Humans and other animals may make natural radiation detectors in their blood.
Some microRNAs, tiny pieces of genetic material that help regulate protein production, change levels in the blood of mice after exposure to radiation, researchers report in the May 13 Science Translational Medicine. Different radiation doses changed levels of different sets of microRNAs, allowing researchers to distinguish which rodents were likely to survive.
“Humanized” mice carrying human blood-producing stem cells had changes in the same radiation-responsive microRNAs as normal mice did. That finding raises hope that the molecules could help predict whether people can recover from high radiation doses, such as those suffered during nuclear accidents.