Nanopore sequencing and assembly of a human genome with ultra-long reads
Research output: Contribution to journal › Article
- UC Santa Cruz Genomics Institute, University of California, Santa Cruz, California, USA.
- Genome Informatics Section, Computational and Statistical Genomics Branch, National Human Genome Research Institute, Bethesda, Maryland, USA.
- USTAR Center for Genetic Discovery, University of Utah, Salt Lake City, Utah, USA.
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada.
- Surgical Research Laboratory, Institute of Cancer & Genomic Science, University of Birmingham, UK.
- DeepSeq, School of Life Sciences, University of Nottingham, Nottingham, UK.
- University of East Anglia
- Department of Biomedical Informatics, University of Utah, Salt Lake City, Utah, USA.
- Department of Computer Science, University of Toronto, Toronto, Canada.
We report the sequencing and assembly of a reference genome for the human GM12878 Utah/Ceph cell line using the MinION (Oxford Nanopore Technologies) nanopore sequencer. 91.2 Gb of sequence data, representing ∼30× theoretical coverage, were produced. Reference-based alignment enabled detection of large structural variants and epigenetic modifications. De novo assembly of nanopore reads alone yielded a contiguous assembly (NG50 ∼3 Mb). We developed a protocol to generate ultra-long reads (N50 > 100 kb, read lengths up to 882 kb). Incorporating an additional 5× coverage of these ultra-long reads more than doubled the assembly contiguity (NG50 ∼6.4 Mb). The final assembled genome was 2,867 million bases in size, covering 85.8% of the reference. Assembly accuracy, after incorporating complementary short-read sequencing data, exceeded 99.8%. Ultra-long reads enabled assembly and phasing of the 4-Mb major histocompatibility complex (MHC) locus in its entirety, measurement of telomere repeat length, and closure of gaps in the reference human genome assembly GRCh38.
|Early online date||29 Jan 2018|
|Publication status||E-pub ahead of print - 29 Jan 2018|