Museum specimen preservation media is a source of historical eDNA

Dr Erin Hahn¹, Dr Alejandro Trujillo-González², Dr Linda Neaves³, Dr Clare Holleley¹

¹Australian National Wildlife Collection, CSIRO, Canberra, Australia, ²Institute for Applied Ecology, University of Canberra, Canberra, Australia, ³Fenner School of Environment and Society, Australian National University, Canberra, Australia

Advancement and wide-spread uptake of eDNA technologies has enabled non-invasive biomonitoring of diverse ecosystems. Recently, these technologies have been extended to museum specimens and ancient samples to gain insight into historical terrestrial and aquatic environments. DNA integrity and accessibility within museum specimens is heavily dependent upon the methods used to preserve the tissues. In particular, the practice of formalin-preservation presents a near insurmountable barrier to genomic investigation. This is unfortunate as these specimens are often preserved intact along with their gut contents and any associated microbes or macroparasites. If the DNA preserved in these specimens were accessible, it could be used to characterise historical ecosystems and species interactions. Here we show how eDNA methodology and recent advances in DNA extraction from formalin-preserved tissues can be coupled to non-destructively recover genetic data from preserved specimens. We filtered preservation media to recover cellular debris from specimen jars archived at the Australian National Wildlife Collection. We then extracted archival DNA from the filtrate using a hot alkaline lysis method and conducted broad-spectrum eDNA metabarcoding to identify the specimens themselves as well as inadvertently co-preserved eukaryotic parasites. Our results show that preservation media is a viable source of eDNA. This method opens a new stream of historical biodiversity data and pushes the boundaries of museum-based genomics.

Biography:

Erin is a conservation geneticist working as a postdoctoral fellow at the Australian National Wildlife Collection at CSIRO. She is working to enable whole genome sequencing and characterisation of gene expression from formalin-preserved museum tissues. Her research will deliver new data streams with which to study how species have historically responded to our changing environment. Erin received her PhD from the University of Arizona in Tucson, Arizona, USA. Her doctoral work on endangered Sonoran pronghorn enabled wildlife managers to identify appropriate captive individuals for mating and release and was the first study characterising population epigenetics in an endangered species. Erin is a passionate science communicator and educator and was recently selected as a Superstar of STEM by Science and Technology Australia.