genome structure variation - (Nov/27/2005 )

I have a *probably* dumb question

Does genome structure, or more precisely, its base composition and things like mutation and substitution rates, vary between different embryonic stages?

Well, Im trying to understand a bit about isochore structures in different species. The basic arguments for their formation are either selective or mutational. Either case, it involves some force acting on the base composition of the whole genome, such that some parts have a higher GC content than others. Regardless of the mechanism(s) responsible (this is still a highly debated topic) my question is: is the basic assumption that the same mutational or selective processes that can lead to differences in base composition, synteny conservation, variable mutation/substitution rates etc, occur on somatic and germ cells?

So back to the first question. Have anyone looked at the DNA of germ cells vs somatic cells at different stages of development? just to find out if throughout the different stages there is no difference between what is happening in germ cell's DNA and somatic cell's DNA.

Hi

l can answer for the below


" So back to the first question. Have anyone looked at the DNA of germ cells vs somatic cells at different stages of development? just to find out if throughout the different stages there is no difference between what is happening in germ cell's DNA and somatic cell's DNA."

RNA is the first formed nucleic acid... by evolution it turns to DNA...

That is there is no difference between germ cell's DNA and somatic cell's DNA.
Somatic cells has 2n Number of chromosomes and germ cells r n

Then n number of cromosomes contains 3*10^9 bases.(in human beings)

ln that 1% is exon and the rest is Junk DNA.

In that 1% ~65 % is for the Developement and Differentiation function and the rest for Systhesis of our need to the Environment.

Nothing happen to DNA from germ cell to somatic cell... just it become double By the parent germ cells and become Zygote (somatic cell)

It may help to proceed ur Question Deeper..

Bye

Siva