From roads to biobanks: Roadkill animals as a valuable source of genetic data

PLoS One. 2023 Dec 7;18(12):e0290836. doi: 10.1371/journal.pone.0290836. eCollection 2023.

Abstract

To protect biodiversity we must understand its structure and composition including the bacteria and microparasites associated with wildlife, which may pose risks to human health. However, acquiring this knowledge often presents challenges, particularly in areas of high biodiversity where there are many undescribed and poorly studied species and funding resources can be limited. A solution to fill this knowledge gap is sampling roadkill (animals that die on roads as a result of collisions with circulating vehicles). These specimens can help characterize local wildlife and their associated parasites with fewer ethical and logistical challenges compared to traditional specimen collection. Here we test this approach by analyzing 817 tissue samples obtained from 590 roadkill vertebrate specimens (Amphibia, Reptilia, Aves and Mammalia) collected in roads within the Tropical Andes of Ecuador. First, we tested if the quantity and quality of recovered DNA varied across roadkill specimens collected at different times since death, exploring if decomposition affected the potential to identify vertebrate species and associated microorganisms. Second, we compared DNA stability across taxa and tissues to identify potential limitations and offer recommendations for future work. Finally, we illustrate how these samples can aid in taxonomic identification and parasite detection. Our study shows that sampling roadkill can help study biodiversity. DNA was recovered and amplified (allowing species identification and parasite detection) from roadkill even 120 hours after death, although risk of degradation increased overtime. DNA was extracted from all vertebrate classes but in smaller quantities and with lower quality from amphibians. We recommend sampling liver if possible as it produced the highest amounts of DNA (muscle produced the lowest). Additional testing of this approach in areas with different environmental and traffic conditions is needed, but our results show that sampling roadkill specimens can help detect and potentially monitor biodiversity and could be a valuable approach to create biobanks and preserve genetic data.

MeSH terms

  • Amphibians
  • Animals
  • Animals, Wild*
  • Biological Specimen Banks*
  • DNA
  • Humans
  • Mammals
  • Vertebrates

Substances

  • DNA

Grants and funding

The authors would like to thank to: Corporación Ecuatoriana para el Desarrollo de la Investigación y Academia - CEDIA for the financial support given to the present research, development, and innovation work through its CEPRA program, especially for the Estudio de parásitos y microbioma de fauna silvestre en dos de las zonas más biodiversas del planeta: Los Andes Tropicales y Chocó-Darién en Ecuador fund (https://cedia.edu.ec/servicio/fondo-idi-universidades/cepra-xvi-2022/); Dirección de Investigación de la Universidad Central del Ecuador for Proyecto Senior 2021 fund (https://www.uce.edu.ec/web/di), and Reading University for SBS Seed Fund and a University International PhD studentship to PMV (https://www.reading.ac.uk/. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.