Figure 1

ZOM based heatmap. The ZOM Based heatmap shows all genomes compared using cluster analysis based on 0^th order Markov chain model predicted tetranucleotide frequencies. It can be seen that the sequenced species from genus Brucella are very similar in terms of tetranucleotide usage patterns, with larger differences found in the more distantly related genera of Agrobacterium and Ochrobactrum. Although all species in genus Brucella are very similar in terms of base composition, as measured using the ZOM based method, several subgroups can be observed. For instance, marine associated (Groups 2 and 4) and terrestrial mammal associated (Groups 1, 3 and 5) species of genus Brucella are segregated into different groups.