The most abundant sequence within the 21-nt class varies from 10%% up to 40%% of total counts in BRASUZ1 leaves sample (Fig. 2).
Firstly, since GAAATT is a relatively abundant sequence within the promoters of Arabidopsis genes with an average of close to two motifs per 1500 bp promoter the chance occurrence of two genes with several motifs within a small cluster of, say, five genes will easily produce false positives.
The most abundant sequences classified within the SEED subsystem of virulence were associated with Ton and Tol transport systems, fluoroquinolone resistance, and other iron transport systems (Figure 3b).
The location of group 1 TCs is strongly biased to introns of genes involved in development (Table 3) and with the exception of ncRNA_05, at chrX_3721726_3721755, which is located immediately downstream of a tRNA-Pro locus, all share a consensus 18 nt sequence (18mer motif), GTCCACCCGGGGGCGCCA, which is also by far the most abundant sequence read within these TCs (31,689 out of 40,129 reads).
Following de-replication of identical sequences, the number of unique, abundant sequences (>10% of total sequences per individual) recovered for each individual ranged from zero to six.
Moreover, the DNA sequence at any site within the genome is not even necessarily an existing sequence, but rather the consensus of the most abundant sequences.
Alu repetitive elements are the abundant sequences in human genome.
Finally, while geographically widely dispersed components include slightly more abundant sequences, not all abundant sequences are widely dispersed.
This transposable element can change its position within the genome, and the LINE-1 gene is one of the most abundant sequences in the human genome and makes up 17% of the human genome.
To do so, we identified the perfect mapping positions of the most abundant piRNA sequences within the peak regions (see Methods for detail).
