Zombies have been a staple of horror movies for many years. The idea that something that has died can somehow come back to life is both fascinating and frightening. But could zombies somehow actually exist in reality?
Scientists started by examining the genes of deceased zebrafish and mice. Initially, "the researchers assumed that genes would shut down shortly after death, like the parts of a car that has run out of gas," according to Science magazine. "What they found instead was that hundreds of genes ramped up." In some cases, genes were active for four days after the fish had died. So, despite death, parts of the animals were as alive as ever.
The study found that the active genes were ones that often help out in emergencies and function to do things like relieve stress or battle inflammation. Other genes that turned on were ones that are usually only needed to aid with sculpting the embryo. Researchers suspect this activity starts because the "cellular conditions in newly dead corpses resemble those in embryos."
Genes that promote cancer also became more active after the animals had died. The study speculates that the activity of these cells may explain why those who get transplants from the recently deceased are at a higher risk of getting cancer themselves. Molecular pharmacologist Ashim Malhotra told Science magazine that this new research could be "used as a diagnostic tool for predicting the quality of a transplant."
In addition, by looking at the genes that are still active in someone who has died, doctors may be able to more accurately determine a time of death. This would be especially helpful when conducting a criminal investigation.
So why do these genes suddenly turn on after the point of death? The researchers speculate that it may be because these genes were kept quiet by other genes that have now been shut off. By looking into this further, scientists may be able to get a better understanding of how all these genes work with each other.