title: Extensive mitochondrial gene arrangements in coleoid Cephalopoda and their phylogenetic implications.
abstract: We determined the complete mitochondrial genomes of five cephalopods of the Subclass Coleoidea (Suborder Oegopsida: Watasenia scintillans, Todarodes pacificus, Suborder Myopsida: Sepioteuthis lessoniana, Order Sepiida: Sepia officinalis, and Order Octopoda: Octopus ocellatus) and used them to infer phylogenetic relationships. In our Maximum Likelihood (ML) tree, sepiids (cuttlefish) are at the most basal position of all decapodiformes, and oegopsids and myopsids form a monophyletic clade, thus supporting the traditional classification of the Order Teuthida. We detected extensive gene rearrangements in the mitochondrial genomes of broad cephalopod groups. It is likely that the arrangements of mitochondrial genes in Oegopsida and Sepiida were derived from those of Octopoda, which is thought to be the ancestral order, by entire gene duplication and random gene loss. Oegopsida in particular has undergone long-range gene duplications. We also found that the mitochondrial gene arrangement of Sepioteuthis lessoniana differs from that of Loligo bleekeri, although they belong to the same family. Analysis of both the phylogenetic tree and mitochondrial gene rearrangements of coleoid Cephalopoda suggests that each mitochondrial gene arrangement was acquired after the divergence of each lineage.
authors.affiliation: Department of Biological Science, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259, Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Akasaki
authors.forename: Masato
authors.initials: M
authors.lastname: Nikaido
authors.forename: Kotaro
authors.initials: K
authors.lastname: Tsuchiya
authors.forename: Susumu
authors.initials: S
authors.lastname: Segawa
authors.forename: Masami
authors.initials: M
authors.lastname: Hasegawa
authors.forename: Norihiro
authors.initials: N
authors.lastname: Okada
mesh_terms: D000818:Animals; D001483:Base Sequence; D049830:Cephalopoda / Q000145:classification* / Q000235:genetics*; D017931:DNA Primers; D004272:DNA, Mitochondrial / Q000235:genetics*; D023061:Gene Order; D016013:Likelihood Functions; D010802:Phylogeny
chemical_list: D017931:DNA Primers; D004272:DNA, Mitochondrial