B6;FVB-Tg(Crh-cre)1Kres/J

Stock number: 011087
Research areas: Neurobiology Research, Research Tools

Description

Cre recombinase in these mice is driven by the truncated mouse Crh promoter, and is expressed in neurons that express Crh.

Detailed description

This strain expresses Cre recombinase from a truncated mouse Crh (corticotropin releasing hormone) promoter. When crossed with a strain containing loxP site flanked sequence, Cre-mediated recombination results in tissue-specific deletion of the sequence. Recombination occurs in more than 90% of neurons that express Crh, such as the CRH (CRF) neurons in the lateral division of the central nucleus of the amygdala, the bed nucleus of the stria terminalis and paraventricular nucleus (PVN).

Development

A 3.0Kb region of the Crh promoter was PCR amplified from mouse bacterial artificial chromosome clone #129A14 and resulting amplicons were topo-cloned into pCR2.1-topo, (Invitrogen, Carlsbad, CA). Incorporated into the primers were restriction sites for later subcloning. The lentivirus backbone, pCMVGFPdNhe was digested with ClaI and SalI to remove the CMVGFP sequence, The linearized lentivirus backbone was ligated to the 3.0Kb Crh promoter (a ClaI/BamHI fragment) and to the Cre coding sequence, (a BamHI/SalI fragment). The LVCRFp3.0Cre construct was linearized with NheI and SphI, purified by electroelution, and diluted to 2ng/ul for pronuclear microinjection into FVB mouse cells by the Emory University Transgenic Core Facility. The donating investigator reported that this strain was backcrossed approximately 4-6 times to C57BL/6 (see SNP results below) prior to sending males to The Jackson Laboratory Repository in 2011. Upon arrival, males were used to cryopreserve sperm. To establish the living mouse colony, an aliquot of the frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).

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 (F2 generation) at The Jackson Laboratory Repository. This revealed 6 of 27 markers, one each on chromosomes 2, 6, 7 and 9, and two markers on chromosome 17, that were not fixed for C57BL/6 allele-type (e.g., still segregating for FVB/N allele-type markers). In addition, all 5 markers that determine C57BL/6J from C57BL/6N were also found to be segregating on chromosomes 8, 11, 13 and 19 (note that these markers are the same for C57BL/6N and FVB/N). These data suggest the mice were backcrossed to C57BL/6 for fewer generations than reported prior to arrival at The Jackson Laboratory Repository, and the mice are most likely now a mix of C57BL/6 (~65-78%) and FVB/N (~22-35%).

Allele

Symbol: Tg(Crh-cre)1Kres
Name: transgene insertion 1, Kerry J Ressler
MGI accession ID: MGI:4457114
Generation method: Transgenic
Attributes: Recombinase-expressing
Marker symbol: Tg(Crh-cre)1Kres
Marker name: transgene insertion 1, Kerry J Ressler
Chromosome: UN
Strain of origin: FVB
Expressed genes: cre,cre recombinase,bacteriophage P1
Site of expression: When crossed with a strain containing loxP site flanked sequence, Cre-mediated recombination results in tissue-specific deletion of the sequence in more than 90% of neurons that express Crh, such as neurons in the lateral division of the central nucleus of the amygdala, the bed nucleus of the stria terminalis and paraventricular nucleus.
Molecular note: A 3.0Kb region of the Crh promoter was PCR amplified from mouse bacterial artificial chromosome clone #129A14. The transgenic construct contains the 3.0Kb Crh promoter ligated to the cre coding sequence. The linearized construct was microinjected into pronuclei of FVB oocytes and a line was generated by crossing to C57BL/6.