title: Left-right asymmetry in the alimentary canal of the Drosophila embryo.
abstract: In many animal groups, left-right (LR) asymmetry within the body is observed. The left and right sides of the body are generally defined with reference to the anterior-posterior (AP) and dorsal-ventral (DV) axes. In this study, we investigated whether LR asymmetry is solely dependent on the AP and DV polarities in Drosophila embryos. We focused on the proventriculus, a posterior part of the foregut, and the hindgut because LR asymmetry in these body parts is highly stable in normal embryos. In embryos with a fully reversed AP polarity, LR asymmetry in both the proventriculus and the hindgut was re-oriented in relation to the reversed AP polarity. This demonstrates that inversion of AP polarity does not affect LR asymmetry of these tissues, and implies that LR asymmetry is specified in relation to the AP and DV polarities. Our findings were not consistent with the alternative hypothesis that LR asymmetry is predetermined by maternal signals that localize asymmetrically along the LR axis in the oocyte and/or early embryo.
authors.affiliation: Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Higashiyama, Okazaki, Aichi 444-8787, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Hayashi
authors.forename: Hikomaru
authors.initials: H
authors.lastname: Aono
authors.forename: Junichi
authors.initials: J
authors.lastname: Ishihara
authors.forename: Sadaaki
authors.initials: S
authors.lastname: Oshima
authors.forename: Hideaki
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Yu-ichi
authors.initials: Y
authors.lastname: Nakazato
authors.forename: Satoru
authors.initials: S
authors.lastname: Kobayashi
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000502:physiology*; D004330:Drosophila; D004625:Embryo, Nonmammalian / Q000196:embryology; D005260:Female; D041981:Gastrointestinal Tract / Q000196:embryology*; D017344:Genes, Insect / Q000502:physiology*; D008297:Male; D009865:Oocytes / Q000502:physiology*