Lake sedimentary dna research on past terrestrial and aquatic biodiversity: Overview and recommendations

The use of lake sedimentary DNA to track the long-term changes in both terrestrial and aquatic biota is a rapidly advancing field in paleoecological research. Although largely applied nowadays, knowledge gaps remain in this field and there is therefore still research to be conducted to ensure the reliability of the sedimentary DNA signal. Building on the most recent literature and seven original case studies, we synthesize the state-of-the-art analytical procedures for effective sampling, extraction, amplification, quantification and/or generation of DNA inventories from sedimentary ancient DNA (sedaDNA) via high-throughput sequencing technologies. We provide recommendations based on current knowledge and best practises.</jats:p

Sampling and Extraction of Ancient DNA from Sediments

Environmental DNA preserved in sediments is rapidly gaining importance as a tool in paleoecology. Sampling procedures for sedimentary ancient DNA (sedaDNA) have to be well planned to ensure clean subsampling of the inside of sediment cores and avoid introducing contamination. Additionally, ancient DNA extraction protocols may need to be optimized for the recovery of DNA from sediments, which may contain inhibitors. Here we describe procedures for subsampling both nonfrozen and frozen sediment cores, and we describe an efficient method for ancient DNA extraction from such samples

Reconstructing past vegetation communities using ancient DNA from lake sediments

The field of ancient DNA has received much attention since the mid-1980s, when the first sequences of extinct species were obtained from museum and archaeological specimens. Early analyses focused on organellar DNA (mitochondrial in animals and chloroplast in plants) as these are present in multiple copies in the cells making isolation and analyses easier. Within the last decade, however, with considerable advances in high-throughput DNA sequencing technology and bioinformatics, it has become possible to analyse the more informative nuclear genome of a larger number of ancient samples and from a larger variety of substrates and environments. Here, we present recent progress made to reconstruct ancient vegetation communities from lake sediments and review recent key findings in the field. We synthesize and discuss the sources of plant DNA in sediment, the issues relating to DNA preservation after deposition, the criteria required for authentication and the technical advances recently made in the field for the analyses and the taxonomic identification of plant ancient DNA sequences obtained from these complex substrates. Together, these advances mean that we are on the way to an explosion of new information for the investigation of ancient plant environments