title: Complete nucleotide sequences of mitochondrial genomes of two solitary entoprocts, Loxocorone allax and Loxosomella aloxiata: implications for lophotrochozoan phylogeny.
abstract: The complete nucleotide sequences of the mitochondrial (mt) genomes of the entoprocts Loxocorone allax and Loxosomella aloxiata were determined. Both species carry the typical gene set of metazoan mt genomes and have similar organizations of their mt genes. However, they show differences in the positions of two tRNA(Leu) genes. Additionally, the tRNA(Val) gene, and half of the long non-coding region, is duplicated and inverted in the Loxos. aloxiata mt genome. The initiation codon of the Loxos. aloxiata cytochrome oxidase subunit I gene is expected to be ACG rather than AUG. The mt gene organizations in these two entoproct species most closely resemble those of mollusks such as Katharina tunicata and Octopus vulgaris, which have the most evolutionarily conserved mt gene organization reported to date in mollusks. Analyses of the mt gene organization in the lophotrochozoan phyla (Annelida, Brachiopoda, Echiura, Entoprocta, Mollusca, Nemertea, and Phoronida) suggested a close phylogenetic relationship between Brachiopoda, Annelida, and Echiura. However, Phoronida was excluded from this grouping. Molecular phylogenetic analyses based on the sequences of mt protein-coding genes suggested a possible close relationship between Entoprocta and Phoronida, and a close relationship among Brachiopoda, Annelida, and Echiura.
authors: Laboratory for Cellular Biochemistry, Department of Molecular Biology, School of Life Science, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan. yokobori@ls.toyaku.ac.jp
authors: Shin-ichi
authors: S
authors: Yokobori
authors: Tohru
authors: T
authors: Iseto
authors: Shuichi
authors: S
authors: Asakawa
authors: Takashi
authors: T
authors: Sasaki
authors: Nobuyoshi
authors: N
authors: Shimizu
authors: Akihiko
authors: A
authors: Yamagishi
authors: Tairo
authors: T
authors: Oshima
authors: Euichi
authors: E
authors: Hirose
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019143:Evolution, Molecular; D016678:Genome / Q000235:genetics*; D054629:Genome, Mitochondrial / Q000235:genetics*; D008957:Models, Genetic; D008974:Mollusca / Q000235:genetics*; D016366:Open Reading Frames; D010802:Phylogeny; D017422:Sequence Analysis, DNA