Nucleotide skews for the main-coding strand of the pterobranch Rhabdopleura compacta compared to other bilaterian mitochondrial genomes. Values of the nucleotide skews of R. compacta are marked by filled black circles (3rd: values for the 3rd codon position of all protein-coding genes; np: values for non- protein coding regions). The nucleotide skew values for other bilaterian mitochondrial genomes are marked by different symbols as indicated in each figure. The values of different phylogenetic groups are visualized by a cross giving the minimum and maximum of the nucleotide skews, and an ellipse with major axis in the direction of the eigenvector of the covariance matrix. Note the strong deviation of the nucleotide skews in R. compacta, similar to the mitochondrial genomes of the parasitic flatworms (Cestoda, Trematoda) and certain nematodes (Chromadorea).
Perseke et al. BMC Evolutionary Biology 2011 11:134 doi:10.1186/1471-2148-11-134