Aquatic Decomposition of Mammalian Corpses: A Forensic Proteomic Approach

Abstract

Methods currently available to estimate the postmortem submerged interval (PMSI) of cadavers in water suffer from poor accuracy, being mostly based on morphological examination of the remains. Proteins present within bones have recently attracted more attention from researchers interested in the estimation of the postmortem interval (PMI) in terrestrial environments. Despite the great potential of proteomic methods for PMI estimation, their application to aquatic environments has not yet been explored. In this study, we examined whether four different types of aquatic environment affected the proteome of mice bones with increasing PMSIs. Results showed that increasing PMSIs can influence the protein abundances more than the different types of water. In particular, the abundance of the muscle protein fructose-bisphosphate aldolase A constantly decreased with increasing PMSIs. Additionally, the protein peptidyl-prolyl cis-trans isomerase showed a significant decrease between controls and aquatic environments. Furthermore, the coagulation factor VII was deamidated only in submerged samples and not in terrestrial controls. Finally, fetuin-A was significantly more deamidated in pond water compared to the other aquatic environments. Overall, this study identified novel potential biomarker candidates that would be useful for the estimation of the PMSI and for the characterization of the type of water involved in criminal investigations.

Keywords: LC−MS/MS; aquatic decomposition; biological aging; bone proteomics; forensic proteomics; forensic science; forensic taphonomy; post-translational modification; postmortem submerged interval; skeletal remains.