title: Wing-to-Leg homeosis by spineless causes apoptosis regulated by Fish-lips, a novel leucine-rich repeat transmembrane protein.
abstract: Growth, patterning, and apoptosis are mutually interactive during development. For example, cells that select an abnormal fate in a developing field are frequently removed by apoptosis. An important issue in this process that needs to be resolved is the mechanism used by cells to discern their correct fate from an abnormal fate. In order to examine this issue, we developed an animal model that expresses the dioxin receptor homolog Spineless (Ss) ectopically in the Drosophila wing. The presence of mosaic clones ectopically expressing ss results in a local transformation of organ identity, homeosis, from wing into a leg or antenna. The cells with misspecified fates subsequently activate c-Jun N-terminal kinase to undergo apoptosis in an autonomous or nonautonomous manner depending on their position within the wing, suggesting that a cell-cell interaction is, at least in some cases, involved in the detection of misspecified cells. Similar position dependence is commonly observed when various homeotic genes controlling the body segments are ectopically expressed. The autonomous and nonautonomous apoptosis caused by ss is regulated by a novel leucine-rich repeat family transmembrane protein, Fish-lips (Fili) that interacts with surrounding normal cells. These data support a mechanism in which the lack of some membrane proteins helps to recognize the presence of different cell types and direct these cells to an apoptotic fate in order to exclude them from the normal developing field.
authors.affiliation: Department of Earth and Planetary System Sciences, Graduate School of Science and Technology, Kobe University, Kobe 657-8501, Japan. yamadach@kobe-u.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Adachi-Yamada
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Harumoto
authors.forename: Kayoko
authors.initials: K
authors.lastname: Sakurai
authors.forename: Ryu
authors.initials: R
authors.lastname: Ueda
authors.forename: Kaoru
authors.initials: K
authors.lastname: Saigo
authors.forename: Michael B
authors.initials: MB
authors.lastname: O'Connor
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakato
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000235:genetics / Q000502:physiology*; D019521:Body Patterning / Q000235:genetics / Q000502:physiology*; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism* / Q000502:physiology*; D004331:Drosophila melanogaster / Q000235:genetics / Q000254:growth & development* / Q000502:physiology; D005121:Extremities / Q000254:growth & development; D015870:Gene Expression; D000090263:Leucine-Rich Repeat Proteins; D008565:Membrane Proteins / Q000235:genetics* / Q000502:physiology*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000235:genetics / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D018336:Receptors, Aryl Hydrocarbon / Q000235:genetics / Q000378:metabolism*; D014921:Wings, Animal / Q000254:growth & development
chemical_list: D029721:Drosophila Proteins; D000090263:Leucine-Rich Repeat Proteins; D008565:Membrane Proteins; D011506:Proteins; D012333:RNA, Messenger; D018336:Receptors, Aryl Hydrocarbon; C112211:ss protein, Drosophila