title: D-JNK signaling in visceral muscle cells controls the laterality of the Drosophila gut.
abstract: Although bilateral animals appear to have left-right (LR) symmetry from the outside, their internal organs often show directional and stereotypical LR asymmetry. The mechanisms by which the LR axis is established in vertebrates have been extensively studied. However, how each organ develops its LR asymmetric morphology with respect to the LR axis is still unclear. Here, we showed that Drosophila Jun N-terminal kinase (D-JNK) signaling is involved in the LR asymmetric looping of the anterior-midgut (AMG) in Drosophila. Mutant embryos of puckered (puc), which encodes a D-JNK phosphatase, showed random laterality of the AMG. Directional LR looping of the AMG required D-JNK signaling to be down-regulated by puc in the trunk visceral mesoderm. Not only the down-regulation, but also the activation of D-JNK signaling was required for the LR asymmetric looping. We also found that the LR asymmetric cell rearrangement in the circular visceral muscle (CVM) was regulated by D-JNK signaling and required for the LR asymmetric looping of the AMG. Rac1, a Rho family small GTPase, augmented D-JNK signaling in this process. Our results also suggest that a basic mechanism for eliciting LR asymmetric gut looping may be conserved between vertebrates and invertebrates.
authors.affiliation: Department of Biological Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
authors.forename: Kiichiro
authors.initials: K
authors.lastname: Taniguchi
authors.forename: Shunya
authors.initials: S
authors.lastname: Hozumi
authors.forename: Reo
authors.initials: R
authors.lastname: Maeda
authors.forename: Masashi
authors.initials: M
authors.lastname: Ooike
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sasamura
authors.forename: Toshiro
authors.initials: T
authors.lastname: Aigaki
authors.forename: Kenji
authors.initials: K
authors.lastname: Matsuno
mesh_terms: D000818:Animals; D019521:Body Patterning; D003433:Crosses, Genetic; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000196:embryology* / Q000378:metabolism; D041981:Gastrointestinal Tract / Q000196:embryology; D048031:JNK Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D020744:rac GTP-Binding Proteins / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; C090146:Rac1 protein, Drosophila; D048031:JNK Mitogen-Activated Protein Kinases; C110854:puc protein, Drosophila; D010749:Phosphoprotein Phosphatases; D020744:rac GTP-Binding Proteins