barto, a list of three dataframes, representing the four genomes
and their pairwise comparisons:
dna_segs
{which is a list of 4 dna_seg
objects, containing all the protein genes for each genome. Obtained
by reading ptt files downloaded from NCBI with
read_dna_seg_from_ptt}.
comparisons{which is a list of 3 comparison
objects, obtained by doing genome-to-genome (fasta files) BLASTS,
and then reading the resulting tab files with
read_comparison_from_blast.}
rnt_segs{which is a list of 4 dna_seg objects,
containing all the RNA genes of the four genomes. Obtained by
reading rnt files downloaded from NCBI with
read_dna_seg_from_ptt}.