Mitochondria can spawn new ‘organelles’ — hinting at how modern cells evolved

When a parasite invades a cell, mitochondria — the cell’s energy producers — respond by shedding their outer layer to form new cellular compartments that digest molecular trash. These new organelles help the parasite to proliferate, possibly because the invader can feed off the degraded material inside the tiny compartments, says immunologist and study co-author Lena Pernas. The findings lend credence to the hypothesis that ancient mitochondria gave rise to the first organelles in complex cells by shedding their outer layer to form new membrane sacs.