Fig 1. Compacted DBG construction over a set of sequences differing by a single point mutation.
In this example two sequences s1 and s2 of length 12 differ by a single letter. (A) All k-mers (k = 4) present in these sequences are listed. A link is drawn between two k-mers when the k − 1 = 3 last nucleotides of the first k-mer equal the 3 first nucleotides of the second k-mer. (B) The bubble pattern represents the SNP C to A; each branch of the bubble represents an allele. (C) Linear paths of the graph are compacted; the compacted DBG of the example only contains four nodes (unitigs) and represents the same variation as the original DBG, which contained 13 nodes (k-mers).