Molecular dissection of the migrating posterior lateral line primordium during early development in zebrafish

Through the combined use of transgenic fish, Fluorescence Activated Cell Sorting and microarray analysis we identified a repertoire of key genes expressed in the migrating primordium and in differentiated neuromasts. We validated the specific expression in the primordium of a subset of the identified sequences by quantitative RT-PCR, and by in situ hybridization. We also show that interfering with the function of two genes, f11r and cd9b, defects in primordium migration are induced. Finally, pathway construction revealed functional relationships among the genes enriched in the migrating cell population.Our results demonstrate that this is a robust approach to globally analyze tissue-specific expression and we predict that many of the genes identified in this study will show critical functions in developmental events involving collective cell migration and possibly in pathological situations such as tumor metastasis.The formation of an embryo and its organ systems requires the coordination of diverse cellular behaviors to achieve proper development of form and function. Cells must migrate, often collectively, and proliferate in a regulated way, while simultaneously carrying out specific developmental programs. A full characterization of these events requires a description of the cellular histories (lineage) and knowledge about the molecules that regulate these processes.Active cell movements take place not only during the development of organisms, but also in processes that occur during adult life. For example, in the immune system, an effective immune response depends on the regulated traffic of its cellular components. Disrupted cell migration also contributes to several important pathological processes, including cancer and chronic inflammatory diseases such as rheumatoid arthritis and multiple sclerosis.To date, most knowledge about cell migration is based on in vitro studies of single cells in two-dimensional cultures. These studies have allowed great progress o