Figure 1. Relationship of rRNA gene vs. genomic GC content for Alphaproteobacteria and mitochondria.

The rRNA gene GC content was calculated from the entire sequence using a perl script, while the genomic GC content was taken from the IMG database. The “other orders” group includes the Caulobacterales, Sphingomonadales, Rhizobiales, Rhodobacterales and Parvularculales.