The butterfly plot of frog (panel A), lizard (panel B) and human functional classes (panel C). Color code of histogram bars is as in Figure 1. Asterisks show bars with an average GC3 content significantly higher than the genomic one (Bonferroni's test, α = 0.05).
Berná et al. BMC Genomics 2012 13:174 doi:10.1186/1471-2164-13-174