Phenotypes Associated with This Genotype

Genotype
MGI:2683143

• Allelic Composition: Sncg^tm1Vlb/Sncg^tm1Vlb
• Genetic Background: B6.129P2-Sncg^tm1Vlb

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

nervous system

nervous system phenotype ( J:86439 , J:92213 )

N • homozygotes are viable, fertile and display no morphological or functional abnormalities of the nervous system relative to wild-type controls (J:86439)

N • normal numbers of motoneurons in five brain stem motor nuclei, including facial, oculomotor, hypoglossal, trigeminal motor, and trochlear nuclei (J:86439)

N • normal numbers of sensory neurons in trigeminal ganglia and L6 lumbar dorsal root ganglia (J:86439)

N • normal morphology and numbers of myelinated A-fibers and unmyelinated C-fibers in adult saphenous nerves (J:86439)

N • normal survival characteristics of P2 trigenimal ganglion neurons in various culture conditions (J:86439)

N • normal sensory recovery after chronic constriction injury (CCI) to the sciatic nerve, suggesting that nerve regeneration and plasticity of early somatosensory pathways remains intact (J:86439)

N • no significant differences in dopamine or its metabolite (DOPAC, 5-HIAA and HVA) levels in the striatum at 9 months of age (J:92213)

decreased susceptibility to dopaminergic neuron neurotoxicity ( J:92213 )

• homozygotes display resistance of SNpc dopaminergic neurons to MPTP neurotoxicity

decreased dopaminergic neuron number ( J:92213 )

• early postnatal (P5) and adult (18 months) homozygotes show a similar (15-20%) reduction in the number of tyrosine hydroxylase (TH)-positive dopaminergic neurons in substantia nigra pars compacta (SNpc) but not in ventral tegmental area (VTA) relative to wild-type controls

• however, no differences in the number of midbrain dopaminergic neurons are detected in SNpc at E18

• also, no significant decrease in the number of TH-positive dopaminergic neurons is noted in SNpc after methyl-phenyl-tetrahydropyridine (MPTP) treatment relative to controls

homeostasis/metabolism

decreased susceptibility to dopaminergic neuron neurotoxicity ( J:92213 )

• homozygotes display resistance of SNpc dopaminergic neurons to MPTP neurotoxicity

behavior/neurological

behavior/neurological phenotype ( J:86439 , J:92213 )

N • adult male homozygotes show normal behavioral reflex responses to noxious radiant heat and graded mechanical stimuli in the CCI model of neuropathic pain (J:86439)

N • homozygotes are behaviorally normal and show no detectable motor dysfunction in either constant speed or accelerating rotarod tests (J:92213)

cellular

decreased susceptibility to dopaminergic neuron neurotoxicity ( J:92213 )

• homozygotes display resistance of SNpc dopaminergic neurons to MPTP neurotoxicity