An international team of scientists led by Roderic Guigó of the Center for Genomic Regulation in Barcelona (Spain) has revealed that l will changes in gene expression in different tissues triggered by death may be used to predict the exact time of death of an individual.
In the study published in Nature Communications , the researchers suggest that by analyzing certain readily available tissues (for example, adipose or skin tissue), the post-mortem interval (time since death) can be determined with considerable precision , which could have implications for forensic analysis to find out the exact time of death of an individual.
It all started with the GTEx project, which aims to create a reference database and tissue bank for scientists to study how genomic variants affect gene activity and disease susceptibility.
GTEx was designed to apply sampling techniques to as many tissues as possible from a large number of individuals in order to understand the causal effects of genes and variants, and which tissues contribute to predisposition to the disease.
“ The GTEx data allows us to ask questions about genetic variation and its effects on gene expression in a tissue and in many tissues. Since the samples we use are from deceased donors, we need to find out if there were changes in gene expression related to death or the moment of death, so we could better model our predictions about the variation between tissues and in the disease “, explains Roderic Guigó, leader of the work.
To understand tissue-specific changes to gene expression after a person’s death, Guigó and his colleagues studied RNA sequencing data from more than 7,000 samples from 36 different tissues obtained from 540 donors within the GTEx project.
Their results show that time since death has an effect on gene expression and that this effect varies from tissue to tissue. The authors developed models for the prediction of the post-mortem interval based on these changes in tissue-specific gene expression using high-throughput cell sequencing.
“We found that many genes change expression at relatively short postmortem intervals, largely tissue-specific. This information helps us better understand variation and also enables us to identify transcription events that are triggered by death in a patient. organism “, adds Pedro G. Ferreira, co-author of the study.
“ We show that RNA sequencing in some key tissues could become a powerful tool to aid forensic pathology ,” the researchers wrote.
Reference: Ferreira G. Pedro, et al. “The effects of death and post-mortem cold ischemia on human tissue transcriptomes” Nature Communications (2018) 9: 490. DOI: 10.1038 / s41467-017-02772-x
