ELI5: Explain Like I'm 5

Paternal mtDNA transmission

Okay kiddo, you know how babies inherit traits from their moms and dads? Well, usually these traits come from tiny things inside our cells called chromosomes.

Now, one part of our cells is called the mitochondria, which is responsible for making energy that our body uses to function. Mitochondria also have their own special kind of DNA, called mtDNA.

Normally, we learn in science that mtDNA is passed down from mothers to their children. But sometimes, in very rare cases, a man can pass down his own mtDNA to his children too.

This happens when there is a mistake that occurs during the process of making a baby. Sometimes, the sperm that carries the father's mtDNA manages to sneak its way past the egg that usually holds only the mother's mtDNA. And when that happens, the baby ends up with some of the dad's mtDNA as well.

It's important to remember that this doesn't happen very often, so it's still mostly true that people inherit their mtDNA from their moms. But when it does happen, it can be pretty interesting to study and learn about!