Number of Total ORFs versus Number of Distinct Transporter Families or Average Number of Paralogs per Family

<p>The number of total ORFs in the genome for each of the 141 sequenced prokaryotic and eukaryotic organisms (<i>x</i>-axis) was plotted as a function of either the number of distinct transporter families (A) or the average number of paralogs per family (B) (<i>y</i>-axis). Blue diamonds represent prokaryotic organisms and red squares represent eukaryotic organisms. Trend line and power correlation <i>R</i>² value are shown for prokaryotes and eukaryotes, respectively. A group of α-Proteobacteria are enclosed by a circle (see text for discussion).