Actinobacterial species tree showing the distribution of marine adaptation genes. The Actinobacteria are color coded according to major taxonomic affiliations. Species names are listed vertically and marine adaptation genes (MAGs) listed horizontally across the top of the table. Colored boxes indicate the distribution of each MAG. The names of the 38 strains used in the comparative genomic analyses are colored in pink while the last two columns indicate the genome sequences used for the gene gain and loss analyses. Strains highlighted in blue are of marine origin. Branch support is listed on each node; red values indicate a likelihood of 90 or higher, orange indicates values between 60 and 89 while blue indicates support values below 60. The Coriobacteridae were chosen as the root. Pst, Liv, Partial 2, and Mrp represent all genes in the respective operons. See Additional file 4 for detailed tree parameters.