K-means clusters of T. elongatus and M K-means clusters of T. elongatus and M. ruber relative mRNA abundance profiles that share correlated expression patterns over irradiance- and pO2-controlled steady states. K-means clusters of T. elongatus and M. ruber relative mRNA abundance profiles that share correlated expression patterns over irradiance- and pO2-controlled steady states. Heavy black lines represent the centroid (i.e., eigen-gene) calculated within each cluster. Cluster A, 201 T. elongatus plus 259 M. ruber genes; cluster B, 255 T. elongatus plus 188 M. ruber genes; cluster C, 971 T. elongatus plus 444 M. ruber genes; cluster D, 914 T. elongatus plus 324 M. ruber genes; cluster E, 211 T. elongatus plus 328 M. ruber genes; cluster F, 187 T. elongatus plus 309 M. ruber genes; cluster G, 913 T. elongatus plus 468 M. ruber genes; cluster H, 888 T. elongatus plus 387 M. ruber genes. Heat maps show the expression patterns [log2(RPKM/mean)] for specific functional genes from each organism. Hans C. Bernstein et al. mSystems 2017; doi:10.1128/mSystems.00181-16