3% of the human genome is the coding region. Can any one tell me what the rest (97%) is good for?

Question

3% of the human genome is the coding region. Can any one tell me what the rest (97%) is good for?

Answer 1

it depends on what time of development during the lifespan

some genes are turned off or on in different periods of development

that's known as epigenetics

also you have areas completely turned off, and areas like telomeres where it's just a bunch of repeats

you can have "junk" dna too, tandem repeats, psedogenes, alu elements, small interspersed nucleotide repeats (snips), restriction fragment length polymorphisms rfelps,

women turn off an entire x chromosome

and also you have homologus chromosomes (that's 50% of your DNA) which is prettymuch duplicated, most of that is turned off because you already have one set working

however i would say there is more than just 3% coding region

some useful things that aren't coded but needed - promoters, enhancers, untranslated regions of genes, and more -- people are still discovering areas in our genome that we didn't know had uses

Answer 2

Largely unknown, but this is a major area of research.

Could be involved in gene regulation.

Could be involved in maintaining the integrity of the rest of the DNA.

It used to be thought of as 'junk', but that theory is being disproven...gradually...

Answer 3

Watch out for the Junkers, if we dont know something we like to call it junk. We may learn more soon enough.

Answer 4

It's good at getting itself copied.

I'm not sure that we know the exact proportion of junk, but it is clear there is a lot of it and not just in humans but in almost all organisms.

The only thing that DNA is evolved to do is make copies of itself. Coding DNA helps make copies of itself by making a good copying machines (organisms). Non-coding DNA is evolved to hitch a ride along with the rest of the genome.

One could look at this and say that it is dreadfully inefficient for cells to bother to make copies of all that junk. However, since the non-coding junk isn't "seen" by selection, it is rarely subject to elimination by selection.

There are some interesting experiments where small bits of RNA are put in competition with copies of themselves inside test tubes. In this unnatural environment, the RNA does optimize itself because shorter strands are easy to make.