B6.Cg-Ucn^{tm1.1(cre/EGFP)Rpa}/J

Stock number: 039757
Product name: Ucn^Cre
Research areas: Neurobiology Research, Research Tools

Description

Ucn^Cre mice constitutively express a Myc-tagged, nuclear-localized cre recombinase (mnCre) fused to an EGFP reporter from the mouse urocortin (Ucn) promoter in Ucn-expressing neurons of the Edinger Westphal (EW) nucleus. These mice enable the measurement of Ucn neuron activity (calcium signaling) as well as the direct manipulation of neuronal activity.

Detailed description

Neurons expressing urocortin 1 (Ucn) in the Edinger Westphal (EW) nucleus have been hypothesized to play an important role in regulating both behavioral domains and responses to stress.

Ucn^Cre mice constitutively express a Myc-tagged, nuclear-localized cre recombinase (mnCre) fused to an EGFP reporter from the mouse Ucn promoter. Expression of EGFP and Cre are restricted to Ucn-expressing neurons of the Edinger-Westphal nucleus (Ucn^EW) in adult mice. Some cortical expression has been seen during development. Homozygous mice are fertile and appear normal in all respects. No phenotypic differences were detected between males and females.

Genetic crosses to cre-dependent calcium indicator (e.g. Ai162, Stock No. 031562) and optogenetic (e.g. Rosa26^LSL-ChR2 Ai32 mice, Stock No. 024109) effector lines have made it possible to measure calcium signaling and drive neuronal activity specifically in Ucn^EW neurons.

Development

IRES-mnCre:GFP and an FRT-flanked SV40-neomycin cassette were inserted just 3' of the termination codon in exon 2 of the mouse Ucn gene (NM_021290.2 - chr5:31,137,989-31,138,895). The IRES-mnCre:GFP cassette carries an internal ribosome entry sequence (IRES) and Cre recombinase with N-terminal Myc tag and nuclear localization signals (NLS) fused to green fluorescent protein followed by a SV40 polyadenylation sequence. The mutation was created in (129S6/SvEvTac x C57BL/6)F1-derived G4 embryonic stem (ES) cells. Resultant progeny were bred with Gt(ROSA)26Sor-FLP recombinase mice to remove the FRT-flanked SV40-neomycin cassette. The donating investigator reports the mice were then backcrossed to C57BL/6J mice for more than 6 generations prior to sending males to The Jackson Laboratory. Upon arrival in 2024, sperm was cryopreserved. To establish a live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).

Allele

Symbol: Ucn^{tm1.1(cre/EGFP)Rpa}
Name: targeted mutation 1.1, Richard D Palmiter
MGI accession ID: MGI:7719857
Generation method: Targeted
Attributes: Recombinase-expressing; Reporter; Epitope tag
Synonyms: Ucn^Cre
Marker symbol: Ucn
Marker name: urocortin
Marker synonyms: UCN1; UI; UROC
Chromosome: 5
Strain of origin: (129S6/SvEvTac x C57BL/6NCrl)F1
Molecular note: IRES-mnCre:GFP and an FRT-flanked SV40-neomycin cassette were inserted just 3' of the termination codon in exon 2 of the mouse Ucn gene (NM_021290.2 - chr5:31137989-31138895). The IRES-mnCre: GFP cassette carries an internal ribosome entry sequence (IRES) and Cre recombinase with N-terminal Myc tag and nuclear localization signals (NLS) fused to green fluorescent protein followed by a SV40 polyadenylation sequence. FLP recombinase removed the FRT-flanked SV40-neomycin cassette.