Scientists discover 1st-of-its-kind cell part born from a swallowed microbe

In a groundbreaking discovery, scientists uncovered the first known structure in complex cells that's capable of drawing nitrogen from the atmosphere and converting it into a form that the cell can use.

They've dubbed the newfound cell part the "nitroplast." And according to two recent studies, the researchers think it likely evolved 100 million years ago.

The nitroplast probably developed from a bacterium in the ocean, after the microbe was engulfed by an algal cell. The bacteria and algae were previously thought to be living in symbiosis, with the microbe supplying nitrogen in a form the algae could use and the algae providing the microbe with a home.

But it turns out that the microbe took on a new form long ago, becoming a full-fledged cell structure, or organelle, with a metabolism directly linked to that of the algae.

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"It's very rare that organelles arise from these types of things," Tyler Coale, a postdoctoral scholar at the University of California, Santa Cruz (UCSC) and lead author of one of two recent studies that identified the nitroplast, said in a statement.

The discovery is only the fourth known example in Earth's History of "primary endosymbiosis," a process by which a eukaryotic cell — a cell where DNA is enclosed in a nucleus, as in all Animals, plants and fungi — swallows a prokaryotic cell, which lacks a nucleus. In this case, a eukaryotic algal cell swallowed a prokaryotic bacterial cell.