[HN Gopher] Bacteria store memories and pass them on for generat...
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       Bacteria store memories and pass them on for generations
        
       Author : geox
       Score  : 231 points
       Date   : 2023-11-22 00:20 UTC (22 hours ago)
        
 (HTM) web link (news.utexas.edu)
 (TXT) w3m dump (news.utexas.edu)
        
       | turtleyacht wrote:
       | Researchers discover a single dimension of measurement of iron--
       | in low, "balanced," and high levels of concentration--persist
       | behavior for several generations, disappearing by the seventh.
        
         | nightfly wrote:
         | So bacteria store data on magnetic tape, heh
        
       | tomohelix wrote:
       | Here is the preprint and free version:
       | 
       | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10441380/
        
       | molticrystal wrote:
       | Along similar lines of interesting memory studies of simpler
       | lifeforms, there is an article titled "These Decapitated Worms
       | Regrow Old Memories Along with New Heads"[0] and study [1] which
       | can alter your assumptions on how and where memories are stored
       | and retrieved.
       | 
       | Also there were claims starting in the 50s where planarians were
       | taught a maze or to respond to certain stimuli and then fed to
       | other planarians and that the trait would sometimes transfer as
       | well. I don't know if any of those studies were reproduced, thus
       | the claims might be dubious, but it would be interesting if they
       | were true.
       | 
       | [0] https://www.smithsonianmag.com/science-nature/these-
       | decapita...
       | 
       | [1] https://pubmed.ncbi.nlm.nih.gov/13881412/
        
         | lcnPylGDnU4H9OF wrote:
         | > alter your assumptions on how and where memories are stored
         | and retrieved
         | 
         | I remember reading an anecdote about a baby who didn't like
         | being held by their father, who happened to beat the baby's
         | mother during pregnancy. No idea of the veracity of the story
         | but something about it had me thinking similarly about
         | "instincts" and where they come from. The meaning of the word
         | does seem to be a lot like memories that are "passed on for
         | generations".
        
           | simonh wrote:
           | In late stage pregnancy babies in the womb can hear voices,
           | and can often identify their father after birth by their
           | voice immediately after birth. Violence often includes a lot
           | of shouting, and physiological stress on the victim which
           | would affect the baby. I'm guessing the baby learned to
           | associate these.
        
           | ianmcgowan wrote:
           | n=1, but I sang to both my daughters in the womb (different
           | songs) and after they were born singing "their" song would
           | calm them down a lot faster. I don't think this is as much
           | "instincts" as it is "very early experiences".
        
             | moehm wrote:
             | Make it n=2.
        
           | jl6 wrote:
           | Babies develop a preference for their primary caregiver, who
           | is usually the mother.
           | 
           | Young children generally are more cautious around men than
           | women, which is probably good risk management. Instinctive?
           | Possibly.
        
             | Hendrikto wrote:
             | > probably good risk management
             | 
             | Is it, though? This data [0] says otherwise.
             | 
             | [0]: http://www.breakingthescience.org/SimplifiedDataFromDH
             | HS.php
        
               | thegiogi wrote:
               | Did they start collecting data 100k years ago? Cause that
               | is the timescale for this stuff no?
        
               | dotancohen wrote:
               | This is an extraordinarily important point to make,
               | especially in light of the GP comment and the perception
               | that it reflects.
        
               | jl6 wrote:
               | That's one very specific type of risk, and a thankfully
               | rare one. (That also appears to be a men's rights
               | activist site with an axe to grind on this subject).
               | 
               | A more neutral source:
               | 
               | https://bjs.ojp.gov/content/pub/pdf/htus8008.pdf
               | 
               | ... which suggests the opposite (but there's not much in
               | it).
               | 
               | In terms of broader risks, males commit a clear majority
               | of violent offences and a vast majority of sexual
               | offences.
               | 
               | This isn't even just a human thing. Male primates (and
               | mammals generally) exhibit more aggressive behavior than
               | females. It's probably a deep consequence of anisogamous
               | sexual differentiation:
               | 
               | https://www.cell.com/trends/ecology-
               | evolution/fulltext/S0169...
        
         | 0134340 wrote:
         | >Also there were claims starting in the 50s where planarians
         | were taught a maze or to respond to certain stimuli and then
         | fed to other planarians and that the trait would sometimes
         | transfer as well
         | 
         | So superpowers were transferred when ate? Kirby devs were on to
         | something.
        
         | zoklet-enjoyer wrote:
         | Genes can transfer between species, so I don't see why this
         | wouldn't be possible.
         | 
         | https://en.m.wikipedia.org/wiki/Horizontal_gene_transfer
        
           | tetris11 wrote:
           | That's typically through parasitic/grafting/symbiotic
           | relationships, and even that takes a few half millienia of
           | repeated symbiosis and selective pressures to take. What's
           | being described here is much faster and much more immediate.
        
             | culi wrote:
             | In micro-organisms, HGT happens in a very short timeframe.
             | In fact, some soil fungi have been observed to somehow
             | purposely increase their rates of HGT when put in a new and
             | stressful environment. Borrowing genes from entire other
             | domains of life like bacteria or archaea. Also study after
             | study keeps showing that rates of HGT in complex
             | multicellular species like fish[0][1] and even humans.[2]
             | I'm not trying to be sensational (and generally agree it's
             | likely not that relevant to the current discussion) but one
             | thing that's clear from our consistent underestimation of
             | the prevalence of HGT is that there's still a lot more to
             | it than we currently understand
             | 
             | [0] https://www.quantamagazine.org/dna-jumps-between-
             | animal-spec...
             | 
             | [1] https://www.nature.com/articles/srep18676
             | 
             | [2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5379729/
        
               | tetris11 wrote:
               | thanks for the extra material!
        
         | selcuka wrote:
         | Not only simpler lifeforms. Cases with humans that may indicate
         | a memory transfer after organ transplants are also documented:
         | 
         | https://pubmed.ncbi.nlm.nih.gov/31739081/
         | 
         | > The acquisition of donor personality characteristics by
         | recipients following heart transplantation is hypothesized to
         | occur via the transfer of cellular memory
         | 
         | http://www.namahjournal.com/doc/Actual/Memory-transference-i...
         | 
         | > There have been perplexing reports of organ transplant
         | receivers claiming that they seem to have inherited the memory,
         | experiences and emotions of their deceased donors, and which
         | are causing quirky changes in their personality.
        
           | NL807 wrote:
           | Yeah, find these highly dubious. A heart transplant is quite
           | a traumatic event, both physically and emotionally, who knows
           | what side effects the patients were experiencing after the
           | procedure.
        
             | BiteCode_dev wrote:
             | Yes but the heart contains a lot of neurons so it's an
             | interesting theory.
        
               | culi wrote:
               | Over half of all neurotransmitters, including 80-95% of
               | seratonin, originates in the gut. I wouldn't be surprised
               | to hear a microbiome-based theory of personality but
               | cellular memory is a new one to me
               | 
               | Possibly related: it turns out horizontal gene transfer
               | is way more common in humans than we could expect and we
               | really don't have a good explanation for how it's
               | happening
               | 
               | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5379729/
        
               | hollerith wrote:
               | Over half of all neurotransmitters originates in the gut,
               | but the barrier preventing the entry of neurotransmitters
               | into the brain is very effective in healthy individuals.
               | 
               | Signals from the gut to the brain arrive via the vagus
               | nerve and probably also the other cranial nerves.
        
               | culi wrote:
               | Interesting! The way I've often heard it is that "over
               | half of neurotransmitters _originate_ in the gut " --
               | making it sound like it's talking about the
               | neurotransmitters already at the brain. Do you have any
               | citations that could clarify this?
        
               | hollerith wrote:
               | I probably learned that fact from an episode of
               | neuroscientist Andrew Huberman's podcast--more likely
               | than not episode one:
               | 
               | https://youtu.be/H-XfCl-HpRM
        
               | tux3 wrote:
               | Neurotransmitters are used all over the body. A lot is
               | centralized in the brain, but the periphery also uses
               | neurons and neurotransmitters.
               | 
               | Neurotransmitters in general don't particularly imply
               | they're being used in the brain. Some neurotransmitters
               | travel through the body, but a larger fraction are
               | produced locally by a cell and intended only for close
               | neighbors.
        
           | serf wrote:
           | that concept is part of the premise of Parasite Eve, a great
           | novel, turned into a shitty movie, turned into an alright
           | game.
        
             | tetris11 wrote:
             | Same as "The Marked heart" / "Palpito" / "Herzschlag" on
             | Netflix.
             | 
             | (For those about to watch it: the soul-vibing Neighbours-
             | esque intro song is all part of the charm of this show. The
             | shittier the intro, the more dramatic the needless
             | melodrama is in contrast)
        
         | wnoise wrote:
         | The planarian result was probably insufficiently sterilizing
         | the maze, and following previous scent-trails.
        
           | dejj wrote:
           | Feynman quoted a Mr. Young for admirable rigorousness in
           | maze-running experiments.
           | 
           | "Finding Mr Young"[1] identifies him as: "Mr Young was
           | probably Quin Fischer Curtis, in his theses published in
           | 1931/1936, as part of John F. Shepard's multi-decade research
           | programme at the University of Michigan into 'floor cues',
           | going well beyond just putting sand on the floor."
           | 
           | 1: https://gwern.net/maze
        
         | dalbasal wrote:
         | It's all very abstract, and hard to narrow objectively,
         | considering considering that we don't really know what a
         | "memory" or skill is. The mechanism.
        
         | agumonkey wrote:
         | hehe, that's the first thought that came to mind.
         | 
         | I don't know about people in biology in general, but it seems a
         | whole new space of considerations.. topological communication,
         | spread of information..
         | 
         | and if people are curious about other aspects of this, google
         | peter reddien, he had a lab who focused on planaria
         | regeneration too, and by playing with location and numbers of
         | cuts they triggered some cascading patterns of regeneration
         | (think
         | https://www.explainxkcd.com/wiki/index.php/File:iso_paper_si...
         | but with biological tissue and organs)
        
         | culi wrote:
         | Plants too seem to be able to pass down epigenetic memories
         | 
         | https://www.cell.com/trends/plant-science/fulltext/S1360-138...
         | 
         | Given this and the recent discovery that plants can pass down
         | RNA through mycorrhizal networks and can recognize their own
         | offspring, it seems plausible that memories can also be passed
         | through mycorrhizal networks.
         | 
         | What stories does the soil hold?
        
           | lagniappe wrote:
           | I've long had this crackpot theory that mycorrhizal networks
           | are to plants what skin and digestive microbiome are to
           | humans
        
             | culi wrote:
             | Not that crackpot imo. The essential difference between
             | animals and fungi is that at some point one group decided
             | to digest things internally with a stomach (animals) and
             | another group decided to digest things externally with
             | enzymes (fungi). This external relationship to nutrients
             | might make fungi as an organism simply more modular and
             | able to make more interesting symbiotic relationships.
             | Acting not just as partners but organs of a larger body
        
       | djha-skin wrote:
       | We do too. It's called epigenetics.
        
         | mjfl wrote:
         | but epigenetics usually stores information over much shorter
         | timescales than generations. For example, cellular identity is
         | stored epigenetically - whether a cell is a neuron or a white
         | blood cell.
        
           | dghughes wrote:
           | Study finds epigenetic changes in children of Holocaust
           | survivors https://www.research.va.gov/currents/1016-3.cfm
           | 
           | I often wonder if my Irish ancestors genes passed on trauma
           | through my family to me. With 900 years of invasion, war,
           | famine, and strife you'd think something like that would be
           | passed on.
        
             | dotancohen wrote:
             | The Irish have always been the underdogs of history, like
             | the Jews. Is there anything that you could recommend me to
             | read about the Irish situation?
        
         | bohadi wrote:
         | I think we will find more examples countering our modern idea
         | of discrete organisms separated across generations.
         | 
         | Consider again the glider translated across space time. Is it
         | the same glider after 1,2,10 generations in time?
         | 
         | I always found it curious the ancient archons had rulerships
         | which kept continuity in nominative identity across individuals
         | for several generations. The social practice continues with the
         | first, the second, III, IV etc.
         | 
         | The epigenetic view supports it.
        
           | somenameforme wrote:
           | Then you get examples like Marcus Aurelius -> Commodus,
           | betraying all genetic and epigenetic reason alike. The apple
           | doesn't fall far from the tree, except when it does.
        
         | pjscott wrote:
         | Epigenetics is real, of course, but approximately nothing is
         | passed between generations in humans. Here's a good rundown
         | from a geneticist:
         | 
         | https://www.razibkhan.com/p/you-cant-take-it-with-you-straig...
         | 
         | The actual biological reality is fascinating, and so much more
         | interesting than the distorted version you get from
         | unscientific fabulists.
        
           | pazimzadeh wrote:
           | Huh? The article is able to summarize in one sentence what he
           | thinks epigenetics is not, but is not able to summarize what
           | it actually is. The post is clearly designed to make the
           | reader feel like they are smarter than some other tribe, who
           | don't believe that observations have molecular underpinnings.
           | The Post-it notes analogy is also highly inaccurate and adds
           | nothing.
           | 
           | Epigenetics is one way that cells have of turning on and off
           | the genes that are expressed. The same way that you can
           | 'comment' a piece of code out using some special flags.
           | 
           | What is special about it is that it turns out that your mom's
           | experience during pregnancy (and your experience during
           | development) can affect which genes are turned on and off in
           | your cells.
           | 
           | The classic example of this is that children of starving
           | mothers such as during the holocaust, or during other
           | famines, often went on to be overweight, because they were
           | conditioned to be in 'starvation mode' so the genes for
           | uptake of nutrients were more turned on, or the genes for
           | decreasing wastefulness were turned off.
           | 
           | It doesn't take much imagination to see how some of these
           | things could reinforce each other, or alternate, over
           | multiple generations.
        
       | dopylitty wrote:
       | There's another form of bacterial memory that is actually part of
       | their immune system protecting against phages (viruses that
       | attack bacteria).
       | 
       | The bacteria cut up the phage genome when they're first attacked
       | and (if they survive) store pieces in their own genome. Then when
       | they detect the phage genes again they produce anti-phage
       | defenses.
       | 
       | The system is called "clustered regularly interspaced short
       | palindromic repeats". It's also known as CRISPR (better known for
       | other work :)
        
         | bitwize wrote:
         | I find it interesting how the literal antivirus mechanism used
         | by those bacteria resemble antivirus _software_ : have a
         | repository of virus-code signatures that are checked against.
        
           | mrguyorama wrote:
           | How else would you build such a system? It's probably easier
           | than evolving a way to execute DNA/RNA in a sandbox or
           | heuristically evaluating it. Life already had a reliable,
           | extendable, self managing database system, so easier to
           | repurpose that!
        
         | flawn wrote:
         | brought back school memories! yeah, that mechanism is pretty
         | fire.
        
       | tiku wrote:
       | Always wondered if the human brain could do an offsite backup
       | somewhere else, redundant in the brain or perhaps in the gut.
        
         | tiku wrote:
         | And what if this system was used in the animal world for
         | instant danger recognition etc. we as humans don't need that
         | anymore, because we always grow up in a fast changing
         | environment, where that kind of knowledge is almost obsolete.
        
           | amatecha wrote:
           | Ah yeah like the system that makes people irrationally
           | terrified of spiders and snakes and stuff? haha :)
        
             | okr wrote:
             | Why irrational? Never opened a toilet with a snake in it?
             | Or spiders, that crawl over your hand, when you reach for
             | the toothbrush? >:)
        
         | tap-snap-or-nap wrote:
         | It seems more like an edge-side processes and cache in many
         | different parts of the body and organs than an off-site backup.
        
         | katzenversteher wrote:
         | My hope is that the brain is basically just a "consciousness"
         | receiver and does not create it. Brain damage results in bad
         | reception, people with schizophrenia receive signals not
         | intended for them, people with alien hand syndrome have their
         | brain split into several receivers and so on.
         | 
         | If that were the case, the body (including the brain) could die
         | but the consciousness could continue to exist.
        
           | mrguyorama wrote:
           | That's what the religious and philosophical concept of a soul
           | is.
           | 
           | How would these signals be driven? What mechanism is used for
           | signalling?
        
       | dukeofdoom wrote:
       | Makes me wonder if there is a chemical mechanism by which humans
       | pass information to each other as well, to combat an infection.
       | If one human develops an ability to combat and infection to a
       | novel virus, is there a mechanism by which antibody information
       | is shared to other people. Infections eventually always fizzle
       | out in the end.
       | 
       | In times of war and stress, how a society can come together and
       | work in unison to defeat the threat. It seems like there's more
       | to it than patriotism. Why should one individuals be willing to
       | die for the benefit of others...Very often young man, who have
       | not yet reproduced. Seems like an evolutionary dead end
       | behaviour. Is there some Psycho/chemical mechanism by which its
       | triggered.
       | 
       | The way so many people were scared of covid, that fear spread and
       | like a virus infected the society.
        
       | riffraff wrote:
       | I'm pretty sure this is part of the plot in Children of Ruin by
       | Tchaikovsky. It's a good book.
        
         | tetris11 wrote:
         | Children of Time would be a closer match in terms of the
         | ingestible knowledge transfer. Also, siderant: the rest of the
         | series is not as great. I'd recommend new readers to try the
         | first book (Time), and then maybe skim through the second
         | (Ruin), and ignore the third (Memory).
        
           | jghn wrote:
           | Having just wrapped up Memory I found Time to be great. I
           | thought Ruin was a slog, although I did love it at first. It
           | was just a bad copy of the first. And while I thought the
           | ending was telegraphed too much, I did enjoy how Memory was
           | very different.
           | 
           | Came across a thread on Reddit recently about these three and
           | many people made the point that Ruin & Memory are so
           | different from each other in terms of sequels that which is
           | the "good one" is a polarizing discussion.
        
           | thegiogi wrote:
           | As a balance to your opinion, I thoroughly enjoyed all three.
           | Sure the first hit's different, but they all deserve the
           | attention.
        
       | dejj wrote:
       | "These iron memories persist for at least four generations and
       | disappear by the seventh generation."
       | 
       | Make note that for example "when well fed, E. coli bacteria
       | divide once every 20 minutes"[1], making that iron memory last
       | for 80 to 140 minutes. Though that may still be longer than it
       | takes them to discard a plasmid (genetic "loose change" on e.g.
       | immunity resistance) when competing for reproductive speed.
       | 
       | 1: Nick Lane, "Power, Sex, Suicide. Mitochondria and the meaning
       | of life", 2nd ed., 2018, p. 175
        
         | rusticpenn wrote:
         | That type of plasticity is important for the survival of the
         | species ( if the memories are important enough, then the later
         | generations would have used it and it will probably remain)
        
       | samuell wrote:
       | I wish there was more bio stuff on HN in general. Or that there
       | was an HN for bio. (There is https://biostars.org , which is not
       | at all really the same thing, more like a help forum).
        
         | fikama wrote:
         | Yep me too. There is also a discord server "biocord" which
         | seems nice, but for some reason I am just unable to use
         | discord. I don't enjoy hanging there as much as on regular news
         | aggregators as HN and Reddit.
         | 
         | I was also musing about making one myself using lobste.rs
         | GitHub. But I never looked into it much.
        
       | 2-718-281-828 wrote:
       | i don't get it. just read the text and all i find is a murky
       | association of iron levels and some fuzzy interpretation of the
       | term "memory".
        
       | throwaway4aday wrote:
       | No one's mentioned Michael Levin's work yet? Surprising.
       | 
       | https://www.frontiersin.org/articles/10.3389/fnsys.2022.7682...
       | 
       | https://www.frontiersin.org/articles/10.3389/fpsyg.2019.0268...
       | 
       | https://tbiomed.biomedcentral.com/articles/10.1186/s12976-01...
       | 
       | https://pubmed.ncbi.nlm.nih.gov/29148257/
        
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       (page generated 2023-11-22 23:02 UTC)