B6;129P2-Syt1^tm5Sud/J

Stock number: 006386
Product name: Synaptotagmin1 D232N Mutant
Research areas: Neurobiology Research

Description

These mice carry a targeted point mutation in the synaptotagmin I gene. The apparent Ca2+ affinity of the double C2 domain fragment is not altered, but tightness of the Ca2+/phospholipid/double C2 domain complex affinity is decreased. Increased synaptic depression is found during repetitive stimulation. The mutation does not induce any major changes in synaptic transmission. This mutant mouse strain represents a model that may be useful in studies of synaptic neurotransmitter release.

Detailed description

Mice homozygous for this targeted point mutation are viable and fertile and do not display any gross physical or behavioral abnormalities. No structural are introduced changes to the mutant protein and no major changes in protein levels are detected. Intrinsic Ca²⁺binding and Ca²⁺-dependent phospholipid binding by the isolated C2A domain are severely reduced. The apparent Ca²⁺affinity of the double C2 domain fragment is not altered, but tightness of the Ca²⁺/phospholipid/double C2 domain complex affinity is decreased. Increased synaptic depression is found during repetitive stimulation. The mutation does not induce any major changes in synaptic transmission. This mutant mouse strain represents a model that may be useful in studies of synaptic neurotransmitter release.

Development

A targeting vector was used to create a D232N substitution in the exon encoding residues 214-269 and insert a floxed neomycin resistance gene into the flanking intron. The construct was electroporated into 129P2/OlaHsd-derived E14.1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts. Chimeric animals were crossed with C57BL/6. The strain has been minimally backcrossed to C57BL/6 by the donating laboratory.

Allele

Symbol: Syt1^tm5Sud
Name: targeted mutation 5, Thomas C Sudhof
MGI accession ID: MGI:2388629
Generation method: Targeted
Attributes: Hypomorph; Inserted expressed sequence
Marker symbol: Syt1
Marker name: synaptotagmin I
Chromosome: 10
Strain of origin: Not Specified
Molecular note: An aspartate to asparagine missense mutation (D232N) was introduced into the C2A domain via homologous recombination. Western blot of brain homogenates from homozygous mutant animals verified the presence of protein expression.