Phenotypes associated with this allele

• Allele Symbol: Tbr1^tm1.1Csbd
• Allele Name: targeted mutation 1.1, Eunjoon Kim
• Allele ID: MGI:6388548
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Tbr1^tm1.1Csbd/Tbr1^tm1.1Csbd	involves: C57BL/6J	MGI:6388549
ht2	Tbr1^tm1.1Csbd/Tbr1^+	involves: C57BL/6J	MGI:6388550

Genotype
MGI:6388549

hm1

• Allelic Composition: Tbr1^tm1.1Csbd/Tbr1^tm1.1Csbd
• Genetic Background: involves: C57BL/6J

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

mortality/aging

preweaning lethality, complete penetrance ( J:281878 )

• homozygotes are not detected at P7

Genotype
MGI:6388550

ht2

• Allelic Composition: Tbr1^tm1.1Csbd/Tbr1⁺
• Genetic Background: involves: C57BL/6J

behavior/neurological

abnormal habituation to a new environment ( J:281878 )

♂ • mice show reduced habituation to the novel open-field environment

decreased thigmotaxis ( J:281878 )

♂ • mice spend an increased amount of time in the center of the open-field test, indicating anxiolytic-like behavior

increased anxiety-related response ( J:281878 )

♂ • 3 month old males exhibit enhanced anxiety-like behavior, spending more time in the closed arms and less time in the open arms of the elevated plus-maze test and spending less time in the light chamber of the light-dark test

increased grooming behavior ( J:281878 )

♂ • mice show modestly increased repetitive self-grooming during the light-off period, but not during the light-on period

increased vertical activity ( J:281878 )

♂ • mice show an increase in rearing in Laboras cages during the light-off period, but not during the light-on period

♂ • however, mice show normal levels of locomotor activity in the open-field test

increased locomotor activity ( J:281878 )

♂ • in Laboras cages, mice show modest hyperactivity during the first 6 hours on day 1 (light-off period), although total locomotion over 3 days does not change in light-off or light-on periods

abnormal social/conspecific interaction behavior ( J:281878 )

♂ • 3 month old males exhibit reduced social interaction in direct social-interaction

♂ • however, mice show normal social approach and social novelty recognition in the three-chamber test for social interaction and pups show normal levels of social communication by USVs upon separation from their mothers

nervous system

abnormal brain interneuron morphology ( J:281878 )

• the number of parvalbumin (PV)+ interneurons in superficial cortical layers of the cortex is decreased at 3 months of age, whereas their number is increased in deep cortical layers

• however, no differences in the total numbers of SST+, PV+, or VIP+ interneurons are seen and no difference in the thickness of the neocortex in the prelimbic region of the medial prefrontal cortex at P5

increased excitatory postsynaptic current frequency ( J:281878 )

• increase in frequency, but not amplitude, of spontaneous excitatory postsynaptic currents (sEPSCs) in layer 6 pyramidal neurons at 11-12 weeks of age

• however, no differences in neuronal excitability of mPFC layer 6 pyramidal neurons is seen

increased miniature inhibitory postsynaptic current frequency ( J:281878 )

• increase in the frequency, but not amplitude, of miniature inhibitory postsynaptic currents (mIPSCs) in layer 6 pyramidal neurons at 11-12 weeks of age indicating that inhibitory synaptic transmission onto medial prefrontal cortex (mPFC) layer 6 pyramidal neurons is increased

• increase in the frequency, but not amplitude, of spontaneous inhibitory postsynaptic currents (sIPSCs) in layer 6 pyramidal neurons at 11-12 weeks of age

• however, no differences in the frequency or amplitude of mEPSCs is seen

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
autism spectrum disorder		DOID:0060041		J:281878