“EPFL scientists have discovered that a simple shape change in mitochondria helps cells evenly distribute their mitochondrial DNA, solving a long-standing puzzle.”
“To generate energy for cells, mitochondria carry their own small genome called mitochondrial DNA (mtDNA). Each cell contains hundreds to thousands of copies of mtDNA, packaged into clusters known as nucleoids. Scientists have known that nucleoids are regularly spaced inside mitochondria. This pattern ensures that mtDNA is passed down when cells divide and that genes on mtDNA are uniformly expressed among mitochondria.”
"Problems with the function of mitochondria and mtDNA can have far-reaching consequences for the health of the cell and the organism as a whole. They are linked to metabolic and neurological diseases like liver failure and encephalopathy or associated with aging and neurodegenerative diseases like Alzheimer’s and Parkinson’s."
“Having established the importance of mtDNA for the proper function of mitochondria, a key question has remained unanswered: how do cells achieve such precise and robust spacing of nucleoids?”
“Proposed mechanisms related to mitochondrial fusion, fission, or molecular tethering cannot explain it, since nucleoid spacing is maintained even when they are disrupted,” says Suliana Manley, professor at the Laboratory of Experimental Biophysics (LEB) at EPFL."
'Now, Manley has led a study with Juan Landoni, postdoctoral fellow at the LEB, that has identified the mechanism behind mtDNA distribution: a previously underestimated phenomenon known as “mitochondrial pearling.” This is a transient transformation during which mitochondria take on a “beads-on-a-string” appearance. This helps separate clusters of mtDNA and redistribute nucleoids, ensuring remarkably uniform spacing."
More details at;