B6;129S-Grp^{tm1.1(EGFP/cre)Zfc}/J

Stock number: 033174
Product name: Grp^Cre-KI
Research areas: Neurobiology Research, Research Tools

Description

Grp^Cre-KI knock-in/knock-out mice have an enhanced green fluorescent protein sequence (EGFP) fused to a Cre Recombinase sequence (cre) into the ATG start codon of the gastrin releasing peptide (Grp) gene. These mice are useful when for characterizing innervation of Grp sensory neurons and studying the role of Grp spinal neurons in itch and pain.

Detailed description

Grp^Cre-KI knock-in/knock-out mice have an enhanced green fluorescent protein sequence (EGFP) fused to a Cre Recombinase sequence (cre) inserted into the ATG start codon of the gastrin releasing peptide (Grp) gene. GRP is an itch-specific neurotransmitter that transmits itch from sensory neuron primary afferents to GRP-receptor (GRPR) neurons.

When Grp^Cre-KI mice are bred with mice containing loxP-flanked sequence(s), Cre-mediated recombination will result in deletion of the floxed sequence(s) in the Cre-expressing cells of the offspring. Cre recombination and EGFP expression occurs in sensory neurons that innervate the skin. EGFP is detectable following immunohistochemistry, and it not observable by direct fluorescence.

Of note, a strain containing floxed Grp is available as Stock No. 033096.

Development

The Grp^Cre-KI targeting vector was designed to insert an enhanced green fluorescent protein sequence (EGFP) fused to a Cre Recombinase sequence (cre) into the ATG start codon of the gastrin releasing peptide (Grp) gene. The construct was electroporated into 129S7/SvEvBrd-Hprt⁺-derived AB1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6J blastocysts and resulting chimeric mice were bred with C57BL/6J mice for at least 3 generations by the donating laboratory.



Upon arrival at The Jackson Laboratory, sperm was cryopreserved. It was later discovered that the males shipped to The Jackson Laboratory still contained the neo cassette. Subsequently, these mice were bred with Flpo recombinase expressing mice (Stock No. 012930) to remove the neo cassette and progeny were crossed to B6129SF2/J mice (Stock No. 101045) to remove the Flpo-expressing transgene. Mice were maintained on a mixed B6;129 genetic background by breeding to B6129SF1/J mice (Stock No. 101043) or wildtype mice from the colony.

Allele

Symbol: Grp^{tm1.1(EGFP/cre)Zfc}
Name: targeted mutation 1.1, Zhou-Feng Chen
MGI accession ID: MGI:6285760
Generation method: Targeted
Attributes: Recombinase-expressing; Reporter; Null/Knockout
Synonyms: Grp^Cre-KI
Marker symbol: Grp
Marker name: gastrin releasing peptide
Marker synonyms: BLP; BN; GRP-10; MGC:37475; preproGRP; proGRP
Chromosome: 18
Strain of origin: 129S7/SvEvBrd-Hprt1⁺
Site of expression: Cre recombination and EGFP expression occurs in sensory neurons that innervate the skin.
Molecular note: The targeting vector was designed to insert an enhanced green fluorescent protein sequence (EGFP) fused to a Cre Recombinase sequence (cre) followed by a FRT-flanked neomycin cassette into the exon 1 ATG start codon of the gene. Flp-mediated recombination removed the FRT-flanked neo cassette. Immunohistochemistry and RNA in situ hybridization confirms the absence of Grp.