Insight into the adaptive evolution of mitochondrial genomes in intertidal chitons

ABSTRACT The intertidal zone is one of the most stressful environments, with extreme shifts in temperature, salinity, pH and oxygen concentration. Marine molluscs, particularly chitons that belong to category ecologically significant organisms, survive this environment, are ideal systems for studying stress adaptation. Mitochondria known be critical energy homeostasis, changes environmental factors result their dysfunction consequent injury organism. Intertidal organisms exception respect because they capable maintaining mitochondrial integrity. Here, we used genetic components from seven infer phylogenetic relationships. Selection analyses on individual protein-coding genes (PCGs) were performed identify map potentially adaptive residues modelled structures respiratory chain complexes. results showed amino acid sites under diversifying selection all PCGs, indicating genome undergoing evolution. Such observed proton pump as well translocation channel transmembrane helices surrounding loop regions, thus implying functional modification proteins essential survival dynamic environment zone.