[HN Gopher] Largest bacterium ever discovered has unexpectedly c...
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Largest bacterium ever discovered has unexpectedly complex cells
Author : amichail
Score : 108 points
Date : 2022-02-24 12:50 UTC (10 hours ago)
(HTM) web link (www.science.org)
(TXT) w3m dump (www.science.org)
| catlifeonmars wrote:
| From further down in the article:
|
| > Furthermore, that cell includes two membrane sacs, one of which
| contains all the cell's DNA, Volland and colleagues report in
| their 18 February preprint on bioRxiv. Volland calls that sac an
| organelle and that's "a big new step" that implies the two
| branches of life are not as different as previously thought,
| Carvalho says. "Perhaps it's time to rethink our definition of
| eukaryote and prokaryote!" agrees Petra Levin, a microbiologist
| at Washington University in St Louis. "It's a supercool story."
|
| IMO, they really buried the lede on this one by focusing on the
| size of the bacterium and not on the convergent evolution of an
| apparent nucleus in a prokaryote.
| maxk42 wrote:
| Why would they call these the largest when things like this [0]
| exist? It's my understanding that even these large cells aren't
| the largest.
|
| [0] https://www.australiangeographic.com.au/blogs/creatura-
| blog/...
| flobosg wrote:
| That's an eukaryotic alga, not a bacterium.
| maxk42 wrote:
| Perhaps I am misinformed but I was taught bacteria come in
| both prokaryotic and eukaryotic varieties. Are algae not
| bacteria?
| flobosg wrote:
| Bacteria are always prokaryotes since they lack nucleus and
| membrane-bound organelles. Algae (both single-celled and
| multicellular ones) are more complex and thus eukaryotic.
| That being said, photosynthetic bacteria (cyanobacteria) do
| exist and were known as "blue-green algae" in the past, but
| that term has fallen out of use.
| Karawebnetwork wrote:
| I am wary to bring the topic up but I wonder if this might have
| some degree of connection with what people call morgellons
| disease.
|
| The bactarium shown in the video looks very similar to what
| people describe.
|
| My understanding is that morgellons is largely seen as
| psychosomatic or "fake". I now wonder if some people might have
| similar bacteria on them and that it might explain some of the
| symptoms.
| danachow wrote:
| The problem with this theory, despite lobbied funding for the
| Morgellons foundation with very extensive testing including
| histological and biochemical, no evidence of an organism has
| been found associated with it. It's not like nobody has looked.
| likpok wrote:
| It would be easy to determine if Morgellons was caused by a
| bacteria or some other physical thing: you can take samples and
| look at them under the microscope. When the CDC did just that
| (looked at samples of the fibers), they found them to be likely
| cotton.
|
| If this were the cause of morgellons then their result would be
| "morgellons caused by infestation with unknown large bacteria"
| not "people with morgellons have no physical evidence of
| infestation".
| unfocussed_mike wrote:
| Nope. There is some fringe theory about a bacterium but
| Morgellons is almost certainly delusional parasitosis and the
| fibres are just that - fibres from clothes.
|
| It emerged from an odd nexus of Munchausens, Munchausens by
| proxy, internet diagnosis and schizophrenia. So it's not "fake"
| but it might be faked.
|
| Morgellons is a really fascinating mini model of Qanon, in a
| way; it now "exists" as a "thing" that has to be discussed,
| even though it doesn't exist as a thing.
| Karawebnetwork wrote:
| Let me rephrase that. I wonder if some of the people who are
| labeled under Morgellon's disease have had an actual
| encounter with such a bacteria.
|
| You have written elsewhere that "Morgellons is something that
| people only ever "have" if they go looking for it."
|
| My experience with the concept is similar to that, but
| different. I first heard about it in the context of a
| building that had what is now called "sick building
| syndrome." In short, a combination of poor air circulation,
| bathrooms that weren't properly ventilated on the outside,
| and an HVAC system that hadn't been cleaned in over a decade.
|
| People were unknowingly sick, but had nothing to show for it
| except the odd particle found on their skin. So the logical
| people did what logical people do and looked for an answer.
| Some went to dermatologists who only gave the answer "there
| are signs of an unknown infection" and provided creams. For
| some, this is enough to move on. While others need the exact
| answer to find peace. So there you have it, a bunch of
| educated people on search engines writing "redness on the
| skin with dust particles", "infection only in one room",
| "small itchy filaments on the skin", etc. Soon enough,
| "Morgellons" appeared in the results and was the topic of
| conversation.
|
| Now obliviously it wasn't "Morgellons". Air quality tests
| were performed and revealed the presence of spores, which led
| to the discovery that the bathroom vent was not properly
| installed and that the HVAC system was long overdue for
| cleaning.
|
| However, if these tests had not been performed and the
| building owner had not been cooperative, you would have a
| large group of engineers believing in Morgellons, as that was
| the only "logical" explanation at the time.
|
| This brings us back to my question, "I wonder if this might
| have something to do with what people call Morgellon's
| disease." Not necessarily as an explanation of Morgellons but
| as an explanation of some of the reported symptoms. If I had
| on my body the exact same bacteria as the one in the short
| video of the article and went to a search engine to find the
| answer, I would very likely fall on Morgellon's disease.
|
| It's entirely possible that 100% of the people who claim to
| have seen filaments moving on their skin were imagining
| things, that they all have a mental health issue.
|
| But coming from a fibromyalgia household where the women in
| my family were led to believe their illness was imaginary
| ("female hysteria") for decades, some of them wasting years
| on powerful antipsychotic and antidepressant medications, I
| am very wary of dismissing self-reported symptoms as
| psychosomatic.
| unfocussed_mike wrote:
| > But coming from a fibromyalgia household where the women
| in my family were led to believe their illness was
| imaginary ("female hysteria") for decades, some of them
| wasting years on powerful antipsychotic and antidepressant
| medications, I am very wary of dismissing self-reported
| symptoms as psychosomatic.
|
| I'm glad they are getting help.
|
| (Also good job with the HVAC and the building; an
| unprovably unpleasant environment can mess with people's
| lives)
|
| But it's worth noting as others have that Morgellons is
| based on a specific claim (strange microscopic growths out
| of the skin) that is testable. The things that
| sufferers/believers think are their disease turn out to be
| cellulose in nature. In other words, cotton microfibres.
| bayesian_horse wrote:
| Delusional parasitosis is quite the opposite of
| "Munchhausen's". Sufferers can't even be described as
| hypochondriac. It's a psychiatric disorder, and they seek
| help because they suffer.
|
| In "Munchhausen's" people seek suffering to get help, to
| oversimplify by a few magnitudes. But it's really not the
| same thing.
|
| And QAnon-followers are in their majority not suffering from
| psychotic delusions.
| unfocussed_mike wrote:
| > Delusional parasitosis is quite the opposite of
| "Munchhausen's".
|
| It's possible for things to exist in a nexus between
| opposites, is it not? Morgellons is something that people
| only ever "have" if they go looking for it. Self-diagnosis
| of extreme, rare, "special" diseases that rational people
| disbelieve, and Munchausens are not that far apart, surely.
|
| > And QAnon-followers are in their majority not suffering
| from psychotic delusions.
|
| I didn't say that -- or mean it. [0]
|
| What I said was that the emergence of Morgellons -- an
| internet phenomenon -- is a small model of what later
| happened with QAnon. Both are non-true, at leas partly
| fabricated, online phenomena, that simultaneously do not
| exist and cannot be ignored.
|
| The problem comes when you have a bunch of people who are
| scientifically ignorant, predisposed towards a simple
| belief that explains things for them, and several bad faith
| actors (in QAnon's case, Cernovich and the Watkins family,
| in the Morgellons case, the Morgellons Research Foundation
| and several blogs). What you end up with is a self-
| reinforcing bubble of belief around a fallacy that cannot
| then be ignored, like scar tissue around a tiny fragment of
| talc.
|
| [0] That said, there are for certain delusional aspects of
| QAnon. It has a Millerite nature and is also spawning even
| more fringe cults like the JFK reincarnation faction; it
| absolutely is unpicking people's control over their
| psychoses, as can be seen from the January 6 defendants.
| [deleted]
| sva_ wrote:
| The article seems to imply that this organism is single-cellular:
|
| > _Its threadlike single cell is visible to the naked eye,
| growing up to 2 centimeters--as long as a peanut--and 5000 times
| bigger than many other microbes._
|
| The study[0] however speaks of "cells" in plural, and "daughter
| cells". It would've really surprised me if that really had been a
| single cell - unless I'm misunderstanding something here.
|
| edit: I stand corrected. Misunderstood it.
|
| [0] from other comment:
| https://www.biorxiv.org/content/10.1101/2022.02.16.480423v1....
| actually_a_dog wrote:
| Believe it or not, that's not even _close_ to the largest
| unicellular organism. One of the largest is _Valonia
| ventricosa_ , a species of algae that has spherical or ovoid
| cells "with a diameter that ranges typically from 1 to 4
| centimetres (0.4 to 1.6 in) although it may achieve a diameter
| of up to 5.1 centimetres (2.0 in) in rarer cases." [0]
|
| ---
|
| [0]:
| https://en.wikipedia.org/wiki/Valonia_ventricosa#Physiology_...
| undersuit wrote:
| My favorite large unicellular organisms are Xenophyophorea.
| They have multiple nuclei probably because the diffusion of
| transcription processes over an 8 inch diameter cell would be
| just too slow with a single central nucleus.
|
| https://en.wikipedia.org/wiki/Xenophyophorea
| bayesian_horse wrote:
| Point being those algae are eukaryotic. The article is about
| an unusually large bacterium (prokaryotic) which has some
| eukaryotic features.
| stdbrouw wrote:
| First subheading of the study: "Thiomargarita magnifica is a
| centimeter-long, single bacterial cell". They apparently stick
| together, but do constitute individual organisms.
| R0b0t1 wrote:
| There is precedence for cells being that large. I can't
| remember the organism name, but there is actually some
| macroscopic single cell organism. It cheats by having multiple
| nuclei, among other things.
| sva_ wrote:
| Yeah, but the cell of such single-celled organisms are
| usually round or in one segment. This one looks like it has
| several segments, and still be a single cell, which is
| fascinating. Perhaps it is blurring the line between single
| cellular and multi cellular a bit, which might be the point
| that the article was trying to make.
| adrian_b wrote:
| What is new here is that this is a bacteria, not a nucleate
| cell. Large eukaryote cells, even over 10 cm (4 inches), are
| well known. Almost all normal bacteria have a diameter under
| 100 micrometer, usually much less.
|
| The article explains that the huge size for a bacteria seems
| to be enabled by 2 features, first a large water-filled
| vesicle inside, so that the living part of the cell is around
| the periphery of the cell, within short distances from the
| cell membrane, and second, a special compartment for DNA
| which provides some of the functions of a nucleus in an
| eukaryote (nucleate) cell.
| throwamon wrote:
| You may be thinking of _Valonia ventricosa_ (bubble algae),
| though I believe there are others.
| bochoh wrote:
| Chicken and ostrich eggs are both single cells that are quite
| large as well
| bayindirh wrote:
| But it's an eukaryote cell. Not prokaryote.
| jessriedel wrote:
| No, they claim that most of the filament is a single cell,
| albeit with compartmentalized DNA:
|
| > Strikingly, all techniques consistently showed that each
| filament was one continuous cell for nearly its entire length
| with no division septa, including the partial constrictions
| towards the apical pole. Only the most apical few buds were
| separated from the filament by a closed constriction and
| represented daughter cells
|
| "Apical" means the apex of the filament. In other words, toward
| the end of the filament the cell starts pinching off
| ("budding") to create daughter cells as part of its
| reproductive cycle. But the away from the end, the cell is
| contiguous. Fig. S2 is highly recommended.
| tombert wrote:
| How is complexity measured in this case? I'm not disagreeing, I'm
| just curious.
| Kichererbsen wrote:
| Disclaimer: I am not a biologist or whatever someone who
| studies this stuff is called. But from what I've been able to
| gather, actually having the RNA be in it's own membrane (an
| "organelle" they're calling it in the article) is not something
| you'd usually expect in a bacterium. If I remember correctly,
| they're more "soupy" inside.
| unfocussed_mike wrote:
| It's largely based on the bacterium's nuanced views on late
| nineties experimental electronica.
| adrian_b wrote:
| The complete research article:
|
| https://www.biorxiv.org/content/10.1101/2022.02.16.480423v1
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