- We are spending enormous amounts of money and effort trying to discover signs of life on Mars and other places in outer space.
- However, we have not even acquainted ourselves with so many mysterious and weird life forms right here on Earth.
- They live in ocean depths, in caves, in forests, in ancient and remote geological areas, and in other places of difficult access to scientists.
- The question is, at the rate we are pillaging and polluting our planet, will those creatures survive our depredations long enough for us to find them alive?
We all have eukaryotic cells with mitochondria for energy making. The following discovery changes a fundamental notion they taught you in biology class.
The strange creatures that defy biology: Organisms power themselves in a different way to every other plant, animal and fungus on the planet
Not much to look at,
but this guy is a revolutionary
- A single-celled organism called Monocercomonoides lacks mitochondria,
- Mitochondria are believed to be essential for eukaryotic cells by generating power for cells
- Mitochondria use oxygen and sugar to produce packets of chemical energy.
- But monocercomonoides uses a chemical process involving sulphur.
- Researchers say that rather than evolving without mitochondria, the creatures lost them at some point in their past
Biologists have discovered a strange single-celled creature which lacks the usual cellular 'power stations needed' to produce energy.
It was thought all complex cells, including animals, plants and fungi, contained the tiny power-producing organs called mitochondria.
But a team in the Czech Republic has discovered a microscopic creature that contains no trace of them at all, making them a biological oddity.
Researchers have known about monocercomonoides (pictured) for more than 80 years, and the organisms are related to single-celled human parasites which live in low-oxygen environments. Rather than evolving without mitochondria, biologists believe the cells lost these organs at some point in their evolutionary past
Eukaryotic cells, which include animals, plants and fungi, contain many of energy producing mitochondria, which produce chemical energy. Pictured are mouse fibroblast cells, with the DNA contained within the nucleus (blue), and thousands of energy producing mitochondria (green) clearly visible
Included in the eukaryotic cell group we find animals, plants, fungi and a host of other life forms.
Mitochondria generate the power for cells by using oxygen and sugar to produce packets of chemical energy called ATP.
But instead of using these organs to produce energy, scientists believe the single-celled creatures use a chemical process involving sulphur.
'In low-oxygen environments, eukaryotes often possess a reduced form of the mitochondrion, but it was believed that some of the mitochondrial functions are so essential that these organelles are indispensable for their life,' explained Dr Anna Karnkowska, a researcher at the University of British Columbia in Vancouver.
'We have characterised a eukaryotic microbe which indeed possesses no mitochondrion at all.'
Rather than evolving without mitochondria, biologists believe the cells lost these power organs at some point in their evolutionary past.
Instead, it is thought the cells swapped traded DNA with bacteria – in a process known as gene transfer – in order to inherit a sulphur transfer process which produces energy.
Instead of using mitochondria to produce energy, scientists believe Monocercomonoides (pictured) use a chemical process involving sulphur, which they may have inherited from bacteria
The findings are published today in the journal Current Biology.
The authors explained: 'This is the first example of a eukaryote lacking any form of a mitochondrion, demonstrating that this organelle is not absolutely essential for the viability of a eukaryotic cell.'
Researchers have known about species of Monocercomonoides for more than 80 years, and the organisms are related to single-celled human parasites, which live in low-oxygen environments.
But new analysis of the creature's genome, led by researchers in the Czech Republic and Canada, showed they lacked mitochondrial proteins.
The team believes Monocercomonoides have 'evolved beyond the known limits that biologists circumscribed'.
'This amazing organism is a striking example of a cell which refuses to adhere to the standard cell biology text book, and we believe there may be many more similar examples in the so far hidden diversity in the world of microbial eukaryotes - the protists,' said Karnkowska.
The researchers said they'd now like to learn more about how these organisms function.
They'd also like to better characterise Monocercomonoides and its relatives to understand their discovery in a broader, evolutionary context.
'Existence of such organism proves the fact that a eukaryotic cell - cells with a true nucleus - can live without mitochondrion,' said Dr Vladimir Hampl, a biologist at Charles University in Prague and senior author of the study.
The biologist said the team now aims to find out at which point in the past these creatures lost their mitochondria, adding there may be a whole group of organism to which the creature belongs, called oxymonads, which lack the organelles.
Dr Hampl told MailOnline: 'Before we knew about this organism, it seemed that mitochondrion is present in all eukaryotic cells, even if in some it does not produce energy, which is otherwise the best know function of it.
'Still, even without the energy production, the mitochondria were performing other essential metabolism without which the cell could not live.
'In this organism, probably due to an evolutionary consequences, all essential functions of mitochondrion has been lost and the organelle has been dispensed as well. This organism makes all his living by the cytosolic pathways. '
Inside a mitochondrion
WHAT ARE MITOCHONDRIA?
- In every cell in the body, mitochondria are responsible for producing energy (in the form of ATP) which the cell needs to function.
- If our cells do not have energy, then the tissues or body organs that the cells are made up of do not work properly.
- It is thought mitochondria evolved independently from eukaryotic cells and the two joined at some point in the very distant evolutionary past, when a common ancestor of animals, plants and fungi engulfed a smaller independent organism
LIFE WITHOUT MITOCHONDRIA
- New research from biologists in the Czech republic and Canada has revealed a complex cell which contains no trace of mitochondria.
- The creature is a type of single-celled organism called a Monocercomonoides and is at odds with the idea that mitochondria are essential components of eukaryotic cells - which include animals, plants, fungi.
- Researchers have known about species of monocercomonoides for more than 80 years, and the organisms are related to single-celled human parasites, which live in low-oxygen environments.
- Rather than evolving without mitochondria, biologists believe that the cells lost these power organs at some point in their evolutionary past.
- The team aims to find out at exactly which point in the past the creatures lost their mitochondria, adding that there may be a whole group of organism to which the creature belongs which also lack the organelles.
- The findings are significant because they go against what biologists widely held, that mitochondria are essential components of eukaryotic cells
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