The mitochondrial subgenomes of the nematode Globodera pallida are mosaics: evidence of recombination in an animal mitochondrial genome.

We sequenced four mitochondrial subgenomes from the potato cyst nematode Globodera pallida, previously characterized as one of the few animals to have a multipartite mitochondrial genome. The sequence data indicate that three of these subgenomic mitochondrial circles are mosaics, comprising long, multigenic fragments derived from fragments of the other circles. This pattern is consistent with the operation of intermitochondrial recombination, a process generally considered absent in animal mitochondria. We also report that many of the duplicated genes contain deleterious mutations, ones likely to render the gene nonfunctional; gene conversion does not appear to be homogenizing the different gene copies. The proposed nonfunctional copies are clustered on particular circles, whereas copies that are likely to code functional gene products are clustered on others.