Shank3flox ex4-9 mice possess loxP sites flanking the ankyrin repeat domains (exons 4-9) of the Shank3 gene. These mice are suitable for use in making tissue-specific conditional mutations when used in conjunction with a Cre-expressing strain.
Joseph D Buxbaum, Mount Sinai School of Medicine
The Shank3flox ex4-9 allele has loxP sites flanking exons 4-9 of the SH3/ankyrin domain gene 3 (Shank3) gene. When bred to mice that express Cre recombinase, the resulting offspring will have the sequences encoding the ankyrin repeat domains deleted in the cre-expressing tissues. As SHANK3 is necessary for forming functional glutamatergic synapses between receptors and cytoskeletal/scaffolding elements, these floxed mice may be used to generate tissue-specific Shank3 deletions for studying synaptic glutamate receptor development/function, transmission and plasticity, as well as Shank3 haploinsufficiency, neurobehavioral manifestations of 22q13 deletion syndrome and/or autism spectrum disorders.
A targeting vector was designed to insert a loxP site upstream of exon 4, and an frt-flanked PGK-neo cassette followed by a second loxP site all downstream of exon 9 of the targeted gene. The construct was electroporated into B6.Cg-Thy1a-derived Bruce4 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts. Chimeric males were bred with C57BL/6NTac females to establish the colony. Next, mutant mice were bred with FLP-expressing mice (undisclosed genetic background) to remove the frt-flanked PGK-neo cassette. The donating laboratory reported the resulting Shank3flox ex4-9 mice were then bred to C57BL/6NTac for two-to-three generations (and the FLP gene was removed) prior to sending to The Jackson Laboratory Repository in 2012 (see SNP note below). Upon arrival, sperm was frozen from these mice. To establish our live colony (from 2012-2013), they were bred to C57BL/6NJ inbred mice (Stock No. 005304) for at least one generation. Of note, while backcrossing the donating investigator did not assay their colony at the Thy1 locus. As such, these mice may be segregating for the NZB-derived Thy1a allele (from Bruce4 ES cells) or the C57BL/6-derived Thy1b allele.
A 32 SNP (single nucleotide polymorphism) panel analysis, with 27 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the rederived living colony at The Jackson Laboratory Repository. While the 27 markers throughout the genome suggested a C57BL/6 genetic background, all 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating. These data suggest the mice sent to The Jackson Laboratory Repository (and used for cryopreserving sperm) in 2012 were on a C57BL/6J genetic background.
|Allele Name||targeted mutation 1.1, Joseph D Buxbaum|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Gene Symbol and Name||Shank3, SH3 and multiple ankyrin repeat domains 3|
|Strain of Origin||B6.Cg-Thy1a|
|Molecular Note||A loxP site was inserted upstream of exon 4 and an FRT flanked neo cassette and second loxP site were inserted downstream of exon 9 via homologous recombination. Flp mediated recombination removed the neo cassette.|
|Mutations Made By|| |
Joseph Buxbaum, Mount Sinai School of Medicine
When maintaining a live colony, homozygous mice may be bred together.
When using the Shank3flox ex4-9 mouse strain in a publication, please cite the originating article(s) and include JAX stock #017889 in your Materials and Methods section.