The overall objective of the FlyLight Project is to produce large anatomical data sets, highly characterized collections of GAL4 drivers, and genetic and computational tools that function synergistically to enable studies of the Drosophila nervous system. We believe the reagents and research tools we are developing are critical to the progress of the field and that Janelia can play a key role in developing them.
We work closely with many labs and project teams at Janelia, and are actively engaged with both internal and external scientists who bring expert anatomical knowledge of specific regions of the Drosophila nervous system to generate a comprehensive library of Split-GAL4 driver lines covering the majority of the larval and adult CNS.
GAL4 driver lines that employ a single enhancer (Generation 1 lines) do not produce cell-type specific expression patterns (Jenett et al). To produce lines with the desired specificity, we employ an intersectional strategy. Two constructs that each drive the expression of a non-functional half of the GAL4 protein under the control of a different enhancer are brought together in the same fly. Only those cells in which both enhancers are active produce functional GAL4 (Luan et al 2006, Pfeiffer et al 2010).
Diagram of the split-GAL4 approach
Example of the split-GAL4 approach. The enhancer fragments from the Generation 1 lines R20G03 and R19F09 were used to make activation domain (AD) and DNA-binding domain (DBD) lines. When present in the same fly these constructs generate a highly specific expression pattern consisting of only two neurons in the adult nervous system. Arrow points to the cell body of one neuron (see Aso et al).