title: Mitochondrial DNA variation and phylogenetic relationships among five tuna species based on sequencing of D-loop region.
abstract: In order to assess the DNA sequence variation and phylogenetic relationship among five tuna species (Auxis thazard, Euthynnus affinis, Katsuwonus pelamis, Thunnus tonggol, and T. albacares) out of all four tuna genera, partial sequences of the mitochondrial DNA (mtDNA) D-loop region were analyzed. The estimate of intra-specific sequence variation in studied species was low, ranging from 0.027 to 0.080 [Kimura's two parameter distance (K2P)], whereas values of inter-specific variation ranged from 0.049 to 0.491. The longtail tuna (T. tonggol) and yellowfin tuna (T. albacares) were found to share a close relationship (K2P = 0.049) while skipjack tuna (K. pelamis) was most divergent studied species. Phylogenetic analysis using Maximum-Likelihood (ML) and Neighbor-Joining (NJ) methods supported the monophyletic origin of Thunnus species. Similarly, phylogeny of Auxis and Euthynnus species substantiate the monophyly. However, results showed a distinct origin of K. pelamis from genus Thunnus as well as Auxis and Euthynnus. Thus, the mtDNA D-loop region sequence data supports the polyphyletic origin of tuna species.
authors.affiliation: a South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Faculty of Fisheries and Protection of Waters, University of South Bohemia in Ceske Budejovice , Vodnany , Czech Republic and.
authors.forename: Girish
authors.initials: G
authors.lastname: Kumar
authors.affiliation: a South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Faculty of Fisheries and Protection of Waters, University of South Bohemia in Ceske Budejovice , Vodnany , Czech Republic and.
authors.forename: Martin
authors.initials: M
authors.lastname: Kocour
authors.affiliation: b Biological Oceanography Division , National Institute of Oceanography , Panaji , India.
authors.forename: Swaraj Priyaranjan
authors.initials: SP
authors.lastname: Kunal
mesh_terms: D000818:Animals; D001483:Base Sequence; D004272:DNA, Mitochondrial / Q000737:chemistry* / Q000235:genetics*; D014644:Genetic Variation; D005843:Geography; D016013:Likelihood Functions; D009690:Nucleic Acid Conformation; D010802:Phylogeny; D017422:Sequence Analysis, DNA / Q000379:methods*; D014413:Tuna / Q000235:genetics*
chemical_list: D004272:DNA, Mitochondrial
keywords: DNA marker; Indian Ocean; genetic variation; mtDNA; phylogeny