Five new mitogenomes of Phylloscopus (Passeriformes, Phylloscopidae): Sequence, structure, and phylogenetic analyses.

The genus Phylloscopus belongs to the order Passeriformes and subfamily Phylloscopinae within the family Sylviidae. Phylloscopus, a small insectivore widely distributed in the old world, includes 66 species and 112 subspecies. We identified five new Phylloscopus mitogenomes: P. tenellipes (16,904 base pairs (bp), MK390475), P. coronatus (16,905 bp, MK533705), P. borealis (16,881 bp, MK390476), P. schwarzi (16,920 bp, MK411584), and P. borealoides (16,904 bp, MN125373). All contained 37 genes, including 13 protein-coding genes, two rRNA genes, 22 tRNA genes, and two control regions. Seven Phylloscopus species were compared to the five new mitogenomes and the published complete P. inornatus and P. proregulus mitochondrial sequences. The genetic distance of 13 single protein-coding genes exhibited low variation within all seven Phylloscopus mitogenomes. Based on the Ka/Ks ratios, the molecular evolution patterns of single protein-coding genes were relatively consistent among Phylloscopus bird species. Phylogenetic analysis verified that subspecies of the Pale-legged Leaf Warbler P. tenellipes borealoides could be promoted to the Sakhalin Leaf Warbler P. borealoides. Gene order and genome organization information is useful to understand evolutionary relationships among Phylloscopus species. The complete mitogenomes of these five Phylloscopus species provide genetic markers for species identification, population genetics, and phylogeographic studies of birds.