Biologists Discover Unknown Powers in Mighty Mitochondria
Mitochondria are most famous as sources of metabolic energy. But by splitting and combining, they can also release chemical signals to regulate cell activities, including the generation of neurons.
Of all the organelles to be found inside eukaryotic cells, the DNA-sheltering nuclei might be the best-known, but the mitochondria are surely not far behind. Mitochondria are familiar as bean-shaped structures floating in the cytoplasm, and they are almost inevitably referred to as “powerhouses” of the cell because they generate adenosine triphosphate (ATP), the fuel for most metabolic processes. For more than a century, biologists believed that energy production was their only role.
But that simple picture of mitochondria is turning out to be shockingly incomplete.
Mitochondria may look static and uniform in textbooks, but as researchers recognized early on, in reality the organelles change shape constantly through cycles of fusion (in which they combine and elongate) and fission (in which they split and shrink). They form highly dynamic, short-lived tubular networks threading throughout a cell. Recently, it has become clear that mitochondria also perform signaling and regulatory functions that are only indirectly related to their job as energy providers. In the past few years, research has revealed that one of their key roles is in controlling the development and ultimate role of stem cells.
Now scientists at the University of Ottawa in Canada have provided evidence that the morphing shapes of mitochondria powerfully influence neurogenesis, the development of neurons. In making this discovery, the scientists have pieced together a connection between the organelle’s shape transitions and how it carries out its signaling functions.
Read more at Quanta