Morphogenetic apoptosis: a mechanism for correcting discontinuities in morphogen gradients.
Smooth gradients of the morphogens Hh, Dpp, and Wg are required for proper development of Drosophila imaginal discs. Here, it is reported that, when a discontinuity is generated between two adjacent cells in the reception of either the Dpp or Wg signal, then cells on either side of the discontinuity boundary undergo apoptosis by activating the c-Jun N-terminal Kinase (JNK) pathway. Furthermore, in the medial region of the wing imaginal disc, the JNK pathway is also activated if cells do not receive the proper levels of Dpp and Hh signals. These observations suggest that cells within a developing field have the ability to access their spatial positions by comparing the level of morphogen signal they receive with that of their neighbors. This phenomenon is likely related to the process of cell competition, and we suggest that it is an evolutionarily important mechanism that helps prevent abnormal tissue specification and growth during development.
Adachi-Yamada
Takashi
T
Department of Sciences for Natural Environment, Faculty of Human Development, Kobe University, Japan.
O'Connor
Michael B
MB
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D002450:Cell Communication / Q000502:physiology; D004330:Drosophila / Q000196:embryology* / Q000502:physiology; D029721:Drosophila Proteins / Q000502:physiology; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D053823:Hedgehog Proteins; D009024:Morphogenesis; D011518:Proto-Oncogene Proteins / Q000502:physiology; D015398:Signal Transduction; D051155:Wnt1 Protein
D029721:Drosophila Proteins; D053823:Hedgehog Proteins; D011518:Proto-Oncogene Proteins; D051155:Wnt1 Protein; C064196:dpp protein, Drosophila; C074622:wg protein, Drosophila; C077245:hh protein, Drosophila