Cool Science Stories You May Have Missed in 2015

One of the biggest ocean stories of 2015 was the decision by the U.S. Food and Drug Administration to approve genetically engineered salmon for sale and consumption. Although the overwhelming amount of scientific evidence to date agrees that genetically modified organisms (GMOs) are safe to eat, many people are still debating the environmental consequences of introducing GMO crops and livestock into the consumer market. The worry is that an altered creature could get out and breed with its unaltered kin, which could have unforeseen consequences on wild ecosystems.

That’s where “Deadman” and “Passcode” come in. Developed by researchers at Harvard and MIT, these cellular signals were coded into the bacterium Escherichia coli as safeguards against the spread of genetically engineered microbes. If Passcode senses a predetermined change in the surrounding environment, it activates Deadman, which causes the bacterial cells to self-destruct by producing a lethal toxin.

For now, the safeguard only works in bacteria, but the researchers think the same mechanism could be used to design GMO crops that kill themselves if they spread beyond their intended fields. The work appeared in December in Nature Chemical Biology.