[HN Gopher] Ushikuvirus: Newly discovered virus may offer clues ...
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       Ushikuvirus: Newly discovered virus may offer clues to the origin
       of eukaryotes
        
       Author : rustoo
       Score  : 46 points
       Date   : 2026-01-08 04:39 UTC (18 hours ago)
        
 (HTM) web link (www.tus.ac.jp)
 (TXT) w3m dump (www.tus.ac.jp)
        
       | Chance-Device wrote:
       | Incidentally, anyone know what is going on with this image -
       | "Cryo-EM map of a center slice of the ushikuvirus particle":
       | https://journals.asm.org/cms/10.1128/jvi.01206-25/asset/1357...
       | 
       | It's one quarter of an image flipped horizontally and then
       | vertically, you can see the patterns.
       | 
       | It's a bit odd to do that? Shouldn't it just be the original EM
       | image?
        
         | jiggawatts wrote:
         | Rampant fraud in science papers has reached the point where
         | hobbyists can point out obviously fake charts and graphics even
         | in prestigious journals.
         | 
         | Publish or perish needs to end.
        
         | RicoElectrico wrote:
         | According to this article the image is computed and not really
         | directly captured
         | https://www.chemistryworld.com/news/explainer-what-is-cryo-e...
        
         | observationist wrote:
         | https://www.sciencedirect.com/science/article/pii/S104784772...
         | - there are similar results in this paper, too.
         | 
         | After a bit of digging - it looks like it's done to sharpen
         | features as one of the standard steps in producing these
         | images. Where there are rotational symmetries in the things
         | they're looking at, they focus on the smallest unit, and then
         | rotate accordingly. If you had a trilateral symmetry, or
         | hexagonal structure, they'd rotate 3 or 6 times around the
         | center.
         | 
         | You're not getting a real image of the thing, but apparently
         | it's got data from those other segments mixed in with the
         | rotations, so you're getting a kind of idealized structure, to
         | make the details being studied pop out, but if you have some
         | sort of significant deviation, damage, or non symmetric feature
         | it'll show up as well.
         | 
         | It's called "imposed symmetry"
         | https://discuss.cryosparc.com/t/what-is-actually-occuring-wh...
         | 
         | Neat stuff, cool thing to catch!
        
         | Bjartr wrote:
         | I think that might just be the original and it simply is
         | symmetrical to that degree. I found a few more examples of
         | "cryo-em center slices" and I've yet to find one that doesn't
         | have really strong symmetry down to the small dot patterns.
         | 
         | A different paper, this figure shows a number of cryo-em
         | images, including a simulation, and they all show the same
         | degree of pattern symmetry
         | https://www.researchgate.net/figure/Central-sections-through...
         | 
         | First figure in this third paper also shows symmetry of small
         | patterns https://journals.asm.org/doi/10.1128/jvi.00990-22
        
           | Chance-Device wrote:
           | Thanks, those examples make it pretty clear.
           | 
           | I still think it's super weird that it looks exactly like an
           | EM image, but is generated. Anyway, good to know!
        
       | possiblelion wrote:
       | Interesting, hope that these discoveries can be used to fight
       | those amoeba's which cause infections as well!
        
       | embedding-shape wrote:
       | I remember someone talking about "last universal common ancestor"
       | at some point, the single "origin of the cells" or something. Is
       | that the same as the "archaeal ancestor" they're referring to
       | here? And is the "archaeal ancestor" the same as the "Primitive
       | archael cell" mentioned in the last image in the article?
       | (https://www.tus.ac.jp/en/mediarelations/20251219_9539_03.png)
        
         | Tagbert wrote:
         | From what I know - There are two sister groups, the Archae and
         | Bacteria. Their ancestor would be LUCA. The first Archae would
         | be the archaeal ancestor. There should be a first bacteria to
         | match that.
         | 
         | I believe that Eukaryotes then from Archae.
        
         | pfdietz wrote:
         | I believe "archaeal cell" is referring to an Archaea, one of
         | the three branches of life. All three branches derive from a
         | more distant ancestor, LUCA. LUCA was undoubtedly preceded by
         | other ancestors, but there is (by definition) nothing else
         | branching from them that has survived.
        
           | Terr_ wrote:
           | I anticipate the definition will become increasingly
           | subjective as we find biology-messiness inconsistent with our
           | concepts of ancestry.
           | 
           | For example, suppose horizontal gene transfer occurs from
           | organism X to organism Y. Does that mean Y is now a branch of
           | X?
           | 
           | * Does it depend on _how much_ was transferred?
           | 
           | * Does it matter only if the specific sequence was passed
           | down? If so, how much mutation is too much mutation?
           | 
           | * What if the same end-result occurred through a retrovirus
           | instead of a plasmid. Is the virus an ancestor too?
           | 
           | * What if the swap was simultaneous and bidirectional?
           | 
           | * What about transitive links to organisms W, V, U that did
           | the same?
           | 
           | * Are mitochondria "us" yet? If so, are we the ancestors if
           | they redevelop enough machinery to "escape"?
           | 
           | etc.
        
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       (page generated 2026-01-08 23:00 UTC)