A novel common triplet profile for GC-rich prokaryotic genomes

It has been reported that there is a majority triplet profile among genomes, which was considered as a reflection of general mechanisms of genome evolution (Albrecht-Buehler, 2007). However, there are actually, according to our further analysis and at least among prokaryotic genomes, two common triplet profiles: one is from low-GC content genomes; the other is from high-GC content genomes. Both common profiles would be direct reflections of GC content variations and strand symmetry of genomic sequences.