Evolution and Distribution of Teleost myomiRNAs: Functionally Diversified myomiRs in Teleosts.
Myosin heavy chain (MYH) genes belong to a multigene family, and the regulated expression of each member determines the physiological and contractile muscle properties. Among these, MYH6, MYH7, and MYH14 occupy unique positions in the mammalian MYH gene family because of their specific expression in slow/cardiac muscles and the existence of intronic micro(mi) RNAs. MYH6, MYH7, and MYH14 encode miR-208a, miR-208b, and miR-499, respectively. These MYH encoded miRNAs are designated as myomiRs because of their muscle-specific expression and functions. In mammals, myomiRs and host MYHs form a transcription network involved in muscle fiber-type specification; thus, genomic positions and expression patterns of them are well conserved. However, our previous studies revealed divergent distribution and expression of MYH14/miR-499 among teleosts, suggesting the unique evolution of myomiRs and host MYHs in teleosts. Here, we examined distribution and expression of myomiRs and host MYHs in various teleost species. The major cardiac MYH isoforms in teleosts are an intronless gene, atrial myosin heavy chain (amhc), and ventricular myosin heavy chain (vmhc) gene that encodes an intronic miRNA, miR-736. Phylogenetic analysis revealed that vmhc/miR-736 is a teleost-specific myomiR that differed from tetrapoda MYH6/MYH7/miR-208s. Teleost genomes also contain species-specific orthologs in addition to vmhc and amhc, indicating complex gene duplication and gene loss events during teleost evolution. In medaka and torafugu, miR-499 was highly expressed in slow/cardiac muscles whereas the expression of miR-736 was quite low and not muscle specific. These results suggest functional diversification of myomiRs in teleost with the diversification of host MYHs.
Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo, 113-8657, Japan.
Bhuiyan Sharmin
BS
Siddique
Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo, 113-8657, Japan. akino@mail.ecc.u-tokyo.ac.jp.
Shigeharu
S
Kinoshita
Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo, 113-8657, Japan.
Chaninya
C
Wongkarangkana
Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo, 113-8657, Japan.
Shuichi
S
Asakawa
Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo, 113-8657, Japan.|School of Marine Bioscience, Kitasato University, Minami-ku, Sagamihara, Kanagawa, 252-0373, Japan.
Shugo
S
Watabe
D000818:Animals; D005075:Biological Evolution; D019295:Computational Biology; D004625:Embryo, Nonmammalian; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D015723:Gene Library; D006325:Heart Atria / Q000254:growth & development / Q000378:metabolism; D006352:Heart Ventricles / Q000254:growth & development / Q000378:metabolism; D006801:Humans; D007814:Larva / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D005810:Multigene Family; D009206:Myocardium / Q000378:metabolism*; D018995:Myosin Heavy Chains / Q000235:genetics* / Q000378:metabolism; D009928:Organ Specificity; D009990:Oryzias / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D010802:Phylogeny; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D013045:Species Specificity; D023741:Takifugu / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D015027:Zebrafish / Q000235:genetics / Q000254:growth & development / Q000378:metabolism
D029941:Fish Proteins; D035683:MicroRNAs; D020033:Protein Isoforms; D018995:Myosin Heavy Chains
Myosin heavy chain; Teleost; miR-499; miR-736; microRNA; myomiR