Ancient DNA (aDNA)

Duration:

10/2020-xx.xx.xxxx

Problem statement

Recent advances in extraction, sequencing and bioinformatics have paved the way for sequencing of ancient DNA (aDNA) from marine sediments (Armbrecht et al., 2020). This is important because the vast majority of marine organisms do not leave fossil remains and accessing their genomic remains will open new avenues for paleoceanography and paleoecology. Analyses of aDNA metabarcodes have shown that DNA from pelagic ecosystems deposited on the seafloor preserves informative signatures of pelagic ecosystems (Morard et al., 2018). The success of aDNA application in sedimentary cores hinges on the capacity to retrieve those genomic remains and identify their taxonomic origin in order to exploit their paleoceanographic potential. The objectives of the ENABLER project ancient DNA therefore encompass the development of novel methodological approaches and their application to research questions within the EXC Cluster. Advances in methodology include the automation of protocols for the efficient extraction of aDNA from sedimentary material at high-throughput and low risk of contamination, and the development of bioinformatic workflows for cross-domain high-sensitivity and high-specificity taxonomic classification of metagenomic aDNA data set and in-silico contamination detection. The developed approaches will be applied to sedimentary material from different regions with distinctive oceanographic features: the confluence of the Gulf Stream and the Labrador Current off Newfoundland (samples available), the Mediterranean and Black Sea (samples available), South Georgia Island south of the Antarctic Polar Front (samples available), and the highly productive Mauritanian margin (sampling scheduled in 2021). These sites feature various types of sedimentary material from which aDNA could be exploited to reconstruct past ecosystems, and will serve as a groundwork for future paleoceanographic studies.