Chromosomal assembly of the Antarctic toothfish (Dissostichus mawsoni) genome using third-generation DNA sequencing and Hi-C technology

Abstract

鳞头犬牙南极鱼（ Dissostichus mawsoni）是一类分布于南纬60度以下的南大洋的南极鱼科动物。鳞头犬牙南极鱼在零下温度的环境中生存，因此，它是研究狭温性冷适应机制的理想生物模型。在该研究中，我们测序并组装了鳞头犬牙南极鱼的三代高质量基因组（1062 个scaffolds，scaffolds N50为36.98Mb，最长的scaffold长度为46.82Mb）。基因组分析显示，鳞头犬牙南极鱼基因组中包含40.87%的重复序列。结合生物信息学预测、转录组测序、可变剪接分析（Iso-Seq），我们鉴定了32914个鳞头犬牙南极鱼蛋白编码基因，为进一步研究南极犬牙鱼类的极冷环境适应性研究提供了极宝贵的基因资源。新组装的鳞头犬牙南极鱼的高质量参考基因组为深入研究南极犬牙鱼冷环境适应的基因组机制与生物资源保护都具有极其重要的意义。.The Antarctic toothfish, Dissostichus mawsoni, belongs to the Nototheniidae family and is distributed in sub-zero temperatures below S60° latitude in the Southern Ocean. Therefore, it is an attractive model species to study the stenothermal cold-adapted character state. In this study, we successfully generated highly contiguous genome sequences of D. mawsoni, which contained 1 062 scaffolds with a N50 length of 36.98 Mb and longest scaffold length of 46.82 Mb. Repetitive elements accounted for 40.87% of the genome. We also inferred 32 914 protein-coding genes using in silico gene prediction and transcriptome sequencing and detected splicing variants using Isoform-Sequencing (Iso-Seq), which will be invaluable resource for further exploration of the adaptation mechanisms of Antarctic toothfish. This new high-quality reference genome of D. mawsoni provides a fundamental resource for a deeper understanding of cold adaptation and conservation of species.