How the placenta evolved from an ancient virus • Hacker News Board

Re: How the placenta evolved from an ancient virus

#61

Post by matheusmoreira » Wed, Jan 06, 2021, 3:15 PM UTC

studiecomput wrote: post #47

chrisma0 wrote: post #7

Retroviruses and our coexistence with them is fascinating to me. Fun fact: "About 8 percent of human DNA comes from viruses inserted into our genomes in the distant past, in many cases into the genomes of our pre-human ancestors millions of years ago." https://newsroom.uw.edu/news/genes-%E2%80%98fossil%E2%80%99-... Endogenous retrovirus Wiki page: https://en.wikipedia.org/wiki/Endogenous_retrovirus

Another wild thought: Is it possible that the solution for harmful retroviruses, like HIV, are retroviruses itself? If retroviruses can overwrite or fuse with our DNA, can't we overwrite it back by making a retrovirus ourselves? I'm not familiar with this topic at all, but it's super interesting.

The problem with pathological viruses is they take over the cells themselves and make them fabricate more viruses until they burst. In these cases there is no living cell left to reprogram.

In the case of HIV it's even worse since it targers certain immune cells. It will eventually kill most of them if it's allowed to replicate unchecked, crippling its host's immune response.

Re: How the placenta evolved from an ancient virus

#62

Post by koeng » Wed, Jan 06, 2021, 3:23 PM UTC

jacquesm wrote: post #58

sradman wrote: post #55

Magnificent. The placenta uses a protein named syncytin [1] to attach to the cells of the uterus. This protein is expressed by a retrovirus that was integrated into animal DNA over 100 million years ago. This reminds me of Lynn Margulis’ discovery that mitochondria and chloroplasts are ancient bacteria incorporated into the cell [2]. [1] https://en.wikipedia.org/wiki/Syncytin-1 [2] https://en.wikipedia.org/wiki/Lynn_…

I don't recall where I read it but I recall that the nucleus of a cell started out as a captive bacterium.

Not likely for nucleus - https://doi.org/10.3389/fmicb.2020.571831

Gemmata obscuriglobus is pretty interesting, and one could imagine how you go from it to nucleus https://en.wikipedia.org/wiki/Gemmata_obscuriglobus

Re: How the placenta evolved from an ancient virus

#63

Post by koeng » Wed, Jan 06, 2021, 3:24 PM UTC

remram wrote: post #50

vbezhenar wrote: post #21

Earlier quoted context omitted.

Just a wild thought: if aliens wanted to change a genome of some species, what are the chances they would construct viruses to do that? AFAIK CRISP uses something similar.

That would probably only work if it gave the altered species a significant advantage (or if you had a system to detect and penalize/eliminate individuals depending on their genome, at scale).

Or you gene drive them.

Re: How the placenta evolved from an ancient virus

#64

Post by Karawebnetwork » Wed, Jan 06, 2021, 3:37 PM UTC

scotty79 wrote: post #38

Weird how antivaxxers use this obscure bit of knowledge to get scared about similarity of covid S-protein to syncytin and immune response to covid vaccine (why not covid itself?) making pregnancy harder or impossible.

Some context: https://sciencebasedmedicine.org/it-was-inevitable-that-anti...

Please do not mistake this comment as antivaxx nonsense, the article linked discredits both the theory and the scientists who started it all.

Re: How the placenta evolved from an ancient virus

#65

Post by lsiunsuex » Wed, Jan 06, 2021, 3:50 PM UTC

welfare wrote: post #51

remram wrote: post #49

Earlier quoted context omitted.

I'm not aware of a context where immortal refers to organisms that can't be killed by accidents and predators. In mythology and novels alike, vampires, gods, elves, ..., are all called immortal and still can be killed.

It's called Biological Immortality[1] and there are a few examples of animals that are considered immortal. [1] - https://en.wikipedia.org/wiki/Biological_immortality

I thought crocodiles or alligators (forget which one) were immortal and they tend to die only because they get so big and can't eat enough to maintain life eventually. But, they're not on this list?

Re: How the placenta evolved from an ancient virus

#66

Post by jgilias » Wed, Jan 06, 2021, 4:00 PM UTC

pps wrote: post #60

jgilias wrote: post #30

It is also being researched how endogenous retroviruses are part of aging. The very rough idea being that at some point long in past a retrovirus became endogenous and provided a pathway for aging increasing the evolutionary rate of that organism, which would then out-compete most of the immortal organisms with time. Something like: https://pubmed.ncbi.nlm.nih.gov/20346965/

That's incredibly interesting! Do you know some (pop)science books that could help learn more about viruses? I found two that sound good from description: "Viruses: A Very Short Introduction" by Dorothy H. Crawford and "A Planet of Viruses" by Carl Zimmer. Would you recommend any of these or something else?

I'm not really in a position to suggest a good book on viruses. I found out about this from a pop-sci book on latest research on aging and longevity.

When it comes to viruses though, there's one more very fascinating hypothesis. That the cell nucleus itself was once actually a virus that took over some bacteria to do its bidding.

https://en.wikipedia.org/wiki/Viral_eukaryogenesis

Re: How the placenta evolved from an ancient virus

#67

Post by RandomWorker » Wed, Jan 06, 2021, 4:11 PM UTC

This is also described in a recent book called “world of viruses.” Worth reading, as there is way more fascinating things I learned about viruses reading this book. Like that there are super big viruses the size of bacteria that are the closest point between a cell and a virus, a fascinating discussion about if viruses are dead or alive, and that there are 55 types of viruses found in a random blue birds that could hop in to humans like the West Nile virus did not so long ago.

Re: How the placenta evolved from an ancient virus

#68

Post by BurningFrog » Wed, Jan 06, 2021, 4:13 PM UTC

jgilias wrote: post #30

It is also being researched how endogenous retroviruses are part of aging. The very rough idea being that at some point long in past a retrovirus became endogenous and provided a pathway for aging increasing the evolutionary rate of that organism, which would then out-compete most of the immortal organisms with time. Something like: https://pubmed.ncbi.nlm.nih.gov/20346965/

Since I had to look it up...

endogenous

- having an internal cause or origin.

- growing or originating from within an organism.

Re: How the placenta evolved from an ancient virus

#69

Post by scotty79 » Wed, Jan 06, 2021, 4:21 PM UTC

Karawebnetwork wrote: post #64

scotty79 wrote: post #38

Weird how antivaxxers use this obscure bit of knowledge to get scared about similarity of covid S-protein to syncytin and immune response to covid vaccine (why not covid itself?) making pregnancy harder or impossible.

Some context: https://sciencebasedmedicine.org/it-was-inevitable-that-anti... Please do not mistake this comment as antivaxx nonsense, the article linked discredits both the theory and the scientists who started it all.

Thank you! Have you found anything that would indicate any level of actual similarities between S protein and syncytine? Beyond both of them being of virus origin and starting with letter S?

I couldn't find anything stronger than "german doctors say" which means nothing.

Re: How the placenta evolved from an ancient virus

#70

Post by ARandomerDude » Wed, Jan 06, 2021, 4:27 PM UTC

It's amazing how quickly people leap to conclusions in the field of evolutionary biology. Fact: a portion of the placenta's protein sequence is very similar or identical to a virus. Unsubstantiated (and pretty wild) conclusion: the placenta is the product of that virus. We would never accept that kind of mythology in software, medicine, law, etc. – why do it here?