@article {834381, title = {GFP reporters detect the activation of the Drosophila JAK/STAT pathway in vivo.}, journal = {Gene Expr Patterns}, volume = {7}, number = {3}, year = {2007}, month = {2007 Jan}, pages = {323-31}, abstract = {JAK/STAT signaling is essential for a wide range of developmental processes in Drosophila melanogaster. The mechanism by which the JAK/STAT pathway contributes to these processes has been the subject of recent investigation. However, a reporter that reflects activity of the JAK/STAT pathway in all Drosophila tissues has not yet been developed. By placing a fragment of the Stat92E target gene Socs36E, which contains at least two putative Stat92E binding sites, upstream of GFP, we generated three constructs that can be used to monitor JAK/STAT pathway activity in vivo. These constructs differ by the number of Stat92E binding sites and the stability of GFP. The 2XSTAT92E-GFP and 10XSTAT92E-GFP constructs contain 2 and 10 Stat92E binding sites, respectively, driving expression of enhanced GFP, while 10XSTAT92E-DGFP drives expression of destabilized GFP. We show that these reporters are expressed in the embryo in an overlapping pattern with Stat92E protein and in tissues where JAK/STAT signaling is required. In addition, these reporters accurately reflect JAK/STAT pathway activity at larval stages, as their expression pattern overlaps that of the activating ligand unpaired in imaginal discs. Moreover, the STAT92E-GFP reporters are activated by ectopic JAK/STAT signaling. STAT92E-GFP fluorescence is increased in response to ectopic upd in the larval eye disc and mis-expression of the JAK kinase hopscotch in the adult fat body. Lastly, these reporters are specifically activated by Stat92E, as STAT92E-GFP reporter expression is lost cell-autonomously in stat92E homozygous mutant tissue. In sum, we have generated in vivo GFP reporters that accurately reflect JAK/STAT pathway activation in a variety of tissues. These reporters are valuable tools to further investigate and understand the role of JAK/STAT signaling in Drosophila.}, keywords = {Animals, Animals, Genetically Modified, Drosophila melanogaster, Drosophila Proteins, Embryo, Nonmammalian, Gene Expression Regulation, Developmental, Genes, Reporter, Green Fluorescent Proteins, Janus Kinases, Signal Transduction, STAT Transcription Factors, Suppressor of Cytokine Signaling Proteins, Transcription Factors}, issn = {1567-133X}, doi = {10.1016/j.modgep.2006.08.003}, author = {Bach, Erika A and Ekas, Laura A and Ayala-Camargo, Aidee and Flaherty, Maria Sol and Lee, Haeryun and Perrimon, Norbert and Baeg, Gyeong-Hun} }