Why Only Moms Pass On Cell Energy and What It Means for Us

Ever wondered why only your mom can pass on certain parts of your cells? It's all about the tiny powerhouses in our cells, called mitochondria. They make energy that keeps us alive. Unlike most other DNA, the DNA in mitochondria comes only from our moms. Why? Scientists have been puzzled, but new findings might explain this and even help treat rare diseases. Most animals, including humans, get mitochondrial DNA (mtDNA) only from their mothers. In a rare case, humans can inherit mtDNA from both parents, but it's unusual. In 2016, Professor Ding Xue from the University of Colorado Boulder started looking into why this happens. He found that paternal mtDNA has a self-destruct sequence that's triggered during reproduction.Xue then studied what happens when this sequence doesn't work. He experimented on tiny roundworms with similar tissues to humans. The worms with both parental mtDNA had trouble learning and remembering, and were less active. This isn't surprising, as about 1 in 5,000 humans have mitochondrial diseases with similar symptoms. Surprisingly, Xue found that treating the worms with vitamin K2 improved their learning and memory. This discovery could help understand why inheriting mtDNA from one parent is beneficial. It also opens doors to new treatments for mitochondrial disorders. Xue suggests that delays in eliminating paternal mtDNA might cause these disorders in humans. While roundworms are simple, the findings could lead to future treatments for humans. Giving vitamin K2 to mothers with a family history of mitochondrial disorders might reduce the risk of passing it on.