Relative transcript abundances of photosynthetic reaction center genes of six different phototrophs. The relative transcript abundances of the indicated photosynthetic reaction center genes with most assigned mRNA sequences (SOLiD data set only) are plotted for six different phototrophs. Syne, Synechococcus sp. strain A and B′ Cab, Candidatus Chloracidobacterium thermophilum; GSB, a Chlorobiales population; Rosei, Roseiflexus sp.; Chlor, Chloroflexus sp.; Anaer, novel Anaerolineae-like Chloroflexi population.