DNA discussion

[BioChemistrySoldier]

Just to start of, ive got a small question.

I want other peoples opinions on wether its possible to mutate or replace
the DNA code letters, A G C T.

[asutoshsahu]

By gene therapy ... may be

[Evelyn]

i suppose you could do it but i don't know how

[LilKim]

hmm.. i'm not sure if I understand your question .... could you expand on it a bit?

[BioChemistrySoldier]

What i mean is if you can change the letters we can change the cell itself.
And then controle what the cell does. (like help function another part of our body.) Once scientist can do that then the possibilities to the human body are almost endless.

Its hard to understand and probably very hard to do but its true.

[LilKim]

Well, remember that each different type of cell in the body has EXACTLY the same DNA compososition.

Differences between a cardiac muscle cell and pituitary gland cell .. has to do with the fact that a different set of genes is expressed in one tissue versus the other. it is not because the DNA composition of each cell type is any different.

Thus, it wouldn't be necessary to alter the genetic code to change a cell itself.. you just have to change what DNA is actually transcribed and translated into protein. (cuz different cell types also express different proteins... the proteins are what makes a endocrine cell..and endocrine cell)

The other HUGE problem is that DNA is Highly highly highly conserved between organism. THis is a result of evolution "choosing" genetic compositions that are most-compatible with life. SO, changing DNA sequences is EXTREMELY tricky... and 1 nucleotide changes can be the difference between life and death.

HOwever!!! if scientist were to have abetter understanding of transcriptional control.. they'd be more able to manipulate cells.. by changing which genes are expressed versus repressed.

.. i hope i've addressed your question.. and you understand

good luck!
- KIM

[BioChemistrySoldier]

Yes thanks.
I guess i should review more before i study deeper into the subject.

[BioChemistrySoldier]

But if i wanted to place a cell into another living organism that did not make a specific protein or something (plant or animal)

Would it die,

eventually multiply and settle,

or cause serious problems to the organsim of which i inserted it?

[LilKim]

well, if you just transplanted a cell... sometimes it would live.. sometimes it wouldn't function normally... but in many situations it would die.

however, if you know the gene that were responsible for making a particular protein... you can insert a "foreign" gene into a cell ... and if done under all of the correct conditions your cell will express the protein from the DNA you inserted.

[BioChemistrySoldier]

That bit of info is going to help me, because i want to cross different species. (two types of plants or two types of animal.)

[LilKim]

hmm... crossing two different species is generally.. not possible. There are rare case .. for example you can cross a donkey with a horse and get a mule.

The mule will grow-up and be healthy and fine... however, all mules are sterile... (because they're derived from 2 different species)...

so.. in general it's not possible to cross different species and end up with a completely viable and fertile animal/plant.

[BioChemistrySoldier]

Wouldent that mean theres a mistake in one of the two species gene? or Thats just the way it is?