Correlation between phylogenetically independent contrasts of coding sequence GC3 content and AA usage for 25 nematode species. (a) AAs lysine (Lys), isoleucine (Ile), asparagine (Asn), and tyrosine (Tyr) are used less frequently as the species' coding sequence GC3 content increases. (b) AAs alanine (Ala), glycine (Gly), arginine (Arg), and proline (Pro) are used more frequently as the coding sequence GC3 content increases. AA, amino acid.
Mitreva et al. Genome Biology 2006 7:R75 doi:10.1186/gb-2006-7-8-r75