Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center (DKFZ), Heidelberg, Germany.
School of Biological Sciences, Illinois State University, Normal, IL, USA.
Nat Ecol Evol. 2018 Mar;2(3):567-573. doi: 10.1038/s41559-018-0467-9. Epub 2018 Feb 5.
The marbled crayfish Procambarus virginalis is a unique freshwater crayfish characterized by very recent speciation and parthenogenetic reproduction. Marbled crayfish also represent an emerging invasive species and have formed wild populations in diverse freshwater habitats. However, our understanding of marbled crayfish biology, evolution and invasive spread has been hampered by the lack of freshwater crayfish genome sequences. We have now established a de novo draft assembly of the marbled crayfish genome. We determined the genome size at approximately 3.5 gigabase pairs and identified >21,000 genes. Further analysis confirmed the close relationship to the genome of the slough crayfish, Procambarus fallax, and also established a triploid AA'B genotype with a high level of heterozygosity. Systematic fieldwork and genotyping demonstrated the rapid expansion of marbled crayfish on Madagascar and established the marbled crayfish as a potent invader of freshwater ecosystems. Furthermore, comparative whole-genome sequencing demonstrated the clonality of the population and their genetic identity with the oldest known stock from the German aquarium trade. Our study closes an important gap in the phylogenetic analysis of animal genomes and uncovers the unique evolutionary history of an emerging invasive species.
大理石纹螯虾 Procambarus virginalis 是一种独特的淡水螯虾，具有非常近期的物种形成和孤雌生殖特征。大理石纹螯虾也是一种新兴的入侵物种，已经在各种淡水生境中形成了野生种群。然而，由于缺乏淡水螯虾的基因组序列，我们对大理石纹螯虾的生物学、进化和入侵传播的理解一直受到阻碍。我们现在已经建立了大理石纹螯虾基因组的从头组装草案。我们确定了基因组大小约为 35 亿个碱基对，并鉴定了 >21,000 个基因。进一步的分析证实了它与沼泽螯虾 Procambarus fallax 的密切关系，并且还建立了具有高水平杂合性的三倍体 AA'B 基因型。系统的实地调查和基因分型表明，大理石纹螯虾在马达加斯加迅速扩张，并确立了它是淡水生态系统的有力入侵物种。此外，比较全基因组测序证明了该种群的克隆性及其与德国水族馆贸易中最古老的已知种群的遗传同一性。我们的研究填补了动物基因组系统发育分析中的一个重要空白，并揭示了一个新兴入侵物种的独特进化历史。
