College of Resources and Environmental Sciences, China Agricultural University, Beijing, China.
Beijing Key Laboratory of Biodiversity and Organic Farming, Beijing, China.
Commun Biol. 2021 Jan 29;4(1):135. doi: 10.1038/s42003-021-01659-4.
Earthworms (Annelida: Crassiclitellata) are widely distributed around the world due to their ancient origination as well as adaptation and invasion after introduction into new habitats over the past few centuries. Herein, we report a 1.2 Gb complete genome assembly of the earthworm Amynthas corticis based on a strategy combining third-generation long-read sequencing and Hi-C mapping. A total of 29,256 protein-coding genes are annotated in this genome. Analysis of resequencing data indicates that this earthworm is a triploid species. Furthermore, gene family evolution analysis shows that comprehensive expansion of gene families in the Amynthas corticis genome has produced more defensive functions compared with other species in Annelida. Quantitative proteomic iTRAQ analysis shows that expression of 147 proteins changed in the body of Amynthas corticis and 16 S rDNA sequencing shows that abundance of 28 microorganisms changed in the gut of Amynthas corticis when the earthworm was incubated with pathogenic Escherichia coli O157:H7. Our genome assembly provides abundant and valuable resources for the earthworm research community, serving as a first step toward uncovering the mysteries of this species, and may provide molecular level indicators of its powerful defensive functions, adaptation to complex environments and invasion ability.
由于起源古老，以及在过去几个世纪中引入新栖息地后的适应和入侵，蚯蚓（环节动物门：多毛纲）在世界各地广泛分布。在此，我们报告了一种基于第三代长读测序和 Hi-C 图谱相结合策略的环毛蚓基因组完整组装，大小为 12 亿碱基对。该基因组共注释了 29256 个蛋白质编码基因。重测序数据分析表明，这种蚯蚓是三倍体物种。此外，基因家族进化分析表明，与环节动物门中的其他物种相比，环毛蚓基因组中基因家族的全面扩张产生了更多的防御功能。iTRAQ 定量蛋白质组学分析表明，在环毛蚓体内有 147 种蛋白质的表达发生了变化，16S rDNA 测序表明，当蚯蚓与致病性大肠杆菌 O157:H7 一起孵育时，环毛蚓肠道中 28 种微生物的丰度发生了变化。我们的基因组组装为蚯蚓研究界提供了丰富而有价值的资源，为揭示该物种的奥秘迈出了第一步，并可能为其强大的防御功能、对复杂环境的适应能力和入侵能力提供分子水平的指标。
