Randall W. Phillis

Associate Professor of Biology, University of Massachusetts

Email: rphillis@bio.umass.edu
R. Phillis Biology Dept Website

Ph.D.: Indiana University
Postdoctoral Training: University of Wisconsin

Molecular Genetics of Neural Develoment in Drosophila

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.

Representative publications:

Brainerd, E. L., S. S. Slutz, E. K. Hall and R. W. Phillis (2001). "Patterns of genome size evolution in tetraodontiform fishes." Evolution Int J Org Evolution 55(11): 2363-8.

Murphey, R. K., P. C. Caruccio, M. Getzinger, P. J. Westgate and R. W. Phillis (1999).
"Dynein-dynactin function and sensory axon growth during Drosophila metamorphosis: A role for retrograde motors." Dev Biol 209(1): 86-97.

Reddy, S., Jin, P., Trimarchi, J., Caruccio, P., Phillis, R.W. and Murphey, R.K. (1997) Mutant molecular motors disrupt neural circuits in Drosophila. J. Neurobiol. 33, 711-723

Phillis, R.W., Statton, D., Caruccio, P. and Murphey, R.K. (1996) Mutations in the 8kDa dynein light chain gene disrupt sensory axon projections in the Drosophila imaginal CNS. Development 122, 2955-2963.

Gorczyca, M., Phillis, R.W. and Budnik, V. (1994) The role of tinman, a mesodermal cell fate gene, in axon pathfinding during the development of the transverse nerve in Drosophila. Development 120, 2143-2152.

Phillis, R.W., Bramlage, A.T., Wotus, C., Whittaker, A, Gramates, L.S., Seppala, D., Farahanchi, F, Caruccio, P. and Murphey, R.K. (1993) Isolation of mutations affecting neural circuitry required for grooming behavior in Drosophila melanogaster. Genetics 133, 581-592.