Key Laboratory of Forest Protection of State Forestry and Grassland Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, China.
Nextomics Biosciences Institute, Wuhan, China.
Mol Ecol Resour. 2020 Jul;20(4):1023-1037. doi: 10.1111/1755-0998.13169. Epub 2020 Jul 13.
Dendrolimus spp. are important destructive pests of conifer forests, and Dendrolimus punctatus Walker (Lepidoptera; Lasiocampidae) is the most widely distributed Dendrolimus species. During periodic outbreaks, this species is said to make "fire without smoke" because large areas of pine forest can be quickly and heavily damaged. Yet, little is known about the molecular mechanisms that underlie the unique ecological characteristics of this forest insect. Here, we combined Pacific Biosciences (PacBio) RSII single-molecule long reads and high-throughput chromosome conformation capture (Hi-C) genomics-linked reads to produce a high-quality, chromosome-level reference genome for D. punctatus. The final assembly was 614 Mb with contig and scaffold N50 values of 1.39 and 22.15 Mb, respectively, and 96.96% of the contigs anchored onto 30 chromosomes. Based on the prediction, this genome contained 17,593 protein-coding genes and 56.16% repetitive sequences. Phylogenetic analyses indicated that D. punctatus diverged from the common ancestor of Hyphantria cunea, Spodoptera litura and Thaumetopoea pityocampa ~ 108.91 million years ago. Many gene families that were expanded in the D. punctatus genome were significantly enriched for the xenobiotic biodegradation system, especially the cytochrome P450 gene family. This high-quality, chromosome-level reference genome will be a valuable resource for understanding mechanisms of D. punctatus outbreak and host resistance adaption. Because this is the first Lasiocampidae insect genome to be sequenced, it also will serve as a reference for further comparative genomics.
松毛虫是针叶林的重要破坏性害虫，而马尾松毛虫（鳞翅目：枯叶蛾科）是分布最广的松毛虫种类。在周期性爆发期间，这种物种据说会“放无烟火”，因为大面积的松林会迅速而严重受损。然而，人们对这种森林昆虫独特生态特征的分子机制知之甚少。在这里，我们结合太平洋生物科学公司（PacBio）RSII 单分子长读和高通量染色体构象捕获（Hi-C）基因组关联读长，为马尾松毛虫生成了一个高质量的染色体水平参考基因组。最终组装得到的基因组大小为 614Mb，contig 和 scaffold N50 值分别为 1.39Mb 和 22.15Mb，96.96%的 contigs锚定在 30 条染色体上。根据预测，该基因组包含 17593 个蛋白质编码基因和 56.16%的重复序列。系统发育分析表明，马尾松毛虫与斜纹夜蛾、甜菜夜蛾和松尺蠖的共同祖先分化了约 1.089 亿年。在马尾松毛虫基因组中扩张的许多基因家族在异生物质生物降解系统中显著富集，特别是细胞色素 P450 基因家族。这个高质量的染色体水平参考基因组将成为理解马尾松毛虫爆发和宿主抗性适应机制的宝贵资源。由于这是第一个被测序的枯叶蛾科昆虫基因组，它也将作为进一步比较基因组学的参考。
