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The genes you don't get from your parents (but can't live without) - Devin Shuman

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Inside our cells, each of us has a second set of genes completely separate from our 23 pairs of chromosomes. And this isn’t just true for humans— it’s true of every animal, plant, and fungus on Earth. This second genome belongs to our mitochondria, an organelle inside our cells. So why are they so different from anything else in our bodies? Devin Shuman explores the purpose of mitochondrial DNA.

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The implications of mitochondrial DNA (mtDNA) extend far beyond cellular evolution. mtDNA gives us a glance into the history of humanity, the way our bodies age, the dramatic results when our mtDNA fails us, and the novel science of trying to prevent that failure.

A trip to the past: Mitochondrial DNA has been an integrated part of our cells since millions of years before humans were even a species. Since mtDNA is inherited directly from our mothers, can we use it to trace people back to our original mother? MtDNA does allow us to follow a direct route through our ancestors, compared with nuclear DNA that creates the multi-branched family “tree” people are used to seeing. So, the simple answer is yes - sort of. We have dubbed this original mtDNA ancestor “Mitochondrial Eve” and while we are all related on some level, it isn’t quite as simple as an original Adam and Eve. Mitochondrial "Eve" Is Not the First Female in a Species. We can however use our mtDNA to trace our maternal family lines through haplogroups and learn more about the migration of our ancestors. You can learn more through PBS.org.

A trip to the doctor: Mitochondria are the power producers of our cells and use food and oxygen to create the energy our organs need to function through the electron transport chain. However, mitochondria play a role far beyond being the batteries for our bodies. When our bodies get sick or stop working, our mitochondria are often involved. For example, the  mitochondria are involved in inflammation—such as using mtDNA that escapes the confines of the cell as an inflammatory signal. That mtDNA transitions from a set of instructions for our body to an alarm system when something is wrong. Meanwhile, as we age, our mtDNA accumulates mutations that then lead to cell death and help trigger our aging process. Mitochondria, in sickness and in health, are so crucial that mitochondrial dysfunction has been implicated in many common diseases including, but not limited to, autism, cancer, Alzheimer’s disease, diabetes, and obesity. For those with a mtDNA mutation causing Mitochondrial Disease this dysfunction can have fatal consequences.

A trip to the future: MtDNA and mitochondrial disease research does give a silver lining to that dysfunction. Our understanding of these conditions is leading scientific discoveries and new ways to alter the very relationship we have with our mtDNA. A groundbreaking way to stop mitochondrial disease has led to the concept of ‘three-parent’ babies" with one child being born in 2016. Meanwhile for another type of mtDNA disease, TK2-related mtDNA depletion syndrome, scientists have successfully packaged a DNA base pair (one of the four letters that write our DNA code) into a medication. Who would have thought one day we’d be essentially bottling DNA to supplement bacteria that is over 1.5 billion years old? Hopefully one day we can harness this understanding of the mitochondria and create treatments for common diseases too.

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Meet The Creators

  • Educator Devin Shuman
  • Director Luísa Holanda
  • Narrator Addison Anderson
  • Storyboard Artist Luísa Holanda
  • Animator Murilo Jardim
  • Art Director Luísa Holanda
  • Music Gabriel Maia
  • Sound Designer Gabriel Maia
  • Hype Producer Taíla Soliman
  • Director of Production Gerta Xhelo
  • Editorial Director Alex Rosenthal
  • Producer Bethany Cutmore-Scott
  • Editorial Producer Elizabeth Cox

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