View Program - 63rd Annual Drosophila Research Conference

Most animal species show allometric growth, which means that different organs and tissues grow at different rates relative to each other. Understanding the mechanisms of how different tissues grow is important, since it can provide insight about unique signals and pathways required for development of different organs. The Drosophila larval trachea is an excellent model for tissue-specific growth, since larvae are transparent and the trachea can be easily visualized. In addition, we and other labs have identified a small number of genes that are required for growth specifically in the larval trachea. Two of these genes are uninflatable (uif) and G-protein coupled receptor kinase 2 (Gprk2). uif encodes a single pass transmembrane protein that is expressed on the apical surface in epithelial cells, and is strongly expressed in the trachea. Loss of Uif results in larval lethality with trachea that are roughly have the relative size of that found in wild type larvae. Gprk2 encodes the only non-neuronal G-protein receptor kinase encoded by Drosophila. Loss of Gprk2 also results in larval lethality, but the mutant larvae have long and highly convoluted trachea. In other developmental contexts, Gprk2 is required to phosphorylate G-protein coupled receptors to mark them for endocytosis and functional attenuation. Preliminary results indicate that Uif levels are higher in Gprk2 mutant larval trachea, raising the possibility that Gprk2 may promote the endocytosis of Uif. We are looking at the genetic and biochemical interactions between uif and Gprk2, and their effect on growth through the insulin signaling pathway.

Investigating the role of Uif and Gprk2 in tissue-specific growth of the larval trachea