Dead bodies are able to return to life in a strange, Zombie-like state, according to a disturbing new study published in Nature Communications.
An international team of scientists has found that genes continue to function even after a person's death, and in some cases, cells can try to "repair".
BBC News reports: In addition to providing important research findings for science, they also hope it can aid in forensic science.
Inside the cells of our bodies, life boils under the powerful influence of our genes; this process is controlled by a number of internal and external factors.
Understanding gene activity provides a complete understanding of what an individual cell, tissue or organ does in a healthy and diseased state.
A gene is a piece of DNA that defines the sequence of a specific polypeptide or functional RNA.
DNA is a macromolecule (one of the three main ones, the other two are RNA and proteins), which provides storage, transmission from generation to generation and the implementation of the genetic program for the development and functioning of living organisms. DNA contains information about the structure of various types of RNA and proteins.
Some of the RNAs directly control the processes that take place in the cell, but most of the RNA becomes the basis for proteins.
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Scientists often measure RNA transcripts when they want to know what's going on in our cells.
A transcript is an RNA molecule resulting from the transcription of a piece of DNA.
Transcriptomics of individual cells is an area of biological research in which the main tool is the methods of quantitative analysis of gene expression in individual cells.
Internal work
But getting samples to study is not easy.
Blood is relatively easy to obtain, but cutting off a hand or sticking a needle into a living person's heart or liver is not a trivial task.
Thus, scientists rely on a relatively rich source of samples - tissues and organs removed after death.
While studies of post-mortem specimens can provide important information about the body’s inner workings, it’s unclear if these specimens really represent what happens during life.
Another inconvenient factor is that samples are rarely taken immediately after death, instead, the body is stored until an autopsy occurs and sampling occurs only after that.
And it is this dependence of the preservation of samples after dissection that was the study of Professor Roderic Guigó, a leading biologist at the Barcelona Institute of Science and Technology, and his team.
“One could expect that with the death of a person there would be a decline in gene activity,” he explained.
“And this decline could affect the correct interpretation of the transcriptomics data.”
After death
To verify that this is the case, the team used RNA sequencing on postmortem samples collected within 24 hours of the death of patients and on several blood samples collected from patients before death, and, as Professor Guigó explained, what they found was amazing:
“Cell response to human death. We saw the amazing thing that some genes are activated, which means that after death there is still some activity at the level of transcription,”he said.
Although the exact reason why the genes remained active is not yet clear, Professor Guigó has one possible explanation: “I assume that one of the main changes is related to the cessation of blood flow, so I would say that the main environmental change is hypoxia, lack of oxygen. but I have no proof for that yet."
What the study showed is a set of predictions for post-death RNA changes for the various tissues studied.
And understanding the changes in RNA levels that occur after death could also be key in future criminal investigations.
“We have come to the conclusion that there is a signature or fingerprint in the post-death gene expression pattern that could eventually be used in forensic medicine, but we are not drawing a final conclusion yet, nor do we say we have an exact method that can be used in this area,”said Professor Guigó.
Despite the fact that the data was the same for different corpses, and the exact time elapsed since death can be estimated using RNA levels, Professor Guigó clarified that more work is needed before applying this in forensic science and forensics, and then it will become reality.
