New theory of introns

[rakuenso]

I just read an article in Scientific American that challenges the central dogma for eukaroytic cells. To sum it up, instead of the introns going to waste, some of it become micro RNAs that allows extremely complex organisms like us to exist. This would also explain eukaroytic cells have introns because they are beneficial and thus would survive under natural selection. However, prokaryotes do not have a nucleus necessary to perform the splicing needed by introns.

 

Any thoughts?

[Sorcerer]

This could be tested by looking at how conserved introns are between species, if the introns are as conserved at the exons then the hypothesis would hold up.... I however doubt this will be the case, my personal favourite hypothesis is that they are buffer zones, which take the brunt of the mutations protecting the genes from deleterious mutations...... I think it might weak if agrued against properly though, I haven't thought about it much.

[rakuenso]

However, one especially strange thing is that introns have lower mutation rates than exons. Which might possibly mean they were more important when natural selection came into play

[Sorcerer]

They were or they are?? Where do you get this information from?

[rakuenso]

They *are* This information came from the October issue of Scientific American (magazine).

[Sorcerer]

Ok, I dont buy this magazine, what papers does it cite as its reference sources, is this just introns or is it all junk DNA? I would like to see if the introns are more conserved intraspecies as well as interspecies (why? I am too drunk to actually think of why, but I know there is something good there)...... which genes were sequenced in this study, I am assuming it was only a few. I think they may need to do a broader study to give definitive evidence if this is the case.

 

I guess the hypothesis is better than my favourite hypothesis though.

[CharonY]

Well there is actually quite a a bit research regarding introns and their function and it is now more or less known that they do carry information that will not directly transform to proteins (that is, get translated). And it ain't some central "dogma". The only dogma i am aware of is the information flow from DNA to mRNA to protein (although in case of reverse transcrpitase activity the information of mRNA might actually lead back to DNA).

 

Same goes to so-called "junk" DNA. For quite a few of them ideas begin to develop what they might be fore (and as such the term junk is clearly a misnomer). Especially the research on small RNAs has led to the discovery of new regualtory roles (or in some cases, splicing functions).

 

Check this for instance http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=14550267

[Shoushou]

Well, As I know of, about 80% of the human genes r non-coding for protiens, some of them r used to synthysize mRNA, & some r representing groups around centromeres, the latter have no exact known function.

I know this makes nothing new, but it may set things more clear..

I'm really very intrested in knowing their function...

Anybody can help??