Fig. 2

The evolutionary dynamics of transportomes composition. (a) Heat-map representation of the changes in the number of members of the transporter classes. To calculate the intra-genomic frequencies, the numbers of transporter members are normalized to the total number of genes per genome. The heat-map is drawn for each class of ion channels, secondary transporters, and ATP-dependent transporters and therefore colors are not comparable between the classes. (b) The fraction of ATP-dependent transporters in the transportomes. All of the variations of ATP-dependent transporters and ABC superfamily except the difference between bacteria and archaea are significant with a p-value less than 0.001. (c) The fraction of secondary transporters in the transportomes. Only the difference between bacteria and animals is not statistically significant (p = 0.635). (d) The fraction of ion channels in the transportomes. All differences, except among fungi, bacteria and archaea, are significant with a p-value less than 0.001. The values on panels b-d are shown as mean +/− t-test based 99% confidence intervals. The variations were also confirmed on the arc sin √x transformed data (See Additional file 2: Data S1). The family names of the transporters can also be found in the Additional file 2: Data S1