Star Wars-inspired bacterium provides glimpse into life

Dec 09, 2011
Star Wars-inspired bacterium provides glimpse into life
Midichloria mitochondrii inside the mitochondria of the tick Ixodes ricinus (A), and structure of the M. mitochondrii genome (B). Of relevance here is the fifth circle from the outside, which shows the position of flagellar genes.

(PhysOrg.com) -- A bacterium whose name was inspired by the Star Wars films has provided new clues into the evolution of our own cells and how they came to possess the vital energy-producing units called mitochondria.

The University of Sydney research investigated the Midichloria mitochondrii- named after helpful Star Wars , called Midi-chlorians, that live inside cells and grant the mystical power known as The Force. It has revealed that may have entered our cells though a parasitic bacterium that used a tail to swim and could survive with almost no oxygen.

The work, published in this month's issue of Molecular Biology and Evolution, challenges traditional explanations of how the ancestors of mitochondria first entered our cells between one and a half and two billion years ago. It also sheds new light on a process recognized as one of the major transitions in the history of .

"Our results challenge the paradigm - shown in every biology textbook - that mitochondria were passive bacteria gobbled up by a primordial cell," says co-author Dr. Nathan Lo from the University of Sydney's School of .

"We have found instead that the mitochondrial ancestor most likely had a flagellum, so was able to move, and possibly acted as a parasite, rather than prey, on early ," added Dr. Lo, who collaborated with scientists from Italy and Spain on the research.

Eukaryotes include all forms of animal and plant life on earth that are more complex than bacteria. They differ from simpler life forms because their cells have both a nucleus and mitochondria, which are like little batteries that generate energy to power the cell.

"How eukaryotic cells evolved remains one of the most vexing problems in biology," said Dr. Lo.

"Mitochondria are actually highly reduced bacteria, with their own set of DNA, that reside in our cells. It has long been thought that this relationship developed when an ancient eukaryotic cell engulfed the mitochondrial ancestor.

"But there is still mystery around the question of how exactly the mitochondrial ancestor was engulfed, and how it survived in the oxygen-poor atmosphere of early eukaryotic life."

For clues Dr. Lo and collaborators studied Midichloria mitochondrii- a bacterium they discovered in 2004 and successfully obtained permission from director George Lucas to name after the Star Wars Midi-chlorians. M. mitochondrii is from the Rickettsiales family, considered to be the closest living relatives of the ancestor of mitochondria.

"We studied M. mitochondrii because its genome has never been analysed and because it is the only bacterium known to be able to enter into the mitochondria of living cells," said Dr. Lo.

After determining the DNA sequence of M. mitochondrii's entire genome, Dr. Lo and collaborators found the bacterium contained 26 genes coding for an entire flagellum - including all the key components such as hook, filament and basal body.

He also found a second set of genes which coded for enzymes that would allow the bacterium to survive in low-oxygen environments. These genes have never been seen before in bacterial relatives of mitochondria.

Dr. Lo says: "We found these two sets of genes were inherited from the common ancestor shared by M. mitochondrii and our own mitochondria. Mitochondria's ancestor most likely possessed a flagellum, which is a key characteristic of many parasitic bacteria.

"Our results show the ancestor of mitochondria probably played a much more active, even parasitic, role in the early interactions with its eukaryotic host than previously thought. They also explain how the relationship could have evolved in the low-oxygen environments of two billion years ago.

"This should cause a rethink of how the symbiosis between mitochondria and eukaryotic originally developed - one of the most controversial topics in biology."

Explore further: Fighting bacteria—with viruses

Provided by University of Sydney

5 /5 (7 votes)

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kevinrtrs
1.3 / 5 (19) Dec 09, 2011
How eukaryotic cells evolved remains one of the most vexing problems in biology, said Dr. Lo.

The simplest answer is that it did NOT evolve but were created fully functional in the first place, including the mitochondria.
If they didn't have mitochondria before the intrusion of the so-called bacteria, where and how did cells get the energy to survive and drive all the molecular machinery that's required for LIFE?
One has to shake the head at the way the logic works in this evolutionary thought space.
Because it is not possible to explain how mitochondria was created inside the cell in the first place - a really, truly vexing problem in itself - they had to remove it from the cell by inventing a scenario that would simplify the intractable problem. Then using that scenario as fact, it then became generally accepted that that is the way life happened. Now it only remains to be shown that somehow the mitochondria arose miraculously by itself because how did the bacteria get it?
antialias_physorg
4.5 / 5 (11) Dec 09, 2011
The simplest answer is that it did NOT evolve but were created

Soooo..postulating an all powerful, intelligent creator that was not himself created in some way is 'simpler'?

This must be a new definition of the word 'simple' I hadn't heard of before.

One has to shake the head at the way the logic works in this evolutionary thought space.

Try it. Maybe some of the fluff will fall out of your ears.
88HUX88
Dec 09, 2011
This comment has been removed by a moderator.
CHollman82
4.4 / 5 (7) Dec 09, 2011
How eukaryotic cells evolved remains one of the most vexing problems in biology, said Dr. Lo.

The simplest answer is that it did NOT evolve but were created fully functional in the first place


Not only is that NOT the simplest answer, in that it invokes a magical entity of incomprehensible power, which is FAR more complicated than the complication you are trying to alleviate with it, but it is possibly the most irrational and least supported answer you or anyone else could come up with.

CHollman82
5 / 5 (3) Dec 09, 2011
Who the fuck is "Mabus" and why is he giving me 1 ratings?

Creationist lurkers are the worst... No wait, creationist commentators are worse...
Pirouette
1.8 / 5 (5) Dec 09, 2011
Who the fuck is "Mabus" and why is he giving me 1 ratings?

Creationist lurkers are the worst... No wait, creationist commentators are worse...


Probably FrankH. . . .or one of his aliases. . . .he does that to me, Rygg2, Nou and other members. Seriously CH, you haven't noticed yet how some members want to get even with you because you prove you're more knowledgeable?
Pirouette
3.7 / 5 (3) Dec 09, 2011
kevin. . . .you can't provide the evidence for it. . .it's all conjecture and nothing more that life began fully formed with ALL its components and ready to run. Comes the time when and if scientists can actually FIND that evidence, then you might be vindicated. But it's not happening, so stop knocking your head against a wall. You can believe what you will, but you don't have to try to convince with something unconvincing.
With me, I understand that I am chemistry and a part of Nature, therefore my God is Nature/Chemistry. It would have been nice to have a God who can do good things for you, but the God of the Bible isn't doing anything. . .not even for the JEWS. It's ALL a big fallacy, and someday you might come to that conclusion too. Everyone needs to accept responsibility for their own actions, and it's up to each person not to be blinded by false claims and corruption.
FrankHerbert
0.8 / 5 (56) Dec 09, 2011
CH, you haven't noticed yet how some members want to get even with you because you prove you're more knowledgeable?

"The Paranoid Style in American Politics"
http://karws.gso....yle.html

American politics has often been an arena for angry minds.... I call it the paranoid style simply because no other word adequately evokes the sense of heated exaggeration, suspiciousness, and conspiratorial fantasy that I have in mind....

Of course this term is pejorative, and it is meant to be; the paranoid style has a greater affinity for bad causes than good. But nothing really prevents a sound program or demand from being advocated in the paranoid style. Style has more to do with the way in which ideas are believed than with the truth or falsity of their content.... The paranoid style is an old and recurrent phenomenon in our public life which has been frequently linked with movements of suspicious discontent.
Pirouette
1 / 5 (3) Dec 09, 2011
Dayum. . .yet ANOTHER thread ruined by the sudden appearance of FrankHerbert$hithead who hates it when I post a comment regarding the topic that the thread is all about. That FrankHerbfart, he be hating my comments cuz he think HE be the boss of Physorg and be telling everyone what to do. He got hisself some FRIENDS now and dey ALL be butt buddies and having some fun following people around. He be showing up every time I makes a comment. Just like that, he be there like a shot to shut me up. . .LOL
Deesky
5 / 5 (2) Dec 09, 2011
@Kev

The simplest answer is that god did NOT evolve but was created fully functional in the first place.

If they didn't have god before the intrusion of the so-called religious 'thinkers', where and how did god get the energy to survive and drive all the universal machinery that's required for LIFE?

One has to shake the head at the way the theist logic works in this rational thought space.

Because it is not possible to explain how god was created inside the universe in the first place - a really, truly vexing problem in itself - they had to remove god from the universe by inventing a magical scenario that would simplify the intractable problem of their tiny minds.

Then using that simplistic scenario as fact, it then became generally accepted that that is the way god happened. Now it only remains to be shown that somehow that god arose miraculously by itself.
MarkyMark
5 / 5 (1) Dec 10, 2011

One has to shake the head at the way the logic works in this evolutionary thought space.

Try it. Maybe some of the fluff will fall out of your ears.
Sadly his head is all fluff it seems.