Department of Fisheries, Wildlife and Conservation Biology, Minnesota Aquatic Invasive Species Research Center, University of Minnesota, St. Paul, MN 55108, USA.
University of Minnesota Genomics Center, Minneapolis, MN 55455, USA.
G3 (Bethesda). 2022 Feb 4;12(2). doi: 10.1093/g3journal/jkab423.
The zebra mussel, Dreissena polymorpha, continues to spread from its native range in Eurasia to Europe and North America, causing billions of dollars in damage and dramatically altering invaded aquatic ecosystems. Despite these impacts, there are few genomic resources for Dreissena or related bivalves. Although the D. polymorpha genome is highly repetitive, we have used a combination of long-read sequencing and Hi-C-based scaffolding to generate a high-quality chromosome-scale genome assembly. Through comparative analysis and transcriptomics experiments, we have gained insights into processes that likely control the invasive success of zebra mussels, including shell formation, synthesis of byssal threads, and thermal tolerance. We identified multiple intact steamer-like elements, a retrotransposon that has been linked to transmissible cancer in marine clams. We also found that D. polymorpha have an unusual 67 kb mitochondrial genome containing numerous tandem repeats, making it the largest observed in Eumetazoa. Together these findings create a rich resource for invasive species research and control efforts.
斑马贻贝（Dreissena polymorpha）继续从其欧亚大陆的原生范围扩散到欧洲和北美洲，造成数十亿美元的损失，并极大地改变了入侵的水生生态系统。尽管存在这些影响，但对于 Dreissena 或相关双壳类动物，可用的基因组资源却很少。尽管 D. polymorpha 基因组高度重复，但我们已结合长读测序和基于 Hi-C 的支架构建技术，生成了高质量的染色体尺度基因组组装。通过比较分析和转录组学实验，我们深入了解了可能控制斑马贻贝成功入侵的过程，包括贝壳形成、贻贝丝的合成以及耐热性。我们鉴定出多个完整的蒸汽船样元件，这是一种逆转录转座子，与海洋蛤类的传染性癌症有关。我们还发现 D. polymorpha 拥有一个不寻常的 67kb 线粒体基因组，其中包含许多串联重复序列，使其成为在真后生动物中观察到的最大的线粒体基因组。这些发现为入侵物种的研究和控制工作提供了丰富的资源。
