1. Poly(T) variation in heteroderid nematode mitochondrial genomes is predominantly an artefact of amplification.
- Author
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Riepsamen AH, Gibson T, Rowe J, Chitwood DJ, Subbotin SA, and Dowton M
- Subjects
- Animals, Base Sequence, DNA, Mitochondrial genetics, DNA-Directed DNA Polymerase chemistry, DNA-Directed DNA Polymerase metabolism, Databases, Nucleic Acid, Electron Transport Complex IV genetics, INDEL Mutation, Molecular Sequence Data, Sequence Alignment, Sequence Analysis, DNA, Artifacts, Genetic Variation, Genome, Helminth, Genome, Mitochondrial, Nucleic Acid Amplification Techniques methods, Poly T genetics, Tylenchoidea genetics
- Abstract
We assessed the rate of in vitro polymerase errors at polythymidine [poly(T)] tracts in the mitochondrial DNA (mtDNA) of a heteroderid nematode (Heterodera cajani). The mtDNA of these nematodes contain unusually high numbers of poly(T) tracts, and have previously been suggested to contain biological poly(T) length variation. However, using a cloned molecule, we observed that poly(T) variation was generated in vitro at regions containing more than six consecutive Ts. This artefactual error rate was estimated at 7.3 × 10(-5) indels/poly(T) tract >6 Ts/cycle. This rate was then compared to the rate of poly(T) variation detected after the amplification of a biological sample, in order to estimate the 'biological + artefactual' rate of poly(T) variation. There was no significant difference between the artefactual and the artefactual + biological rates, suggesting that the majority of poly(T) variation in the biological sample was artefactual. We then examined the generation of poly(T) variation in a range of templates with tracts up to 16 Ts long, utilizing a range of Heteroderidae species. We observed that T deletions occurred five times more frequently than insertions, and a trend towards increasing error rates with increasing poly(T) tract length. These findings have significant implications for studies involving genomes with many homopolymer tracts.
- Published
- 2011
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