title: The complete mitochondrial genome of Flustrellidra hispida and the phylogenetic position of Bryozoa among the Metazoa.
abstract: The complete mitochondrial genome of Flustrellidra hispida (Bryozoa, Ctenostomata, Flustrellidridae) was sequenced using a transposon-mediated approach. All but one of the 36 genes were identified (trnS2). The genome is 13,026 bp long, being one of the smallest metazoan mitochondrial genomes sequenced to date with a unique gene order when compared to other Metazoa. The genome has an overall AT richness of 59.4%. We found seven regions of overlaps between tRNAs and protein-coding genes ranging from 2 to 11 nt, and seven regions of overlap between tRNAs, ranging from 1 to 8 nt, resulting in a total number of 46 overlapping nucleotides. Genes nad4, cox2, atp8, and nad3 are terminated by the abbreviated stop codon T and cytb is suggested to terminate on (ACT)AA; we postulate that mRNA editing is required to remove AC for TAA to be functional in terminating translation. Phylogenetic analysis of nucleotide and amino acid data place Flustrellidra in the Lophotrochozoa. DNA for this study originated from two populations resulting in a contig consisting of multiple haplotypes. Twenty-seven SNP sites were detected, the majority occurring in cox1 and nad5. With cox1 already established as a marker in bryozoan studies, we advocate the further testing of nad5.
authors.affiliation: Department of Zoology, Natural History Museum, Cromwell Road, London SW7 5BD, UK. A.Waeschenbach@nhm.ac.uk
authors.forename: Andrea
authors.initials: A
authors.lastname: Waeschenbach
authors.forename: Maximilian J
authors.initials: MJ
authors.lastname: Telford
authors.forename: Joanne S
authors.initials: JS
authors.lastname: Porter
authors.forename: D Timothy J
authors.initials: DT
authors.lastname: Littlewood
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002013:Bryozoa / Q000145:classification* / Q000166:cytology / Q000235:genetics*; D003062:Codon / Q000235:genetics; D018387:Codon, Initiator / Q000235:genetics; D018388:Codon, Terminator / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics*; D016678:Genome / Q000235:genetics*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010802:Phylogeny; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D012343:RNA, Transfer / Q000737:chemistry / Q000235:genetics
chemical_list: D003062:Codon; D018387:Codon, Initiator; D018388:Codon, Terminator; D004272:DNA, Mitochondrial; D012343:RNA, Transfer