“Clonal Genome Evolution and Rapid Invasive Spread of the Marbled Crayfish”, 2018-02-05 (; backlinks):
[media]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 ~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 results also demonstrate that the Madagascar population is genetically homogeneous and extremely similar to the oldest known stock of marbled crayfish founded in Germany in 1995. These findings support the notion that the global marbled crayfish population represents a single clone.
Our study closes an important gap in the phylogenetic analysis of animal genomes and uncovers the unique evolutionary history of an emerging invasive species.
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