B6N.B6-Tg(Nr4a1-EGFP/cre)820Khog/J

Stock number: 018974
Product name: Nur77^GFP
Research areas: Cancer Research, Cell Biology Research, Developmental Biology Research, Hematological Research, Immunology, Inflammation and Autoimmunity Research, Research Tools

Description

The Cre recombinase/green fluorescent protein fusion protein, driven by the Nr4a1 (Nur77) promoter in these mice, is expressed mainly in a subset of myeloid lineage cells of the spleen. These mice may be useful in studying thymocyte positive- and negative-selection as well as lymphocyte activation.

Detailed description

To be more suitable for use with C57BL/6N-congenic Knockout Mouse Project (KOMP) strains with floxed alleles, The Jackson Laboratory Repository chose several Cre recombinase-expressing strains and backcrossed them onto the C57BL/6N genetic background using a marker-assisted, speed-congenic approach. This approach employed 148 single nucleotide polymorphism (SNP) markers that differ between the C57BL/6N and C57BL/6J substrains, covering all 19 chromosomes and the X chromosome. This analysis has determined that all 148 SNP markers are now C57BL/6N allele-type.

It should be noted that the phenotype of these fully C57BL/6N congenic Nur77-GFPCre BAC transgenic mice (Stock No. 018974) could vary from that of the parental line originally described on a less congenic C57BL/6N background. We may modify the fully C57BL/6N congenic strain description if necessary as published results become available.

Development

The Nur77-GFPCre BAC transgene was designed with an eGFP-hCre fusion protein cDNA sequence (enhanced green fluorescent protein fused to a codon-optimized "humanized" Cre to improve translational efficiency in eukaryotic cells) and a TGA STOP codon inserted into the ATG start site of the Nr4a1 locus on the RP24-366J14 mouse bacterial artificial chromosome. Mice harboring the ~135 kbp Nur77-GFPCre BAC transgene on an incipient congenic C57BL/6 background were sent to The Jackson Laboratory Repository in 2011 (~N5 as Stock No. 016617). In 2012, some mice were bred to C57BL/6NJ inbred mice (Stock No. 005304) for many generations using a marker-assisted, speed congenic approach to generate this fully C57BL/6N congenic strain (~N10+; Stock No. 018974). This approach employed 148 single nucleotide polymorphism (SNP) markers that differ between the C57BL/6N and C57BL/6J substrains, covering all 19 chromosomes and the X chromosome. This analysis determined that all 148 SNP markers are now C57BL/6N allele-type.

Allele

Symbol: Tg(Nr4a1-EGFP/cre)820Khog
Name: transgene insertion 820, Kristin A Hogquist
MGI accession ID: MGI:5007644
Generation method: Transgenic
Attributes: Recombinase-expressing
Synonyms: B6-820; Nur77^GFP; Nur77-GFPCre B6-820
Marker symbol: Tg(Nr4a1-EGFP/cre)820Khog
Marker name: transgene insertion 820, Kristin A Hogquist
Chromosome: UN
Strain of origin: C57BL/6J
Expressed genes: GFP,Green Fluorescent Protein,; cre,cre recombinase,bacteriophage P1
Site of expression: GFP is highly expressed in a subset of myeloid lineage cells of the spleen (but not lymph node), while low levels of GFP are observed in T and B lymphocytes.
Molecular note: The 170 kb C57BL/6J mouse bacterial artificial chromosome (BAC) RP24-366J14, containing the entire Nr4a1 locus (Nur77) was obtained. An eGFP-hCre fusion protein cDNA sequence (enhanced green fluorescent protein fused to a codon-optimized "humanized" Cre to improve translational efficiency in eukaryotic cells), a frt-flanked neo cassette, and a TGA STOP codon was inserted into the ATG start site of the Nr4a1 gene on the RP24-366J14 BAC via homologous recombination/BAC recombineering. The frt-flanked neo was removed via arabinose treatment during BAC recombineering. A ~135 kb fragment from the modified BAC harboring the targeted Nr4a1 locus as well as 60 kb sequence flanking each side of the Nr4a1 locus (including the Acvr1b, A330009N23Rik, Grasp, 9430023L20Rik and 6030408B16Rik loci) was purified and then microinjected into C57BL/6J embryos. The resulting Nur77GFP BAC transgenic founder mice were bred with C57BL/6NCr mice. Transgenic mice from the B6-820 founder line were found with high GFP expression levels in myeloid lineage cells from spleen (but not lymph node), as well as low GFP expression levels in T and B lymphocytes.