Project description:In this study, the complete mitochondrial genome of Ariosoma meeki was sequenced, assembled and annotated. The circular genome is 16,154 bp in length with nucleotide composition is 28.42% A, 26.53% T, 19.65% G, and 25.40% C and contains 13 protein-coding genes (PCGs), 21 transfer RNA genes (tRNAs), 2 ribosomal RNA unit genes and a large non-coding region (putative control region). To further explore the evolution relationship of the Anguilliformes, we constructed the phylogenetic tree and found that the A. meeki had closer relationship with Ariosoma shiroanago. This study provided the valuable evidence on phylogenetic relationship of the A. meeki at the molecular level and essential resource for further study the molecular phylogenetic, biogeography and adaptive evolution of this lineage.
Project description:Ariosoma meeki (A. meeki) is a demersal and carnivorous fish species belongs to the family Congridae. Some wild populations of A. meeki are in danger because of the overfishing and environmental pollution. In order to better understand the germplasm resources, the complete mitochondrial genome of A. meeki was firstly determined in this study. The complete mitochondrial genome is 16,404 nucleotides, comprising 12 protein-coding genes, 2 ribosomal RNA genes, 20 tRNA genes, and 2 main non-coding regions, but ND6 and two tRNA genes were not found in the A. meeki mitogenome. The A. meeki mitogenome was currently the first member of Ariosoma genus with gene and tRNA deletion. In addition, phylogenetic analysis result demonstrated that A. meeki and A. shiroanago were clustered in a clade and formed a sister relationship.
Project description:Here, we report information on the complete mitochondrial genome of the firemouth cichlid, Thorichthys meeki (Brind 1918). Illumina HiSeq genome sequencing produced the assembly of a circular mitogenome of 16,527 base pairs (bp) from T. meeki consisting of 46.8% GC nucleotides, 13 protein-coding genes (PCGs), two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and a putative control region as shown in the typical teleost gene composition. The gene order of the T. meeki mitogenome was identical to that of other cichlid species. A maximum likelihood phylogenetic tree based on mitochondrial PCGs showed a close relationship of T. meeki with Thorichthys aureus (Gunther 1862) within Heroini tribe.
Project description:The mitochondrial genome structure of a teleostean group is generally considered to be conservative. However, two types of gene arrangements have been identified in the mitogenomes of Anguilliformes. In this study, we report the complete mitochondrial genome of Ariosoma meeki (Anguilliformes (Congridae)). For this research, first, the mitochondrial genome structure and composition were analyzed. As opposed to the typical gene arrangement pattern in other Anguilliformes species, the mitogenome of A. meeki has undergone gene rearrangement. The ND6 and the conjoint tRNA-Glu genes were translocated to the location between the tRNA-Thr and tRNA-Pro genes, and a duplicated D-loop region was translocated to move upstream of the ND6 gene. Second, comparative genomic analysis was carried out between the mitogenomes of A. meeki and Ariosoma shiroanago. The gene arrangement between them was found to be highly consistent, against the published A. meeki mitogenomes. Third, we reproduced the possible evolutionary process of gene rearrangement in Ariosoma mitogenomes and attributed such an occurrence to tandem repeat and random loss events. Fourth, a phylogenetic analysis of Anguilliformes was conducted, and the clustering results supported the non-monophyly hypothesis regarding the Congridae. This study is expected to provide a new perspective on the A. meeki mitogenome and lay the foundation for the further exploration of gene rearrangement mechanisms.
