| During development of an organism, networks of transcription factors activate and repress expression of genes necessary to specify individual cell fates via distinct cis-regulatory motifs. These developmental networks ultimately lead to the specification of tissue and organ types, which contain highly specialized cells. The question of how the expression of cell-specific genes is regulated to generate a specialized cell type is investigated in detail in the C. elegans AWB chemosensory neuron type. We have found that C. elegans uses partially shared cell specific cis-regulatory motifs to control expression of chemoreceptor genes, while the expression of more broadly expressed genes is regulated via multiple additional pathways. Thus, the cell type-specific features of the AWB neuron type are conferred by multiple cis- and trans-regulatory mechanisms that act in parallel to regulate the expression of the appropriate gene subsets. |
