emx1⁺
• Genetic Background: involves: 129S2/SvPas * C57BL/6J

growth/size/body

growth/size/body region phenotype ( J:84683 )

N • forebrain specific heterozygotes do not become obese unlike mice heterozygous for Bdnf^tm1Lfr