Precise annotation of tick mitochondrial genomes reveals multiple copy number variation of short tandem repeats and one transposon-like element.

We proposed that the accumulation of CNV of STRs in mitochondria may cause aging or diseases. Future tests of the CNV of STRs hypothesis help to ultimately reveal the genetic basis of mitochondrial DNA variation and its consequences (e.g., aging and diseases) in animals. Our study will lead to the reconsideration of the importance of STRs and a unified study of CNV of STRs with longer and shorter repeat units (particularly polynucleotides) in both nuclear and mt genomes.