Scientists Find the First-Ever Animal That Doesn't Need Oxygen To Survive (sciencealert.com) 53
Scientists from Tel Aviv University in Israel discovered that a salmon parasite called Henneguya salminicola doesn't have a mitochondrial genome -- the first multicellular organism known to have this absence. That means it doesn't breathe; in fact, it lives its life completely free of oxygen dependency. ScienceAlert reports: It's a cnidarian, belonging to the same phylum as corals, jellyfish and anemones. Although the cysts it creates in the fish's flesh are unsightly, the parasites are not harmful, and will live with the salmon for its entire life cycle. Tucked away inside its host, the tiny cnidarian can survive quite hypoxic conditions. But exactly how it does so is difficult to know without looking at the creature's DNA -- so that's what the researchers did.
They used deep sequencing and fluorescence microscopy to conduct a close study of H. salminicola, and found that it has lost its mitochondrial genome. In addition, it's also lost the capacity for aerobic respiration, and almost all of the nuclear genes involved in transcribing and replicating mitochondria. Like the single-celled organisms, it had evolved mitochondria-related organelles, but these are unusual too -- they have folds in the inner membrane not usually seen. The same sequencing and microscopic methods in a closely related cnidarian fish parasite, Myxobolus squamalis, was used as a control, and clearly showed a mitochondrial genome. These results show that here, at last, is a multicellular organism that doesn't need oxygen to survive. Exactly how it survives is still something of a mystery. It could be leeching adenosine triphosphate from its host, but that's yet to be determined. But the loss is pretty consistent with an overall trend in these creatures - one of genetic simplification. Over many, many years, they have basically devolved from a free-living jellyfish ancestor into the much more simple parasite we see today. The findings have been published in the journal PNAS.
They used deep sequencing and fluorescence microscopy to conduct a close study of H. salminicola, and found that it has lost its mitochondrial genome. In addition, it's also lost the capacity for aerobic respiration, and almost all of the nuclear genes involved in transcribing and replicating mitochondria. Like the single-celled organisms, it had evolved mitochondria-related organelles, but these are unusual too -- they have folds in the inner membrane not usually seen. The same sequencing and microscopic methods in a closely related cnidarian fish parasite, Myxobolus squamalis, was used as a control, and clearly showed a mitochondrial genome. These results show that here, at last, is a multicellular organism that doesn't need oxygen to survive. Exactly how it survives is still something of a mystery. It could be leeching adenosine triphosphate from its host, but that's yet to be determined. But the loss is pretty consistent with an overall trend in these creatures - one of genetic simplification. Over many, many years, they have basically devolved from a free-living jellyfish ancestor into the much more simple parasite we see today. The findings have been published in the journal PNAS.
Cannot pronounce, attempting render. (Score:2)
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They're ignoring the prior art of Slashdot Editors and Trolls (myself included).
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Speaking of ATP, editors, trolls, and sealing wax... [slashdot.org]
(Although, this might qualify as an advanced persistent threat, I promise you, dear Editors, that Iran will not backdoor our salmon.)
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And don't forget scientist trolling... [wikipedia.org]
This sort of thing makes it really hard to take objectivity in biology seriously...
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I want to see Dawkins deliver a deadpan presentation of the evolutionary development and rigorous biological categorization of Spongiforma squarepantsii [wikipedia.org] sometime soon.
High comedy.
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Cannot pronounce, attempting render.
Cnidaria [ nahy-dair-ee-uh ]
Praise dictionary! [dictionary.com]
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Toydarians might be ugly, but they're not parasites.
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If there is a C (Usually in front of an N or T) in scientific name then the C is silent. Just ask any of those taxonomy 'unts.
Not such a big deal (Score:3, Informative)
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Anyone working in an office has experienced this, I'm guessing.
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It's interesting that the levels of CO2 are so high indoors, and high CO2 levels hamper focus and awareness. Why exactly do people want to work in windowless cubicles or hire expensive employees just to stick them in hermetically sealed work pods?
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Not to mention making them cram themselves into constricting clothes complete with a noose. Even if there isn't a chance in hell anyone not working for the company will see them.
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> Why exactly do people want to work in windowless cubicles
I don't. I want to get paid. The cubicle is a means to an end.
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Indeed. And I'm also in a great walkable little city, with lots of bars and restaurants, coffee shops, stuff going on, concerts, markets, parades, protests, etc. Going to and from work is absolutely delightful, even if being in work isn't.
I actually have some hope that COVID-19 plus our painful, terrible shift to Microsoft Teams VOIP and Office 365 will nudge us to work from home more. If I could just get 1 day a week, it would be amazing. Two might be a little too much, because I'd get like 3-4 days of wor
Re:Not such a big deal (Score:5, Insightful)
In the end O2 is still needed
And nuclear fission is needed to create Oxygen.
But at no point does this organism use O2 molecules, and that is a very big deal as never seen before in a multi-cellular organism.
As is the lack of mitochondria, if I understand correctly, though that has been seen in unicellular Eukaryotas before.
https://en.wikipedia.org/wiki/... [wikipedia.org]
It's like in the 18th century when we thought we had a good idea of what mammals were, then along comes the platypus.
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But it will have to get its oxygen from somewhere, since oxygen is part of cytosine, guanine, and thymine that makes up its DNA.
As suggested that is most likely the ATP they mentioned as that is already the common DNA precursor.
Re:Not such a big deal (Score:5, Informative)
It's a eukaryote that lacks the machinery to do cellular respiration.
Maybe it uses host ATP for that, maybe it uses something else... They don't know yet.
At the base, all life on Earth requires some amount of O2 to exist, because our DNA is made from it.
That doesn't mean we need much of it on an ongoing basis.
Think anaerobic bacteria. But multicellular, and eukaryotic.
Definitely a novel thing.
We don't generally say anaerobic bacteria require oxygen to survive, so this does not either. Whether it gets its atomic oxygen from "food", or leeched metabolic chemicals from its host, it still does not engage in aerobic cellular respiration.
What it means is (Score:2, Interesting)
What it means is that there are now a kabillion jazillion uptillion more planets that could potentially have life on them.
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Except that it doesn't mean that at all. The host still requires oxygen.
When they find a self-sufficient organism that can survive without oxygen, that will be newsworthy.
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Are there really any truly self-sufficient organisms (that we know of)?
Re:What it means is (Score:4, Informative)
Are there really any truly self-sufficient organisms (that we know of)?
All organisms require energy and nutrients, but there are many that do not rely on other lifeforms.
Examples: cyanobacteria, thermophilic archaea
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Re:What it means is (Score:4, Informative)
They metabolize CO2 through photosynthesis with energy from our star, releasing O2.
As far as I know these cyanobacteria are the ancestors of plants, with a common hypothesis being that protozoa like amoeba ate those cyanobacteria, which created evolutionary pressure on the bacteria. Those developed defense mechanisms that allowed them to stay alive within the amoeba by providing it with nutrients and being protected by it in return forming a symbiotic relationship. Eventually the cyanobacteria evolved into chloroplasts and became part of the larger organism what was then the first plant cells.
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if the creature or plant needs oxygen/CO2 then it needs plants to produce the oxygen and visa versa.
CO2 existed in the atmosphere before there was any life. In fact, it was far more common when the earth was abiotic.
Cyanobacteria rely on CO2, but rather than relying on other life to produce it, they would be better off if there was no other life.
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“No human health concerns” (Score:1)
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I believe that it's the amount of cells and how they're used that matters, not the size.
Ahem.
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I wouldn't call a multi-cellular organism an animal that can only be seen under a microscope.
To be fair, if somebody on Slashdot turned out to have a fucking clue that would be a significantly more notable discovery than an anaerobic multi-cellular organism.
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You need to check out pond scum in a microscope then, especially from somewhere like a dairy farm drainage pond. The stuff may be small, but there is no doubt that they're animals. Daphnia, rotofers, paramecia, amebas, are all running around eating each other and anything else they run into. Then there are the euglena, which move like animals but have chloroplasts so they're technically a plant even though some of them are at least partly carnivorous. There are also some species of fungi that are carnivo
Re:No mitochondria (Score:4, Funny)
The force is weak in this one.
That's what Enrico Fermi said. He was a Jedi.
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Evolving terminology (Score:3)
Over many, many years, they have basically devolved from a free-living jellyfish ancestor into the much more simple parasite we see today.
So, "devolving" wasn't a biologically nonexistent thing that Behe made up?
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You won't find it in the actual paper https://www.pnas.org/content/e... [pnas.org] or in other news that reported the same like https://phys.org/news/2020-02-... [phys.org] or https://www.sciencenews.org/ar... [sciencenews.org] or https://www.sciencedaily.com/r... [sciencedaily.com] or https://www.eurekalert.org/pub... [eurekalert.org]
These scientists should use the Internet more (Score:1)
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So how many multi-cellular anaerobic bacteria have you cataloged?
"they break down the oxigen" (Score:2)
"They break down oxygen to produce a molecule called adenosine triphosphate, which multicellular organisms use to power cellular processes."
Really? A nuclear power plant? Break the oxygen? Into oxy and gen? :-)
I think they mean the O2 is used (broken in to 2x O) in producing the ADT...
I am just an EE so I pardon me.
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He's talking about mitochondria fwiw. Later one he goes ... "until now"
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I think they mean the O2 is used (broken in to 2x O) in producing the ADT...
ATP. ADT is a crappy home security company that, while it does consume much oxygen, and is somewhat parasitic, probably isn't what we are talking about here.
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First? (Score:2)
How about those animals that live inside people asses? ...
Like flatworms, politicians,
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Other eukaryotes without mitochondria (Score:3)
There are other eukaryotes without mitochondria
One example is the similarly parasitic Giardia [wikipedia.org]. They are unicellular though, and have a mitosome (mitochondrial remnant without DNA in it).
Monocercomonoides [sciencemag.org] on the other hand, lacks mitochondria completely. Again unicellular, but not parasitic.
Both are assumed to having ancestors that had mitochondria, but then losing them.
I do recall a third organism that appears to never had mitochondria at all (not just losing them like the above two), but I can't find it now.