Scientists Find Olfactory "Memory" Passed Between Generations In Mice 118
New submitter Raging Bool writes "The BBC is reporting that acquired phobias or aversions by mice can be passed on to subsequent generations. From the article: 'Experiments showed that a traumatic event could affect the DNA in sperm and alter the brains and behavior of subsequent generations. A Nature Neuroscience study shows mice trained to avoid a smell passed their aversion on to their 'grandchildren.''"
Take that Darwin (Score:4, Funny)
Score one for Lamarkian evolution. (And epigenetics). I knew Darwin was wrong...
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Wrong? Darwin wrote about Natural Selection. Sounds pretty right to me.
Re:Take that Darwin (Score:5, Insightful)
Let's make sure it can be repeated before celebrating.
Mod parent up. (Score:2)
It's a HUGE jump from finding that traumatic events can alter DNA to finding that training can used to pass specific behaviours through DNA.
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New abstract coming up:
Using neck stretching, we examined the inheritance of parental stretching exposure, a phenomenon that has been frequently observed, but not understood. We subjected F0 giraffes neck stretching conditioning before conception and found that subsequently conceived F1 and F2 generations had an increased neck length. When neck stretching was used to condition F0 giraffes, the neck length of the F1 and F2 generations was complemented by an enhanced anatomical representation of the neck length pathway. Bisulfite sequencing of sperm DNA from conditioned F0 males and F1 naive offspring revealed CpG hypomethylation in the neck length gene. In addition, in vitro fertilization, F2 inheritance and cross-fostering revealed that these transgenerational effects are inherited via parental gametes. Our findings provide a framework for addressing how environmental information may be inherited transgenerationally at behavioral, anatomical and epigenetic levels.
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Just to clarify, that is what the research is claiming:
They showed a section of DNA responsible for sensitivity to the cherry blossom scent was made more active in the mice's sperm.
Both the mice's offspring, and their offspring, were "extremely sensitive" to cherry blossom and would avoid the scent, despite never having experiencing it in their lives.
Re:Mod parent up. (Score:4, Insightful)
Just to clarify, this is epigenetics. They don't believe they are altering DNA, this just changes the way the traits already encoded in the DNA are expressed.
Nothing is being passed through DNA.
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I am more than a layman when it comes to biology of this sort, but my girlfriend is a molecular biologist that was working on diabetic research before she switched labs.
One of the things she worked on (I will explain best I can) is how diabetes gets transferred to offspring. She's told me before that they have wild-types that are not predisposed to diabetes, but when given diets that affect this, the predisposition of the offspring to have diabetes increases.
I understand that this is not quite the same th
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I'm not sure if you're reply was arguing with my post or just a good place to post this info. It is certainly relevant to the article and sounds like it is also epigenetic research.
Since the Mods will never find me this deep in the discussion tree: I too will admit that I never heard of epigenetics until this morning when I saw this article; so, if your girlfriend says the predispositions are totally changing in the DNA or that I'm confusing terminology, I will take her word for it.
I feel like I know stuff,
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Is this a distinction without a difference?
I don't think so. Experiments like these are showing that we can be altered more than we (at least I) thought possible by our (as in organisms') parents environment. However, I say that the distinction that new genes are not being added/subtracted to the genome is a pretty important difference since it better specifies that which can be changed. Also, importantly, the distinction means we don't have to throw out Darwinian evolution and replace it with Lamarkian as the first comment in this thread suggests.
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That would mean there'd be a pre-existing definition of the scent of cherry blossoms, which seems unlikely
Well, "cherry blossoms" no, but acetophenone, which evidently smells like cherry blossoms to reporters "activates a known odorant receptor (Olfr151) ." They also believe they know the gene responsible for setting up this pathway, and when they look at it in parent's gametes after traumatizing the parents: "revealed CpG hypomethylation in the Olfr151 gene" which is saying: some chemical changes that should strengthen the receptors in offspring.
Also, they don't claim an "aversion" was added to the descendents
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Celebrating?
You do understand that this finding makes biology as a science much harder?
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Harder means more complex. And with more complexity comes more possibilities for medicine and genetic treatment. Sounds like a reason for celebration to me.
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You do understand that this finding makes biology as a science much harder?
Is it perverse that I find this sort of thing exciting? It's this sort of thing that reminds us that they will be laughing at our level of scientific understanding 100 years from now.
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Celebrating?
As opposed to what? Bemoaning the fact that we used to be so happy in our ignorance?
You do understand that this finding makes biology as a science much harder?
Yes, well, unfortunately the truth doesn't care how easy you'd like life to be. Science is the pursuit of truth. Yes, the road ahead now looks a little more rubble-strewn, but when there's only one road, stopping to complain isn't going to speed the journey.
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Celebrating?
As opposed to what? Bemoaning the fact that we used to be so happy in our ignorance?
You do understand that this finding makes biology as a science much harder?
Yes, well, unfortunately the truth doesn't care how easy you'd like life to be. Science is the pursuit of truth. Yes, the road ahead now looks a little more rubble-strewn, but when there's only one road, stopping to complain isn't going to speed the journey.
And the thing is, it's not like we haven't suspected things like this for a long time... they were talking about the possibility of inherited neural generation pathways 50 years ago. The only thing that's new is that we now have proof and a more clearly defined theory, so it can't be ignored as purely hypothetical.
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Yes, the road ahead now looks a little more rubble-strewn, but when there's only one road, stopping to complain isn't going to speed the journey.
Stopping to complain? Who said anything about stopping? Celebration sounds more like stopping to me.
What scientist do you think makes more progress? The one that throws a party every time he figures out that he made a mistake? Or the one that says "damn it", and goes back to work?
(Disclaimer: IANAS, not a scientist)
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I duped the comment below, you can bring out the champagne.
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Trofim Denisovitch Lysenko, thou art avenged!
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Slow down, cowboy! Is your sarcasm meter engaged?
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Yes, I'm trying to be funny. :) Lamarckian evolution (sorry for misspelling it in the original post) is pretty much completely discredited. Though at the time it was a good theory, it lacked a reasonable mechanism. While epigenetics displays some Lamarckian behavior, it doesn't completely fulfill the ability to pass on "acquired traits" and doesn't give the long term changes needed for species differentiation.
And of course Darwin was wrong in some respects. He was just much more correct than anyone befor
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Lamarckian evolution applies to memetics.
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Which may be of interest to sociologists and linguists, but not to biologists.
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On the Origin of Species even acknowledges "use and disuse inheritance".
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As long as people acknowledge evolution exists, that's a plus to me. I've grown tired of this ridiculous denial of evolution occurring from fundamentalists/creationists.
michelangelo got his apology... (Score:2)
From the Vatican...eventually. Will the scientific community be more eager to do the same with LaMark?
BTW: Both Darwin and LaMark were correct. Genes' expression, dictated by experience and culture, can be passed on, activating an otherwise inactive gene in later generations.
Yes, I know you had kidding on your mind. I just wanted to get the science straight.
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From the Vatican...eventually. Will the scientific community be more eager to do the same with LaMark?
BTW: Both Darwin and LaMark were correct. Genes' expression, dictated by experience and culture, can be passed on, activating an otherwise inactive gene in later generations.
Yes, I know you had kidding on your mind. I just wanted to get the science straight.
Did you maybe mean Galileo? I'm not sure of your point, though, because the catholics believe in evolution and even the dispute with Galileo was about politics, not science (the church actually agreed with the science in theory, but said the proof had flaws, which modern science confirms -- basically, Galileo got the right answer, but based his thesis on wrong assumptions).
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Maybe they apologized to Michelangelo for asking him to paint the Sistine Chapel ceiling?
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Score one for Lamarkian evolution. (And epigenetics). I knew Darwin was wrong...
...
Score one for Lamarkian evolution. (And epigenetics). I knew Darwin was only partly right...
That might be more accurate...
I wonder, (Score:1)
can an aversion to working for a living be passed on through DNA as well?
Re:I wonder, (Score:4, Funny)
(looks around...)
Yes.
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Yeah, story-justifying techno-babble actually meets reality. Maybe there was some sort of elaborate conspiracy to keep this from us.
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Techno-babble: a term used by non-nerds to describe speech or writing by those more educated than them that they don't understand.
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I thought it was the words in a Star Trek script indicating that the actor should just like totally make some shit up or something.
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Of course there's some made-up shit in any science fiction -- dilythium crystals, mitichlorians, grabonic radiation (that one's mine), but most "technobabble" is actually real words, or words made up from Greek or Latin roots that describe the fictional technology (like "tachyons"). A literate, educated person can make the meanings out by context.
I wrote about that in my journal today. A friend read Nobots and some of the words weren't in her vocabulary. "Those big words -- are they real or can I look 'em u
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PS - The word "robotics" was coined to discuss a fictional piece of engineering, as when Asimov coined it, robots didn't exist.
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No, no it's not, you damned troll.
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Yeah, you dismiss a scientific study because the vocabulary is over your head on a nerd site but I'm the troll?
Go back to 4chan, you noncompos. [readanybooks.net]
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There's nothing "over my head" about throwing out a string of vaguely scientific terms in a way that's frequently semantically meaningless and pretending you said something. It's a cheap mechanic for sci-fi writers who can't write.
I know what "Neutrino flux" means(because both of these concepts are dead simple, in actual physics), and that means understanding why it's a bullshit explanation for why "luck gets reversed"(guess which technobabble laden sci-fi that's from). It's about the difference between l
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We weren't discussing sci-fi when you called it technobabble, we were discussing a study that you called technobabble.
Now go away.
eureka (Score:4, Funny)
This explains why babies see the windows splash screen and begin crying.
BTW, turns out Lamarck got it right.
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BTW, turns out Lamarck got it right.
Not at all. Lamarck's ideas involved concepts such as inheritance through use. e.g. animals that stretch to get higher leaves of trees will stretch their necks and these longer-necked animals pass on that trait to their children. This isn't what happens and it isn't what epigenetics does. Epigenetics add another layer to how natural selection works and might even accelerate natural selection, but it doesn't directly lead to changes in the genetic code and its effects can washed out over a few generations.
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So why are IQ scores getting higher (http://en.wikipedia.org/wiki/Flynn_effect)? The more we use our brain, the smarter our offspring get.
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Or the better equipped our offspring are to that particular style test.
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Re:eureka (Score:5, Insightful)
So why are IQ scores getting higher (http://en.wikipedia.org/wiki/Flynn_effect)? The more we use our brain, the smarter our offspring get.
There are plenty of other, less far-fetched, explanations for the Flynn effect. This is "only" a correlation but it brings up some important issues: http://en.wikipedia.org/wiki/File:IQatWoN_GDP_IQ.png [wikipedia.org]
Don't forget that intelligence is hard to define and test. The IQ test probes some correlates of intelligence, but it can be gamed and you can train for it (which is another reason to be cautious about the Flynn effect--conventional education effectively "trains" people for IQ tests and nowadays more people spend more time in education. The Flynn effect is tailing off in many 1st world countries, which is consistent with this explanation.). e.g. Digit span (forward and backward) is tested in an IQ test. Without training, most people have a hard time reaching ten digits. However, with training you can recall 100 or more digits. You haven't become smarter, you've just trained once particular thing. Ditto with other aspects of the test. This is why those "brain training" games are pseudo-scientific bollocks. They make you better at the game, they don't make you smarter. It's possible that regularly "using" your brain will stave off dementia, and experience in life counts for a lot, but nobody has shown that you become "smarter" through training.
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So why are IQ scores getting higher (http://en.wikipedia.org/wiki/Flynn_effect)?
Didn't get as far as http://en.wikipedia.org/wiki/Flynn_effect#Proposed_explanations [wikipedia.org] , then? Hint: Lamarckian inheritance is not required to explain the Flynn Effect.
The more we use our brain, the smarter our offspring get.
That's not a logical conclusion to draw. The Flynn Effect is a broadly average trend in populations, not a simple case of individual children being more intelligent than their specific parents. It's more memetics than genetics.
Pretty much everyone's general understanding of, say, the laws of the universe is much better today than it was 100 yea
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From http://en.wikipedia.org/wiki/Lamarckism [wikipedia.org]:
"Lamarckism (or Lamarckian inheritance) is the idea that an organism can pass on characteristics that it acquired during its lifetime to its offspring (also known as heritability of acquired characteristics or soft inheritance)."
Intelligence seems to be one of those acquired characteristics. Why wouldn't Lamarckism be a mechanism for the Flynn effect?
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Intelligence seems to be one of those acquired characteristics. Why wouldn't Lamarckism be a mechanism for the Flynn effect?
First, the Flynn Effect doesn't really hint at anything to do with direct inheritance - it's measured across whole generations of populations, not from parent to child. Secondly, intelligence as measured by an IQ test is not solely - quite possibly not even mainly - an inherent property of an organism determined by genetic or epigenetic make up. There are far more likely ways for an organism to pass it on - by education and imitation, for example, and not just from the parents.
One presumes that in this new
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So why are IQ scores getting higher (http://en.wikipedia.org/wiki/Flynn_effect)? The more we use our brain, the smarter our offspring get.
Show me an IQ test that has stayed the same over time -- I think you'll find that as people get better training to score well on IQ tests, IQ tests also shift to be more "fair" to the population in general. I remember administering a "traditional" IQ test from the 50's to someone a few year's back -- they scored abysmally because the test assumed they'd understand concepts and turns of phrase that have completely left our society today. IQ tests used to be very male WASP-centric. Now the same test has a
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From the wikipedia article on the Flynn effect:
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From the wikipedia article on the Flynn effect:
Exactly... but my point is that that's how you'd expect things to work out, based on the set of people under the normalized curve reaching into more global societies. It's just the IQ test methodology bumping up against the global society. IQ tests are known to test how well you score on IQ tests, and also test how well the test makers plotted the questions to the selected curve. They are about as strong an indicator of intelligence as a shotgun clustering is of marksmanship. I say this as someone whose
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I'll refer you to James Flynn explain it: http://www.ted.com/talks/james_flynn_why_our_iq_levels_are_higher_than_our_grandparents.html [ted.com]
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.... tried to change the wording after hitting submit, but only got half-way through. Has hell frozen over yet? I'm still waiting for an edit button.
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.... tried to change the wording after hitting submit, but only got half-way through. Has hell frozen over yet? I'm still waiting for an edit button.
I've been waiting for edit,
I've been waiting so long.
I've been waiting for edit,
and the search goes on.
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Right Conclusion, Wrong Mechanism (Score:3, Funny)
These "scientists" suggest that the "DNA" of the offspring was modified.
In fact, the Flying Spaghetti Monster has modified their results to look this way.
The truth is that His Noodly Appendage is wrapped around each living being and their offspring.
When something happens to a living being, the Flying Spaghetti Monster transfers the sensation down His appendage to the offspring.
RAmen!
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No, it's even simpler than that. All those strands of "DNA" are actually the myriad blessed semolina spawn of HNA the FSM (Peas Be Upon Him). He is not wrapped around us...He is within us, to help mice (and people) learn and advance from their dark and primitive past!
We are all children of the glorious FSM!
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I thought the point of the FSM was to ridicule Christians? In which case invoking His Noodlyness in a scientific article where no one mentioned religion is a non sequitur.
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You thought wrong. The point of the FSM is to highlight the deficiencies of creationism/Intelligent Design. Not all Christians are creationists/Intelligent Design protagonists, and I'm not even sure that all creationists/ID protagonists are Christians.
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I think you meant 'proponents.'
Lamarck (Score:2)
See, Lamarck was just like Tesla - a genius ahead of his time! Darwin/Edison gets all the glory but finally science catches up to the genius of Lamarck/Tesla.
I predict Rube Goldberg is next - his designs just seem insanely complicated, but it will turn out that a mousetrap really is a required step in every mechanical process...
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See, Lamarck was just like Tesla - a genius ahead of his time! Darwin/Edison gets all the glory but finally science catches up to the genius of Lamarck/Tesla.
I predict Rube Goldberg is next - his designs just seem insanely complicated, but it will turn out that a mousetrap really is a required step in every mechanical process...
Screw Lamarck; what this really means is that Alien: Resurrection was a masterpiece.
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You're joking right? Tesla was a fraud. Let the steam punk people flame the crap out of me now.
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I always thought Tesla was an electrical engineer racing to the patent office with new products and ideas like every one else in the late 1800s. I don't know what that has to do with steam punk.
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Only if the mice easily catch fire and pass on combustibility ;-)
Assassin's Creed was right all along (Score:1)
They did not pass "aversion" to their grandkids (Score:5, Informative)
The grandkids had enhanced receptors for that particular smell. They specifically did not test for, and point out in the paper that they do not claim that the AVERSION was passed on, only that F1 and F2 had structures in the brain that are enlarged compared to control, and that are associated with the sense of smell for the chemical that was used to prime the F0 generation.
Much better science-savvy writeup by my cousin on the Nat Geo blog:
http://phenomena.nationalgeographic.com/2013/12/01/mice-inherit-specific-memories-because-epigenetics/ [nationalgeographic.com]
Re:They did not pass "aversion" to their grandkids (Score:5, Informative)
The premise seems to be:
1. There is a gene associated with a brain pathway responding to the smell.
2. The more this gene is expressed, the more the stronger the pathway.
3. Brain functions that depend on this pathway have a feedback mechanism that result in hypomethylation of the gene in at least sperm cells (egg cells weren't mentioned). This increases expression in the descendants. From what I understand, hypo methylation does not entail any alteration of base pair sequences.
4. As the parent post mentioned, this doesn't mean passing on aversion/affinity, but potentially increased sensitivity which may aid in speed of learning these traits.
That's based on my reading of the abstract. The abstract didn't mention any kind of known or discovered chemical signal for the brain activity to result in the hypomethylation in the sperm. My question would be if anything else in the experimental protocol could have triggered this in a manner not directly caused by the brain activity. My next question would be if this work can be reproduced with a different chemical pathway.
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Even in the blog post you link, the enhanced startle response was present in f1 and f2 generations. I read that as the aversion was passed on.
Ten days after this fear training, Dias allowed the animals to mate. And that's where the crazy begins. The offspring (known as the F1 generation) show an increased startle to the fruity smell even when they have never encountered the smell before, and thus have no obvious reason to be sensitive to it. And their reaction is specific: They do not startle to another odor called propanol. Craziest of all, their offspring (the F2 generation) show the same increased sensitivity to acetophenone.
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Yes, for the initial test group. But two things (quotes from blog not TFP):
1. "startle" is not necessarily aversion
For example, the researchers didn’t do a control experiment where the F0 animals are exposed to the fruity odor without the shock. So it’s unclear whether the “memory” they’re transmitting to their offspring is a fear memory, per se, or rather an increased sensitivity to an odor.
and 2. not for the group where they used IVF to create the offspring to eliminate some possible biases:
To control for these possibilities, the researchers performed an in vitro fertilization (IVF) experiment in which they trained male animals to fear acetophenone and then 10 days later harvested the animals’ sperm. They sent the sperm to another lab across campus where it was used to artificially inseminate female mice. Then the researchers looked at the brains of the offspring. They had larger M71 glomeruli, just as before. (The researchers couldn’t perform behavioral tests on these animals because of laboratory regulations about animal quarantine.)
You know, THAT section of DNA. (Score:1)
Old news (Score:2)
Everybody knows that mice inherit the smell of cheese.
But the successful ones avoid it, unless it comes with the smell of dead mouse.
That's why they say:
The second mouse gets the cheese.
Rats! (Score:2)
Are dumb.
Instead they should have created an aversion against rotating
iron wire objects and mazes.
DNA methylation (Score:5, Informative)
Although I don't have any evidence (this is /.), it seems clear that this is probably simply yet another manifestation of DNA methylation.
As I understand it, most of the genome is modulated and/or inactivated by DNA methylation of primarily CpG sites (aparently to prevent junk dna from running amok like in cancer, but also to control differentiation/specialization and). Although the mechanisms and pathways for this are currently not well understood, it seems likely that the proteins that governed the response to this stimulus was effectively coded in the DNA already, but inhibited by DNA methylation. By changing the methylation in the DNA of the gametes this response was able to be passed through to the offspring.
The bigger question is how the methylation is done. If it is done by environmental exposure (e.g, the brain and the gamete cells are over-exposed to the same stimulus from the bloodstream and respond the the same way by changing the methylation pattern to favor a response to that stimulus), that seems fairly straightforward. If, however, the brain can create simulation that causes specific methylation in the gamets, that is a whole nuther ball of wax...
In this experiment they targeted a specific olfactory pathway in the mice (Olfr151) and trained them with a behavior. Apparently, in later generations there was less methylation of the gene corresponding to this pathway providing a more enhanced response to this smell and apparently learned to distinguish this smell better. To me that isn't transferring a memory, it's really more like pre-conditioning to match a learned state.
The difference is subtle, but one way to look at it it like earning money vs inheriting it where the memory is the "how-to-make-money" part and the dna-methylation pattern is the "money". Although the offspring still have money, their behavior is not necessarily the same as the parents.
never say never, it would seem (Score:2)
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Epigenetics (Score:2)
I can't believe this wasn't mentioned in the article... seems like a repeatable experiment to prove its existence.
Genetic memory (Score:2)
This is big news, if you think about it. Really big news. For a long time I've heard the term "genetic memory", but it didn't make sense that such a thing would exist. Yet, when you work with dogs, there are certain breeds which seem to know exactly what their job is and how to do it. It is amazing to see a herding-breed dog, for instance, which has never seen sheep before, start herding them within a few minutes of being introduced to the animal. Intuitively, people have always seemed to know that learn
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I don't think that word means what you think it means...
Pure use of funds and ethically dubious, maybe, but how is this fraudulent?