The rationale behind the exclusive cellular battery supply from the mother and its significance explained.
Laid-Back Take:
Folks get plenty from their parents, like their looks, bloodline, or that insane loyalty to a crummy sports team (even though it sucks, Go, Habs, Go!). But there are less obvious traits too, like our DNA code, which powers everything else. This crucial DNA lives within the mitochondria, the energy factories in our cells. And here's a fun fact - in most animals, including humans, we inherit mitochondrial DNA only from our moms, not our dads.
This biological mystery has left scientists scratching their heads for years. So, in 2016, Ding Xue, a professor at the University of Colorado Boulder, decided to crack the case. He discovered a process that eliminates paternal mitochondrial DNA during reproduction to avoid complications.
"Yeah, it's not exactly flattering, but it's true," Xue stated. "Our DNA moves over because mom's is so much better—the baby won't take dad's."
Since our DNA from the dad is usually useless, it's no wonder that our cells dump it during reproduction! But what if this process doesn't work as intended? What happens when a dad's mitochondria gets passed down?
Well, Xue decided to find out by using C. elegans, tiny roundworms sharing certain tissues with humans like a nervous system, gut, and muscles.
Roundworm Wisdom
According to Xue's findings, published in the journal Science Advances, these altered roundworms weren't affected much in their sensory responses. But they exhibited a reduced ability to learn from negative experiences, moved less frequently, and showed signs of cognitive issues.
These symptoms aren't too far off from those found in humans with mitochondrial diseases – conditions that affect about one in 5,000 people. Previous research in mice showed that having two different mitochondrial DNA sequences led to issues with metabolism, activity level, and cognition.
But here's the kicker—Xue and his fellow researchers found that they could significantly reverse the effects on the roundworms, even bringing their ATP levels back to normal. Treating the roundworms with vitamin K2 revealed that their learning and memory improved.
Xue's study provided two valuable insights. First, having two parents' mitochondrial DNA can lead to adverse effects. Second, and more excitingly, the work could pave the way for future treatments for mitochondrial disorders. Xue speculates that delays in eliminating paternal mtDNA might lead to these disorders in humans.
So, while we can't cure the agony of missing the playoffs (thanks for that, Dad), Xue's research could give hope to those affected by mitochondrial diseases. Although giving humans with these disorders vitamin K2 won't fully cure the conditions, it's possible that providing it to women with a family history of the disease might reduce the chances of passing the disorders on to their kids.
- In the future, understanding the impact of having two parents' mitochondrial DNA, as discovered by Professor Ding Xue, could lead to treatments for mitochondrial diseases, which affect about one in 5,000 people.
- The symptoms exhibited by the altered roundworms, which had inherited mitochondria from both parents, resemble those found in humans with mitochondrial diseases, including cognitive issues and reduced ability to learn from negative experiences.
- According to Xue's study, they found that treating the roundworms with vitamin K2 significantly reversed the adverse effects on their learning, memory, and ATP levels.
- The discovery of the relationship between paternal mtDNA and mitochondrial disorders, as presented by Xue, suggests that delays in eliminating paternal mtDNA might contribute to these conditions in humans, particularly in those with a family history of the disease.
