The nervous system is extremely complex and accurate. Generation of this complicated network involves many biological events, such as cell proliferation, cell degeneration, cell differentiation, neuron remodeling, axon guidance, axon bifurcation, axon extension, synapse formation and plasticity. Our lab seeks to understand the fundamental molecular mechanisms that guide the formation and maintenance of the nervous system using the fruit fly, Drosophila melanogaster, as a model system.

Many genes controlling neuronal development are essential genes. We use the genetic technique called MARCM (Mosaic Analysis with a Repressive Cell Marker) (Lee and Luo, 1999) to manipulate gene expression in a single neuron or a subset of neurons within the developing brains and to examine neuronal morphology at the certain developmental stages. 

Currently, two projects are actively ongoing in the lab. The first project is to study the functions and signaling pathways of Drosophila Dscam (Down Syndrome Cell Adhesion Molecule). Down Syndrome (DS) is the most frequent mental retardation disease caused by a genetic disorder in humans. It occurs in about 1 out of 800 live births among all races and economic groups. Human DSCAM is strongly suggested to be involved in the pathogenesis of DS, and our early studies indicated that Drosophila Dscam, a homologue of human DSCAM, is required for normal axon branching and guidance. Surprisingly, Drosophila Dcsam gene potentially encodes more than 150,000 distinct cell adhesion molecules through mRNA alternative splicing. We are also interested in understanding the biological significance of this tremendous molecular diversity. The second project is to continue the systemic, genome-wide mosaic screens for genes underlying different aspects of neuronal development.