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标题：Induction of metamorphosis from the larval to the polyp stage is similar in Hydrozoa and a subgroup of Scyphozoa (Cnidaria, Semaeostomeae)
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作者：Barbara Siefker ; Michael Kroiher ; Stefan Berking 等
期刊名称：Helgoland Marine Research
印刷版ISSN：1438-3888
出版年度：2000
卷号：54
期号：4
页码：230-236
DOI：10.1007/s101520000053
出版社：BioMed Central
摘要：Larvae of cnidarians need an external cue for metamorphosis to start. The larvae of various hydrozoa, in particular of Hydractinia echinata, respond to Cs , Li , NH4 and seawater in which the concentration of Mg2 ions is reduced. They further respond to the phorbolester, tetradecanoyl-phorbol-13-acetate (TPA) and the diacylglycerol (DAG) diC8, which both are argued to stimulate a protein kinase C. The only well-studied scyphozoa, Cassiopea spp., respond differently, i.e. to TPA and diC8 only. We found that larvae of the scyphozoa Aurelia aurita, Chrysaora hysoscella and Cyanea lamarckii respond to all the compounds mentioned. Trigonelline (N-methylnicotinic acid), a metamorphosis inhibitor found in Hydractinia larvae, is assumed to act by delivering a methyl group for transmethylation processes antagonising metamorphosis induction in Chrysaora hysoscella and Cyanea lamarckii. The three species tested are scyphozoa belonging to the subgroup of semaeostomeae, while Cassiopea spp. belong to the rhizostomeae. The results obtained may contribute to the discussion concerning the evolution of cnidarians and may help to clarify whether the way metamorphosis can be induced in rhizostomeae as a whole is different from that in hydrozoa and those scyphozoa belonging to the subgroup semaeostomeae.
关键词：Cnidaria; Metamorphosis ;Aurelia ;aurita; Cynanea ;lamarckii; Chrysaora ;hysoscella