Randall W. Phillis
Associate Professor of Biology, University of Massachusetts
Ph.D.: Indiana University Postdoctoral Training: University of Wisconsin
In my lab we have been charcterizing a series of mutations that affect the function and anatomy of axon projections within the central nervous system of Drosophila. This project started with the isolation of a series of mutations that affect leg coordination and behavior, and has involved their genetic, molecular, neuroanatomical, and neurophysiological characterization. One of the mutations we have focused on most intensely disrupts the cytoplasmic dynein light chain gene (Cdlc1). To characterize the neuroanatomical effects of Cdlc1 mutations, we have made extensive use of the P[Gal4] enhancer trap system to label the axon projections of specific, identified sensory neurons. Loss of function in this gene causes the axon projections of several classes of sensory neuron to show branching and pathfinding defects within the CNS. Targetted expression experiments have demonstrated that the axon defects result from a cell-autonomous function of this gene. We have also demonstrated that Cdlc1 mutation interacts genetically with mutation in genes encoding other subunits of the cytoplasmic dynein complex. We are currently determining the nature of an apparent stage-specfic onset of the axon defects in development using a temperature-inducible gene construct. We are now applying the approaches and molecular-genetic tools we have developed for the characterization of Cdlc1 mutations to several other mutations we recovered in our screens.