A Novel Mitochondrial Genome Architecture in Thrips (Insecta: Thysanoptera): Extreme Size Asymmetry Among Chromosomes and Possible Recent Control Region Duplication

BMC Genomics. 2015 Jun 9;16(1):439. doi: 10.1186/s12864-015-1672-4.

Abstract

Background: Multipartite mitochondrial genomes are very rare in animals but have been found previously in two insect orders with highly rearranged genomes, the Phthiraptera (parasitic lice), and the Psocoptera (booklice/barklice).

Results: We provide the first report of a multipartite mitochondrial genome architecture in a third order with highly rearranged genomes: Thysanoptera (thrips). We sequenced the complete mitochondrial genomes of two divergent members of the Scirtothrips dorsalis cryptic species complex. The East Asia 1 species has the single circular chromosome common to animals while the South Asia 1 species has a genome consisting of two circular chromosomes. The fragmented South Asia 1 genome exhibits extreme chromosome size asymmetry with the majority of genes on the large, 14.28 kb, chromosome and only nad6 and trnC on the 0.92 kb mini-circle chromosome. This genome also features paralogous control regions with high similarity suggesting a very recent origin of the nad6 mini-circle chromosome in the South Asia 1 cryptic species.

Conclusions: Thysanoptera, along with the other minor paraenopteran insect orders should be considered models for rapid mitochondrial genome evolution, including fragmentation. Continued use of these models will facilitate a greater understanding of recombination and other mitochondrial genome evolutionary processes across eukaryotes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chromosomes / genetics*
  • DNA, Mitochondrial / genetics*
  • Evolution, Molecular
  • Gene Duplication
  • Genome Size
  • Sequence Analysis, DNA
  • Thysanoptera / genetics*

Substances

  • DNA, Mitochondrial