STOCK Shank3^tm4.1Gfng/J

Stock number: 028779
Product name: R1117X Shank3 (Shank3*R1117X knock-in)
Research areas: Developmental Biology Research, Neurobiology Research, Research Tools

Description

The R1117X Shank3 knock-in allele (Shank3*R1117X) harbors the schizophrenia-associated R1117X mutation in Shank3 exon 21 that results in expression of a ~122 kDa truncated SHANK3 protein. Homozygous mice exhibit profound synaptic defects in prefrontal cortex, social dominance behavior and increased level of anxiety-like behavior.

Detailed description

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.

The R1117X Shank3 knock-in allele harbors the schizophrenia-associated R1117X mutation in Shank3 exon 21 that creates a stop codon and results in expression of a ~122 kDa truncated SHANK3 protein.

R1117X Shank3 mice on a mixed C57BL/6J;129S genetic background were characterized in the original publication (Zhou et al. 2016 Neuron 89:147); and this is described below. The donating investigator reports that mice homozygous for the R1117X Shank3 knock-in allele (R1117X^+/+) are viable and fertile, but are inefficient breeders. Homozygotes exhibit synaptic and behavioral phenotypes similar to human schizophrenia. Specifically, R1117X^+/+ exhibit profound synaptic defects in prefrontal cortex, social dominance behavior and increased level of anxiety-like behavior. Heterozygous mice (R1117X^+/-) have ~50% of the wildtype levels of full-length SHANK3 protein, and exhibit a less severe phenotype.

Development

The R1117X Shank3 knock-in allele (Shank3*R1117X) was designed by Dr. Guoping Feng (Massachusetts Institute of Technology) to alter exon 21 of the SH3/ankyrin domain gene 3 (Shank3) on chromosome 15 by changing the DNA sequence of codon 1117 from CGG-to-TGA (arginine-to-stop codon). This R1117X non-sense mutation was first identified in three brothers diagnosed with schizophrenia/schizoaffective disorder between ages 16 and 21 (also with mild-to-moderate mental retardation) without showing obvious autistic features during their childhood. A loxP-flanked PGK-neo-pA cassette was also inserted downstream of the mutant stop codon (but was later removed as described below). The targeting vector was co-electroporated with a pair of TALE nuclease plasmids (designed to facilitate recombination) into 129X1/SvJ x 129S1/Sv)F1-Kitl⁺-derived R1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts. Chimeric mice were bred with C57BL/6J for germline transmission and to establish the colony. The PGK-neo-pA cassette was deleted by breeding to C57BL/6 mice with germline Cre recombinase expression. The resulting R1117X Shank3 mice were backcrossed to C57BL/6J inbred mice (Stock No. 000664) for at least five or six generations (during which the Cre recombinase allele was removed). Next, they were bred to 129S1/SvImJ inbred mice (Stock No. 002448) for at least one generation.

R1117X Shank3 mice on this mixed C57BL/6J;129S genetic background were characterized in the original publication (Zhou et al. 2016 Neuron 89:147), and males with agouti coat color were sent to The Jackson Laboratory Repository in 2016. Upon arrival, sperm was cryopreserved.

To establish our live colony, an aliquot of frozen sperm was used to fertilize B6129SF1 oocytes (Stock No. 101043).

Allele

Symbol: Shank3^tm4.1Gfng
Name: targeted mutation 4.1, Guoping Feng
MGI accession ID: MGI:5775645
Generation method: Targeted
Attributes: Not Applicable
Synonyms: R1117X
Marker symbol: Shank3
Marker name: SH3 and multiple ankyrin repeat domains 3
Chromosome: 15
Strain of origin: (129X1/SvJ x 129S1/Sv)F1-Kitl⁺
Molecular note: The targeting vector was designed to alter exon 21 by changing the DNA sequence of codon 1117 from CGG-to-TGA (arginine-to-stop codon) resulting in a truncated 122 kDa protein. A loxP-flanked PGK-neo-pA cassette was also inserted downstream of the mutant stop codon. Cre-mediated recombination removed the floxed neo cassette. This non-sense mutation was first identified in three brothers diagnosed with schizophrenia/schizoaffective disorder between ages 16 and 21 (also with mild-to-moderate mental retardation) without showing obvious autistic features during their childhood.