IP: Dra. María Victoria Lareu Huidobro

Resumen del proyecto: This project focusses on the creation of enhanced forensic genetic-based tools to enhance investigation of criminal events or terrorist attacks. It centres on the development and optimization of new DNA analysis systems as well as next generation technologies and bioinformatics tools for the generation of statistical prediction models for chronological factors: age of DNA donor and time-of-deposition (in a 24-hour cycle). Specifically, to know the age of the donor of a biological sample or the time of the day when the sample was deposited. The prediction models will be an important part of the guidance provided to investigators when there is an absence of information from conventional means such as eye-witness or a national DNA database entry. Current progress in the epigenetic field, studying DNA methylation, opens an emerging area of research for forensic genetics applications, encompassing, for example, identification of body fluids or differentiation of monozygotic twins (with identical conventional DNA profiles). The epigenome, compared to the genome, is a dynamic entity resulting from the interaction with the environment that influences gene expression regulation (activation/inhibition), via the main mechanism of DNA methylation. The different patterns hyper- or hypomethylation (increased and decreased levels of methylated bases respectively) are specific to certain gene families, either through the lifetime of the organism or during the diurnal/nocturnal cyclical period of twenty-four hours per day. These patterns will be used to develop a predictive tool to allow the inference of the age of the donor and/or the time of the day when material was deposited. In the case of donor age, differences in methylation patterns of genes involved in biological processes such as cell death, cellular proliferation or haematological activity have been observed. In comparison, the prediction of time-of-deposition will require study of clock genes that play a core role in the regulation of circadian rhythms in humans, which lead to metabolic events that periodically oscillate across twenty-four hours of the day. From a forensic point of view, chronological estimation tools, that allow the inference of an individual’s age with an informative level of precision and analysis of time-of-deposition have obvious relevance for knowing more about those present at the scene of crime and their activities. Age is a clear characteristic of a criminal that will guide police investigations without suspects and cannot be disguised. In addition, within the justice field, knowledge of the legal age of an individual is important when considering the definition of an adult or a minor. On the other hand, to know the time-of-deposition of a sample can help exclude suspects that had not been at the crime scene within a given time-frame or can be indicative of the time the crime was committed and therefore can help guide a particular direction to the investigation. Moreover, individual identification of twins continues to be a challenge for forensic genetics therefore, epigenetic biomarkers that allow differentiation of these individuals will be searched. Although twins share identical DNA sequence, it has been observed that their methylation patterns along the genome become different throughout the lifetime. Due to the rapidly accelerating development of next generation sequencing technologies, we consider of major part of the project will centre on the application of compact benchtop high-throughput sequencing systems that can analyze DNA methylation. We intend to use technologies as the Ion TorrentTM (Life Technologies) and iPlex EpiTyperTM (Sequenom) to build the epigenetic chronological toolbox.

Entidad financiadora: Ministerio de Ciencia, Innovación y Universidades