De novo assembly of a wild swan goose (Anser cygnoides) genome.

The swan goose (Anser cygnoides) is the ancestor of the Chinese domestic goose. A previous study reported a scaffold-level genome version for a Chinese indigenous goose breed, and this assembly was used as the swan goose's reference genome. To date, there is still a lack of a chromosome-level genome for the swan goose. Here, we reported a de novo assembly of the genome of a wild swan goose using an integrated strategy that combines Illumina Hiseq, Oxford Nanopore and chromosome conformation capture (Hi-C) sequencing. A total of 134.6 Gb Nanopore data with sequencing coverage of 110.33 and 69.45 Gb Illumina data with coverage of 56.93 were obtained. The genome assembly size was 1153.41 Mb, with a contig N50 of 22.75 Mb. The total size and N50 length of our assembly were larger than the previously reported scaffold-level genome version. In addition, whole-genome sequencing data of 10 geese were mapped to the previous and the current assemblies. On average, 97.88 and 93.18% of the reads were properly mapped and paired into our and the previous assemblies. This high-quality chromosome-level swan goose genome could provide a valuable resource for the utilisation of goose studies and breeding.