A drifting plankton cell is the tiniest life on record — with fewer proteins than many viruses

Floating in ocean plankton, scientists have found the smallest genome ever seen in a living cell — a tiny archaeon named Sukunaarchaeum mirabile, after a small Japanese god. Its entire DNA is just 238,034 base pairs long, encoding only 189 proteins — less than half the previous record-holder, and fewer than some viruses carry. What it kept is the one thing that separates cells from viruses: its own ribosomes, the little machines that read genetic code and build proteins. Everything else — making food, generating energy — it outsources to other organisms. Published today in Current Biology and led by Takuro Nakayama's team at the University of Tsukuba in Japan, with the University of Nottingham, the finding rewrites how simple life can get while still making more of itself.