Phenotypes Associated with This Genotype

Genotype
MGI:2653617

• Allelic Composition: Agrn^tm1Jrs/Agrn^tm1Jrs
• Genetic Background: involves: 129S1/Sv * 129X1/SvJ

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

mortality/aging

perinatal lethality, complete penetrance ( J:33098 )

• mutants appear to develop normally until the last fetal day but die in utero or are stillborn

nervous system

abnormal innervation ( J:33098 )

abnormal innervation pattern to muscle ( J:33098 )

• although an intramuscular nerve trunk forms on time, axons that leave it extend parallel to the myotubes, branch infrequently, and are longer than controls by E15

• few of the axons that exit the main nerve trunk in E18 diaphragm muscles form secondary branches or arbors

decreased CNS synapse formation ( J:79028 )

• synaptogenesis is impaired in superior cervical ganglion neuronal cultures, with mutants showing a decrease in the number of synapses with aggregates of presynaptic synaptophysin and postsynaptic neuronal acetylcholine receptor

• impaired synaptogenesis is not due to defects in neuronal differentiation or neurite outgrowth

abnormal axon morphology ( J:33098 )

• presynaptic nerve differentiation and branching are abnormal

abnormal neuromuscular synapse morphology ( J:33098 )

• impaired postsynaptic differentiation, with a reduction in number, density, and size of postsynaptic acetylcholine receptor clusters on myotubes

• many axons terminate blindly, with no subjacent acetylcholine receptor aggregate and many acetylcholine receptor clusters are uninnervated

• the basal lamina of the synaptic cleft is frequently patchy instead of being continuous

• no junctional folds are seen at E18 synapses while controls have a few of these at this time

increased post-tetanic potentiation ( J:79028 )

• post-tetanic potentiation is greater in mutant superior cervical ganglion than in controls, indicating that synaptic transmission is defective

abnormal paired-pulse inhibition ( J:79028 )

• paired-pulse depression is more pronounced in mutant superior cervical ganglion than in controls