title: Evolution of multipartite mitochondrial genomes in the booklice of the genus Liposcelis (Psocoptera).
abstract: BACKGROUND
  The genus Liposcelis (Psocoptera: Troctomorpha) has more than 120 species with a worldwide distribution and they pose a risk for global food security. The organization of mitochondrial (mt) genomes varies between the two species of booklice investigated in the genus Liposcelis. Liposcelis decolor has its mt genes on a single chromosome, like most other insects; L. bostrychophila, however, has a multipartite mt genome with genes on two chromosomes.
  
  
  RESULTS
  To understand how multipartite mt genome organization evolved in the genus Liposcelis, we sequenced the mt genomes of L. entomophila and L. paeta in this study. We found that these two species of booklice also have multipartite mt genomes, like L. bostrychophila, with the mt genes we identified on two chromosomes. Numerous pseudo mt genes and non-coding regions were found in the mt genomes of these two booklice, and account for 30% and 10% respectively of the entire length we sequenced. In L. bostrychophila, the mt genes are distributed approximately equally between the two chromosomes. In L. entomophila and L. paeta, however, one mt chromosome has most of the genes we identified whereas the other chromosome has largely pseudogenes and non-coding regions. L. entomophila and L. paeta differ substantially from each other and from L. bostrychophila in gene content and gene arrangement in their mt chromosomes.
  
  
  CONCLUSIONS
  Our results indicate unusually fast evolution in mt genome organization in the booklice of the genus Liposcelis, and reveal different patterns of mt genome fragmentation among L. bostrychophila, L. entomophila and L. paeta.
authors.forename: Shi-Chun
authors.initials: SC
authors.lastname: Chen
authors.forename: Dan-Dan
authors.initials: DD
authors.lastname: Wei
authors.forename: Renfu
authors.initials: R
authors.lastname: Shao
authors.forename: Jun-Xia
authors.initials: JX
authors.lastname: Shi
authors.forename: Wei
authors.initials: W
authors.lastname: Dou
authors.affiliation: Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, P, R, China. jjwang7008@yahoo.com.
authors.forename: Jin-Jun
authors.initials: JJ
authors.lastname: Wang
mesh_terms: D000818:Animals; D001483:Base Sequence; D059006:Chromosomes, Insect; D004272:DNA, Mitochondrial / Q000145:classification / Q000378:metabolism; D054629:Genome, Mitochondrial; D007313:Insecta / Q000145:classification / Q000235:genetics*; D024101:Mitochondrial Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D011544:Pseudogenes / Q000235:genetics; D016415:Sequence Alignment; D020506:Untranslated Regions / Q000235:genetics
chemical_list: D004272:DNA, Mitochondrial; D024101:Mitochondrial Proteins; D020506:Untranslated Regions