Phenotypes associated with this allele

• Allele Symbol: Stx1b^tm1Tmis
• Allele Name: targeted mutation 1, Tatsuya Mishima
• Allele ID: MGI:5605503
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Stx1b^tm1Tmis/Stx1b^tm1Tmis	B6.Cg-Stx1b^tm1Tmis	MGI:5605504
cx2	Stx1a^tm1Tfuj/Stx1a^tm1Tfuj Stx1b^tm1Tmis/Stx1b^tm1Tmis	involves: C57BL/6J	MGI:5605505

Genotype
MGI:5605504

hm1

• Allelic Composition: Stx1b^tm1Tmis/Stx1b^tm1Tmis
• Genetic Background: B6.Cg-Stx1b^tm1Tmis

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

mortality/aging

postnatal lethality, complete penetrance ( J:214474 )

• die by P14

growth/size/body

decreased body size ( J:214474 )

• neonates are smaller

nervous system

abnormal synapse morphology ( J:214474 )

• the number of docked vesicles and synaptic density is lower in the synapses of the stratum radiatum of the hippocampal CA1 region, however the total number of synaptic vesicles in the presynaptic terminals is normal

• size of the readily releasable vesicle pool in glutamatergic and GABAergic synapses of neurons is 61% and 30% that of wild-type, respectively

abnormal synaptic vesicle number ( J:214474 )

• at GABAergic synapses, synaptic vesicles in the reluctant component are greater in mutant neurons, with no difference in vesicle recycling rate

• reduction in the number of spontaneous vesicles in the total readily releasable vesicle pool

abnormal synaptic vesicle recycling ( J:214474 )

• at glutamatergic synapses, the vesicle recycling rate is greater than in wild-type, with no difference in effective pool size

abnormal CNS synaptic transmission ( J:214474 )

• reduction in the frequency of spontaneous neurotransmitter release at glutamatergic and GABAergic synapses

abnormal GABA-mediated receptor currents ( J:214474 )

• the mean frequency of GABA(A) receptor-mediated spontaneous miniature inhibitory postsynaptic currents (mIPSCs) is lower in neurons indicating a reduction in the frequency of spontaneous neurotransmitter release at GABAergic synapses

abnormal AMPA-mediated synaptic currents ( J:214474 )

• the mean frequency of AMPA receptor-mediated spontaneous miniature excitatory postsynaptic currents (mEPSCs) are lower in neurons indicating a reduction in the frequency of spontaneous neurotransmitter release at glutamatergic synapses

abnormal miniature excitatory postsynaptic currents ( J:214474 )

• the mean frequency of AMPA receptor-mediated spontaneous miniature excitatory postsynaptic currents (mEPSCs) are lower in neurons indicating a reduction in the frequency of spontaneous neurotransmitter release at glutamatergic synapses

decreased miniature inhibitory postsynaptic current frequency ( J:214474 )

• the mean frequency of GABA(A) receptor-mediated spontaneous miniature inhibitory postsynaptic currents (mIPSCs) is lower in neurons indicating a reduction in the frequency of spontaneous neurotransmitter release at GABAergic synapses

abnormal paired-pulse inhibition ( J:214474 )

• mice show a higher paired-pulse ratio of evoked excitatory synaptic current responses (eEPSCs)

• neurons show initial facilitation until approximately 40 stimuli, followed by overall reduced depression relative to wild-type neurons during a 20 Hz train

• mice show an increase in the paired-pulse ratio of evoked inhibitory synaptic responses (eIPSCs)

• at a 20 Hz stimulatory train, the early rapid depression is weaker in mutant neurons than in wild-type neurons

Genotype
MGI:5605505

cx2

• Allelic Composition: Stx1a^tm1Tfuj/Stx1a^tm1Tfuj; Stx1b^tm1Tmis/Stx1b^tm1Tmis
• Genetic Background: involves: C57BL/6J

mortality/aging

embryonic lethality, complete penetrance ( J:214474 )

• embryonic lethal, time not specified

nervous system

abnormal synapse morphology ( J:214474 )

• neurons show reduced and asynchronous evoked synaptic vesicle release in glutamatergic and GABAergic synapses

decreased excitatory postsynaptic current amplitude ( J:214474 )

• in E12.5 cortical cultures, the amplitude of evoked excitatory synaptic current (eEPSC) responses is smaller than in wild-type cultures and is highly asynchronous

abnormal inhibitory postsynaptic currents ( J:214474 )

• in E12.5 cortical cultures, evoked inhibitory synaptic current (eIPSc) responses are attenuated and asynchronous compared to wild-type cultures

abnormal miniature excitatory postsynaptic currents ( J:214474 )

• in E12.5 cortical cultures, the mean amplitude of miniature excitatory postsynaptic current (mEPSC) is smaller than in wild-type cultures

abnormal miniature inhibitory postsynaptic currents ( J:214474 )

• in E12.5 cortical cultures, the mean frequency and amplitude of miniature inhibitory postsynaptic current (mIPSC) are lower than in wild-type cultures

decreased miniature inhibitory postsynaptic current amplitude ( J:214474 )

• in E12.5 cortical cultures

decreased miniature inhibitory postsynaptic current frequency ( J:214474 )

• in E12.5 cortical cultures