All of dekelron's Comments + Replies

There are several complications addressed in the article, which I did not describe. Anyway, using a "control vector" is considered trivial, and I believe they checked this.

if it has been undergoing close-to-neutral selection, that implies that almost all possible mutations in that region are fitness-neutral.

There is no "neutral" evolution, as all DNA sequences are subject to several constraints, such as maintaining GC content and preventing promoters) from popping out needlessly. There is also large variability of mutation rates along different DNA regions. Together, this results in high variance of "neutral" mutation rate, and because of huge genome, making it (probably) impossible to detect even regi... (read more)

The DNA in the zebrafish was deleted, and the human version was inserted later, without affecting the main DNA (probably using a "plasmid"). Without the human DNA "insert", there was a developmental defect. with either the human DNA insert or the original zebrafish DNA (as an insert), there was no developmental defect, leading to the conclusion that the human version is functionally equivalent to the zebrafish version.

0A1987dM
How do we know whether, by replacing the insert with a random sequence of base pairs the same length, there would be no developmental defect either?
dekelron130

There are pieces of DNA that preserve function, but undergo neutral evolution. A recent nature article found a not-protein-coding piece of DNA that is necessary for development (by being transcribed into RNA), that had underwent close to neutral evolution from zebrafish to human, but maintained functional conservation. That is, taking the human transcript and inserting it into zebrafish spares it from death, indicating that (almost) completely different DNA performs the same function, and that using simple conservation of non-neutral evolution we probably can't detect it.

4philh
I'm having trouble working out the experimental conditions here. I take it they replaced a sequence of zebrafish DNA with its human equivalent, which seemed to have been undergoing nearly neutral selection, and didn't observe developmental defects. But what was the condition where they did observe defects? If they just removed that section of DNA, that could suggest that some sequence is needed there but its contents are irrelevant. If they replaced it with a completely different section of DNA that seems like it would be a lot more surprising.

I wonder why it's called "super" if it's a bad thing...

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2Alicorn
Who says it's bad? It means being more sensitive to taste; it just turns out that some things aren't very nice if you can really taste them. Other stuff tastes great!
3wedrifid
Adverb: Especially; particularly.
4djcb
Ah, thanks! The research was about alcohol and clofibrates: That seems pretty significant! Cheers!

Actually I doubt it's something that complicated. In my opinion, the site is not known because there are few people to publicize it, loop.

Anyhow, ARE there more LWers from Israel? I would really like it if there was a meetup here.

3dbaupp
According to this survey, there are at least 2 people from Israel (from Haifa and Kfar Saba).
dekelron230

Hi all,

I'm 25 from Israel. I worked in programming for 4 years, and have recently decided to move on to more interesting stuff (either math, biology, or neurology, don't know).

I'm new in LW, but have read OB from time to time over over the past 5 years. Several months ago I ran into LW, (re)read a lot of the site, and decided to stick around when I realized how awesome it is.

Nice to meet you all!

Ron

5MichaelVassar
Israel seems like a natural place for LW. Any thoughts on why the memes haven't gotten more traction there yet?
5FAWS
Now that you have some karma you should be able to post in the discussion section. Please make sure your post doesn't look like a spam ad, though.