Please create an account to participate in the Slashdot moderation system

 


Forgot your password?
Close
typodupeerror
×
Science

Scientists Find the First-Ever Animal That Doesn't Need Oxygen To Survive (sciencealert.com) 53

Posted by BeauHD from the first-of-its-kind dept.
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.
This discussion has been archived. No new comments can be posted.

Scientists Find the First-Ever Animal That Doesn't Need Oxygen To Survive More

Scientists Find the First-Ever Animal That Doesn't Need Oxygen To Survive

Comments Filter:
  • "It's a cnidarian, belonging to the same phylum as..." The parasite is now a toydarian.

  • Not such a big deal (Score:3, Informative)

    by Zetaprime1 ( 6236870 ) on Tuesday February 25, 2020 @09:13PM (#59767166)
    So this parasite doesn't need oxygen. It needs an animal that does use oxygen to be its host. Big deal. In the end O2 is still needed for this organism to survive.

    • Anyone working in an office has experienced this, I'm guessing.

      • 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?

        • Humans are very bizarre creatures. I'll never understand them or their motivations.

        • Re: (Score:2)

          by sjames ( 1099 )

          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.

        • > 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.

          • 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)

      by quenda ( 644621 ) on Tuesday February 25, 2020 @11:46PM (#59767522)

      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.

      • Re: (Score:2)

        by fazig ( 2909523 )
        It is a big deal that doesn't use O2 molecules.
        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)

      by DamnOregonian ( 963763 ) on Wednesday February 26, 2020 @04:08AM (#59767898)
      It is a big deal.
      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 that there are now a kabillion jazillion uptillion more planets that could potentially have life on them.

    • Re: (Score:3, Insightful)

      by An0nYm0u5c0wArD ( 6251996 )

      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.

      • Re: (Score:2)

        by samdu ( 114873 )

        Are there really any truly self-sufficient organisms (that we know of)?

        • Re:What it means is (Score:4, Informative)

          by ShanghaiBill ( 739463 ) on Tuesday February 25, 2020 @10:18PM (#59767336)

          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

          • When you say many what is that like 0.01%. I can think of none except perhaps some deep sea plants living off the heat from a volcano and maybe some bacteria, however if the creature or plant needs oxygen/CO2 then it needs plants to produce the oxygen and visa versa. And the list of requirements typically goes dramatically up.

            • Re:What it means is (Score:4, Informative)

              by fazig ( 2909523 ) on Wednesday February 26, 2020 @04:26AM (#59767918)
              GP already mentioned cyanobacteria, which are quite common (algae blooms are mostly cyanobacteria).

              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.
            • He already mentioned some pretty dominant organisms, you're making the mistake of thinking that most life is the sort of thing you can see stomping around eating your roses, when you're more closely related to the roses and the deer or japanese beetles eating them than are the diverse organisms in the dirt related to either you or each other.

            • 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.

      • Re: (Score:3)

        by fintux ( 798480 )
        There are a lot of organisms that don't need a host organism and that are anaerobic. But this is the first discovery of an anaerobic animal. Also, it should be noted that anaerobic environment refers to an environment without free oxygen. If I'm not mistaken, all life that we know of require water (H2O) and other chemical compounds that contain water (like RNA). That's not to say that life couldn't exist somewhere without oxygen, basing on a completely different kind of chemistry. Just that the life that we
  • I’ve caught Coho salmon with these gross white pusballs in their flesh. I don’t care what the TFA says about them being safe to eat, when I find a fish full of them they go straight in the compost bin.

  • Evolving terminology (Score:3)

    by aeropage ( 6536406 ) on Tuesday February 25, 2020 @10:51PM (#59767416)

    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?

  • Anaerobic bacteria have been doing this since 1862

  • "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.

  • Comment removed based on user account deletion

  • How about those animals that live inside people asses?
    Like flatworms, politicians, ...

  • Other eukaryotes without mitochondria (Score:3)

    by kbahey ( 102895 ) on Wednesday February 26, 2020 @10:07AM (#59768560) Homepage

    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.

Slashdot Top Deals

Single tasking: Just Say No.

Close