[swati]

Hello everyone
Introns dont code for proteins.... then what is the significance of introns?

[Wreath]

for example alternative splicing - more variability for making more proteins from 1 gene. for example, you have gene with introns 1,2,3. 1st time you splice I1, I2 and I3 stays in the gene (becoming exon now). 2nd time splice I1, I3 and leave I2 in the gene -> different protein. there are lot of combinations and this is actually principle of making a lot out of almost nothing.

[renge ishyo]

In addition to alternative splicing, it has been known for the past few years or so that many introns can play a role in regulation of gene transcription (link: http://www.citeulike.org/user/gregoryross/article/6067312). For instance, as the article mentions some introns can "upregulate" gene transcription by appearing near the promoter of the gene it appears in.

[ggs]

Hello you all,

Exactly like the two friends are saying. Introns are either necessary for alternative splicing or required for regulation of gene transcription. It is important to add that for decades scientists though that introns is just a part of junk DNA, which actually account for most of human genome. Anyway we have to learn a little bit more about the molecular biology of the genomes to make a final conclusion about it. In my opinion introns are equall part of the genome as exons (coding part) and other sequences. I see introns as another level of complexity to our genomes. Remember that genomes are dynamic structures and presence of non-coding DNA (junk in our opinion) may account for it. Imagine that genome is only a coding sequence for our set of genes (which is approximately 30000). It is possible that such a genome will not have a sequences necessary for its packing (protein interacting sequences), metabolism (replication, condesnation etc) and others.

Klich

www.bio-ggs.blogspot.com