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Rearrangements in the Physarum polycephalum mitochondrial genome associated with a transition from linear mF-mtDNA

Hideo Nomura1, Yohsuke Moriyama, Shigeyuki Kawano

  • 1Laboratory of Plant Life Systems, Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Bldg. FSB-601, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8562, Japan.

Current Genetics
|February 3, 2005
PubMed

Insights

Mitochondrial DNA (mtDNA) in Physarum polycephalum exhibits structural variations due to recombination with the mF plasmid. These rearrangements, occurring in specific regions, lead to polymorphisms in progeny mtDNA.

Area of Science:

  • Mitochondrial genetics
  • Molecular biology
  • Mycology

Background:

  • Physarum polycephalum exhibits uniparental mitochondrial DNA (mtDNA) inheritance.
  • Despite uniparental inheritance, progeny mtDNAs show structural variations, particularly in mF+ plasmodia.

Purpose of the Study:

  • To elucidate the mechanisms generating mtDNA polymorphisms in Physarum polycephalum.
  • To investigate the role of the mitochondrial plasmid mF in mtDNA structural variations.

Main Methods:

  • Restriction fragment length polymorphism (RFLP) analysis
  • Polymerase chain reaction (PCR)
  • Pulse-field gel electrophoresis (PFGE)
  • DNA sequencing

Main Results:

  • Nine distinct mtDNA rearrangement types were identified in progeny.
  • Rearrangements were localized exclusively to the mF regions of the mtDNA.
  • Linear mF-mtDNA recombinants were observed to recircularize.
  • Recombination primarily occurs at the inverted repeat (ID) sequences, leading to mtDNA linearization and subsequent variations.

Conclusions:

  • The mF plasmid is a key factor in generating mtDNA polymorphisms in Physarum polycephalum.
  • Recombination events between the mF plasmid and mtDNA, particularly at ID sequences, drive structural variations.
  • Differences in secondary recombination sites contribute to the observed mtDNA polymorphisms.

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