Because we might need to rewrite them.
For a long time it has been thought that all eukaryotes – organisms in which the DNA is enclosed in a membrane including almost all life we can see – had to contain mitochondria. Known as the “power house” of the cell, these little subunits within the cell provide the organisms with energy and were thus thought to be essential. But it now seems that actually they might not be that essential, as researchers describe the first eukaryote known that lacks mitochondria.
When I read this out to my colleagues, it took a minute for it to sink in, and then they turned their heads and stared at my as if I had just told them that they had found a tribe of humans who were alive despite a lack of a beating heart. The fact that eukaryotic cells have mitochondria is basic, fundemental, something that has been taken for granted this whole time.
But that’s the great thing about science right? We are constantly discovering new things, and realizing ever more that nature has a stubborn way of bleeding through the category boxes we keep trying to squash it into.
So, for the biologists amongst you, what are these eukaryotic cells precisely, and how on Earth can they possibly survive without mitochondria?
Well, apparently, they are gut microbes isolated from a chinchilla, from the Genus Monocercomonoides. The gut is a very low oxygen, high nutrient environment, which is why most gut microbes generally have mitochondria in very reduced numbers and size anyway.
In this study, however, they did not detect the presence of any mitochondrial genes, and these microbes seem to have a cytosolic sulfur mobilization system, usually found in bacteria, which could potentially circumvent mitochondria’s role in mobilizing Fe-S clusters.
The evidence is compelling, but for something this huge it’s going to have to be investigated very thoroughly before the scientific community at large will accept it. Not to mention the fact that the study was published in Current Biology. A perfectly good journal, no doubt about it, but something that rocks the foundations of cell biology will usually find it’s way into Science or Nature. It’s clear that, if this is true and confirmed, Current Biology is about to get one hell of a spike in its Impact Factor.
As for the rest of us mitochondria people? We all want a sample of these microbes. Now.