Population genetics concerns evolution and migration. At the heart of population genetics is fundamental genetic research aimed at the identification and understanding of these patterns. New technologies, such as next-generation sequencing (NGS) are now being explored as methods in population studies and forensic casework.
Professor Peter de Knijff is a key researcher in the field of human identity and forensic testing. He has been head of the Forensic Laboratory for DNA Research since its founding in 1994. He is active in a number of research areas with the common themes of evolutionary- or population-driven questions addressed using genetics. While using all currently available forensic techniques, his research group is also actively involved in research into NGS techniques.
What is the current focus of your research work?
I am active in a number of different research areas. All of these have two things in common: a genetic/genomics approach combined with a population- and evolutionary-driven research question. Some specific areas of research include forensic genetics, such as developing new markers and techniques to detect these markers in challenging forensic crime scene samples. We are also studying ancient DNA at a population level by using the same forensic techniques to isolate and study DNA from historical and ancient skeletal materials. We are currently involved in projects amounting to >1500 individuals. Another project covers detailed genetic analyses among isolated human populations in Nepal, Bhutan, Ghana, Australia, Sudan, Central Africa, and the Maldives. Yet another project is studying the reconstruction of migration routes and population expansions in non-human models, such as gulls, dragonflies, and others.
Can you give us some background on your laboratory?
I run a relatively small laboratory. There are around 12–15 people actively involved in lab work — varying from technicians to postdoctoral staff. We are supported by 2 secretaries and a part-time Quality Manager.
The lab has been ISO 17025 accredited since 1994, the year the lab was founded.
What is your background, and what first attracted you to Leiden University and the Department of Human Genetics?
I trained as a clinical chemistry and medical microbiological research technician. I was allowed to work on my PhD thesis as a technician (which at that time was quite unique), and obtained my PhD in 1992 with a thesis on Apolipoprotein E variants and their variable influence on the lipid metabolism.
In late 1993, I was asked to apply for a new position in the Human Genetics Department. This was actually for the position of Head of the new forensic laboratory for DNA research (FLDO) at Leiden University Medical Center. I was given the position in early 1994, and on April 1, 1994, we entered our first completely empty lab space! This was soon filled with people and equipment, and in July 1994, we had our first case; 94001, a murder that is still an active case.
As the head of a small forensic lab, I am in a unique position and can collaborate intensively with all neighboring genomics and bioinformatics research groups within the Human Genetics Department. We are all driven by the same technology. Without this, it would have been impossible for me to initiate and explore all the studies that are based on newly developed technologies.
Can you tell us an interesting fact about the Forensic Laboratory for DNA Research that most people are not aware of?
The FLDO is essentially an independent laboratory that is integrated into a very large Human Genetics Department. We are almost 100% self-supporting financially and completely depend on our own acquisition capacity. This has many positive aspects, and it constantly necessitates thinking in terms of cost-effectiveness in addition to scientific integrity and quality. It allows us work extremely efficiently.
What are the main technologies used in your lab?
I can’t think of an important technique that I don’t have access to, if required. The bulk of our work is still done on the ABI 3100, but we are now moving rapidly away from capillary electrophoresis.
What do you think is the future of NGS in forensic DNA research?
There are no technical reasons why we should not use NGS in forensics. At present, ethical, legal, political, and financial hurdles still prevent this, but it is not unrealistic to see non-PCR based methods taking over very soon, especially for those complex cases where current technologies do not offer a solution. My group is currently exploring all possible NGS platforms for this purpose.
Can you tell us something about the Forensic Genomics Consortium Netherlands (FGCN)?
Starting January 2009, for a period of five years, the Forensic Genomics Consortium Netherlands (FGCN), of which I am the Scientific Director, is funded by the Netherlands Genomics Initiative (NGI). The FGCN actively pursues the use of new genomic research tools to substantially improve forensic genetic research. The FGCN represents the strategic alliance of 3 Dutch forensic genetic research laboratories: the Netherlands Forensic Institute (NFI), the Forensic Laboratory for DNA Research of Leiden University Medical Center (FLDO-LUMC), and the Department for Forensic Molecular Biology of the Erasmus Medical Center, (FMB-EMC). We plan to achieve 6 major research deliverables in this 5-year time frame:
First, we are looking into the improvement of mixed stain DNA analyses. We will also have a project aimed at better determination of the relative age of a sample, for example, from a crime scene. Determination of the cellular origin of a biological sample, determination of the geographical origin of a cell donor, and determination of the externally visible characteristics of a cell donor are three further projects aimed at increasing the information from cell samples. Finally, we are working on the construction of detailed DNA reference databases
This research strategy is prioritized on the basis of immediate forensic relevance. First, we will concentrate on the first two new research lines which we consider as high risk, but also of utmost importance: mixed-stains analyses and age-of-sample detection.
Secondly, we will concentrate on three research lines for which Dutch law uniquely already provides us the necessary legal support, but for which until recently, we lacked the relevant samples: the cellular origin, the geographic origin, and the externally visible characteristics of the cell donor. We now have access to sufficient important research samples, but still lack the reliable genetic markers. Within this consortium, we will be able to concentrate our research and complete the development of these genetic research tools crucial to criminalistics.
Finally, in order to provide the relevant statistical support for all new genetic results, we have to screen a large number of relevant randomly collected samples in order to build a reference database. This last phase of our consortium plan is less scientifically challenging, but of great importance. Without the reference data, the evidential value of determining the origins and characteristics of a sample will be impossible to evaluate. This will certainly lead to dismissal once used in a court of law.
What are the short- and long-term visions of the FGCN regarding the use of DNA in forensic research?
At present, it is not yet clear what will happen after 2013. We are currently exploring all options in order to continue this consortium for at least another 5 years. The focus will remain on genomics, but we will try to add other disciplines that could be equally important for the analysis of crime scene stains of (presumed) biological origins.
