Potential use of GAPDH m-RNA in estimating PMI in brain tissue of albino rats at different environmental conditions

Abstract

Background: Estimation of the postmortem interval (PMI) is a critical issue in forensic science. Various approaches have been used to determine the PMI including physical, biochemical and entomological methods. Most of these methods have practical limitations or provide insufficient results in certain conditions. Postmortem degradation of RNA may be a useful tool for PMI estimation if there is a correlation between the quantity of residual RNA and the elapsed time. This study aimed to evaluate the use of GAPDH mRNA quantity in the brain as a possible indicator for PMI in different environmental conditions. Methods: Seventy-eight adult female albino rats were sacrificed by cervical dislocation. Rats were divided into five groups, the control group and 4 studied groups left after sacrificing in different conditions (ambient air at 30°C and at 6°C, buried in sand and submerged under water). Brain samples were obtained at different intervals (0, 24, 48 and 96 h postmortem). The mRNA of GAPDH gene of rats' brain was quantitatively detected by qRT-PCR.

Insights into how environment shapes post-mortem RNA transcription in mouse brain

“…Since bodies have different decomposition processes depending on the environment in which they are deposited 31 , 32 , different rates of RNA degradation can be expected. Previous works demonstrated that temperature is a factor that acts directly on RNA degradation 16 , 33 . The degradation profile similarity (Fig.…”

Estimation of the postmortem interval using GAPDH mRNA in skin and heart tissues of albino rats at different environmental conditions

“…Unfortunately, no previously reported studies have examined the correlation between heart or skin mRNA levels and the PMI in bodies buried in sand or submerged under water. Elghamry et al (2017) studied the expression of GAPDH mRNA under such conditions but in brain tissues and reported a significant correlation with the PMI. The different results for the different tissues can be related to the fact that the integrity of RNA differs among different tissues and organs post-mortem (Sampaio-Silva et al 2013).…”

“…Precise estimation of the post-mortem interval (PMI) is crucial at both the civil and criminal levels. The PMI assists in proving and excluding suspects, identifying the exact time of a crime, and solving some legal problems related to inheritance (Elghamry et al 2017).…”

“…GAPDH was selected as the target marker because it is a housekeeping gene that has shown time-dependent quantitative changes with the PMI in several studies (Elghamry et al 2017;Lv et al 2014;Sampaio-Silva et al 2013;Inoue et al 2002).…”

MicroRNAs as Useful Tools to Estimate Time Since Death. A Systematic Review of Current Literature

“…In fact, by knowing the lifecycle of insects that colonize the corpse and the sequence of colonizing insects, the entomologists can obtain longer PMIs. However, these evidences maintain a certain degree of inaccuracy, thus, attention must be paid in interpreting such findings, and, case-by-case evaluation is mandatory, because these environmental changes are context-dependent [37,52,53].…”