DNA and RNA profiling of excavated human remains with varying postmortem intervals
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When postmortem intervals (PMIs) increase such as with longer burial times, human remains suffer increasingly from the taphonomic effects of decomposition processes such as autolysis and putrefaction. In this study, various DNA analysis techniques and a messenger RNA (mRNA) profiling method were applied to examine for trends in nucleic acid degradation and the postmortem interval. The DNA analysis techniques include highly sensitive DNA quantitation (with and without degradation index), standard and low template STR profiling, insertion and null alleles (INNUL) of retrotransposable elements typing and mitochondrial DNA profiling. The used mRNA profiling system targets genes with tissue specific expression for seven human organs as reported by Lindenbergh et al. (Int J Legal Med 127:891-900, 27) and has been applied to forensic evidentiary traces but not to excavated tissues. The techniques were applied to a total of 81 brain, lung, liver, skeletal muscle, heart, kidney and skin samples obtained from 19 excavated graves with burial times ranging from 4 to 42 years. Results show that brain and heart are the organs in which both DNA and RNA remain remarkably stable, notwithstanding long PMIs. The other organ tissues either show poor overall profiling results or vary for DNA and RNA profiling success, with sometimes DNA and other times RNA profiling being more successful. No straightforward relations were observed between nucleic acid profiling results and the PMI. This study shows that not only DNA but also RNA molecules can be remarkably stable and used for profiling of long-buried human remains, which corroborate forensic applications. The insight that the brain and heart tissues tend to provide the best profiling results may change sampling policies in identification cases of degrading cadavers.
KeywordsForensic science Postmortem interval Organ tissue identification mRNA profiling DNA profiling
The authors are grateful to all the donors from whom tissues have been used in this study. We thank Natalie Weiler (Netherlands Forensic Institute), Gina Pineda (InnoGenomics) and Sudhir Sinha (InnoGenomics) for technical assistance. Frank van de Goot and W.J. Mike Groen are thanked for sample collection and providing information on the exhumed bodies. Corina Benschop is thanked for critically reading the manuscript. TS and MvdB received financial support from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 285487 (EUROFORGEN-NoE).
- 10.Pooniya S, Lalwani S, Raina A, Millo T, Dogra TD (2014) Quality and quantity of extracted deoxyribonucleic acid (DNA) from preserved soft tissues of putrefied unidentifiable human corpse. J Lab Phys 6(1):31Google Scholar
- 13.Ebuehi OA, Amode M, Balogun A, Fowora A (2015) Postmortem time affects brain, liver, kidney and heart DNA in male rat. Am J Biochem 5(1):1–5Google Scholar
- 16.de Leeuwe R, Groen WJM, A taphonomic study based on observations of 196 exhumations and 23 clandestine burials, Taphonomy of human remains: Forensic analysis of the dead and the depositional environment. E. Schotmans, N. Márquez-Grant, S. Forbes, Wiley-Blackwell, in press.Google Scholar
- 34.Pineda GM, Montgomery AH, Thompson R, Indest B, Carroll M, Sinha SK (2014) Development and validation of innoQuant™, a sensitive human DNA quantitation and degradation assessment method for forensic samples using high copy number mobile elements Alu and SVA. Forensic Sci Int Genet 13:224–235PubMedCrossRefGoogle Scholar
- 38.Clark MA, Worrell MB, Pless JE (1997) Postmortem changes in soft tissues, Forensic Taphonomy; W.D. Haglund, M.H. Sorg, CRC Press 161Google Scholar