iScience (May 2020)

CONNET: Accurate Genome Consensus in Assembling Nanopore Sequencing Data via Deep Learning

  • Yifan Zhang,
  • Chi-Man Liu,
  • Henry C.M. Leung,
  • Ruibang Luo,
  • Tak-Wah Lam

Journal volume & issue
Vol. 23, no. 5

Abstract

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Summary: Single-molecule sequencing technologies produce much longer reads compared with next-generation sequencing, greatly improving the contiguity of de novo assembly of genomes. However, the relatively high error rates in long reads make it challenging to obtain high-quality assemblies. A computationally intensive consensus step is needed to resolve the discrepancies in the reads. Efficient consensus tools have emerged in the recent past, based on partial-order alignment. In this study, we discovered that the spatial relationship of alignment pileup is crucial to high-quality consensus and developed a deep learning-based consensus tool, CONNET, which outperforms the fastest tools in terms of both accuracy and speed. We tested CONNET using a 90× dataset of E. coli and a 37× human dataset. In addition to achieving high-quality consensus results, CONNET is capable of delivering phased diploid genome consensus. Diploid consensus on the above-mentioned human assembly further reduced 12% of the consensus errors made in the haploid results.

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