(485bm) Dynamic NF-κB Signaling in the Early Drosophila Embryo Patterns Multiple Tissue Types

The ability of a developing organism to generate reliable patterns in the face of natural variation and environmental fluctuations has fascinated several generations of embryologists and naturalists. Despite the increasing knowledge of morphogenetic pattern formation, the molecular relationships between gradient formation and reliability of downstream patterning remain elusive. The Drosophila NF-B homologue, Dorsal (dl), is the only known maternal source of DV positional information in the embryo. A ventral-to-dorsal gradient in nuclear dl concentration is established in the early embryo, and this gradient is responsible for the correct patterning of the DV axis. As such, the ability to generate the stereotypical patterns depends on whether or not patterning by dl ? and factors downstream of it ? are robust. We quantify the dl nuclear gradient as well as gene expression data of known dl target genes ? such as sna, sog, vnd, and ind ? in both wild type and mutant genetic backgrounds. We are using molecular genetics and mathematical modeling to measure the robustness of gene expression patterns, and ask whether these attributes can be explained by the dl gradient alone.