Is there life after death? Some genes turn on after the body's demise, study finds

Scientists hail 'jaw-dropping' discovery about what happens to genes after death

Genes in dead zebrafish were found to remain active for up to four days (Getty)

‘Is there life after death?’ is a question that has dominated human thinking since time immemorial.

But now researchers have discovered that an animal’s genes can ‘live’ on for up to four days after its body has died, Science Magazine reported.

And some genes, including ones that help to create an embryo and others associated with cancer, even turned on or became more active after death.

The research could potentially help reduce the increased risk of getting cancer after transplant and also help forensic scientists work out when a murder victim was killed.

One of the scientists, Professor Peter Noble, of Washington University in Seattle, told Science Magazine that the study was “an experiment of curiosity to see what happens when you die”.

“We can probably get a lot of information about life by studying death,” he added.

The researchers studied what happened to more than 1,000 genes in mice and zebrafish after they died.

Changes in their genes were recorded for up to four days after death in the zebrafish and for two days in the mice.

“We initially thought that sudden death of a vertebrate would be analogous to a car driving down a highway and running out of gas. For a short time, engine pistons will move up and down and spark plugs will spark -- but eventually the car will grind to a halt and ‘die’,” the researchers wrote in an article on the bioRxiv website.

“Yet, in our study we find hundreds of genes are upregulated many hours postmortem, with some upregulated days after organismal death.

“This finding is surprising because in our car analogy, one would not expect window wipers to suddenly turn on and the horn to honk several days after running out of gas.

“Since the postmortem upregulation of genes occurred in both the zebrafish and the mouse in our study, it is reasonable to suggest that other multicellular eukaryotes [forms of life] will display a similar phenomenon.”

Some of the genes were involved in stimulating the immune system or dealing with stress, but others were developmental genes involved in the creation of the embryo that had been dormant since birth.

“What’s jaw-dropping is that developmental genes are turned on after death,” Professor Noble said.

The research could also provide “insights into how to better preserve organs retrieved for transplantation”, the researchers said in the bioRxiv article.

In a separate paper, the researchers outlined how their work might be of use to forensics and police officers investigating murders.

"Many biological, chemical, and physical indicators can be used to determine the postmortem interval – but most are not accurate," they wrote.

They said they had found that changes to genes could be used to “accurately predict post-mortem time in cadavers”.