WHY INTRONS EXIST?

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SHEKHAR
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WHY INTRONS EXIST?

Post by SHEKHAR » Mon Dec 26, 2005 7:12 pm

Although introns have been spliced out after transcription, but why does nature has made a huge amount of introns AND little amount of exons? :?: [/list][/quote]

Avery
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Post by Avery » Tue Dec 27, 2005 2:29 am

I believe that this is still a major research topic. I have heard though of introns acting as the DNA template for a seperate gene. For instance, if there is a silent mutation in the exon for a gene, the intron may be able to code for this. It's sort of like the intron and exon have switched roles.

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MrMistery
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Post by MrMistery » Tue Dec 27, 2005 6:43 pm

Yes, although introns are spliced out, nature has chosen to allow their presence, and we don't know the reasons yet. A hypothesis was stated by avery. another one is that introns help keep DNA structure intact
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SHEKHAR
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Post by SHEKHAR » Tue Dec 27, 2005 7:14 pm

thanks AVERY....
it will help me a lot to understand deeper inside

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Post by hurly » Wed Dec 28, 2005 1:03 pm

It has something to do with evolution.

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Post by 2810712 » Sun Jan 01, 2006 3:47 pm

Let's imagine how this intron-exon system has originated... because one may think that nature has chosen the individuals with this system as a fit individual over those who didn't have it. offcourse this would have been a very very slow selection process.

I know much less about introns , ans of following qs might help in telling why are individuals with introns fittest-
1. what determines whether something is intron or exon?
2. Is there some pattern or relation between intron and exon sequenses of DNA?
3.Do introns match any ancestral genes ?
4. Are introns the major part [ wt.wise] of total DNA?
5. What if we insert intron free gene into a functional cell , is its transcription, translation and replication normal [like intron-having gene]???
6. What if we insert just intron sequences?
7.Is it a way to reduce the probability of mutation in the exons [ as the % of exon DNA is reduced and the exponential rate of mutation is reduced] ?
So many such qs can be asked to get closer to the ans.
I'm very curious about this , please help.

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Post by Ultrashogun » Wed Jan 04, 2006 5:01 am

Introns may have been exons which mutated into their inactive forms.

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mith
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Post by mith » Wed Jan 04, 2006 5:53 am

or spare parts, if deletions or other changes in the code occur, exons might fill in for the missing parts...
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jnkdna
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Post by jnkdna » Sun Jan 08, 2006 10:50 am

i got my nickname from the intron. although i know ppl shouldnt call intrins junk dna, my teacher did and hance the birth of my nick name :jnkdna!
d nyt is darkest just before the dawn

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cytochromeP
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Re: WHY INTRONS EXIST?

Post by cytochromeP » Tue Jan 10, 2006 3:46 am

Hi,

SHEKHAR wrote:WHY INTRONS EXIST? :?:


So that we biologists may have one more extra term to remember. :wink:
Know thyself.

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Post by 2810712 » Tue Jan 10, 2006 12:43 pm

One more pt. here-
what's the meaning of word 'intron' [ related to intra... intrenal segments???]
& why is this term used for what we call introns??? AND same qs about exons[ external segments???]???

This may clarify some more concepts of mine...

hey you really give funcolor cytochromP:D
And jnkdna, I'm being a would-be bioanalyser, when i see a DNA...
i just can't keep me from restriction fragmenting it... so beware... :twisted:
[size=9]note that enzyme to cut u and cytocrome to give it ATP are here!!!

Besides of my contribution, hope that there exist less introns in these fragments [ threads!]. :wink:

Shrei

shamim khaja
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Post by shamim khaja » Tue Jan 17, 2006 11:11 pm

hi,
I think exons interspersed with introns allows for exon shuffling and the creation of modified genes that might have new adaptive functions.
Most of the non-coding DNA is probably adaptive in that it provides chromosomal regions where recombination between homologous portions of chromosomes can take place without disrupting the function of genes.
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