Berg, Celeste ABackman, Lara Beth2013-07-252013-07-252013-07-252013Backman_washington_0250O_11800.pdfhttp://hdl.handle.net/1773/23383Thesis (Master's)--University of Washington, 2013The guidance of fully-formed multicellular tubes is critical to the formation of the vertebrate lungs and kidneys. Using the dorsal appendages (DAs) of developing <italic>Drosophila melanogaster</italic> eggs, I attempted to elucidate what signaling pathways guide formed tubes to their final morphology. I refined and modified an egg-culture based method for assaying DA development, as well as an RNAi-based approach to determine signaling molecules. The results showed that both members of the Wnt family of proteins, such as Wnt2, and Semaphorin-2b contribute to DA guidance in <italic>Drosopila melanogaster</italic> eggs. This knowledge will both help us better understand the formation of DAs in particular and begin to let us discover the mechanisms behind tube guidance in other contexts.application/pdfen-USCopyright is held by the individual authors.Dorsal appendages; Semaphorin; tube guidance; Wnt2Developmental biologyMolecular biologymolecular and cellular biologyThesis