title: Transcriptome analysis of predator- and prey-induced phenotypic plasticity in the Hokkaido salamander (Hynobius retardatus).
abstract: Predator- and prey-induced phenotypic plasticity is widely observed among amphibian species. Although ecological factors inducing diverse phenotypic responses have been extensively characterized, we know little about the molecular bases of variation in phenotypic plasticity. Larvae of the Hokkaido salamander, Hynobius retardatus, exhibit two distinct morphs: the presence of their prey, Rana pirica tadpoles, induces a broad-headed attack morph, and the presence of predatory dragonfly nymphs (Aeshna nigroflava) induces a defence morph with enlarged external gills and a high tail. To compare the genes involved in predator- and prey-induced phenotypic plasticity, we carried out a de novo transcriptome analysis of Hokkaido salamander larvae exposed to either prey or predator individuals. First, we found that the number of genes involved in the expression of the defence morph was approximately five times the number involved in the expression of the attack morph. This result is consistent with the fact that the predator-induced plasticity involves more drastic morphological changes than the prey-induced plasticity. Second, we found that particular sets of genes were upregulated during the induction of both the attack and defence morphs, but others were specific to the expression of one or the other morph. Because both shared and unique molecular mechanisms were used in the expression of each morph, the evolution of a new plastic phenotype might involve both the co-option of pre-existing molecular mechanisms and the acquisition of novel regulatory mechanisms.
authors.affiliation: Graduate School of Fisheries Sciences, Hokkaido University, Hakodate, 041-8611, Japan.|Laboratory of Ecological Genetics, Graduate School of Environmental Science, Hokkaido University, Sapporo, 060-0810, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Matsunami
authors.affiliation: Ecological Genetics Laboratory, National Institute of Genetics, Mishima, 411-8540, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Kitano
authors.affiliation: Teshio Experimental Forest, Field Science Center for Northern Biosphere, Hokkaido University, Toikanbetsu, Horonobe, 098-2943, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Kishida
authors.affiliation: School of Pharmacy, Department of Clinical Medicine (Biostatistics), Kitasato University, Tokyo, 108-8641, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Michimae
authors.affiliation: Laboratory of Ecological Genetics, Graduate School of Environmental Science, Hokkaido University, Sapporo, 060-0810, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Miura
authors.affiliation: Graduate School of Fisheries Sciences, Hokkaido University, Hakodate, 041-8611, Japan.
authors.forename: Kinya
authors.initials: K
authors.lastname: Nishimura
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D000818:Animals; D020869:Gene Expression Profiling; D063191:Odonata; D010641:Phenotype; D011235:Predatory Behavior; D011898:Ranidae; D017422:Sequence Analysis, DNA; D059467:Transcriptome; D014562:Caudata / Q000033:anatomy & histology / Q000235:genetics*
keywords: eco-genomics; gene ontology analysis; phenotypic plasticity; salamander; transcriptome