Stories tagged mitochondria

You know what's cool? Animation. And folks with the same skills used to bring you Red Dead Redemption and Toy Story 3 are also hard at work creating scientific visualizations that show the machinery of life.
Nov
10
2008

Sorry, kid, you're barking up the wrong tree: Otzi ain't yer dad. And, whoever you pops is, I doubt you dressing up like that will make him love you any more.
Sorry, kid, you're barking up the wrong tree: Otzi ain't yer dad. And, whoever you pops is, I doubt you dressing up like that will make him love you any more.Courtesy japi14
I think this came out a couple weeks ago, so maybe it’s old news to y’all—although, technically, I suppose it’s old news to everyone.

Otzi (Remember? Otzi the Iceman?) died alone.

No, wait, that didn’t come out right. Otzi the Iceman didn’t die alone—he probably died surrounded by his killers, after they had shot him in the chest with an arrow, as one of them likely finished him off by clubbing his skull in. What I meant was Otzi died alone in the genetic sense, with no one to carry on his legacy. (His legacy of being a five-foot-five total badass.)

It turns out that Otzi, in spite of his many, many admirable qualities, probably had no children. Or, at least, that Otzi’s lineage has died out since the time of his death.

Previous studies had suggested that Otzi may have had living descendants somewhere in Europe, but recent genetic research has shown that this is unlikely. Italian and British scientists have analyzed the iceman’s mitochondrial DNA—which is passed on solely matrilineally—and the results seem to indicate that Otzi was part of a heretofore unknown genetic line, and one that has probably gone extinct.

Oh, fudge. And here I was, still holding out hope.

What gives, caveladies? What was so bad about the little iceman? Too tough, I’m guessing. The same reason women could never get truly close to the Fonz.

*It occurs to me that Otzi could have had a child himself, and his mitochondrial DNA wouldn’t have been passed on. Maybe he just had equally intimidating sisters.

Oct
01
2008

Cute, nautical, and Scandinavian: But probably smaller.
Cute, nautical, and Scandinavian: But probably smaller.Courtesy hans s
So… we’re learning about genetics, aren’t we? We can’t help it—here we have see-through frogs, there we have genetically engineered vegetables, here we have a fatherless child with the same hair color, eye color, and blood type as me. Genetics are all around us these days, in our schools, in our dinners, and calling our lawyers. As much as we might try to hide from it, the subject is unavoidable.

It’s nice, then, when some aspect of this genetic tsunami can take our minds off of all the tricky stuff. Things like mutant frogs are fun (All those legs! Somebody give them their own cartoon!), but they never last long (The frogs tend to die. Cancel the frog show.)

I think, however, that I may have found a winner: Viking mice. They’re genetically remarkable, and they’re lifespan is the same as any other mouse: about 2 or 3 years. Somebody start work on a Viking Mouse cartoon!

So what we have here is your common house mouse. The house mouse evolved into a variety of different strains as it spread into Western Europe about 3,000 years ago, during the Iron Age. Little French house mice learned to wear berets and smoke cigarettes, German mice developed a love of sausages and efficiency, and so forth; the Iron Age was a wonderful time, and it birthed many of our favorite cultural stereotypes. However, something interesting has come up in a recent genetic study of British house mice.

The surprising result of a nationwide rash of mouse paternity cases, the mice of Britain were surprised to find that they themselves were the products of unexpected parents. Studying their mitochondrial DNA (traceable genetic material from the mother’s side), it appears that most mice from mainland Britain are closely related to mice from Germany (the descendants of little Saxon mice?). Mice from the Orkney Islands of Northern Scotland, however, were found to be “Viking mice,” genetically similar to mice from Norway. And it makes sense—the Orkneys were an important center of the Norwegian Viking “kingdom,” back in the 11th and 12th centuries. These little mousies are the descendants of the warlike Viking mice, who hitched rides across the North Sea in the holds of Viking longboats a thousand years ago. Or… maybe they had their own tiny boats… Viking mice!

We pretty much already knew that Vikings were in the Orkneys at that time, but the genetic evidence from the mice are is a good example of how non-human DNA (mitochondrial DNA in particular) can be a tool for tracking other historical human migrations, and… and…

Just picture those little Viking mice. Tiny helmets, curly little beards, squeaky battle cries… they must have been adorable. Just to see them slaughtering little monk mice, it must have been too cute.

Oh, also, while we’re on the subject of house mice—I noticed this little section in Wikipedia’s article on them. After being accidentally introduced to the south Atlantic Gough Island, house mice, which normally have a body length of about 3 inches, began growing “unusually large” and feeding on albatross chicks. The mice kill the chicks, which can be about a meter tall, by “working in groups and gnawing on them until the bleed to death.” Talk about Viking mice.

Jan
18
2007

A breast cancer cell: Photo from NIH
A breast cancer cell: Photo from NIH

A researcher at the University of Alberta in Edmonton, Canada has discovered a drug that causes cancer cells to die, without harming healthy cells nearby. The drug, called DCA, changes the way cancer cells get energy and, as a side-effect, kills them.

According to the article:

DCA attacks a unique feature of cancer cells: the fact that they make their energy throughout the main body of the cell, rather than in distinct organelles called mitochondria…. DCA reawakened the mitochondria in cancer cells.

Crucially, though, mitochondria do another job in cells: they activate apoptosis, the process by which abnormal cells self-destruct. When cells switch mitochondria off, they become “immortal”, outliving other cells in the tumour and so becoming dominant. Once reawakened by DCA, mitochondria reactivate apoptosis and order the abnormal cells to die.

But perhaps the best thing about this news is that DCA already exists. It has been used for years to treat other diseases, so we know it’s safe to use on humans. And it is not patented – any company can make it cheaply.

The drug still has to go through rigorous testing to see how effective it really is, and what dosage and procedures work best. But if this pans out, it will be exciting news for cancer patients everywhere.

Meanwhile, the number of deaths from cancer in the US dropped for the second straight year. While cancer remains the #2 killer in America (after heart disease), doctors have seen a drop in both the rate of cancer death (the percentage of cancer patients who die from the disease) and the total number of deaths.

Together, these two items make for some very good news in the fight against cancer.