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Coexistence of minicircular and a highly rearranged mtDNA molecule suggests that recombination shapes mitochondrial genome organization

Journal Article


Abstract


  • Recombination has been proposed as a possible mechanism to explain mitochondrial (mt) gene rearrangements, although the issue of whether mtDNA recombination occurs in animals has been controversial. In this study, we sequenced the entire mt genome of the megaspilid wasp Conostigmus sp., which possessed a highly rearranged mt genome. The sequence of the A+T-rich region contained a number of different types of repeats, similar to those reported previously in the nematode Meloidogyne javanica, in which recombination was discovered. In Conostigmus, we detected the end-products of recombination: a range of minicircles. However, using isolated (cloned) fragments of the A+T-rich region, we established that some of these minicircles were found to be PCR artifacts. It appears that regions with repeats are prone to PCR template switching, or PCR jumping. Nevertheless, there is strong evidence that one minicircle is real, as amplification primers that straddle the putative breakpoint junction produce a single strong amplicon from genomic DNA, but not from the cloned A+T-rich region. The results provide support for the direct link between recombination and mt gene rearrangement. Furthermore, we developed a model of recombination which is important for our understanding of mtDNA evolution.

Authors


  •   Mao, Meng (external author)
  •   Austin, Andrew D. (external author)
  •   Johnson, Norman F. (external author)
  •   Dowton, Mark P.

Publication Date


  • 2014

Citation


  • Mao, M., Austin, A. D., Johnson, N. F. & Dowton, M. (2014). Coexistence of minicircular and a highly rearranged mtDNA molecule suggests that recombination shapes mitochondrial genome organization. Molecular Biology and Evolution, 31 (3), 636-644.

Scopus Eid


  • 2-s2.0-84895772648

Ro Metadata Url


  • http://ro.uow.edu.au/smhpapers/1808

Number Of Pages


  • 8

Start Page


  • 636

End Page


  • 644

Volume


  • 31

Issue


  • 3

Place Of Publication


  • http://mbe.oxfordjournals.org/content/31/3/636

Abstract


  • Recombination has been proposed as a possible mechanism to explain mitochondrial (mt) gene rearrangements, although the issue of whether mtDNA recombination occurs in animals has been controversial. In this study, we sequenced the entire mt genome of the megaspilid wasp Conostigmus sp., which possessed a highly rearranged mt genome. The sequence of the A+T-rich region contained a number of different types of repeats, similar to those reported previously in the nematode Meloidogyne javanica, in which recombination was discovered. In Conostigmus, we detected the end-products of recombination: a range of minicircles. However, using isolated (cloned) fragments of the A+T-rich region, we established that some of these minicircles were found to be PCR artifacts. It appears that regions with repeats are prone to PCR template switching, or PCR jumping. Nevertheless, there is strong evidence that one minicircle is real, as amplification primers that straddle the putative breakpoint junction produce a single strong amplicon from genomic DNA, but not from the cloned A+T-rich region. The results provide support for the direct link between recombination and mt gene rearrangement. Furthermore, we developed a model of recombination which is important for our understanding of mtDNA evolution.

Authors


  •   Mao, Meng (external author)
  •   Austin, Andrew D. (external author)
  •   Johnson, Norman F. (external author)
  •   Dowton, Mark P.

Publication Date


  • 2014

Citation


  • Mao, M., Austin, A. D., Johnson, N. F. & Dowton, M. (2014). Coexistence of minicircular and a highly rearranged mtDNA molecule suggests that recombination shapes mitochondrial genome organization. Molecular Biology and Evolution, 31 (3), 636-644.

Scopus Eid


  • 2-s2.0-84895772648

Ro Metadata Url


  • http://ro.uow.edu.au/smhpapers/1808

Number Of Pages


  • 8

Start Page


  • 636

End Page


  • 644

Volume


  • 31

Issue


  • 3

Place Of Publication


  • http://mbe.oxfordjournals.org/content/31/3/636