Adrenal expression of Nr4a2 is increased threefold following LPS challenge in homozygous mice of this strain. Mutant mice may be useful in studies of anti-psychotic drug/neuroleptic therapies and other neurological studies. Although the original analysis of this allele revealed no detectable transcript of any type from this gene in the thymus, findings by Koenis, 2018 (PMID 30111591) indicate the presence of a transcript capable of producing a truncated N-terminal domain (NTD) peptide that can stabilize and activate HIF1A (hypoxia inducible factor 1, alpha subunit).
Jeffrey Milbrandt, Washington University School of Medicine, St. Louis
A neomycin cassette was introduced to exon 2 of the mouse Nr4a1 (nuclear receptor subfamily 4, group A, member 1; also called Nur77 or NGFI-B) gene, blocking the transcription of both the DNA binding domain (DBD) and ligand-binding (LBD) domain. Although the original analysis of this allele revealed no detectable transcript of any type from this gene in the thymus, findings by Koenis, 2018 (PMID 30111591) indicate the presence of a transcript capable of producing a truncated N-terminal domain (NTD) peptide that can stabilize and activate HIF1A (hypoxia inducible factor 1, alpha subunit). Neither the transcriptional nor the translational start of the gene are disrupted.
Eight-month-old homozygotes develop systemic inflammation (PMID 26113803), demonstrating splenomegaly, and severe infiltration of inflammatory cells in several organs including liver, lung, spleen and kidney, in addition to increased hyperplasia of fibrous tissue in the lung, and enlargement of kidney glomeruli. Homozygotes also show increased production of pro-inflammatory cytokines and immunoglobulin, and elicit pro-inflammatory M1-like polarization in macrophages as revealed by increased expression of CXCL11 and INDO, and decreased expression of MRC1.
Following acute neuroleptic administration with dopamine D2 receptor antagonists (haloperidol and/or raclopride), homozygous mice exhibit reduced catalepsy and disrupted neuropeptide responses in the brain. In homozygotes, adrenal expression of Nr4a2 (also called Nurr1) is increased threefold following LPS challenge. Mutant mice may be useful in studies of antipsychotic drug/neuroleptic therapies, schizophrenia, neurobiology, nuclear receptor family transcription pathways, adrenal gland, and steroidogenesis.
Mice homozygous for this targeted mutation are viable and fertile.
A targeting vector was designed to insert a phosphoglycerate kinase-neomycin resistance cassette (PGK-neo) cassette into the coding region of exon 2 of the Nr4a1 gene (also called Nur77 or NGFI-B). This construct was electroporated into 129S2/SvPas-derived D3 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6J blastocysts. Chimeric males were bred with C57BL/6J females to establish heterozygous mice. The donating investigator reports that mutants were bred to C57BL/6 for more than 10 generations and then intercrossed to homozygosity prior to arrival at The Jackson Laboratory (see SNP note below).
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. Two of the 27 markers throughout the genome suggested a 129 genetic background, suggesting an incomplete backcross. Four of 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 were on a mixed C57BL/6J ; C57BL/6N genetic background.
|Allele Name||targeted mutation 1, Jeffrey Milbrandt|
|Allele Type||Targeted (Not Specified)|
|Allele Synonym(s)||classical Nur77-KO; NGFI-B (-); NGFI-B-; Nur77-|
|Gene Symbol and Name||Nr4a1, nuclear receptor subfamily 4, group A, member 1|
|Strain of Origin||129S2/SvPas|
|Molecular Note||Exon 2 was disrupted by the insertion of a neomycin resistance gene 300 bp downstream of the translational start site. A functional portion of the N-terminal domain of the full length gene is expressed.|
When maintaining a live colony, these mice are maintained as homozygotes.
When using the NGFI-B- mouse strain in a publication, please cite the originating article(s) and include JAX stock #006187 in your Materials and Methods section.