A mobile laboratory for ancient DNA analysis

PLoS One. 2020 Mar 18;15(3):e0230496. doi: 10.1371/journal.pone.0230496. eCollection 2020.

Abstract

Mobile devices for on-field DNA analysis have been used for medical diagnostics at the point-of-care, forensic investigations and environmental surveys, but still have to be validated for ancient DNA studies. We report here on a mobile laboratory that we setup using commercially available devices, including a compact real-time PCR machine, and describe procedures to perform DNA extraction and analysis from a variety of archeological samples within 4 hours. The process is carried out on 50 mg samples that are identified at the species level using custom TaqMan real-time PCR assays for mitochondrial DNA fragments. We evaluated the potential of this approach in museums lacking facilities for DNA studies by analyzing samples from the Enlène (MIS 2 layer) and the Portel-Ouest cave (MIS 3 deposits), and also performed experiments during an excavation campaign at the Roc-en-Pail (MIS 5) open-air site. Enlène Bovinae bone samples only yielded DNA for the extinct steppe bison (Bison priscus), whereas Portel-Ouest cave coprolites contained cave hyena (Crocuta crocuta spelaea) DNA together, for some of them, with DNA for the European bison sister species/subspecies (Bison schoetensacki/Bb1-X), thus highlighting the cave hyena diet. Roc-en-Pail Bovinae bone and tooth samples also contained DNA for the Bison schoetensacki/Bb1-X clade, and Cervidae bone samples only yielded reindeer (Rangifer tarandus) DNA. Subsequent DNA sequencing analyses confirmed that correct species identification had been achieved using our TaqMan assays, hence validating these assays for future studies. We conclude that our approach enables the rapid genetic characterization of tens of millennia-old archeological samples and is expected to be useful for the on-site screening of museums and freshly excavated samples for DNA content. Because our mobile laboratory is made up of commercially available instruments, this approach is easily accessible to other investigators.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Archaeology
  • Bison
  • DNA, Ancient / analysis*
  • DNA, Mitochondrial / analysis
  • Fossils
  • Real-Time Polymerase Chain Reaction
  • Sequence Analysis, DNA / methods*

Substances

  • DNA, Ancient
  • DNA, Mitochondrial

Associated data

  • Dryad/10.5061/dryad.8gtht76jz

Grants and funding

This work was supported by the Muséum National d’Histoire Naturelle, MOBILAB, CEA Saclay, LOC1043ELALO, to JME; the University of Perpignan Via Domitia, BQR, to ASLC; and the French Ministry of Culture and Communication through the Pays-de-Loire DRAC/SRA, PGR522017000012 and PGR522018000029, Mécène & Loire Fundation (http://www.mecene-et-loire.fr/), 17 2015/2016, to SS for fieldwork. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.