Cell size control emerges from the vein-dependent coordinated divisions of distinct cell groups in Drosophila wing

During morphogenesis, cell divisions are precisely regulated in space and time. The biological objectives achieved by such regulation are not fully understood, particularly in tissues whose overall size is kept constant. Here, by applying a newly developed lineage-reconstruction pipeline to the Drosophila pupal wing, we reveal that the wing is composed of distinct cell groups that differ in division number, timing, and spatial positioning relative to wing veins. We show that the frequencies of these lineages, together with their initial cell sizes and growth profiles, converge to achieve a highly conserved average cell size. Our data further suggest that distance from wing veins provides spatial information that biases where distinct lineages arise, and that genetic elimination of wing veins suppresses a specific lineage and disrupts cell-size control. Finally, our results point to a multiscale organization of division patterns, in which vein-associated spatial information is integrated with local neighbor effects in a manner that would mitigate mechanical instability within the tissue. Together, these findings delineate a cell-size control mechanism based on coordinated divisions of distinct cell groups, which supports robust morphogenesis and functional tissue design.