Evidence supporting the postulated role of a Wnt ligand in the establishmen
t of planar cell polarity has been elusive, but recent studies show that th
e movement of epithelial cells during vertebrate gastrulation or Drosophila
dorsal closure depends on both a Wnt ligand and the planar cell polarity p
athway. (C) 2000 Elsevier Science Ltd. Ail rights reserved.