Briefing Chat: Stressed mitochondria spawn new 'organelles' in cells

In this episode of the Nature Briefing podcast, hosts Benjamin and Sharmini Bundel explore two groundbreaking scientific stories. The first delves into a surprising cellular phenomenon: when human cancer cells are infected with the parasite Toxoplasma gondii, mitochondria shed their outer membranes and form new structures called 'spots' that engulf lysosomes. This process, while seemingly a cellular defense, actually benefits the parasite—suggesting a novel mechanism of host manipulation. The discovery raises broader evolutionary questions, hinting that such membrane-shedding behavior could have been a key step in the origin of other organelles in eukaryotic cells, potentially reshaping our understanding of how complex cells evolved. The second story transports listeners to the late Cretaceous period, where researchers analyze fossilized chitinous beaks to infer the existence of a colossal 19-meter-long octopus—twice the size of today’s giant squid. Though based on extrapolation from modern cephalopod anatomy, the wear patterns on the beaks suggest this creature may have been a top predator with complex feeding behaviors, possibly even a preference for one side of its mouth. While some scientists remain cautious, the findings offer a tantalizing glimpse into a lost world of giant, intelligent cephalopods.