Open AccessThe complete mitochondrial genome of the mackerel icefish, Champsocephalus gunnari (Actinopterygii: Channichthyidae), with reference to the evolution of mitochondrial genomes in Antarctic notothenioids
Author(s) -
LIN CHUYIN,
LIN WENWEN,
KAO HSIAOWEI
Publication year - 2012
Publication title -
zoological journal of the linnean society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.148
H-Index - 83
eISSN - 1096-3642
pISSN - 0024-4082
DOI - 10.1111/j.1096-3642.2012.00820.x
Subject(s) - biology , mitochondrial dna , genome , gene duplication , zoology , actinopterygii , genetics , evolutionary biology , gene , fishery , fish <actinopterygii>
The mackerel icefish ( Champsocephalus gunnari Lönnberg, 1905) is a ray‐finned fish living in the Southern Ocean around Antarctica. We sequenced the complete mitochondrial (mt) genome of the mackerel icefish and a segment from cytochrome b to the control region (CR) in 32 individuals. The mt genome of the mackerel icefish was rearranged, containing two nicotinamide adenine dinucleotide (reduced form) dehydrogenase subunit 6 ( ND6 ), two tRNA Glu , and two CRs. However, variations in numbers of ND6 and tRNA Glu were observed amongst individuals. These variations included type 1 (containing two ND6 and two tRNA Glu ), type 2 (containing one ND6 , one incomplete ND6 , and one tRNA Glu ), and type 3 (containing one ND6 and one tRNA Glu ). The gene orders of types 1 and 2, and variations in numbers of ND6 and tRNA Glu were not previously found in any Antarctic notothenioids, whereas type 3 is the same as that of Racovitzia glacialis . Phylogenetic analyses of CR DNA sequences showed that duplicated CRs of the same species formed a monophyletic group, suggesting that duplication of CRs occurred in each species. The frequent duplication of mt genomes in Antarctic notothenioids is an unusual feature in vertebrates. We propose that interspecific hybridization and impairment of mismatch repair might account for the high frequency of gene duplications and rearrangement of mt genomes in Antarctic notothenioids.