Overlap graphs and <i><b>de Bruijn</b></i> graphs: data structures for <i><b>de novo</b></i>genome assembly in the big data era

Abstract

Background De novo genome assembly relies on two kinds of graphs: de Bruijn graphs and overlap graphs. Overlap graphs are the basis for the Celera assembler, while de Bruijn graphs have become the dominant technical device in the last decade. Those two kinds of graphs are collectively called assembly graphs. Results In this review, we discuss the most recent advances in the problem of constructing, representing and navigating assembly graphs, focusing on very large datasets. We will also explore some computational techniques, such as the Bloom filter, to compactly store graphs while keeping all functionalities intact. Conclusions We complete our analysis with a discussion on the algorithmic issues of assembling from long reads ( e.g., PacBio and Oxford Nanopore). Finally, we present some of the most relevant open problems in this field.