Phenotypes associated with this allele

• Allele Symbol: Gabpa^tm1Pjh
• Allele Name: targeted mutation 1, Paul J Hertzog
• Allele ID: MGI:3711315
• Summary: 1 genotype

Jump to	Allelic Composition	Genetic Background	Genotype ID
cn1	Gabpa^tm1Pjh/Gabpa^tm1Pjh Tg(ACTA1-cre)79Jme/0	involves: 129X1/SvJ * C57BL/6 * SJL	MGI:3712148

Genotype
MGI:3712148

cn1

• Allelic Composition: Gabpa^tm1Pjh/Gabpa^tm1Pjh; Tg(ACTA1-cre)79Jme/0
• Genetic Background: involves: 129X1/SvJ * C57BL/6 * SJL

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

nervous system

abnormal neuromuscular synapse morphology ( J:121356 )

• 76% of soleus NMJs show less branching than controls, but appear relatively normal and are classed as type 1, while 24% of soleus NMJs show only a single ring structure (type 2); diaphragm and sternomastoid muscles show similar proportions of the two NMJ types

• type 1 soleus NMJs show increased total area and area occupied by acetylcholine receptors, but percentage of area occupied by AChRs is unchanged relative to controls; 76% increase in area occupied by AChRs corresponds to a 1.8-fold increase in number of AChRs in the synaptic region in 3 month old mice relative to controls

• type 2 soleus NMJs are of equal area to control NMJs, but show a significant decrease in percentage of area occupied by AChRs

• distribution and appearance of mitochondria, synaptic vesicles, or postsynaptic junctional folds are the same in mutant and control soleus and diaphragm muscles

abnormal PNS synaptic transmission ( J:121356 )

• amplitudes of miniature endplate currents (MEPCs) and endplate currents (EPCs) are significantly reduced at NMJs; EPCs show a significant decrease (171 uV) relative to control (277 uV)

• mean EPC amplitudes are similar to MEPC amplitudes in controls

abnormal channel response ( J:121356 )

• decay constants, a measure of channel opening time, are significantly longer at soleus and diaphragm NMJs of mutants at 3 months of age, compared to controls; decay constants range from 100-150 mseconds in mutants compared to 30-40 mseconds for controls

abnormal synaptic acetylcholine release ( J:121356 )

• spontaneous and evoked transmitter release at the NMJ is reduced relative to controls

decreased neurotransmitter release ( J:121356 )

• mean quantal content is significantly lower at mutant NMJs than in controls

muscle

muscle phenotype ( J:121356 )

N • no differences in growth and development of skeletal muscle is seen between mutant and control, non-transgenic mice between 1 and 6 months of age; no gait abnormalities result from any muscular abnormalities

N • electrophysiological alterations do not result in significant changes in fatigability (at 1 year) or strength (from 1-6 months)