PhD. Candidate – Developing next generation genetic markers to determine eDNA and non-human touch DNA profiles as forensic biotrace evidence

This is a job offer for a Doctoral Candidate (DC) for European Doctoral Network “Natural Traces” (Project 101120165, Horizon Europe, see https://cordis.europa.eu/project/id/101120165). The DC will be engaged in cutting-edge research in the context of the use of enviromental DNA (eDNA) and non-human DNA in forensic recognition and interpretation. eDNA has seen significant research and debate in recent years mainly in conservation biology and biodiversity studies, however there is a lack of its application in the forensic science. Similarly, non-human touch DNA and its secondary transfer is a strongly neglected field today in forensics, altough touch DNA of human origin is very deeply investigated. The research objective is to extend eDNA and non-human DNA investigation methods in the forensic identification. Candidate aims to develope methods for eDNA sampling and to establish metagenomic DNA profiles. The candidate should: (i) determine the eukaryotic eDNA profiles from a number of sources and samples, (ii) comparing eDNA profiles by locality and by individuals, (iii) persistance and time span of eDNA from different sources, (iv) study of mixed biological samples for their eDNA. The genetic identification of several OTUs (Operational Taxonomical Units) in the mixed source samples by next generation DNA profiles is both biological and statistical issue, that requests the validation of likelihood ratio methods by applying Bayesian approach. The members of the project network, including the PhD supervisor for this DC, are associate members of European Network of Forensic Science Institutes (ENFSI), which will ensure adequate and useful integration of the outcomes of the project for the benefit of European forensic science.

Hypotheses and Plan: Several recent research shows that environmental DNA (eDNA) can be used to track different species and taxa and can be detected in a wide range of environmental samples (air, water, soil, etc.). eDNA can be naked DNA, fragments of cells, spores or pollen, minute pieces of a leaf, animal and human skin flakes, whole organisms such as soil or dust mites, feces of mites or insects etc. Minimal amounts of non-human DNA residues can be also recorded on solid surfaces, which are not visually detectable and are often transferred to the surface by a touch or contact of animals. Secondary transfer of these touch DNA may also occur. DC will develope methods for sampling and determine the eukaryotic eDNA profile of human clothing and touch non-human DNA of surface samples. To reach close to species level resolution of the samples long sequencing approach will be developed and employed.

Objectives:

• Determine the eukaryotic eDNA profile from a number of sources.
• Comparing eDNA profiles by locality and by individuals.
• Determine time span of eDNA from different sources.
• Study of whole (mixed) soil samples for their eDNA (pro- and eukaryotic).

Expected Progress: The successful candidate will contribute to the advancement of forensic science by achieving the following milestones.

• Developement and validation of methods for sampling and determining eDNA profiles of clothing and other surface samples.
• Discrimination of individuals by their specific eDNA and touch DNA profiles, as well as localities.
• Collaboration with DN project members to exchange data, simulate cases, share results and experiences, and validate findings.
• Dissemination of research outcomes through publications, presentations, and participation in relevant conferences and workshops.