Forensic aspects of gene expression signatures for age determination in bruises as evaluated in an experimental porcine model
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Determining the age of bruises and the force used to inflict the trauma is of crucial importance in both human and veterinary forensic pathology. In the present study, the expression of more than 50 different genes in subcutaneous fat and muscle tissue from experimental bruises in pigs was investigated. The aim was to evaluate if expression signatures of selected genes were capable of determining bruises according to age and the force of impact. Eighteen experimental pigs were anesthetized, and on each animal four blunt traumas were inflicted on the back with a low, moderate or high force. The pigs were euthanized from 1 to 10 h after infliction of the trauma and subcutaneous fat and muscle tissues were sampled. As control, subcutaneous fat and muscle tissues were sampled from two un-injured pigs. Quantitative real-time polymerase chain reaction was performed to evaluate mRNA expression of genes involved in inflammation, tissue damage and repair. Expression signatures of thirteen selected genes in subcutaneous fat but not in muscle tissue reflected the age of bruises with a precision of approximately ±2 h. Moreover, the gene expression signature in the subcutaneous fat was to some extend able to separate bruises inflicted with different forces. Expression signatures of selected genes in the subcutaneous fat will increase the precision of the age determination of bruises in pigs. Further, due to the similarity of porcine and human skin physiology and immunity, these results might also provide valuable information in human forensic science.
KeywordsAge estimation Bruise Force estimation Gene expression signature qPCR
The authors wish to thank Karin Tarp at Section for Immunology and Vaccinology, National Veterinary Institute, Technical University of Denmark, for skilled technical assistance with RNA extraction and qPCR analysis.
Compliance with ethical standards
The project was funded by University of Copenhagen, Denmark and National Veterinary Institute, Technical University of Denmark. The funding source had no involvement in the experimental design, analysis and interpretation of the results.
Conflict of interest
The authors declare that they have no conflict of interest.
All applicable international, national and/or institutional guidelines for the care and use of animals were followed. The experimental procedure was approved by the Danish Animal Inspectorate (2013–15–2934 − 00849).
This article does not contain any studies with human participants performed by any of the authors.
- 1.Barington K, Jensen HE. Experimental animal models of bruises in forensic medicine – a review. Scand J Lab Anim Sci. 2015;41:14.Google Scholar
- 9.Saukko P, Knight B. The pathology of wounds. In: Saukko P, Knight B, editors. Knight’s forensic pathology. London: Arnold; 2004. p. 136–73.Google Scholar
- 10.Barington K, Jensen HE. A novel, comprehensive and reproducible porcine model for the timing of bruises in forensic pathology. Forensic Sci Med Pathol. 2016;12:58–67.Google Scholar
- 12.Lader ES, Ambion Inc. Example 2 preparation of an exemplary RNAlaterTM RNA preservation medium. In: Methods and reagents for preserving rna in cell and tissue samples. 2012. http://www.google.ch/patents/CA2298841C?hl=de&cl=en. Accessed 20 Mar 2017.
- 13.Dawson HD. A comparative assessment of the pig, mouse and human genomes. In: McAnulty PA, Dayan AD, Ganderup NC, Hastings KL, editors. The minipig in biomedical research. Boca Raton: CRC Press; 2012. p. 323–42.Google Scholar