title: The mitochondrial genome of Frankliniella intonsa: insights into the evolution of mitochondrial genomes at lower taxonomic levels in Thysanoptera.
abstract: Thrips is an ideal group for studying the evolution of mitochondrial (mt) genomes in the genus and family due to independent rearrangements within this order. The complete sequence of the mitochondrial DNA (mtDNA) of the flower thrips Frankliniella intonsa has been completed and annotated in this study. The circular genome is 15,215bp in length with an A+T content of 75.9% and contains the typical 37 genes and it has triplicate putative control regions. Nucleotide composition is A+T biased, and the majority of the protein-coding genes present opposite CG skew which is reflected by the nucleotide composition, codon and amino acid usage. Although the known thrips have massive gene rearrangements, it showed no reversal of strand asymmetry. Gene rearrangements have been found in the lower taxonomic levels of thrips. Three tRNA genes were translocated in the genus Frankliniella and eight tRNA genes in the family Thripidae. Although the gene arrangements of mt genomes of all three thrips species differ massively from the ancestral insect, they are all very similar to each other, indicating that there was a large rearrangement somewhere before the most recent common ancestor of these three species and very little genomic evolution or rearrangements after then. The extremely similar sequences among the CRs suggest that they are ongoing concerted evolution. Analyses of the up and downstream sequence of CRs reveal that the CR2 is actually the ancestral CR. The three CRs are in the same spot in each of the three thrips mt genomes which have the identical inverted genes. These characteristics might be obtained from the most recent common ancestor of this three thrips. Above observations suggest that the mt genomes of the three thrips keep a single massive rearrangement from the common ancestor and have low evolutionary rates among them.
authors.affiliation: College of Plant Protection, Nanjing Agricultural University and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, China; Institute of Plant Protection and Agro-Products Safety, Anhui Academy of Agricultural Sciences, Hefei 230031, China.
authors.forename: Dankan
authors.initials: D
authors.lastname: Yan
authors.affiliation: College of Plant Protection, Nanjing Agricultural University and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, China.
authors.forename: Yunxia
authors.initials: Y
authors.lastname: Tang
authors.affiliation: College of Plant Protection, Nanjing Agricultural University and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, China.
authors.forename: Min
authors.initials: M
authors.lastname: Hu
authors.affiliation: College of Plant Protection, Nanjing Agricultural University and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, China.
authors.forename: Fengquan
authors.initials: F
authors.lastname: Liu
authors.affiliation: Institute of Plant Protection and Agro-Products Safety, Anhui Academy of Agricultural Sciences, Hefei 230031, China.
authors.forename: Dongfang
authors.initials: D
authors.lastname: Zhang
authors.affiliation: College of Plant Protection, Nanjing Agricultural University and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, China. Electronic address: fanjq@njau.edu.cn.
authors.forename: Jiaqin
authors.initials: J
authors.lastname: Fan
mesh_terms: D000818:Animals; D001483:Base Sequence; D019143:Evolution, Molecular; D020862:GC Rich Sequence; D015321:Gene Rearrangement; D049750:Genome, Insect; D054629:Genome, Mitochondrial; D019901:Locus Control Region; D008969:Molecular Sequence Data; D012343:RNA, Transfer / Q000235:genetics; D061149:Thysanoptera / Q000145:classification / Q000235:genetics*
chemical_list: D012343:RNA, Transfer
keywords: Frankliniella intonsa; Lower taxonomic levels; Mitochondrial genomes evolution; Strand asymmetry; Thysanoptera