significantly reduced expression of EGFP in muscle tissue, and mosaicism was seen also. When these embryoes reached adulthood, they were mated with a wild type strain, and the resulting clutches had significantly less progeny that expressed the EGFP in the muscle tissue (0-4%). These results show, that not only is FLPe highly effective in somatic cells, it is also highly effective in the germline of zebrafish. In plants Creation of "phytosensors" or "sentinels" in Arabidopsis thaliana and Tobacco Phytosensors are genetically modified plants that can report the presence of biotic or abiotic contaminants. Obviously, the production of these engineered plants have great agricultural and laboratory promise. However, creating an appropriate reporter vector has shown to be problematic. cis-regulatory elements play a major role in the transcriptional activation of genes in plants, and many are not well understood. Many phytosensors either under express their reporter genes or report false-positives due to synthetic promoters. The authors of Rao et al. (2010) utilized the FLP recombinase tool for the production of a highly efficient phytosensors. The authors used a heat shock promoter to induce the production of FLP while a FRT-flanked vector separated the CaMV 35S promoter from the beta-glucuronidase gene (GUS). When the plants were exposed to heat-shock, FLP-induction led to the excision of the FRT-flanked vector, effectively moving the GUS gene directly downstream of the CaMV 35S promoter. The activation of GUS led to the leaves of the plants to change from green to blue; thus, the phytosensor effectively reported stress to the model system! With Cre-recombinase Production of the gate-way-ready inducible MiRNA (GRIM) expression system RNA interference (RNAi) has caused a paradigm shift in the expression of genes and potential gene knockouts in Eukaryotes. Before the production of the GRIM expression system, the creation of RNAi vectors was expensive and time consuming. The vectors were produced by the traditional copy-and-paste molecular cloning method. Garwick-Coppens et al. (2011) developed a much more efficient method for the production of RNAi vectors in which expression of the RNAi can be knocked-in using Cre-recombinase and knocked-out using Flp-recombinase. The novel GRIM Expression System allows for the much faster generation of expression vectors containing artificial RNAi constructs. The authors went on to show that their expression system works quite effectively in human embryonic kidneys (HEK) cells, a common human immortalized cell line in molecular research. See also Site-specific recombinase technology Recombinase-mediated cassette exchange Cre recombinase