Analysis on the Correlation Relationships between the Temperature Range Condition and the Genic GC Content Levels of Prokaryotes

We here analyzed the correlation between the genic GC content and the temperature range conditions of prokaryotes. To identify those genes whose surrounding GC levels exhibit patterns different for organisms under different temperature conditions but transcending phylogenetic boundaries, we first focused on the complete list of organisms, then partial lists of organisms with one phylum being excluded, and finally organisms of the same phylum but of different temperature conditions. To further validate the identified correlation relationships, we examined to what extent the temperature condition of an organism can be predicted based on the GC levels surrounding the selected genes. The overall prediction accuracy was 96.80% if based on the genes derived from the complete list of organisms, and 95.45% if based on the 17 phylum-independent genes. If the phylum-specific genes were used, the prediction accuracy was 90.00% and 95.63% for organisms of the Euryarchaeota and Firmicutes phyla, respectively. These results demonstrated the predictability of the temperature range conditions of prokaryotic organisms based on their genic GC levels surrounding certain genes, as well as the correlation between this particular duo of ecological and genomic traits.