title: Sequence and comparison of mitochondrial genomes in the genus Nerita (Gastropoda: Neritimorpha: Neritidae) and phylogenetic considerations among gastropods.
abstract: In the present study, we determined the mitochondrial DNA (mtDNA) sequence of three Neritas, Nerita versicolor, Nerita tessellata, and Nerita fulgurans. We present an analysis of the features of their gene content and genome organization and compare these within the genus Nerita, and among the main gastropod groups. The new sequences were used in a phylogenetic analysis including all available gastropod mitochondrial genomes. Genomic lengths were quite conserved, being 15,866bp for N. versicolor, 15,741bp for N. tessellata and 15,343bp for N. fulgurans. Intergenic regions were generally short; genes are transcribed from both strands and have a nucleotide composition high in A and T. The high similarity in nucleotide content of the different sequences, gene composition, as well as an identical genomic organization among the Nerita species compared in this study, indicates a high degree of conservation within this diverse genus. Values ​​of Ka/Ks of the 13 protein coding genes (PCGs) of Nerita species ranged from 0 to 0.18, and suggested different selection pressures in gene sequences. Bayesian phylogenetic analyses using concatenated DNA sequences of the 13 PCGs and the two rRNAs, and of amino acid sequences strongly supported Neritimorpha and Vetigastropoda as sister groups.
authors.affiliation: Grupo de Investigación en Evolución, Sistemática y Ecología Molecular, Universidad del Magdalena, Santa Marta, Colombia. Electronic address: moarquezm@hotmail.com.
authors.forename: Moises
authors.initials: M
authors.lastname: Arquez
authors.affiliation: The Australian Museum, 6 College Street, Sydney 2010, Australia. Electronic address: don.colgan@austmus.gov.au.
authors.forename: Donald
authors.initials: D
authors.lastname: Colgan
authors.affiliation: Grupo de Investigación en Evolución, Sistemática y Ecología Molecular, Universidad del Magdalena, Santa Marta, Colombia. Electronic address: lydaraquelcastro@hotmail.com.
authors.forename: Lyda R
authors.initials: LR
authors.lastname: Castro
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001482:Base Composition / Q000235:genetics; D001483:Base Sequence; D001499:Bayes Theorem; D017931:DNA Primers / Q000235:genetics; D049851:Gastropoda / Q000235:genetics*; D023061:Gene Order / Q000235:genetics; D054629:Genome, Mitochondrial / Q000235:genetics*; D008957:Models, Genetic; D058977:Molecular Sequence Annotation; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D017931:DNA Primers
keywords: Ka/Ks; Nerita fulgurans; Nerita tessellata; Nerita versicolor; mt genome rearrangements; mtDNA