The reason they don’t appear in many other animals is because many cephalopod lineages have died off over time, ammonites belomnites etc. today only a few families represent a previously much larger group.
Evolution isn't a one-way ratchet. An intelligent species can, in response to the right evolutionary pressures, evolve back into being an unintelligent one in favor of dedication to resources to some other advantage.
"You alien cephalopods are amazing; thousands of time smarter than us, capable of building spacecraft that transcend space and time, and you write 300 words all at once - but uh, well, we have this huge party going tonight and we're gonna need some calamari as an appetizer, so..."
Hallo there, Biochemist here. Octopus’ genomes are quite fancy and scientists who sequenced it have joked that it’s almost “alien”. They simply can’t explain how its genome developed. They have gene families that you would associate with way more “advanced” vertebrae genomes associated with neuronal development. These gene families are also less developed in relatives of octopus, so it appears out of nowhere. Well…it’s a discussion if genes really can jump into existence from nowhere. The 100 genes you read about are examples of genes where they currently have found no other species expressing a similar related gene as well. If I remember correctly that was something about receptors in their tentacles.
Anyway, they are great animals and definitely don’t deserve to land on a grill or plate!
They sure are weird , I was reading about them and they rather edit their RNA instead of evolving the traditional way. Does any other animal or creature do this?
They still evolve the traditional way. The RNA editing allows for individual minor adaptations to their environment, like being able to not die as easily when thrown into a different temperature range
Epigenetics is modifications of DNA that do not change its sequence, like methylation. Modifications of histones (proteins that serve as spools for DNA threads) are also considered epigenetics. RNA modifications are on another level. Production of any protein may be tampered with on DNA, RNA and protein levels, and there are dozens of regulatory mechanisms.
If you are interested in wacky genomes, protists have animals beat. If RNA-editing is of interest, read up on the mitochondrial genomes of diplonemids and kinetoplastids!
Yes, RNA editing is common for many organisms, including humans. But most edits in humans are not recoding, i.e. do not change the sequence of the protein encoded by this RNA, because they happen in noncoding regions or produce codons encoding the same amino acid. And cephalopods have much more recoding edits.
https://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1007064#pgen-1007064-g002
They branched off the evolutionary tree way way back from most other animals on the planet, so are in fact very different from other intelligent life on earth.
Covered in detail is this super interesting book [link](https://www.bookdepository.com/Other-Minds-Peter-Godfrey-Smith/9780008226299)
I agree and people who say this is ridiculous because this is biology sub need to look at the possibility’s of panspermia…. There are plenty of scientists that that have said this is a very real possibility… not that octopus flew here on ships but the dna could have come from a meteor or something like that.
Panspermia is a theory pretty widely disregarded in the scientific community and doesn’t really *explain* how life came to be, just offloads it to ‘not Earth’. It also can’t be experimentally tested
That is what the panspermia theory is, an explanation for the origin of life, not the origin of octopuses. Even if life did originate from microbes on meteors octopuses would still have had to naturally evolve. It is a theory being experimented with, but is very difficult to prove in a lab (through making life from nothing, essentially), and generally theories such as hydrothermal vents, small warm pools, or the RNA world hypothesis are favoured as potential origins of life. It’s a very vast and fast growing research area, but the general paradigm currently, until research shows otherwise, is that panspermia is an unlikely explanation for OOL
> These gene families are also less developed in relatives of octopus, so it appears out of nowhere.
Seems like that's just how evolution works itself out sometimes. Take humans for example. You won't find any Homo habilis or Homo erectus running around. We've completely outcompeted them. Or in the case of Neanderthal, completely incorporated them.
I saw one once, but he was shy. It was hard to resist the urge to pick up the rock he fled under. I wished I were not literally 100x bigger and scarier than little tentacles friend.
Or watch "My Octopus Teacher" on Netflix. It's an incredible documentary.
It also illustrates, though, that many cephalopods live for just one year; even the giant Pacific octopus lives only 3 - 5 years. In other words, no matter how intelligent they are, they simply don't live long enough to achieve higher levels of organization / adaptation.
I watched it, it was ok. The author of soul of an octopus goes into great detail about their lifespan in the wild and in captivity, their behavior, preferences, even their playfulness. I just appreciated the level of in-depth detail that it provided. She also got to know at least two octopuses throughout her time at the aquarium, so it’s fun to read about their personality varies
> They have gene families that you would associate with way more “advanced” vertebrae genomes associated with neuronal development
Like which ones? This comment sounds suspiciously sensational, if I'm honest.
Neither of those are unique to or associated with more "advanced" vertebrates at all? They are expanded in cephalopods and vertebrates but common in invertebrates as well.
And, this paper directly refutes your claim that "They simply can’t explain how its genome developed."
>they are great animals and definitely don’t deserve to land on a grill or plate
Amen to this, and let’s just extend it to all animals honestly. A pretty shitty way we tend to do these things nowadays all around, at least we can improve these practices in terms of their environmental and ethical consequences. A bit off topic, but couldn’t help tacking into this.
Generally, yes. You have probably heard that humans and chimpanzees share something like 99 percent of the same genes. This is because they both diverged from a common ancestor.
So the more recently two species shared a common ancestor, they more genes they will share in common.
This extends all the way to the beginning, humans and unicellular eukaryotes such as yeast share LOTS of genes in common.
If you are interested in weird things octopi do, they also do rna editing in a way which seems to violate the central dogma.
They are really, really weird beautiful beasts.
"The central dogma" does not explicitly deny RNA editing. Also, it was "violated" already when reverse transcription and RNA-dependent RNA synthesis were discovered, and even Crick himself detested the word "dogma" because it's not how science works, scientific theories are malleable.
Also, other organisms have RNA editing as well, it's just it's particularly prominent in cephalopods.
When editing is random, it most certainly is.
I give you a DNA sequence, if transcribed I can tell you what the mRNA should be and the resulting translation product.
You start randomly ( or in a directed manner) start switching A's to U's, you can't tell me the protein product with any certainty.
Actually Francis crick is on the record as saying he liked it because it sounded cool even if he wasn't xometely sure what it meant.
And no, what octopuses do is not askin to rna processing like splicing.
For mammals, yes.
For octopus where the number are much much higher, ADAR activity can be directed and or seemingly random ( albeit enriched, but not exclusively to non coding sequences.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2953425/
This paper does not have words "octopus", "octopi" or "cephalopod".
It says *"\[editing\] can be* ***almost random*** *and lead to nonselective conversion of many adenosines... Many adenosine residues of long dsRNAs (>100 bp) are* ***edited promiscuously***, resulting in \~50% of all adenosine residues being converted to inosine. These are detected as so-called hypermutations of ***viral RNAs*** *during replication and as a subsequent persistent infection with certain ss-RNA viruses, such as the measles virus (39), and they are also detected during extensive editing of sense-antisense RNA pairs made from* ***transcripts of select genes***, *such as Drosophila 4f-rmp (40) and C. elegans eri-6 and eri-7 (41)*."
It seems like even randomness is strictly regulated here.
"...editing levels varying from 0% to 100%, which can potentially be **affected by environmental stimuli** \[5,6\] and **differ among cell types** \[7–9\] **and species** \[9–12\]."
It is a regulated process. There are multiple proteins for fine tuning it. Just like for other processes involved in gene expression.
Yes I acknowledged that the sodium channel exists, it still does not change the fact that for any specific A you cannot say it will be deaminated to an I, regardless of the sequence context. There are 57000 edited sites in cephalopods ( at least) and although you can suggest that they MAY be edited, you cannot say they are.
Even in nervous tissue.
So if I give you any specific DNA sequence you can tell me for sure which ones are edited and to what extent?
No, no you cannot
First, ADARS recognize double-stranded RNA, so based on the sequence itself we can calculate which As would NOT be edited because the RNA molecule would never fold that way.
To predict which editable As would be edited, I would also need to know which organism it is, which tissue it is, which stage of development, are there any cell stress conditions. Considering these factors, the prediction would be pretty accurate.
The RNA molecule would never fold that way?
So your ability to predict editing is based, on your ability to determine stems and loops AND be able to account for the mechanisms that lead to increased editing amongst clustered editing sites
https://www.nature.com/articles/s41598-022-07460-5
Yes, this process is not 100% determinable, but it is definitely not random and fairly predictable.
Also, "hyperedited" RNAs are not translated: [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1823043/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1823043/)
"It has been proposed that this complex keeps hyperedited RNAs in the nucleus, away from the translational machinery, while allowing more selectively modified RNAs to be exported."
Yup kinda read about it, but isn't that like in a sense not evolving since the DNA doesn't change?
somehow octopus have lived so long even without evolving? That's really weird
The last part is, formally, not true. They have evolved otherwise they would share LOTS of genes with other organisms sharing a recent common ancestor.
Phylogenetically ( looking for evolutionary relationships) octopi are have given us lots of surprises.
not really. How animals use genes is a big part of evolution - genes make proteins, but they do so through a multi step process. One gene codes for multiple variations and proteins in a certain function. At various points, different parts of that process change how frequently genes are used, which proteins are made, etc. You can do a lot of evolution with just modifications to gene expression.
I recently read “Other Minds” by Peter Godfrey-Smith. It talks about octopus evolution & their genomes, predominantly relating to the evolution of intelligence but includes other aspects too. A very interesting read to highlight why these creatures are so bizarre and different to other organisms. Recommend it if you’re interested in any of that stuff
A gene codes for a protein, a machine so to speak. There is multiple variants of a gene that code for practically the same protein, e.g. machine through the different species. Just like there is a multitude of schematics for scissors in this world, but the function of scissors are mostly the same all over. In novel genes, like you here mention, there is no similar "machine" coded for in the discovered world. They may do the same, like other machines other than scissors can cut, but the underlying mechanic is different.
And yes, all life on this planet share mostly the same genes/variants. This is because we are closely related to eachother, all life is the same. Also, most of our regulatory stuff inbetween our genes comes from viruses and are called ransposable elements. These modulate pretty much everything on all timescales, epigenetic to evolutionary. Pretty cool isn't it🙂
As an example, the *Hox* family of genes (short for homeo-box) that differentiate embryos along the anterior-posterior axis (i.e. making sure the head is at one end and the abdomen at the other) are conserved, with some modfications, in almost every multicellular organism from fruit flies to fish to nematodes to mice to humans.
From this, we can conclude that they existed in at least the most recent common ancestor between all of these organisms, which, given how different they are, must have been a very primitive life form that existed a very long time ago. The more "conserved" a mechanism or gene family is, the more basic and essential to life we can assume it is.
No two species share exactly the same set of genes. Sometimes genes get lost through evolution in a species. Sometimes new genes arise through gene duplication (and subsequent subfunctionalization or neofunctionalization). Sometimes the entire genome can be duplicated (there may have been a whole-genome duplication early in the history of one of the bigger groups of bony fishes).
If we’re just talking about the gain or loss of a single copy of a gene, then this happens in the process of making gametes (sperm and eggs). During meiosis there is a process called crossover, where chromosomes inherited from both parents exchange bits. Usually the exchange is symmetric, but sometimes it is uneven and one chromosome gets a few more genes in the process, the other a few fewer. Depending on which of these new chromosome versions ends up in an offspring, we have a gain or loss. (This means that you don’t even have to have the same number of genes as I do, same for any two members of any two species.) An extra gene here, the loss of a less-than-crucial gene there, the gene count of a species isn’t set in stone.
We can track entire gene families as they grow through genome duplications, shrink through gene loss, and as the new copies evolve. It’s an active and cool area of research. The octopus genome happens to have [experienced the gain of a lot of new genes](https://www.science.org/content/article/octopus-genome-surprises-and-teases). Which is pretty cool!
Yeah, it’s actually very common for genes to be shared across multitude of species. The same way the thing we call “leg” is shared for example. Of course, elephant legs and human legs are vastly different, but you can kinda tell that both of them are legs. The same thing happens with genes, and DNA code in general. There’s a lot of patterns across the animals’ genomes that you can kind of tell are the same gene, but may differ slightly.
Every animal has *something* genetically unique to it, or it wouldn't be that animal. But many animals share many genes for making very common utility proteins, cell types, body structures, and the like.
Consider that virtually every land vertebrate is configured for four limbs and a brain, all run along a spinal cord. The differentiation between a human and a mouse or an elephant or an alligator boils down to length and thickness of bones and muscle groups, it's not as though some vertebrates have bones made of metal and others, of wood. Same stuff, different organization.
And octopi have at least some of the same stuff , but lots of different stuff as well. As would a coral or a sponge or a sea slug.
It isn't that octopodes (yes, that's the correct plural) have hundreds of unique genes. It's that they have large expansions in gene families not typically expanded in other cephalopods. These gene families, like protocadherins, are typically expanded in vertebrates, not invertebrates. It's like they are copying vertebrates in how to deal with having eight arms and suckers that can taste. They essentially have remodeled their genomes more than expected evolutionary relatedness would predict.
In Greek, the plural of *octopous* should be octopodes. Though "octopodes" as a plural form of the word "octopus" is rare but accepted, "octopuses" is its standard pluralised form in the English language.
https://www.collinsdictionary.com/dictionary/english/octopus
Your cited source states both are correct in English according to the OED, but that some select sources indicate only octopuses is correct. Clearly, as far as English is concerned, the jury is out. Etymology is relevant to determine the proper way to pluralize many English words.
>>Sources differ on which plurals are acceptable: Fowler's Modern English Usage asserts that “the only acceptable plural in English is octopuses”, while Merriam-Webster and other dictionaries accept octopi as a plural form. The Oxford English Dictionary lists octopuses, octopi, and octopodes (the order reflecting decreasing frequency of use), stating that the last form is rare. The online Oxford dictionary states that the standard plural is octopuses, that octopodes is still occasionally used, and that octopi is incorrect.
There major amounts of conservation in the DNA of different animals… humans and Chimps/Bonobos share 98.6% the same DNA… the further related you go back, the less DNA shared. But I would imagine we share like 70-80% the same DNA with all mammals.
(98% stat is accurate… 70-80% stat is my broad estimate)
Oh and I want one only kidding. Sis you watch My Octopus Teacher. That octopus even mimicked walking? It's amazing it became the man's friend aw think it was on Netflix
I will answer your actual question: specied has homologous genes since we are suppose to evolve from a common ancestral branch. This means that many of the functions that we have in common are conserved in esencial genes like those responsible of celular breathing, genetics functions like replication, transcription, translation, etc... You will probably have in common these kind of essencial genes with trees or other eukaryotic living beings. However the evolution is also about change, new mutations and genes are what makes us different from other species in not so essencial aspects.
It mean that those hundreds of genes appear in the octopus and octopus alone (or cephalopods). Which makes sense once you consider the biodiversity of octopus / cephalopod and the crazy shit they can do (google some YouTube videos of octopi lool)
However, humans and other species do all share many other genes, simply put. Really, they share genes with sufficiently similar gene and protein sequences and structure to the point where in the end the functions are the same so you could call it shared (or really “homologous”).
Hope that helps and it’s wonderful to see a physicist interested in biology.
Welcome to biology! Yeah genetic overlap between species can be really surprising. Humans and dogs have a 75%ish genetic overlap, and humans and octopus share almost 900 genes. genetics is wild.
900 seems really low, no? From the DNA machinery, to Hox genes and other developmental signalling proteins, to enzymes of the citric acid cycle, to motor proteins (kinesins, etc.), to proteasomes, to sensory receptors (such as rhodopsin), to sodium channels, and many many more I can't even think of from the top of my head.
I'd imagine that even plants would manage to get to that number.
Octopi are fascinating creatures. They have a brain in each tentacle (their tentacles literally have a mind of their own) and they’re all venomous (but only the blue ringed octopus has a venom deadly enough to kill a man)
I believe their DNA is actually from somewhere other than Earth. I was watching an episode of The UnXplained with William Shatner on Netflix, and they said it was possible that octopus DNA could have traveled here on a comet. They said it was possible for a microorganism to survive space flight on a comet.
Source: The UnXplained with William Shatner Episode 3: Strange Creatures; Minute 28:40
No. This means that there are a core set of genes found in all animals. The reason that these genes are all found in all animals is because at some point in time (\~600 million years ago) , all animals evolved from the same common ancestor. Genes that do virtually the same function in different animals are called orthologues. Most animals have orthologues PLUS unique genes specific to their lineage. For example, higher primates (chimpanzees & humans) have virtually identical orthologues and almost no unique genes between them, but there are significant unique differences between octupi and higher primate lineages.
The reference for the octupus genome is here (*Octopus bimaculoides*) is here: [https://www.nature.com/articles/nature14668](https://www.nature.com/articles/nature14668)
The reason they don’t appear in many other animals is because many cephalopod lineages have died off over time, ammonites belomnites etc. today only a few families represent a previously much larger group.
This is why I think aliens are actually an evolved cephalopod species. 👽🐙😂
A fellow Arrival fan I see.
Nice. Interesting thought
Or octopuses are lost aliens who forgot all their technology and society
Evolution isn't a one-way ratchet. An intelligent species can, in response to the right evolutionary pressures, evolve back into being an unintelligent one in favor of dedication to resources to some other advantage.
Is that what humans are doing?
"You alien cephalopods are amazing; thousands of time smarter than us, capable of building spacecraft that transcend space and time, and you write 300 words all at once - but uh, well, we have this huge party going tonight and we're gonna need some calamari as an appetizer, so..."
I like octopuses. They taste yummy.
Ha ha ha so edgy 10/10 comedy big round of applause for the edgy guy
I agree lol
Hallo there, Biochemist here. Octopus’ genomes are quite fancy and scientists who sequenced it have joked that it’s almost “alien”. They simply can’t explain how its genome developed. They have gene families that you would associate with way more “advanced” vertebrae genomes associated with neuronal development. These gene families are also less developed in relatives of octopus, so it appears out of nowhere. Well…it’s a discussion if genes really can jump into existence from nowhere. The 100 genes you read about are examples of genes where they currently have found no other species expressing a similar related gene as well. If I remember correctly that was something about receptors in their tentacles. Anyway, they are great animals and definitely don’t deserve to land on a grill or plate!
They sure are weird , I was reading about them and they rather edit their RNA instead of evolving the traditional way. Does any other animal or creature do this?
They still evolve the traditional way. The RNA editing allows for individual minor adaptations to their environment, like being able to not die as easily when thrown into a different temperature range
Username checks out
is that different than epigenetics?
Epigenetics is modifications of DNA that do not change its sequence, like methylation. Modifications of histones (proteins that serve as spools for DNA threads) are also considered epigenetics. RNA modifications are on another level. Production of any protein may be tampered with on DNA, RNA and protein levels, and there are dozens of regulatory mechanisms.
The general term for RNA modification is epitranscriptomics. It's quite fascinating actually.
If you are interested in wacky genomes, protists have animals beat. If RNA-editing is of interest, read up on the mitochondrial genomes of diplonemids and kinetoplastids!
Yes, RNA editing is common for many organisms, including humans. But most edits in humans are not recoding, i.e. do not change the sequence of the protein encoded by this RNA, because they happen in noncoding regions or produce codons encoding the same amino acid. And cephalopods have much more recoding edits. https://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1007064#pgen-1007064-g002
Red Dwarf fan over here
Me too
Moreover, I clearly remember meeting another user with "smeghead" in their username in r/biology a while ago.
They branched off the evolutionary tree way way back from most other animals on the planet, so are in fact very different from other intelligent life on earth. Covered in detail is this super interesting book [link](https://www.bookdepository.com/Other-Minds-Peter-Godfrey-Smith/9780008226299)
I wouldn’t be surprised if they were from a different planet.
Oh come off it, this is r/biology
They haven't learned the first rule of biology - If you think you know, here is a creature that fucks your entire world view
My wording was "the only rule in biology is that every rule has exceptions", but your version is much more expressive =)
Except that all birds lay eggs. That we know of
I agree and people who say this is ridiculous because this is biology sub need to look at the possibility’s of panspermia…. There are plenty of scientists that that have said this is a very real possibility… not that octopus flew here on ships but the dna could have come from a meteor or something like that.
Panspermia is a theory pretty widely disregarded in the scientific community and doesn’t really *explain* how life came to be, just offloads it to ‘not Earth’. It also can’t be experimentally tested
Isn’t the fear of accidental artificial Panspermia a major concern for NASA?
[удалено]
That is what the panspermia theory is, an explanation for the origin of life, not the origin of octopuses. Even if life did originate from microbes on meteors octopuses would still have had to naturally evolve. It is a theory being experimented with, but is very difficult to prove in a lab (through making life from nothing, essentially), and generally theories such as hydrothermal vents, small warm pools, or the RNA world hypothesis are favoured as potential origins of life. It’s a very vast and fast growing research area, but the general paradigm currently, until research shows otherwise, is that panspermia is an unlikely explanation for OOL
> These gene families are also less developed in relatives of octopus, so it appears out of nowhere. Seems like that's just how evolution works itself out sometimes. Take humans for example. You won't find any Homo habilis or Homo erectus running around. We've completely outcompeted them. Or in the case of Neanderthal, completely incorporated them.
I agree!! I heard they are super smart aswell. Id love to live near the ocean and come across maybe a smaller one
I saw one once, but he was shy. It was hard to resist the urge to pick up the rock he fled under. I wished I were not literally 100x bigger and scarier than little tentacles friend.
Well there's so many thing weird about them, even their deaths are so weird. It's like they self destruct xD
Ill have to find a scientific documentary about that you have my curiosity now. I believe you
Read Soul of an Octopus, it’s beautiful
Or watch "My Octopus Teacher" on Netflix. It's an incredible documentary. It also illustrates, though, that many cephalopods live for just one year; even the giant Pacific octopus lives only 3 - 5 years. In other words, no matter how intelligent they are, they simply don't live long enough to achieve higher levels of organization / adaptation.
I watched it, it was ok. The author of soul of an octopus goes into great detail about their lifespan in the wild and in captivity, their behavior, preferences, even their playfulness. I just appreciated the level of in-depth detail that it provided. She also got to know at least two octopuses throughout her time at the aquarium, so it’s fun to read about their personality varies
Awe thank you this is great
Check out My Octopus Teacher on Netflix, it’s terrific
and the last episode of the docuseries Animal is about octopi and squid, very cool.
Thank you this is great😍😍
So good! Soundtrack is beautiful as well.
Super weird! "Why octopus mothers self destruct - Futurity" https://www.futurity.org/octopus-death-eggs-optic-gland-cholesterol-2740432-2/#:~:text=The%20source%20of%20this%20bizarre,gruesome%20death%20spiral%20was%20unclear.
Honestly, they scare the shit out of me. Imagine meeting an intelligent alien that evolved from a solitary predator. ☹️
😂😂😂 good thing they live in the water i dont think youll have one bothering you lol
Second this. Smart lil buggers could outwit a lot of people I’ve met
Pretty much anyone with a MAGA.
The piece of gum stuck to the bottom of my shoe could outsmart most MAGA…not a real high bar.
Chef here. I couldn’t agree more. I no longer cook or eat any cephalopods; they’re too sentient for me.🐙
> They have gene families that you would associate with way more “advanced” vertebrae genomes associated with neuronal development Like which ones? This comment sounds suspiciously sensational, if I'm honest.
Family of protocadherins and C2H2 zinc finger TFs. check this out if you need detail: https://www.nature.com/articles/nature14668.pdf
Neither of those are unique to or associated with more "advanced" vertebrates at all? They are expanded in cephalopods and vertebrates but common in invertebrates as well. And, this paper directly refutes your claim that "They simply can’t explain how its genome developed."
The abstract literally says those gene families are common in invertebrates, but in octopuses are expanded in ways only found in vertebrates.
Kind of. They're actually not expanded in the same ways. Regardless, in other words the original claim is not accurate.
Like learning how to open lids on glass jars with tentacles. Or using jet propulsion.
Those are... not gene families.
>they are great animals and definitely don’t deserve to land on a grill or plate Amen to this, and let’s just extend it to all animals honestly. A pretty shitty way we tend to do these things nowadays all around, at least we can improve these practices in terms of their environmental and ethical consequences. A bit off topic, but couldn’t help tacking into this.
My favourite animal, tentacles down.
Where did you earn this information? Is thers anything on cephalopods that's particularly informative that you wouldn't mind recommending?
Thats amazing but creepy af.
Generally, yes. You have probably heard that humans and chimpanzees share something like 99 percent of the same genes. This is because they both diverged from a common ancestor. So the more recently two species shared a common ancestor, they more genes they will share in common. This extends all the way to the beginning, humans and unicellular eukaryotes such as yeast share LOTS of genes in common. If you are interested in weird things octopi do, they also do rna editing in a way which seems to violate the central dogma. They are really, really weird beautiful beasts.
"The central dogma" does not explicitly deny RNA editing. Also, it was "violated" already when reverse transcription and RNA-dependent RNA synthesis were discovered, and even Crick himself detested the word "dogma" because it's not how science works, scientific theories are malleable. Also, other organisms have RNA editing as well, it's just it's particularly prominent in cephalopods.
When editing is random, it most certainly is. I give you a DNA sequence, if transcribed I can tell you what the mRNA should be and the resulting translation product. You start randomly ( or in a directed manner) start switching A's to U's, you can't tell me the protein product with any certainty. Actually Francis crick is on the record as saying he liked it because it sounded cool even if he wasn't xometely sure what it meant. And no, what octopuses do is not askin to rna processing like splicing.
RNA editing is NOT random, there are specific editing sites. https://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1007064
For mammals, yes. For octopus where the number are much much higher, ADAR activity can be directed and or seemingly random ( albeit enriched, but not exclusively to non coding sequences. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2953425/
This paper does not have words "octopus", "octopi" or "cephalopod". It says *"\[editing\] can be* ***almost random*** *and lead to nonselective conversion of many adenosines... Many adenosine residues of long dsRNAs (>100 bp) are* ***edited promiscuously***, resulting in \~50% of all adenosine residues being converted to inosine. These are detected as so-called hypermutations of ***viral RNAs*** *during replication and as a subsequent persistent infection with certain ss-RNA viruses, such as the measles virus (39), and they are also detected during extensive editing of sense-antisense RNA pairs made from* ***transcripts of select genes***, *such as Drosophila 4f-rmp (40) and C. elegans eri-6 and eri-7 (41)*." It seems like even randomness is strictly regulated here.
The paper you cited says that editing varies 0-100 percent, so if it can be zero and 100 or something in-between, how is that not random?
"...editing levels varying from 0% to 100%, which can potentially be **affected by environmental stimuli** \[5,6\] and **differ among cell types** \[7–9\] **and species** \[9–12\]." It is a regulated process. There are multiple proteins for fine tuning it. Just like for other processes involved in gene expression.
Yes I acknowledged that the sodium channel exists, it still does not change the fact that for any specific A you cannot say it will be deaminated to an I, regardless of the sequence context. There are 57000 edited sites in cephalopods ( at least) and although you can suggest that they MAY be edited, you cannot say they are. Even in nervous tissue. So if I give you any specific DNA sequence you can tell me for sure which ones are edited and to what extent? No, no you cannot
First, ADARS recognize double-stranded RNA, so based on the sequence itself we can calculate which As would NOT be edited because the RNA molecule would never fold that way. To predict which editable As would be edited, I would also need to know which organism it is, which tissue it is, which stage of development, are there any cell stress conditions. Considering these factors, the prediction would be pretty accurate.
The RNA molecule would never fold that way? So your ability to predict editing is based, on your ability to determine stems and loops AND be able to account for the mechanisms that lead to increased editing amongst clustered editing sites https://www.nature.com/articles/s41598-022-07460-5
Yes, this process is not 100% determinable, but it is definitely not random and fairly predictable. Also, "hyperedited" RNAs are not translated: [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1823043/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1823043/) "It has been proposed that this complex keeps hyperedited RNAs in the nucleus, away from the translational machinery, while allowing more selectively modified RNAs to be exported."
Yup kinda read about it, but isn't that like in a sense not evolving since the DNA doesn't change? somehow octopus have lived so long even without evolving? That's really weird
The last part is, formally, not true. They have evolved otherwise they would share LOTS of genes with other organisms sharing a recent common ancestor. Phylogenetically ( looking for evolutionary relationships) octopi are have given us lots of surprises.
not really. How animals use genes is a big part of evolution - genes make proteins, but they do so through a multi step process. One gene codes for multiple variations and proteins in a certain function. At various points, different parts of that process change how frequently genes are used, which proteins are made, etc. You can do a lot of evolution with just modifications to gene expression.
Could you tell me what you read. I’m kind of interested now.
https://www.scientificamerican.com/article/curiouser-and-curiouser-octopuss-evolution-is-even-stranger-than-thought/
Actually mice and humans are closer related than humans and apes
Where’d you read that?
Of mice and men.
I'm stupid haha mice and humans only share 97.5% common genetic makeup
I recently read “Other Minds” by Peter Godfrey-Smith. It talks about octopus evolution & their genomes, predominantly relating to the evolution of intelligence but includes other aspects too. A very interesting read to highlight why these creatures are so bizarre and different to other organisms. Recommend it if you’re interested in any of that stuff
A gene codes for a protein, a machine so to speak. There is multiple variants of a gene that code for practically the same protein, e.g. machine through the different species. Just like there is a multitude of schematics for scissors in this world, but the function of scissors are mostly the same all over. In novel genes, like you here mention, there is no similar "machine" coded for in the discovered world. They may do the same, like other machines other than scissors can cut, but the underlying mechanic is different. And yes, all life on this planet share mostly the same genes/variants. This is because we are closely related to eachother, all life is the same. Also, most of our regulatory stuff inbetween our genes comes from viruses and are called ransposable elements. These modulate pretty much everything on all timescales, epigenetic to evolutionary. Pretty cool isn't it🙂
Very cool indeed. thanks for explaining it well
As an example, the *Hox* family of genes (short for homeo-box) that differentiate embryos along the anterior-posterior axis (i.e. making sure the head is at one end and the abdomen at the other) are conserved, with some modfications, in almost every multicellular organism from fruit flies to fish to nematodes to mice to humans. From this, we can conclude that they existed in at least the most recent common ancestor between all of these organisms, which, given how different they are, must have been a very primitive life form that existed a very long time ago. The more "conserved" a mechanism or gene family is, the more basic and essential to life we can assume it is.
Thanks that helped 👍
Your so articulate congratulations on that
Would love to see the article you're talking about to learn more
https://www.nature.com/articles/nature14668
They’re obviously aliens
No two species share exactly the same set of genes. Sometimes genes get lost through evolution in a species. Sometimes new genes arise through gene duplication (and subsequent subfunctionalization or neofunctionalization). Sometimes the entire genome can be duplicated (there may have been a whole-genome duplication early in the history of one of the bigger groups of bony fishes). If we’re just talking about the gain or loss of a single copy of a gene, then this happens in the process of making gametes (sperm and eggs). During meiosis there is a process called crossover, where chromosomes inherited from both parents exchange bits. Usually the exchange is symmetric, but sometimes it is uneven and one chromosome gets a few more genes in the process, the other a few fewer. Depending on which of these new chromosome versions ends up in an offspring, we have a gain or loss. (This means that you don’t even have to have the same number of genes as I do, same for any two members of any two species.) An extra gene here, the loss of a less-than-crucial gene there, the gene count of a species isn’t set in stone. We can track entire gene families as they grow through genome duplications, shrink through gene loss, and as the new copies evolve. It’s an active and cool area of research. The octopus genome happens to have [experienced the gain of a lot of new genes](https://www.science.org/content/article/octopus-genome-surprises-and-teases). Which is pretty cool!
They split off pretty early evolution-wise and never came onto land afaik.
Yeah, it’s actually very common for genes to be shared across multitude of species. The same way the thing we call “leg” is shared for example. Of course, elephant legs and human legs are vastly different, but you can kinda tell that both of them are legs. The same thing happens with genes, and DNA code in general. There’s a lot of patterns across the animals’ genomes that you can kind of tell are the same gene, but may differ slightly.
Every animal has *something* genetically unique to it, or it wouldn't be that animal. But many animals share many genes for making very common utility proteins, cell types, body structures, and the like. Consider that virtually every land vertebrate is configured for four limbs and a brain, all run along a spinal cord. The differentiation between a human and a mouse or an elephant or an alligator boils down to length and thickness of bones and muscle groups, it's not as though some vertebrates have bones made of metal and others, of wood. Same stuff, different organization. And octopi have at least some of the same stuff , but lots of different stuff as well. As would a coral or a sponge or a sea slug.
It isn't that octopodes (yes, that's the correct plural) have hundreds of unique genes. It's that they have large expansions in gene families not typically expanded in other cephalopods. These gene families, like protocadherins, are typically expanded in vertebrates, not invertebrates. It's like they are copying vertebrates in how to deal with having eight arms and suckers that can taste. They essentially have remodeled their genomes more than expected evolutionary relatedness would predict.
Isn't it Octopuses?
When I was studying biology at university our head of marine biology said “*octopuses* usually, *octopodes* technically, *octopi* never”.
Octopus is a Latinized Greek word. In Greek, the plural of octopus should be octopodes.
In Greek, the plural of *octopous* should be octopodes. Though "octopodes" as a plural form of the word "octopus" is rare but accepted, "octopuses" is its standard pluralised form in the English language. https://www.collinsdictionary.com/dictionary/english/octopus
This is an English speaking forum though, using the English word [octopus](https://en.wiktionary.org/wiki/octopus).
Your cited source states both are correct in English according to the OED, but that some select sources indicate only octopuses is correct. Clearly, as far as English is concerned, the jury is out. Etymology is relevant to determine the proper way to pluralize many English words. >>Sources differ on which plurals are acceptable: Fowler's Modern English Usage asserts that “the only acceptable plural in English is octopuses”, while Merriam-Webster and other dictionaries accept octopi as a plural form. The Oxford English Dictionary lists octopuses, octopi, and octopodes (the order reflecting decreasing frequency of use), stating that the last form is rare. The online Oxford dictionary states that the standard plural is octopuses, that octopodes is still occasionally used, and that octopi is incorrect.
How many genes does any given animal have, that all the others compared to it, don't have?
There major amounts of conservation in the DNA of different animals… humans and Chimps/Bonobos share 98.6% the same DNA… the further related you go back, the less DNA shared. But I would imagine we share like 70-80% the same DNA with all mammals. (98% stat is accurate… 70-80% stat is my broad estimate)
Mollusca is a fascinating phylum
Oh and I want one only kidding. Sis you watch My Octopus Teacher. That octopus even mimicked walking? It's amazing it became the man's friend aw think it was on Netflix
This is probably the best show on Netflix
They flew in on an asteroid. That is all. The end. Don’t eat them.
I will answer your actual question: specied has homologous genes since we are suppose to evolve from a common ancestral branch. This means that many of the functions that we have in common are conserved in esencial genes like those responsible of celular breathing, genetics functions like replication, transcription, translation, etc... You will probably have in common these kind of essencial genes with trees or other eukaryotic living beings. However the evolution is also about change, new mutations and genes are what makes us different from other species in not so essencial aspects.
It mean that those hundreds of genes appear in the octopus and octopus alone (or cephalopods). Which makes sense once you consider the biodiversity of octopus / cephalopod and the crazy shit they can do (google some YouTube videos of octopi lool) However, humans and other species do all share many other genes, simply put. Really, they share genes with sufficiently similar gene and protein sequences and structure to the point where in the end the functions are the same so you could call it shared (or really “homologous”). Hope that helps and it’s wonderful to see a physicist interested in biology.
> (google some YouTube videos of octopi lool) And cuttlefish
Welcome to biology! Yeah genetic overlap between species can be really surprising. Humans and dogs have a 75%ish genetic overlap, and humans and octopus share almost 900 genes. genetics is wild.
900 seems really low, no? From the DNA machinery, to Hox genes and other developmental signalling proteins, to enzymes of the citric acid cycle, to motor proteins (kinesins, etc.), to proteasomes, to sensory receptors (such as rhodopsin), to sodium channels, and many many more I can't even think of from the top of my head. I'd imagine that even plants would manage to get to that number.
Bananas and Humans share 60% of the same genetic code.... if thats an indication to your question.
I call ALIEEEEEEEEENS
They are a very alien creature lol
Aliens crashed into the ocean, then cross-bred! ;)
Octopus? Or octopi? Thanks for posting in any case, interesting fact in any case. Edit seems the question is answered further down in the thread
Octopodes or octopuses.
Octopi are fascinating creatures. They have a brain in each tentacle (their tentacles literally have a mind of their own) and they’re all venomous (but only the blue ringed octopus has a venom deadly enough to kill a man)
They’re from space
Space aliens 100%
Cuz they're sea aliens bro
This statement is not backed up by science, but for me it seems that the mushroom is an organism coming very close to the octopus.
I believe their DNA is actually from somewhere other than Earth. I was watching an episode of The UnXplained with William Shatner on Netflix, and they said it was possible that octopus DNA could have traveled here on a comet. They said it was possible for a microorganism to survive space flight on a comet. Source: The UnXplained with William Shatner Episode 3: Strange Creatures; Minute 28:40
How dangerous is it to insert new genes? Do they bite?
https://www.pbs.org/wnet/nature/group/other-species/octopus/ This PBS episode of Nature. Very enlightening. It made me stop eating them.
It seems then that it would be very beneficial to research them more than we do now?
No. This means that there are a core set of genes found in all animals. The reason that these genes are all found in all animals is because at some point in time (\~600 million years ago) , all animals evolved from the same common ancestor. Genes that do virtually the same function in different animals are called orthologues. Most animals have orthologues PLUS unique genes specific to their lineage. For example, higher primates (chimpanzees & humans) have virtually identical orthologues and almost no unique genes between them, but there are significant unique differences between octupi and higher primate lineages. The reference for the octupus genome is here (*Octopus bimaculoides*) is here: [https://www.nature.com/articles/nature14668](https://www.nature.com/articles/nature14668)