Gt(ROSA)26Sor^{tm1.1(CAG-Venus/GMNN,-Cherry/CDT1)Jkn}

A single copy of the Fucci2a transgene under the control of the CAG promoter was inserted into the Rosa26 locus by homologous recombination. The Fucci2a transgene consists of a bicistronic reporter of cell cycle progression, expressing mVenus-hGem(1/110), consisting of mVenus reporter fused to the 110 amino acid N-terminus of the human Geminin protein, and mCherry-hCdt1(30/120), consisting of a truncated human Cdt1 protein containing amino acids 30-120. Both proteins are expressed as a fusion using the Thosea asigna virus 2A (T2A) self cleaving peptide sequence. The fusion protein expressed from this construct should predictably produce equimolar quantities of both cell cycle probes after self cleavage. No Fucci2a construct expression was observed in R26Fucci2aR animals due to the strong transcriptional stop sequences contained in the floxed-Neo-pA stop cassette. Upon cre-mediated recombination, strong expression of the Venus (green) and Cherry (red) fluorescent proteins is seen in actively cycling cells. Cre-mediated recombination removed the STOP cassette. (J:267034)