DNA rearrangements such as sister chromatid exchanges (SCEs) are sensitive indicators of genomic stress and instability, but they are typically masked by single-cell sequencing techniques. We developed Strand-seq to independently sequence parental DNA template strands from single cells, making it possible to map SCEs at orders-of-magnitude greater resolution than was previously possible. On average, murine embryonic stem (mES) cells exhibit eight SCEs, which are detected at a resolution of up to 23 bp. Strikingly, Strand-seq of 62 single mES cells predicts that the mm9 mouse reference genome assembly contains at least 17 incorrectly oriented segments totaling nearly 1% of the genome. These misoriented contigs and fragments have persisted through several iterations of the mouse reference genome and have been difficult to detect using conventional sequencing techniques. The ability to map SCE events at high resolution and fine-tune reference genomes by Strand-seq dramatically expands the scope of single-cell sequencing.
Access optionsAccess options
Subscribe to Journal
Get full journal access for 1 year
only $20.17 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
Sequence Read Archive
We thank J. Brind'Amour and S. Rentas for discussions and J. Schein and C. Carter (Genome Sciences Centre) for BACs. We also thank K. Gan for help with preliminary MNase experiments. U.N. was supported by a Fellowship for Prospective Researchers from the Swiss National Science Foundation (project no. PBBEP3_131554). Work in the Hirst laboratory is supported by Canadian Institutes of Health Research grant RMF-92093. Work in the Lansdorp laboratory is supported by grants from the Canadian Institutes of Health Research (RMF-92093 and 105265), the US National Institutes of Health (R01GM094146) and the Terry Fox Foundation (018006). P.M.L. is a recipient of an Advanced Grant from the European Research Council.
Supplementary Figures 1–14 and Supplementary Tables 1 and 2
This PDF document provides chromosome ideograms and coverage statistics for four whole-genome shotgun (WGS) libraries and 62 Strand-seq libraries. The first two pages provide a summary table (pages 1–2) that lists all single-cell libraries, with clickable links to the ideograms. The table also summarizes library information such as cell input, synchronization and BrdU/Hoechst/UV treatment as well as coverage statistics including percent genomic coverage, the number of unique reads with a mapping quality score of at least 20 (q20, see Online Methods) and a summary of the number of observed chromosomes with SCEs or aneuploidy. Each library is presented on a single page (pages 3–68) with Watson and Crick reads mapped on chromosome ideograms (see main manuscript). The ideograms are the output of our bioinformatic analysis of inherited templates (BAIT) analysis pipeline (see Online Methods). The information from the summary table appears for each library. The average reads per megabase for both Watson and Crick reads appears below each chromosome in orange and blue numbers, respectively. Aneuploid chromosomes are identified with 'monosomy' or 'trisomy' written below the chromosome ideogram, with the percentage indicating the proportion of reads compared to the average genomic read depth. The overall reads per megabase for the entire genome is found in the bottom right of each page. Because the length of the horizontal orange and blue lines projecting from the chromosome ideograms represents the total number of reads per 200-kb bin (see main manuscript), the library ideograms were scaled to prevent high coverage libraries from overlapping between adjacent chromosomes (scale factor).
About this article
Current Opinion in Systems Biology (2018)