De novo genome assembly of a Han Chinese male and genome-wide detection of structural variants using Oxford Nanopore sequencing

Advances in third-generation sequencing technologies provide an opportunity to investigate the complex organizational structure of the genome and unravel the genetic mechanisms of disease and physiological traits. Here we report the sequencing and de novo assembly of a healthy male northern Han Chinese genome and detection of structural variants using only nanopore sequencing data. We performed de novo assembly after filtering the raw data.

Then, we aligned the assembled contigs to the human reference genome, and visualized chromosomes plot, which illustrated the contiguity of the nanopore assembly. Additionally, genomic structural variants were detected using a structure variation detection tool with long-read sequencing data. Median coverage depth was 30-fold and the read N50 was 27,136 bp. 96.51% of reads had at least one alignment to the human reference genome. The final assembled genome was 2.85 GB in size, with an N50 contig size of 5.4 MB. We identified 20,085 structural variants.

Third-generation sequencing technologies have many advantages in de novo whole-genome assembly and detection of structural variants. Our results provide reference data for disease research, and can be used as a novel population-specific dataset of structural variants to support the efficient development of personalized precision medicine.