Gt(ROSA)26Sor^{tm1(CAG-mNeonGreen/mRuby2)Mnz}

A CAG promoter, loxP-flanked STOP/neomycin cassette in reverse transcriptional orientation, a FRET-based INDIcator of Apoptosis (INDIA) cassette, a single FRT site (remaining after Flp-expressing bacteria were used to excise an FRT-flanked IRES-EGFP cassette from the targeting vector), and polyA were introduced to intron 1. The INDIA reporter consists of an optimized fluorescence (Forster) resonance energy transfer (FRET) pair: N-terminally Myc-tagged mNeonGreen and mRuby2 linked by an 18 amino acid peptide containing an aCasp3-cleavage site (DEVDG). When aCasp3 (Casp3, caspase 3; a marker for apoptosis) cleaves the linker, mNeonGreen and mRuby2 are separated, resulting in FRET loss (FRET<->) and increased emission from mNeonGreen. Non-apoptotic cells retaining uncleaved mNeonGreen/mRuby2 (FRET<+>) demonstrate more yellow fluorescence indicating a lower ratio of mNeonGreen/FRET fluorescence emission. (J:261534)