December 18, 2014


Tubes generally start as buds that dramatically elongate during development, but the cell rearrangements that occur during tubulogenesis are not completely understood. Saxena and colleagues recently used the developing fly renal system to track cell movements during tube formation. Tubule elongation primarily occurs through convergent extension, during which cells intercalate along the length of the tube. During these rearrangements, the number of cells around the circumference of the tube drops as the number of cells along the tube increases. Saxena and colleagues show that epidermal growth factor localized at the tip cells of the distal end of the tube guides the polarity of cell rearrangements, via polarization of Myosin II within individual cells. Finally, without proper tube elongation, animals have abnormal excretory function and osmoregulation, leading to lethality. In the images above, the top row shows failure of tube elongation after laser ablation of the distal tip cells (arrowheads). Bottom row shows normal tube elongation without laser ablation of tip cells (arrowheads).

Saxena, A., Denholm, B., Bunt, S., Bischoff, M., VijayRaghavan, K., & Skaer, H. (2014). Epidermal Growth Factor Signalling Controls Myosin II Planar Polarity to Orchestrate Convergent Extension Movements during Drosophila Tubulogenesis PLoS Biology, 12 (12) DOI: 10.1371/journal.pbio.1002013