B6.Cg-Shank3^tm2Bux/J

Stock number: 032158
Product name: Shank3^flox4-22
Research areas: Developmental Biology Research, Neurobiology Research, Research Tools

Description

Shank3^{flox ex4-22} mice possess loxP sites flanking exons 4-22 of the SH3 and multiple ankyrin repeat domains 3 (Shank3) gene. These mice are suitable for use in making complete tissue-specific Shank3 knock-out mice and may be useful for studying autism spectrum disorder (ASD), Phelan-McDermid syndrome and schizophrenia.

Detailed description

The Shank3^{flox ex4-22} allele has loxP sites flanking exons 4-22 of the SH3 and multiple ankyrin repeat domains 3 (Shank3) gene. SHANK3 is a synaptic scaffolding protein expressed in the postsynaptic density (PSD) of excitatory synapses. SHANK3 mutations have been identified in cases of intellectual disability such as autism spectrum disorder (ASD), Phelan-McDermid syndrome and schizophrenia. Homozygous mice are viable and fertile. When bred to mice that express Cre recombinase, the resulting offspring will have the entire coding region of Shank3 deleted in the cre-expressing tissues.

When Shank3^{flox ex4-22} mice are bred to CMV-Cre mice (Stock No. 006054), exons 4-22 are excised. The resulting strain, Shank3^Δex4-22, exhibit strong escape behavior and avoidance of inanimate objects in novel object recognition, repetitive novel object contact, marble burying and nest building tasks, indicating increased novelty-induced anxiety. Similarly, increased freezing is observed during fear conditioning training and amygdala-dependent cued retrieval. Deficits are observed in both initial training and reversal in the Barnes maze and in contextual fear memory that are memory tasks involving hippocampal-prefrontal circuits. In contrast, working memory in the Y-maze spontaneous alternation test is not altered. These deficits are more pronounced in homozygotes, with an intermediate phenotype observed in heterozygotes.

Of note, Shank3^Δex4-22 mice are available as Stock No. 032169.

Shank3^{flox ex4-9} mice, with loxP sites flanking the ankyrin repeat domains, are available as Stock No. 017889.

Development

The Shank3^{flox ex4-9} 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, downstream of exon 9 of the SH3 and multiple ankyrin repeat domains 3 (Shank3) gene. The construct was electroporated into B6.Cg-Thy1^a-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 resulting Shank3^{flox ex4-9} mice were then bred to C57BL/6NTac for two-to-three generations, and the FLP gene was removed. These Shank3^{flox ex4-9} mice are available at The Jackson Laboratory as Stock No. 017889.

ES cells from these Shank3^{flox ex4-9} mice were then retargeted by the donating investigator to carry a third loxP site downstream of exon 22. This new line of Shank3^{flox ex4-22} mice were maintained on a C57BL/6NTac genetic background. Upon arrival at The Jackson Laboratory, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6NJ oocytes (Stock No. 005304).

 

Allele

Symbol: Shank3^tm2Bux
Name: targeted mutation 2, Joseph D Buxbaum
MGI accession ID: MGI:6161684
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Synonyms: Shank3^{flox ex4-22}
Marker symbol: Shank3
Marker name: SH3 and multiple ankyrin repeat domains 3
Marker synonyms: DEL22q13.3; PROSAP2; PSAP2; SCZD15; SPANK-2
Chromosome: 15
Strain of origin: B6.Cg-Thy1^a
Molecular note: ES cells from Shank3^tm1.1Bux mice were retargeted to carry a third loxP site downstream of exon 22. The allele contains a loxP site inserted upstream of exon 4, a second loxP site inserted downstream of exon 9, and a third loxP site downstream of exon 22.