Mitochondrial genome sequences of Artemia tibetiana and Artemia urmiana： assessing molecular changes for high plateau adaptation

• Published in: Science China. Life sciences 2013-05, Vol.56 (5), p.440-452
• Main Authors: Zhang, HangXiao, Luo, QiBin, Sun, Jing, Liu, Fei, Wu, Gang, Yu, Jun, Wang, WeiWei
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Anostraca; Artemia; Artemia - classification; Artemia - genetics; Artemia tibetiana; Artemia urmiana; Base Sequence; Biomedical and Life Sciences; Crustacea; D-loop区; Electron Transport Complex IV - chemistry; Electron Transport Complex IV - genetics; Genome, Mitochondrial - genetics; Geography; Iran; Life Sciences; Marine; Mitochondrial Proteins - chemistry; Mitochondrial Proteins - genetics; Models, Molecular; Molecular Sequence Data; Protein Structure, Secondary; Protein Structure, Tertiary; Research Paper; Sequence Analysis, DNA - methods; Sequence Homology, Amino Acid; Sequence Homology, Nucleic Acid; Species Specificity; Tibet; 丰年虫; 分子; 卤虫; 基因组序列; 线粒体蛋白; 评估; 青藏高原
• ISSN: 1674-7305; 1869-1889
• DOI: 10.1007/s11427-013-4474-4

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 iso- lates 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 be- tween 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 termina- tion-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.