Title: Eight-cluster structure of chloroplast genomes differs from similar one observed for bacteria,
Abstract: Previously, a seven-cluster pattern claiming to be a universal one in
bacterial genomes has been reported. Keeping in mind the most popular theory of
chloroplast origin, we checked whether a similar pattern is observed in
chloroplast genomes. Surprisingly, eight cluster structure has been found, for
chloroplasts. The pattern observed for chloroplasts differs rather
significantly, from bacterial one, and from that latter observed for
cyanobacteria. The structure is provided by clustering of the fragments of
equal length isolated within a genome so that each fragment is converted in
triplet frequency dictionary with non-overlapping triplets with no gaps in
frame tiling. The points in 63-dimensional space were clustered due to elastic
map technique. The eight cluster found in chloroplasts comprises the fragments
of a genome bearing tRNA genes and exhibiting excessively high
$\mathsf{GC}$-content, in comparison to the entire genome.