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 regions having quarter of neutral mutation rate. I think this is the case here.
This extends what zslastsman written regarding structure.
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.
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.
I wonder why it's called "super" if it's a bad thing...
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.
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
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.