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

Abstract

Background and objectives: Post-mortem interval (PMI) estimation is an important topic in forensic sciences. Several methods have been used to determine the PMI, but most of these provide inaccurate results under certain conditions. The degradation of RNA after death has been reported to be a useful tool for PMI estimation. This study aimed to evaluate the potential use of skin and heart GAPDH mRNA levels for determining the PMI under different environmental conditions. Methods: Seventy-eight adult female albino rats were sacrificed by cervical dislocation. Then, rats divided into the control group and four experimental groups left under different conditions (in ambient air at 30°C and at 6°C, buried in sand and submerged under water at an air temperature of 30°C). The skin and heart samples were obtained at different time points (0, 24, 48, and 96 h post-mortem), and the GAPDH mRNA level in each sample was detected by qRT-PCR. Results: The GAPDH mRNA levels decreased with increasing PMI in all study groups. There were significant negative correlations between the heart GAPDH mRNA level and the time interval in all studied groups, while the skin GAPDH mRNA level only showed negative correlations under certain conditions. Conclusion: The GAPDH mRNA level in rat heart and skin could be a useful marker for PMI estimation under various environmental conditions.

Pathological and clinicopathological features of canine and feline bladder disease

“…The other two samples were from 2008 and 2014 and the fixation time is not known, however it is possible that these samples could have had a lower fixation time as well. In addition, the post-mortem interval has some impact on RNA quality, as RNA starts degrading immediately after death and in fact the level of RNA degradation has been used to estimate post-mortem interval (119). Secondly, optimisation was not successful for the NGF primers, which unfortunately prevented assessment of this promising BPS biomarker in our samples.…”