title: Gene sequence variations and expression patterns of mitochondrial genes are associated with the adaptive evolution of two Gynaephora species (Lepidoptera: Lymantriinae) living in different high-elevation environments.
abstract: The adaptive evolution of animals to high-elevation environments has been extensively studied in vertebrates, while few studies have focused on insects. Gynaephora species (Lepidoptera: Lymantriinae) are endemic to the Qinghai-Tibetan Plateau (QTP) and represent an important insect pest of alpine meadows. Here, we present a detailed comparative analysis of the mitochondrial genomes (mitogenomes) of two Gynaephora species inhabiting different high-elevation environments: G. alpherakii and G. menyuanensis. The results indicated that the general mitogenomic features (genome size, nucleotide composition, codon usage and secondary structures of tRNAs) were well conserved between the two species. All of mitochondrial protein-coding genes were evolving under purifying selection, suggesting that selection constraints may play a role in ensuring adequate energy production. However, a number of substitutions and indels were identified that altered the protein conformations of ATP8 and NAD1, which may be the result of adaptive evolution of the two Gynaephora species to different high-elevation environments. Levels of gene expression for nine mitochondrial genes in nine different developmental stages were significantly suppressed in G. alpherakii, which lives at the higher elevation (~4800m above sea level), suggesting that gene expression patterns could be modulated by atmospheric oxygen content and environmental temperature. These results enhance our understanding of the genetic bases for the adaptive evolution of insects endemic to the QTP.
authors.affiliation: State Key Laboratory of Grassland Agro-Ecosystems, College of Pastoral Agricultural Science and Technology, Lanzhou University, Lanzhou 730020, China; Evo-devo Institute, School of Life Sciences, Nanjing University, Nanjing 210023, China.
authors.forename: Qi-Lin
authors.initials: QL
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Grassland Agro-Ecosystems, College of Pastoral Agricultural Science and Technology, Lanzhou University, Lanzhou 730020, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Grassland Agro-Ecosystems, College of Pastoral Agricultural Science and Technology, Lanzhou University, Lanzhou 730020, China.
authors.forename: Tian-Xuan
authors.initials: TX
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Grassland Agro-Ecosystems, College of Pastoral Agricultural Science and Technology, Lanzhou University, Lanzhou 730020, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Wang
authors.affiliation: BGI-Shenzhen, Shenzhen 518000, China.
authors.forename: Qian-Hua
authors.initials: QH
authors.lastname: Zhu
authors.affiliation: Evo-devo Institute, School of Life Sciences, Nanjing University, Nanjing 210023, China; Nanjing Institute of Geology and Paleontology, Nanjing 210008, China. Electronic address: chenjy@nju.edu.cn.
authors.forename: Jun-Yuan
authors.initials: JY
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Grassland Agro-Ecosystems, College of Pastoral Agricultural Science and Technology, Lanzhou University, Lanzhou 730020, China. Electronic address: yuanml@lzu.edu.cn.
authors.forename: Ming-Long
authors.initials: ML
authors.lastname: Yuan
mesh_terms: D000222:Adaptation, Physiological; D000531:Altitude; D000818:Animals; D050259:Genes, Mitochondrial; D019476:Insect Proteins / Q000737:chemistry; D009036:Moths / Q000145:classification / Q000235:genetics* / Q000254:growth & development / Q000502:physiology*; D009245:NADH Dehydrogenase / Q000737:chemistry; D059467:Transcriptome
chemical_list: D019476:Insect Proteins; D009245:NADH Dehydrogenase
keywords: Gene expression; Grassland caterpillars; High-elevation adaptation; Mitochondrial genome; Qinghai-Tibetan Plateau