Planar cell polarity in the larval epidermis of Drosophila and the role of microtubules.

We investigate planar cell polarity (PCP) in the Drosophila larval epidermis. The intricate pattern of denticles depends on only one system of PCP, the Dachsous/Fat system. Dachsous molecules in one cell bind to Fat molecules in a neighbour cell to make intercellular bridges. The disposition and orientation of these Dachsous-Fat bridges allows each cell to compare two neighbours and point its denticles towards the neighbour with the most Dachsous. Measurements of the amount of Dachsous reveal a peak at the back of the anterior compartment of each segment. Localization of Dachs and orientation of ectopic denticles help reveal the polarity of every cell. We discuss whether these findings support our gradient model of Dachsous activity. Several groups have proposed that Dachsous and Fat fix the direction of PCP via oriented microtubules that transport PCP proteins to one side of the cell. We test this proposition in the larval cells and find that most microtubules grow perpendicularly to the axis of PCP. We find no meaningful bias in the polarity of microtubules aligned close to that axis. We also reexamine published data from the pupal abdomen and find no evidence supporting the hypothesis that microtubular orientation draws the arrow of PCP

Research data supporting "Planar cell polarity in the larval epidermis of Drosophila and the role of microtubules"

Two csv files (Comets_Acells.csv, Comets_Pcells.csv) containing the measurements of the angle of microtubule growth determined by tracing EB1::EGFP comets in Anterior and Posterior Compartment cells from the ventral epidermis of wildtype Drosophila third instar larvae as detailed in the article text. The first two sets of digits in each TrackID column identify the larva and cell in which the measurements were taken. A csv file (Ds-EGFP_wt.csv) containing normalized peak intensities of Ds::EGFP at anterior and posterior cell boundaries of the ventral epidermis of wildtype Drosophila third instar larvae as detailed in the article text. A similar file (Ds-EGFP_ectoDs.csv) with data of larvae overexpressing ectoDs in tendon cells.Wllcome Trust Grant 10706

Planar cell polarity in the larval epidermis of Drosophila and the role of microtubules.

Peer reviewed: TrueWe investigate planar cell polarity (PCP) in the Drosophila larval epidermis. The intricate pattern of denticles depends on only one system of PCP, the Dachsous/Fat system. Dachsous molecules in one cell bind to Fat molecules in a neighbour cell to make intercellular bridges. The disposition and orientation of these Dachsous-Fat bridges allows each cell to compare two neighbours and point its denticles towards the neighbour with the most Dachsous. Measurements of the amount of Dachsous reveal a peak at the back of the anterior compartment of each segment. Localization of Dachs and orientation of ectopic denticles help reveal the polarity of every cell. We discuss whether these findings support our gradient model of Dachsous activity. Several groups have proposed that Dachsous and Fat fix the direction of PCP via oriented microtubules that transport PCP proteins to one side of the cell. We test this proposition in the larval cells and find that most microtubules grow perpendicularly to the axis of PCP. We find no meaningful bias in the polarity of microtubules aligned close to that axis. We also reexamine published data from the pupal abdomen and find no evidence supporting the hypothesis that microtubular orientation draws the arrow of PCP