FSG: Fast String Graph Construction for De Novo Assembly of Reads Data

  • Paola Bonizzoni
  • Gianluca Della Vedova
  • Yuri Pirola
  • Marco PrevitaliEmail author
  • Raffaella Rizzi
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 9683)


The string graph for a collection of next-generation reads is a lossless data representation that is fundamental for de novo assemblers based on the overlap-layout-consensus paradigm. In this paper, we explore a novel approach to compute the string graph, based on the FM-index and Burrows-Wheeler Transform (BWT). We describe a simple algorithm that uses only the FM-index representation of the collection of reads to construct the string graph, without accessing the input reads. Our algorithm has been integrated into the SGA assembler as a standalone module to construct the string graph.

The new integrated assembler has been assessed on a standard benchmark, showing that FSG is significantly faster than SGA while maintaining a moderate use of main memory, and showing practical advantages in running FSG on multiple threads.


External Memory Bloom Filter Input String String Graph Haplotype Assembly 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer International Publishing Switzerland 2016

Authors and Affiliations

  • Paola Bonizzoni
    • 1
  • Gianluca Della Vedova
    • 1
  • Yuri Pirola
    • 1
  • Marco Previtali
    • 1
    Email author
  • Raffaella Rizzi
    • 1
  1. 1.DISCoUniversity of Milano-BicoccaMilanItaly

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