title: Identification of a novel uromodulin-like gene related to predator-induced bulgy morph in anuran tadpoles by functional microarray analysis.
abstract: Tadpoles of the anuran species Rana pirica can undergo predator-specific morphological responses. Exposure to a predation threat by larvae of the salamander Hynobius retardatus results in formation of a bulgy body (bulgy morph) with a higher tail. The tadpoles revert to a normal phenotype upon removal of the larval salamander threat. Although predator-induced phenotypic plasticity is of major interest to evolutionary ecologists, the molecular and physiological mechanisms that control this response have yet to be elucidated. In a previous study, we identified various genes that are expressed in the skin of the bulgy morph. However, it proved difficult to determine which of these were key genes in the control of gene expression associated with the bulgy phenotype. Here, we show that a novel gene plays an important role in the phenotypic plasticity producing the bulgy morph. A functional microarray analysis using facial tissue samples of control and bulgy morph tadpoles identified candidate functional genes for predator-specific morphological responses. A larger functional microarray was prepared than in the previous study and used to analyze mRNAs extracted from facial and brain tissues of tadpoles from induction-reversion experiments. We found that a novel uromodulin-like gene, which we name here pirica, was up-regulated and that keratin genes were down-regulated as the period of exposure to larval salamanders increased. Pirica consists of a 1296 bp open reading frame, which is putatively translated into a protein of 432 amino acids. The protein contains a zona pellucida domain similar to that of proteins that function to control water permeability. We found that the gene was expressed in the superficial epidermis of the tadpole skin.
authors.affiliation: Laboratory of Marine Molecular Biochemistry, Department of Nihon University College of Bioresource Sciences, Fujisawa, Japan. mori.tsukasa@nihon-u.ac.jp
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Mori
authors.forename: Hiroko
authors.initials: H
authors.lastname: Kawachi
authors.forename: Chiharu
authors.initials: C
authors.lastname: Imai
authors.forename: Manabu
authors.initials: M
authors.lastname: Sugiyama
authors.forename: Youichi
authors.initials: Y
authors.lastname: Kurata
authors.forename: Osamu
authors.initials: O
authors.lastname: Kishida
authors.forename: Kinya
authors.initials: K
authors.lastname: Nishimura
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D007814:Larva; D008969:Molecular Sequence Data; D009088:Mucoproteins / Q000235:genetics*; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D010641:Phenotype; D011235:Predatory Behavior / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D011898:Ranidae / Q000502:physiology*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D058949:Uromodulin
chemical_list: D018076:DNA, Complementary; D009088:Mucoproteins; D012333:RNA, Messenger; D058949:Uromodulin