These c-Kit Cre-ires-GFP mice, used to trace the lineage of Kit-expressing cardiac cells, express cre recombinase and nuclear-localize EGFP from the mouse Kit (also called c-Kit) promoter. Expression of the targeted Kit gene is eliminated.
Jeffery D. Molkentin, Cincinnati Children's Hospital
These KitCre mice, used to trace the lineage of Kit (KIT proto-oncogene receptor tyrosine kinase; also called c-Kit)-expressing cardiac cells, express cre recombinase and nuclear-localized EGFP from the mouse Kit promoter. Expression of the targeted Kit gene is eliminated.
Heterozygous mice display defects in pigment cell migration resulting in varying degrees of white belly spotting and white paws. Heterozygotes are viable and fertile with no other overt phenotype. Expression of cre/GFP has been confirmed in heart, lung, kidney, liver, spleen, intestine, testis, skin, and skeletal muscle of homozygous animals via Western blot. The IRES-driven nuclear GFP displays low expression but can be detected in rare Kit+ cells without antibody staining.
Homozygotes are devoid of Kit expression and die shortly after birth.
A cre-ires-GFP-polyA cassette tagged with a nuclear localization signal followed by a FRT-flanked neomycin cassette was inserted in-frame into the mouse c-Kit (Kit) gene, replacing a 66 bp region including the ATG site in exon 1. The mutation was created in C57BL/6N-Atm1Brd-derived JM8A3 embryonic stem (ES) cells. Correctly targeted ES cells were aggregated with recipient 8-cell embryos and chimeric mice were bred to C57BL/6J mice. Heterozygotes were then bred to Flp-expressing mice (see Stock No. 009086) to remove the neo cassette. This strain was backcrossed to C57BL/6J for 10 generations by the donating laboratory.
|Allele Name||targeted mutation 1.1, Jeffery D Molkentin|
|Allele Type||Targeted (Recombinase-expressing, Reporter, Null/Knockout)|
|Gene Symbol and Name||Kit, KIT proto-oncogene receptor tyrosine kinase|
|Strain of Origin||C57BL/6N-Atm1Brd|
|Molecular Note||A cDNA encoding a cre-IRES-nlsEGFP (cre recombinase separated by an internal ribosomal entry site from the nuclear localized EGFP coding sequence) cassette and an frt-flanked neomycin selection marker were cloned in-frame at the Kit ATG start site in exon 1. Homologous recombination was performed in ES cells which were aggregated with 8-cell embryos to generate chimeras. Chimeras were crossed to knock-in flp-expressing mice to delete the neo marker. Animals produce a bicistronic transcript for production of cre and EGFP proteins.|
Heterozygotes are viable and fertile. Homozygotes are devoid of Kit expression, and die shortly after birth. Heterozygotes are black with a white belly spot. The donating laboratory reports that breeding heterozygous males with C57BL/6J females results in fewer and smaller litter sizes. Crosses involving heterozygous female mice are recommended.
When using the KitCre; Kit-Cre-IRES-eGFPnls mouse strain in a publication, please cite the originating article(s) and include JAX stock #032051 in your Materials and Methods section.