129-Gt(ROSA)26Sor^{tm1(CAG-EGFP)Luo}/J

Stock number: 006053
Product name: MADM-GG
Research areas: Cell Biology Research, Research Tools

Description

These knock-in mice were developed to serve as controls for use with the mosaic analysis with double markers (MADM) system that allows simultaneous labeling and gene knockout in clones of somatic cells or isolated single cells in vivo. This strain carries only the green fluorescent protein, EGFP (G).

Detailed description

MADM-GG mice are viable with no gross behavioral or observable abnormalities. Regardless of Cre-recombination, these mice express EGFP as their N- and C-terminal coding sequences are interrupted by the beta-actin intron in-frame. High EGFP expression in every cell can be visualized in vivo and in fixed samples. These mutant mice are a control EGFP-expressing strain for use with MADM (mosaic analysis with double markers) mice (see Stock No. 006041 [MADM-GR (EGFP/Dsred2)] and Stock No. 006067 [MADM-RG (Dsred2/EGFP)]). Using the MADM system, a researcher can generate genetic mosaics in which an individual organism contains somatic cells of different genotypes. This allows the researcher to ascertain lineal relationships and pleiotropic gene function in multicellular organisms. These mice may also be useful in studies of cell differentiation and mitosis.

Mice harboring this MADM-GG mutation are also available congenic on a C57BL/6J genetic background (see Stock No. 006071), providing a control strain for the C57BL/6J congenic MADM-GR (Stock No. 006075) and MADM-RG (Stock No. 006080) strains.

Development

A targeting vector was designed to contain the N-terminal portion of a mutant enhanced green fluorescent protein (mut4-EGFP; Okada et al, Exp Neurol 1999 156:394-406), beta-globin intronic sequence (itself containing a loxP-flanked neomycin resistance gene), and remaining "in-frame" C-terminal portion of mut4-EGFP. This construct (GG) is preceded by the cytomegalovirus beta-actin enhancer-promoter and followed by the SV40 T antigen poly A signal, allowing for ubiquitous and high-level expression of the reporter genes. This entire construct was inserted into the Gt(ROSA)26Sor locus via electroporation of (129X1/SvJ x 129S1/Sv)F1-derived R1 embryonic stem (ES) cells. Correctly targeted ES cells were microinjected in C57BL/6 blastocysts and chimeric progeny were established. Mutant mice were bred to 129S1/SvImJ (Stock No. 002448) for one generation, and then intercrossed to homozygosity before arriving at The Jackson Laboratory.

Allele

Symbol: Gt(ROSA)26Sor^{tm1(CAG-EGFP)Luo}
Name: targeted mutation 1, Liqun Luo
MGI accession ID: MGI:3623345
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); Reporter
Marker symbol: Gt(ROSA)26Sor
Marker name: gene trap ROSA 26, Philippe Soriano
Chromosome: 6
Strain of origin: (129X1/SvJ x 129S1/Sv)F1-Kitl⁺
Expressed genes: GFP,Green Fluorescent Protein,
Site of expression: widespread expression; control strain for Stock No. 006067 and Stock No. 006041
Molecular note: A construct containing the CMV beta-actin enhancer/promoter, SV40 poly(A) signal, and encoding the N-terminal and C-terminal halves of a mutant enhanced green fluorescent protein (EGFP) separated by a beta-globin intron containing a loxP-flanked neomycin resistance gene, was knocked into ES cells at the ROSA26 locus. The two parts of the coding sequence are separated by the intron but still in the same reading frame. Ubiquitous GFP expression occurs in the absence of cre-mediated recombination.