Zombie Genes Thursday Open Comments

When do we actually die?

Doctors in a Canadian intensive care unit have stumbled on a very strange case – when life support was turned off for four terminal patients, one of them showed persistent brain activity even after they were declared clinically dead.

For more than 10 minutes after doctors confirmed death through a range of observations, including the absence of a pulse and unreactive pupils, the patient appeared to experience the same kind of brain waves (delta wave bursts) we get during deep sleep. And it’s an entirely different phenomenon to the sudden ‘death wave’ that’s been observed in rats following decapitation.

Then there the cases of genes that actually FIRE UP after death!

Led by microbiologist Peter Noble, a team from the University of Washington has been investigating the gene activity in deceased mice and zebrafish, prompted by previous research that identified a handful of genes in human cadavers that were active more than 12 hours after death.

The researchers ended up identifying more than 1,000 genes that were still functioning even days after death, but it wasn’t like they were taking a bit longer to sputter out than the rest of the body – they actually increased their activity.

In mice, 515 genes were seen kicking into gear, and were functioning at full capacity up to 24 hours after death. In the zebrafish, 548 genes retained their function for four whole days after the animals had died before showing any signs of winding down.

Some of these zombie genes are developmental, some of them not so beneficial:

What’s maybe even stranger than that is the fact that these ‘postmortem’ genes weren’t just any genes, they were the kind of genes that ramp up during emergencies.

As Mitch Leslie reports for Science Magazine, we’re talking about tasks like stimulating inflammation, firing up the immune system, and counteracting stress. Some of the genes they identified usually switch on to help form an embryo, and then are never heard of again… except after death, apparently.

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

It’s not all beneficial genes, though, the team also found that certain genes that promote cancer growth also sparked after death in these animals, prompting the researchers to suggest that in a newly deceased corpse, the body reverts to the cellular conditions of a rapidly developing embryo.

“While transplantation is a life-saving therapy… it also puts recipients at an increased risk for developing cancer, in part because of medications…,” says Eric A. Engels of the US National Institutes of Health’s (NIH) National Cancer Institute.
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The crazy amounts of immune-suppressing drugs transplant recipients have to take to make sure their body doesn’t reject the organ could partly explain the heightened risk of cancer, but active postmortem genes in the organ could also be at play, Noble told Science Magazine.

Interesting. When we die, it seems our body tries to revive itself up to days later, and in the process turns on developmental genes AND cancerous genes as well. That makes sense – they are both involved in rapid reproduction and growth of cells. The impact this could have on transplant patients is profound – treating them for cancer as part of their rejection therapy.

Maybe this is why zombies look the way they do.

Puts “born again Christian” in a whole new light, too.