unitig

In the simplest of terms: a run of nodes (kmers) in the de Bruijn graph.

Unitig definition: A maximal run of de Bruijn nodes (kmers, each with an orientation) where all nodes must have in-degree and out-degree exactly 1, with the exception of in-degree of the first node and out-degree of the last node (they may have any number). Additionally, a unitig must not visit a kmer more than once.

Kmer orientation can be FORWARD (kmer-key) or REVERSE (reverse-complement of kmer-key).

When normalised, a unitig starts from the lowest kmer. If it is a cycle, the first kmer is also in the forward orientation. Normalising a set of kmers allows us to define a definitive set of unitigs for a graph.

You can pull normalised unitigs out of a graph with the mccortex31 unitigs command.