I had read this one a week ago. Wondered how big of a deal this discovery is. Seems like it may help learn more about cancer too. But was too lazy to post, or figured if it mattered someone else would do it. So thanks. Now hopefully someone can emphasized texttell me how much this matters. @Rumraket will tell me it’s just headlights changing color again…lol I remembered that but have no idea now what it was in reference to.
Yeah sort of. Conversion of an RNA sequence back to its DNA complement (called reverse transcription) is not new and was first observed (in the 1950’s) to be catalyzed by a retroviral enzyme called reverse transcriptase. What’s striking about this discovery is that it showed our cells polymerase theta can do this reverse transcription as well.
Again we see the authors rail against a strawman version of the Central Dogma of biology:
According to Crick, the Central Dogma of biology posits that “once (sequential) information has passed into a protein, it cannot get out again”. In other words, the CD of biology allows the flow of information from DNA —> DNA, DNA —> RNA, RNA —> RNA, RNA —> DNA, DNA —> Proteins and RNA —> Proteins. So its pretty obvious that Jefferson’s study in no way unsettles the CD of biology.
The CD of biology forbids the flow of information from Proteins —> DNA, Proteins —> RNA and Proteins —> Proteins. If any of these transitions are discovered, then it would refute the CD of biology. What Jefferson’s study shoots in the head is the "sequence hypothesis (which died in the 1950’s, so I guess he is shooting a dead horse and is proud about it ) postulated by James Watson, not the CD of biology.
You can read Crick’s articles (where that quote came from) yourself:
As far back as 1958, Crick himself called out a misrepresentation of the CD of biology. Here is his article:
Of course, thanks to Larry Moran I discovered this correction a few years ago. At first I was skeptical of Larry’s correction, until I read Crick’s article myself. Its scary though that a lot of accomplished scientists including some of the professors in my undergrad university still get the CD of biology wrong.
Heh, that was about the discovery that RNA can be used as an extracellular signaling molecule.
This is even worse I think. This here from the intro is simply flat out false:
But polymerases were thought to only work in one direction DNA into DNA or RNA. This prevents RNA messages from being rewritten back into the master recipe book of genomic DNA.
False. It was never thought to work in only one direction. At some point it was only known to work in one direction, but I don’t know of anyone ever claiming it couldn’t occur. On the contrary, Francis Crick even mentioned the possibility of RNA->DNA explicitly in his 1958 paper on the central dogma.
Now, Thomas Jefferson University researchers provide the first evidence that RNA segments can be written back into DNA
False. They’re not the first to provide evidence of this. Reverse transcription was known about since 1963.
which potentially challenges the central dogma in biology
False. The central dogma says you can’t get sequence information from proteins back into nucleic acids, it doesn’t say you can’t move from one nucleic acid to another.
Mammalian cells were already known to have reverse transcriptases, and reverse transcription does not violate the so-called “central dogma of molecular biology”.
It seems to me the most interesting discovery here is that Polθ can act both as a DNA polymerase and a reverse-transcriptase, and that it seems to have a function in DNA repair. I wonder if it can even function as an RNA-dependent RNA polymerase under the right circumstances. Regardless, the former is an interesting-enough discovery in itself to have been worthy of both writing a paper and a news article about, so it’s just sad they decided to soup up their press release even further with flatly false, historically ignorant assertions.
Science journalism and the complicity of many scientists and their institutions in sensationalizing and exaggerating their claims is a depressing state of affairs.
It seems like a cool finding, but reverse transcription of RNA to DNA is something that we have known for decades that retrotransposons (and retroviruses) do all the time.
No, w we’ve known that for a long time too. The SD article is just wrong. The novelty of the paper is that it identifies the particular protein responsible for some of that activity.
Echoing this,I strongly recommend that folks stop using sites like Science Daily. Their articles are particularly prone to click-bait headlines, exaggerations, and deeply misleading framing.
Yeah like telomerase.
Yeah. I edited my response to that effect. Thanks.
In addition to transposons, we have known of processed pseudogenes for decades now.
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