Parameters that influence bipartite reporter system expression in <i>Caenorhabditis elegans</i>

The development of bipartite reporter systems in Caenorhabditis elegans has lagged by more than a decade behind its adoption in Drosophila, the other invertebrate model commonly used to dissect biological mechanisms. Here, we characterize many parameters that influence expression in recently developed C. elegans bipartite systems. We examine how DNA binding site number and spacing influence expression and characterize how these expression parameters vary in distinct tissue types. Furthermore, we examine how both basal promoters and 3' UTR influence the specificity and level of expression. These studies provide both a framework for the rational design of driver and reporter transgenes and molecular and genetic tools for the creation, characterization, and optimization of bipartite system components for expression in other cell types.