Fig. 6

The intraspecific structural polymorphisms and phylogenetic relationships among mitochondrial genomes of U. virens. a Highly variable U. virens mitochondrial genomes are represented by large fragment gain/loss polymorphisms. The top line illustrates mitochondrial gene annotations in the reference strain UV8b. The genes are indicated by red, rRNAs by blue and tRNAs by green. The mitochondrial sequences of other strains were aligned to the reference one, and the deletions and insertions are indicated by the horizontal dashed lines and the bubbles, respectively. The insertion sites are indicated by red triangles below bubbles. b The phylogeny of eight U. virens strains based on mitochondrial intronic sequences. The shared intronic sequences were used to construct the phylogenetic tree, since exonic sequences are extremely conserved