The asymmetric subcellular localisation of components of the planar polarity pathway

Recent studies in Drosophila have shown that during the establishment of planar cell polarity in the developing wing, the protein products of several key planar polarity genes adopt asymmetric subcellular localisations. These asymmetric distributions precede other signs of overt polarisation of the cells in the planar axis, and prefigure the final polarity adopted. This review describes what is known about this phenomenon and its genetic control. Possible mechanisms for establishing asymmetric subcellular localisations, and its likely significance, are discussed.