B6;SJL-Rxrg^em1Nses Rarb^em1Nses/J

Stock number: 038929
Product name: Rarb/Rxrg dKO
Research areas: Neurobiology Research, Research Tools

Description

Rarb/Rxrg dKO mice contain two CRISPR-mediated mutations resulting in the deletion of Rarb and Rxrg genes. This strain is useful when studying synaptic plasticity and the role of retinoic acid receptors during development.

Detailed description

Rarb/Rxrg dKO mice contain two CRISPR-mediated mutations resulting in the deletion of retinoic acid receptor, beta (Rarb) and retinoid X receptor gamma (Rxrg) genes. Rarb and Rxrg encode receptors for retinoic acid, a diffusible biologically active derivative of vitamin A involved in neural tube patterning, neurogenesis, cell differentiation, and synaptic function. They both exhibit higher anterior to lower posterior gradients of expression. RARB-RXRG heterodimer has been previously shown to mediate RA signaling in the adult mouse cortex and striatum and be required for learning, locomotion, and dopamine signaling. Alterations in RA signaling have been implicated in the pathophysiology of autism spectrum disorder (ASD) and schizophrenia (SCZ).

This strain has a CRISPR-mediated knock-out of exon 9 and part of intron 10 of the Rarb gene. This region includes part of the ligand binding domain and results in total elimination of receptor activity. This strain also has a CRISPR-mediated knock-out of exons 3 and 4 of the of the Rxrg gene. This region includes a large part of DNA binding domain. RARB and RXRG mediate RA signaling in the developing mouse prefrontal cortex (PFC) as evidence by a reduction of RA signaling compared to control mice, and a less extensive reduction of RA signaling in the anterior cingulate area and retrosplenial area. Furthermore, expression of frontally enriched RA regulated genes, Cbln2 and Meis2, which are induced by RA in humans were reduced in the dKO mice.

Mice that are homozygous for this allele are viable and fertile.

Development

Rarb/Rxrg dKO mice contain two CRISPR-mediated deletions. The first deletion is of exon 9 and part of intron 10 of the retinoic acid receptor, beta (Rarb) gene. This region includes α-helical sheets H4 to H8 and part of the ligand binding domain. Deletion of this region results in a frameshift in the C-terminal region and total elimination of receptor activity. Guide RNAs (gaaattaatacgactcactatagggagaGCCCCACTGTTGAGGTTGAT and gaaattaatacgactcactatagggagaCTCCTGCTATCCAGACCGCC) and Cas9 nuclease mRNA were introduced into the cytoplasm of zygotes derived from B6SJLF1/J mice with well recognized pronuclei. Correctly targeted embryos were transferred to pseudopregnant females. Rarb^- mice were identified by sequencing and PCR and further backcrossed to C57BL/6J mice (Stock No. 000664) to remove any off-target sites.

Another CRISPR-mediated deletion results in the removal of exon 3 and 4 of the retinoid X receptor gamma (Rxrg) gene. This region includes a large part of DNA binding domain. Guide RNAs (gaaattaatacgactcactatagggagaCTCACATGCACGCGCCTTGC gaaattaatacgactcactatagggagaCAGGCTGCACGCGACTCTAT) and Cas9 nuclease mRNA were introduced into the cytoplasm of zygotes derived from B6SJLF1/J mice with well recognized pronuclei. Correctly targeted embryos were transferred to pseudopregnant females. Rxrg^- mice were identified by sequencing and PCR and further backcrossed to C57BL/6J mice to remove any off-target sites.

Rarb^-/- and Rxrg^-/- mice were bred together and double knock-out mice were maintained on a C57BL/6J 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/6J oocytes (Stock No. 000664).

Allele

Symbol: Rarb^em1Nses
Name: endonuclease-mediated mutation 1, Nenad Sestan
MGI accession ID: MGI:7425385
Generation method: Endonuclease-mediated
Attributes: Null/Knockout
Marker symbol: Rarb
Marker name: retinoic acid receptor, beta
Marker synonyms: Hap; MCOPS12; NR1B2; RAR beta 2; RARbeta; RARbeta1; RARbeta2; RRB2
Chromosome: 14
Strain of origin: (C57BL/6J x SJL/J)F1/J
Molecular note: CRISPR-cas9 mediated recombination using guide RNAs created a deletion that removed all of exon 9.

Allele

Symbol: Rxrg^em1Nses
Name: endonuclease-mediated mutation 1, Nenad Sestan
MGI accession ID: MGI:7425386
Generation method: Endonuclease-mediated
Attributes: Null/Knockout
Marker symbol: Rxrg
Marker name: retinoid X receptor gamma
Marker synonyms: NR2B3; RXRC; RXRgamma; RXR-gamma
Chromosome: 1
Strain of origin: (C57BL/6J x SJL/J)F1/J
Molecular note: CRISPR-cas9 mediated recombination using guide RNAs created a deletion spanning exons 3 and 4.