We investigated cell shape changes during wound closure in the Drosophila larval epidermis. During reepithelialization, epidermal cells permanently change shape from pentagonal or hexagonal to irregular forms. This process requires zipper, a gene encoding the Drosophila nonmuscle myosin II heavy chain. Following wounding, myosin II is localized at the wound margin and at the rear end of individual cells located within several rows from the wound hole. The c-Jun N-terminal kinase (JNK) pathway is essential for this myosin II localization. These results suggest that not only the wound leading edge but also the cells lying distal to the leading edge cells actively participate in epithelial cell sheet migration during wound hole closure. (C) 2010 Elsevier Inc. All rights reserved.