Estimating time of death based on the biological clock

Area of Science:

• Forensic Science
• Molecular Biology
• Chronobiology

Background:

• The biological clock, or circadian rhythm, persists in tissues after death.
• Estimating the time of death is crucial in forensic investigations.
• Molecular clock genes offer potential biomarkers for postmortem interval determination.

Purpose of the Study:

• To investigate the utility of biological clock gene expression for estimating time of death.
• To analyze circadian oscillations of clock genes in postmortem tissues.
• To identify specific gene ratios as reliable indicators of time since death.

Main Methods:

• Real-time RT-PCR analysis of clock gene expression (mPer2, mBmal1, hPer2, hBmal1, hRev-Erbα) in mouse and human autopsy tissues.
• Examination of gene expression oscillations within 72 hours postmortem.
• Correlation of gene expression ratios with estimated time of death.

Main Results:

• Circadian oscillations of mPer2/mBmal1 and hPer2/hBmal1 were detected in mouse and human tissues up to 48 and 72 hours postmortem, respectively.
• The hRev-Erbα/hBmal1 ratio exhibited higher oscillation amplitude and proved more suitable for time of death estimation.
• Specific hRev/hBmal1 ratio ranges correlated with distinct time windows of death.

Conclusions:

• Gene expression analysis of biological clock components is a viable method for estimating time of death.
• The hRev-Erbα/hBmal1 ratio offers a promising molecular tool for forensic applications.
• Circadian gene expression patterns provide valuable insights into postmortem changes.