This methodology and interpretation emphasizes dominance of a sequence in a sample and disregards low abundant sequences (<5 10% in abundance) as intra-genomic variants that are not important [18], [29], [70].
With more than a million copies scattered across the chromosomes, Alu elements, which run about 300 bases in length, are the most abundant sequences in the human genome.
Involving PCR (with suitable primers) means that results will be biased towards the more abundant sequences while underrepresented portions may be disregarded.
At least a third of the 10 abundant sequences were of fecal origin.
Gram-negative Bacteriodetes were the second most abundant sequences identified for both fresh and dry manure samples.
Members of Bacteriodetes and Actinobacteria were the second most abundant sequences identified from dry and fresh manure samples, respectively.
Phylogenetic analysis of the 10 most abundant sequences indicates that members of Clostridia followed by Bacteroidia predominated in fresh manure (Figure 2).
We also used complex network methods to construct a non-redundant database of miRNA candidates by selecting the most abundant sequences as representative of each cluster.
Following the most recent update to miRBase, far more of the most abundant sequences in our library corresponded with the updated miRBase reference, pointing toward the latter explanation.
A range of proteins considered to be ubiquitous in cellular processes also ranked among the most abundant sequences that could be annotated.
Although Firmicutes represented approximately 50% of the 10 most abundant sequences, aerosols from the Sonoma dairy also contained sequences of Bacteriodetes and Actinobacteria, identified previously with animal feces.
