title: Mitochondrial genome sequences of Artemia tibetiana and Artemia urmiana: assessing molecular changes for high plateau adaptation.
abstract: Brine shrimps, Artemia (Crustacea, Anostraca), inhabit hypersaline environments and have a broad geographical distribution from sea level to high plateaus. Artemia therefore possess significant genetic diversity, which gives them their outstanding adaptability. To understand this remarkable plasticity, we sequenced the mitochondrial genomes of two Artemia tibetiana isolates from the Tibetan Plateau in China and one Artemia urmiana isolate from Lake Urmia in Iran and compared them with the genome of a low-altitude Artemia, A. franciscana. We compared the ratio of the rate of nonsynonymous (Ka) and synonymous (Ks) substitutions (Ka/Ks ratio) in the mitochondrial protein-coding gene sequences and found that atp8 had the highest Ka/Ks ratios in comparisons of A. franciscana with either A. tibetiana or A. urmiana and that atp6 had the highest Ka/Ks ratio between A. tibetiana and A. urmiana. Atp6 may have experienced strong selective pressure for high-altitude adaptation because although A. tibetiana and A. urmiana are closely related they live at different altitudes. We identified two extended termination-associated sequences and three conserved sequence blocks in the D-loop region of the mitochondrial genomes. We propose that sequence variations in the D-loop region and in the subunits of the respiratory chain complexes independently or collectively contribute to the adaptation of Artemia to different altitudes.
authors: CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 101300, China.
authors: Hangxiao
authors: H
authors: Zhang
authors: Qibin
authors: Q
authors: Luo
authors: Jing
authors: J
authors: Sun
authors: Fei
authors: F
authors: Liu
authors: Gang
authors: G
authors: Wu
authors: Jun
authors: J
authors: Yu
authors: Weiwei
authors: W
authors: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001156:Artemia / Q000145:classification / Q000235:genetics*; D001483:Base Sequence; D003576:Electron Transport Complex IV / Q000737:chemistry / Q000235:genetics; D054629:Genome, Mitochondrial / Q000235:genetics*; D005843:Geography; D007492:Iran; D024101:Mitochondrial Proteins / Q000737:chemistry / Q000235:genetics*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D017422:Sequence Analysis, DNA / Q000379:methods*; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D018609:Tibet
chemical_list: D024101:Mitochondrial Proteins; D003576:Electron Transport Complex IV