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Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Environmental Science / Faculty of Environmental Earth Science >
Peer-reviewed Journal Articles, etc >
Gene up-regulation in response to predator kairomones in the water flea, Daphnia pulex
This item is licensed under:Creative Commons Attribution 2.0 Generic
| Title: | Gene up-regulation in response to predator kairomones in the water flea, Daphnia pulex |
| Authors: | Miyakawa, Hitoshi Browse this author | | Imai, Maki Browse this author | | Sugimoto, Naoki Browse this author | | Ishikawa, Yuki Browse this author | | Ishikawa, Asano Browse this author | | Ishigaki, Hidehiko Browse this author | | Okada, Yasukazu Browse this author | | Miyazaki, Satoshi Browse this author | | Koshikawa, Shigeyuki Browse this author | | Cornette, Richard Browse this author | | Miura, Toru Browse this author |
| Issue Date: | 30-Apr-2010 |
| Publisher: | BioMed Central |
| Journal Title: | BMC Developmental Biology |
| Volume: | 10 |
| Start Page: | 45 |
| Publisher DOI: | 10.1186/1471-213X-10-45 |
| Abstract: | Background: Numerous cases of predator-induced polyphenisms, in which alternate phenotypes are produced in response to extrinsic stimuli, have been reported in aquatic taxa to date. The genus Daphnia (Branchiopoda, Cladocera) provides a model experimental system for the study of the developmental mechanisms and evolutionary processes associated with predator-induced polyphenisms. In D. pulex, juveniles form neckteeth in response to predatory kairomones released by Chaoborus larvae (Insecta, Diptera). Results: Previous studies suggest that the timing of the sensitivity to kairomones in D. pulex can generally be divided into the embryonic and postembryonic developmental periods. We therefore examined which of the genes in the embryonic and first-instar juvenile stages exhibit different expression levels in the presence or absence of predator kairomones. Employing a candidate gene approach and identifying differentially-expressed genes revealed that the morphogenetic factors, Hox3, extradenticle and escargot, were up-regulated by kairomones in the postembryonic stage and may potentially be responsible for defense morph formation. In addition, the juvenile hormone pathway genes, JHAMT and Met, and the insulin signaling pathway genes, InR and IRS-1, were up-regulated in the first-instar stage. It is well known that these hormonal pathways are involved in physiological regulation following morphogenesis in many insect species. During the embryonic stage when morphotypes were determined, one of the novel genes identified by differential display was up-regulated, suggesting that this gene may be related to morphotype determination. Biological functions of the up-regulated genes are discussed in the context of defense morph formation. Conclusions: It is suggested that, following the reception of kairomone signals, the identified genes are involved in a series of defensive phenotypic alterations and the production of a defensive phenotype. |
| Rights: | http://creativecommons.org/licenses/by/2.0 |
| Type: | article |
| URI: | http://hdl.handle.net/2115/43648 |
| Appears in Collections: | 環境科学院・地球環境科学研究院 (Graduate School of Environmental Science / Faculty of Environmental Earth Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 三浦 徹
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