Temporal and Mechanistic Analysis of Bnl/Btl FGF Signaling during Terminal Cell Branching Morphogenesis in Drosophila Larval Stages

Abstract

Improper branching due to abnormal cellular signaling is a driving factor for many congenital diseases involving angiogenesis in humans. To better understand these defects, developmental biologists have long used the Drosophila melanogaster tracheal system as a model for branched tube formation. While previous research has demonstrated a requirement for components of the Bnl/Btl (FGF/FGFR) signaling pathway during tracheal network formation, there is limited understanding of its role and essential time frames in promoting unicellular branching of specialized tracheal terminal cells during larval growth. This study investigates the temporal requirements of this pathway and whether it promotes branching through transcriptional or cytoskeletal mechanisms. Using genetic tools to perturb signaling during larval stages, we characterize pathway activity and its role in terminal cell morphogenesis. This work provides insight into how a single cell forms a complex branched structure with subcellular lumens.