NICHDNinety-six hours after 43 zebrafish were frozen to death and 48 hours after 20 mice had their necks snapped, specific cells within their bodies were still hard at work. Gene transcription continued apace, and occasionally increased, according to a study published today (January 25) in Royal Society Open Biology. Genes linked to embryonic development, stress, and cancer were among those increasingly transcribed into RNA, researchers at the University of Washington and their colleagues reported. The results suggest that organismal death is an orderly, predictable process, and could help forensic scientists pinpoint time of death, plus help explain why organs from recently deceased donors seem to be more prone to cancer.
“Death is a time-dependent process,” said coauthor Peter Noble, whose group studies the postmortem transcriptome and microbiome. “We define the window between the time of organismal death and the time when not all cells are dead as ‘the twilight of death,’” he explained. “We found that there was a successional pattern to this time—more or less waves of transcription abundances. The shutdown is not random, it’s step-wise.”
Forensic scientists have long been interested in how bodies decay, especially as a way of determining time of death in criminal investigations. When Noble first began studying the phenomenon five years ago at Alabama State University, others had already tried to determine time of death by measuring microbial populations on the body surfaces of dead animals. Noble wondered ...
