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There are cells that continue to function even after a person dies.
Through analysis of samples post mortem , an international team discovered scientific or some genes even became more active after death.
The details of the study were published in Nature Communications .
They hope it will be useful to develop new forensic techniques .
Under the influence of genes
Within the cells of our body, life develops under the powerful influence of our genes , controlled by a wide range of internal and external triggers.
Understanding genetic activity sheds light on what a cell, organ or tissue can do, whether healthy or sick .
The genes are enclosed in the DNA present in our cells that, when they are active, produce a molecule known as RNA transcription.
Some types of RNA control processes that develop in cells and others are transformed into prototypes for proteins.
It is the transcription of RNA that scientists often measure when they want to know what happens in cells and that analysis is called transcriptome.
Obtaining samples for this type of study is not always easy.
It is relatively easy to get blood , but inserting a needle into a person’s heart or liver is not.
Scientists then have to work with organs and tissue samples that are obtained post mortem .
Although these samples can provide valuable information about what happens inside an inert body, it is not clear if they represent processes that develop in life.
Another adverse factor for the research is that samples are rarely obtained immediately after a person dies.
In general, the bodies are preserved for further examination and that is when parts are extracted to be analyzed.
The researchers, led by Professor Roredic Guigó, computational biologist at the Institute of Science and Technology of Barcelona, used RNA c olectado within 24 hours of death and some blood samples collected before the patient died.
What they discovered was surprising.
” There is a reaction of the cells to the death of an individual, we saw some passages, some genes, that were active and that means that, sometimes, after death there is still some activity at the level of transcription,” Guigó said.
Changes in the environment
Although the exact reason why the genes remain active is unknown, Professor Guigó has a possible explanation.
“I would say one of the biggest changes is due to the cessation of blood flow .Then the most significant change probably hypoxia, lack of oxygen , but I have no proof of that.”
What the study did was to establish a set of predictions of changes in post-mortem RNA levels and that understanding could be crucial for criminal investigations.
“We conclude that there is a signature or a fingerprint in the pattern in which the genes are expressed after death, which can be used by forensic science, but we can not say that we now have a method to be used in the field,” clarified Guigó.
The data were consistent between different corpses and can be established more accurately the time passed since death based on RNA levels.
Professor Guigó explained, however, that much remains to be done .
” More research is needed, longer post mortem intervals , not just 24 hours , taking into account the age of the person and the cause of death, all of which must be taken into account if we are going to turn this into a useful tool”, He said.