Signal-based optical map alignment

PLoS One. 2021 Sep 30;16(9):e0253102. doi: 10.1371/journal.pone.0253102. eCollection 2021.

Abstract

In genomics, optical mapping technology provides long-range contiguity information to improve genome sequence assemblies and detect structural variation. Originally a laborious manual process, Bionano Genomics platforms now offer high-throughput, automated optical mapping based on chips packed with nanochannels through which unwound DNA is guided and the fluorescent DNA backbone and specific restriction sites are recorded. Although the raw image data obtained is of high quality, the processing and assembly software accompanying the platforms is closed source and does not seem to make full use of data, labeling approximately half of the measured signals as unusable. Here we introduce two new software tools, independent of Bionano Genomics software, to extract and process molecules from raw images (OptiScan) and to perform molecule-to-molecule and molecule-to-reference alignments using a novel signal-based approach (OptiMap). We demonstrate that the molecules detected by OptiScan can yield better assemblies, and that the approach taken by OptiMap results in higher use of molecules from the raw data. These tools lay the foundation for a suite of open-source methods to process and analyze high-throughput optical mapping data. The Python implementations of the OptiTools are publicly available through http://www.bif.wur.nl/.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromosome Mapping
  • Genomics / methods*
  • High-Throughput Nucleotide Sequencing
  • Optical Restriction Mapping / methods*
  • Sequence Analysis, DNA

Grants and funding

This work is part of the Open Technology Programme with project number 14516, (partly) financed by the Netherlands Organisation for Scientific Research (NWO), domain Applied and Engineering Sciences, and supported by Bayer CropScience NV, Genetwister Technologies BV, Rijk Zwaan BV and SESVanderHave NV. Yeast optical map data was generated in a ZonMW Enabling Technologies Hotels project (435002001). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.