A sensitized genetic screen to identify novel regulators and components of the Drosophila janus kinase/signal transducer and activator of transcription pathway.
The JAK/STAT pathway exerts pleiotropic effects on a wide range of developmental processes in Drosophila. Four key components have been identified: Unpaired, a secreted ligand; Domeless, a cytokine-like receptor; Hopscotch, a JAK kinase; and Stat92E, a STAT transcription factor. The identification of additional components and regulators of this pathway remains an important issue. To this end, we have generated a transgenic line where we misexpress the upd ligand in the developing Drosophila eye. GMR-upd transgenic animals have dramatically enlarged eye-imaginal discs and compound eyes that are normally patterned. We demonstrate that the enlarged-eye phenotype is a result of an increase in cell number, and not cell volume, and arises from additional mitoses in larval eye discs. Thus, the GMR-upd line represents a system in which the proliferation and differentiation of eye precursor cells are separable. Removal of one copy of stat92E substantially reduces the enlarged-eye phenotype. We performed an F1 deficiency screen to identify dominant modifiers of the GMR-upd phenotype. We have identified 9 regions that enhance this eye phenotype and two specific enhancers: C-terminal binding protein and Daughters against dpp. We also identified 20 regions that suppress GMR-upd and 13 specific suppressors: zeste-white 13, pineapple eye, Dichaete, histone 2A variant, headcase, plexus, kohtalo, crumbs, hedgehog, decapentaplegic, thickveins, saxophone, and Mothers against dpp.
Bach
Erika A
EA
Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA. erika.bach@med.nyu.edu
Vincent
Stephane
S
Zeidler
Martin P
MP
Perrimon
Norbert
N
D000818:Animals; D004268:DNA-Binding Proteins / Q000378:metabolism*; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics*; D005434:Flow Cytometry; D008855:Microscopy, Electron, Scanning; D016133:Polymerase Chain Reaction; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D050791:STAT Transcription Factors; D015534:Trans-Activators / Q000378:metabolism*
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D050791:STAT Transcription Factors; C105675:Stat92E protein, Drosophila; D015534:Trans-Activators; D011505:Protein-Tyrosine Kinases