| The focus of this thesis is to further our understanding of an evolutionarily conserved transcription factor, Scalloped (Sd), and how it can interact with a nuclear protein called Vestigial (Vg) to form a selector complex to organize Drosophila wing fate. The possible role of Sd in Drosophila eye morphogenesis was also examined.;The collection of Sd constructs was also subjected to an over-expression assay in the Drosophila eye. It was predicted that similar to the situation in the wing, Sd possibly interacts with an unknown factor for proper eye morphogenesis. Again, the linker domain of Sd serves an important yet unknown function in eye development.;With respect to wing development, previous studies had discovered that Sd provides the DNA binding component while Vg serves as the activating component of the Sd-Vg complex. Vg requires Sd to enter the nucleus and the relative concentration of the two proteins is vital to the proper development of the wing. Sd may be divided into the N-terminal domain, TEA DNA binding domain, Vg interacting domain (VID), linker domain (intervening region between the TEA DNA binding domain and the VID), and the C-terminal domain. These domains were determined by sequence alignment with the human homolog of Sd, Transcription Enhancer Factor 1 (TEF-1) or via in vitro experimentation. To understand the mechanism of wing gene activation by the Sd-Vg complex, and to examine the defined domains of Sd in an in vivo assay, various Sd constructs with deletions or interruptions in these domains were tested for their ability to rescue two recessive viable wing alleles of sd (sdETX4 and sd 58d). The results are consistent with the idea that the TEA DNA binding domain binds DNA, while the VID and the C-terminal domain are required to form a stable complex with Vg. The linker region was found to serve an unknown yet vital role in wing development, while the N-terminal domain is not necessary for the development of this tissue. |
