Calcium as a Signal Integrator in Drosophila Wing Imaginal Disc Development

Understanding organ development requires an understanding of how individual cells make decisions, and how those decisions integrate into system-wide properties. However, in many systems the pieces of this puzzle are poorly understood, or the puzzle requires assembly. The Drosophila wing is a powerful model system for studying how local cellular decisions are integrated into the system-wide phenomenon of morphogenesis. Calcium signaling is a well-studied pathway central to cellular decision making. Recent advances in live-imaging of calcium signaling have empowered studies into the role of calcium in development that were previously impossible. This thesis examines the role of cellular decision making at the cellular, tissue, and organ scale. In Chapter 1, an overview of the role that second messengers like calcium signaling play in signal integration at the cellular, tissue, and organ level is presented. In Chapter 2, the role that local topology plays at the organ level in calcium signaling in the developing wing imaginal disc is examined. Cell division is one of the major cell decisions that calcium signaling informs. In Chapter 3, mechanical modeling is used to predict the primary mechanical drivers of cell shape changes in dividing cells in the wing disc. In Chapter 4, the dynamics of calcium signaling in the developing wing are quantitatively characterized, and calcium activity is linked to organ size. In Chapter 5, the effects of perturbations to calcium signaling genes on adult wing morphology are quantitatively investigated. Finally, Chapter 6 offers thoughts and perspective, and contains proposals for future work.