PLANAR POLARIZATION OF DROSOPHILA AND VERTEBRATE EPITHELIA

Our understanding of the actin and microtubule rearrangements that gen erate planar polarity in Drosophila and in vertebrate epithelia has be en extended by recent discoveries. Three different Rho family proteins have been shown to mediate polarization in the wing and the eye of Dr osophila. In vertebrates, the importance of myosin VIIa has been uncov ered by mutations that cause defects in planar polarization in the ear . Advances in our understanding of the Frizzled pathway, which coordin ates planar polarization in Drosophila, are moving the field closer to understanding the links between signal transduction and polarized cyt oskeletal reorganization.