B6.129(SJL)-Dlgap3^tm2.1Gfng/J

Stock number: 038291
Product name: Sapap3 cKI; FX

Research areas: Neurobiology Research, Research Tools

Description

SAPAP3 cKI (FX) knock-in/knock-out mice have inverted exons 8-10 of the Dlgap3 (DLG associated protein 3 or SAPAP3) gene. Homozygous mice exhibit compulsive grooming and alterations in dorsolateral striatum circuit function. This strain may be useful for research in OCD-like (obsessive-compulsive disorder) motor behaviors.

Of note, a conditional knock-out allele, SAPAP3 cKO, is distributed as B6.129(SJL)-Dlgap3^tm3.1Gfng/J (Stock No. 038331).

Detailed description

Dlgap3 (DLG associated protein 3 or SAPAP3) encodes a postsynaptic anchoring protein located at corticostriatal synapses. Loss of SAPAP3 is associated with OCD-like (obsessive-compulsive disorder) motor behaviors.

SAPAP3 cKI (FX) knock-in/knock-out mice have inverted exons 8-10 flanked by the FLEx cassette (inward-facing lox2272:loxP sites). The inversion of exon/introns 8-10 creates a frameshift resulting in degradation of Dlgap3 transcripts. Heterozygous cKI mice are viable and fertile, however, homozygous cKI mice are small and weak. The donating investigator indicates that homozygotes are not used for breeding. Homozygous null (cKI) mice develop compulsive grooming behaviors beginning at 3 months of age. In the dorsolateral striatum, excitability of striatal projection neurons (SPNs) is enhanced, as is dendritic excitability of direct pathway SPNs. Homozygotes exhibit an increase in cholinergic interneurons (CINs) density in the dorsal striatum and an increase in evoked acetylcholine release. Cre-mediated recombination reverses the inversion creating the wild type allele (plus the loxP/lox2272 sites left in the introns).

Of note, a conditional knock-out allele, SAPAP3 cKO, is distributed as B6.129(SJL)-Dlgap3^tm3.1Gfng/J (Stock No. 038331).

Development

The SAPAP3 cKI (FX) allele was created to have an inverted Dlgap3 exons 8-10 (Ensemble ID: ENSMUSE00001223455, ENSMUSE00000400411, ENSMUSE00000335250, and introns) that is flanked with the FLEx cassette (inward-facing lox2272:loxP sites), followed by a FRT-flanked neomycin resistance cassette. The inversion creates a reading frame shift resulting in a null allele. The targeting vector was electroporated into 129X1/SvJ x 129S1/Sv)F1-Kitl⁺-derived R1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts. Chimeric males were bred with C57BL/6J females for germline transmission and to establish the colony. Next, the mice were bred with B6.Cg-Tg(ACTFLPe)9205Dym/J (Stock No. 005703) mice for germline deletion of the neo cassette. The resulting mice were backcrossed to C57BL/6J inbred mice for at least 5 generations. Upon arrival, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).

Allele

Symbol: Dlgap3^tm2.1Gfng
Name: targeted mutation 2.1, Guoping Feng
MGI accession ID: MGI:7523891
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); Null/Knockout
Synonyms: SAPAP3 cKI
Marker symbol: Dlgap3
Marker name: DLG associated protein 3
Marker synonyms: Dap3; DAP-3; Prpl8; PSD-95/SAP90-binding protein 3; SAP90/PSD 95 associated protein 3; SAPAP3; SPAPA3
Chromosome: 4
Strain of origin: (129X1/SvJ x 129S1/Sv)F1-Kitl⁺
Molecular note: The targeted allele is created to have an inverted exons 8-10 ((Ensemble ID: ENSMUSE00001223455, ENSMUSE00000400411, ENSMUSE00000335250, and introns) flanked with the FLEx cassette (inward-facing lox2272:loxP sites), followed by a FRT-flanked neomycin resistance cassette. The inversion creates a reading frame shift resulting in a null allele. Flp-mediated recombination removes the neo cassette.