Homozygous synapsin I knockout mice exhibit seizures, delayed axonal outgrowth and delayed synapse formation. These mice may be useful in studying the role of synapsin I in neurodevelopment.
Hung-Teh Kao, Nathan Kline Institute
Paul Greengard, Rockefeller University
Syn1, the most abundant member of the synapsin family of neuronal phophoproteins, is associated with neurotransmitter release and synaptogenesis. Synapsin I localizes to presynaptic terminals. Synapsin proteins are associated with autism. The synapsin I knockout allele has a PGK-neo cassette replacing exon 1 of the Syn1 gene. Homozygous mice exhibit a delay in the outgrowth of presynaptic neurites, axonal elongation and synapse formation in hippocampal neurons. Beginning at two months of age, mice experience spontaneous seizures. Homozygous mice are viable and fertile with no reported reproductive deficiency.
A targeting vector was designed by Dr. Paul Greengard (Rockefeller University) to
replace exon 1 of the synapsin I gene (Syn1) on chromosome X with a PGK-neomycin cassette. The construct was electroporated into 129P2/OlaHsd-derived E14 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts, and chimeric males were bred with C57BL/6J females to establish the colony. The resulting mice were bred with C57BL/6 wildtype mice for at least ten generations prior to sending males to The Jackson Laboratory Repository in 2015.
|Allele Name||targeted mutation 1, Paul Greengard|
|Allele Type||Targeted (Null/Knockout)|
|Allele Synonym(s)||Syn1tm1Lli; SynI-|
|Gene Symbol and Name||Syn1, synapsin I|
|Strain of Origin||129P2/OlaHsd|
|Molecular Note||Exon 1 was replaced by a neomycin selection cassette inserted by homologous recombination. Western blot analysis of homozygous mutant brain tissues indicated an absence of both protein isoforms, Synapsin Ia and Synapsin Ib, produced by the endogenous locus.|
While maintaining a live colony, these mice are bred as homozygotes.
When using the Syn 1 KO mouse strain in a publication, please cite the originating article(s) and include MMRRC stock #41436 in your Materials and Methods section.