[The relationship between GAPDH mRNA multiple location degradation and advanced stage postmortem intervals].

Area of Science:

• Molecular biology
• Forensic science
• Gene expression analysis

Context:

• Accurate determination of postmortem interval (PMI) is crucial in forensic investigations.
• Housekeeping genes like GAPDH are often used as internal standards, but their degradation patterns require careful study.
• Understanding mRNA degradation dynamics in specific tissues is key to refining PMI estimation.

Purpose:

• To investigate the degradation patterns of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA at various sites within the same tissue.
• To assess the utility of different GAPDH mRNA degradation sites for deducing advanced stage postmortem intervals (PMI).

Summary:

• GAPDH mRNA degradation was analyzed at six sites (5'-cap to 3'-end) in rat brain cortex over 12 days postmortem using real-time RT-PCR.
• Degradation rates varied across sites, with sites 4-6 (near the 3'-end) degrading slower than sites 1-3.
• Ratios of specific GAPDH mRNA sites (e.g., 1-3/6) correlated with postmortem periods, indicating potential for PMI estimation.

Impact:

• Provides a method for more precise estimation of advanced postmortem intervals using specific mRNA degradation markers.
• Highlights the importance of selecting appropriate gene regions for molecular clock applications in forensic science.
• Contributes to the development of molecular tools for forensic investigations and time-of-death determination.