2 types of gene therapy (1 Viewer)

[.ben]

which gene therapy do we have ot know about?

1. insert corrected gene into retrovirus--->insert virus into human target cells---> human able to produce protein----> feeling better

OR

2. insert corrected gene into retrovirus--->allow retrovirus to attack stem cells taken out of body--->corrected stem cells cultured--->insert corrected stem cells into body


TKS

 

[Survivor39]

The latter one doesn't sound right. I think you meant "stem cells taken out of the blastocyst", right? How can you take out stem cells in the human body, and fix those few cells and insert them back into a body and expect those cells to work in the context of the entire organ/body? Remember there are billions of cells in your body don't have the corrected gene.

 

[.ben]

I got it from Heinemann biology. Mabye i misunderstood it :/

"The normal ADA gene has been identified and its sequence known. Copies of the gene are made and inserted into retroviruses used as the gene vectors. The retroviruses then infect human target cells taken and cultured from the child with the disease. These target cells are then injected back into the child."

 

[Dr_Doom]

That's genetic engineering.

The first one you posted is gene therapy.

 

[.ben]

Ok now i'm really confused :/

so let's clarify:

Gene therapy is where you put good genes in viral vectors and then insert these vectors into the human body to cure diseases etc

Genetic engineering in tampering with genes?

And transgenic species is where you mess with genes and insert them into organisms?

Finally, how do you make transgenic organisms is find a gene, get it into a bacterial plasmid. allow it to multiply, take the multiplied genes and shoot them into cells?

EDIT: ALso, Polymerase chain reaction serves the same purpose as copying DNA onto bacterial plasmids so that they can replicate right?

 

[Dr_Doom]

Correct. Except you don't tamper with genes. You get genes and tamper with the original DNA structure of the species by inserting new genes.

 

[.ben]

Wait a minute, if you have PCR and microinjection, biolistics etc why do you still need recombinant plasmid DNA or vice versa?

 

[Dr_Doom]

Because once you extract the gene using restriction enzymes, you need to copy it over and over to make many copies using PCR. Then once the copies are made you use microinjection, genegun etc to insert all the genes

 

[Dr_Doom]

Here's a summary I found in the spectrum of life book

Recombinant DNA technology:

1. Gene is cut out of the chromosome of one species using a restriction enzyme.
2. Circular piece of DNA (plasmid), present in bacterial cells is removed from the cells and cut open with the same enzyme. The bacterium Escherichia coli is commonly used as the source of the plasmid.
3. The 'cutout' gene is mixed with the bacterial plasmids. Because they have been cut with the same enzyme, the cut ends of the plasmid and the ends of the gene match. Therefore a plasmid recombines with the gene spliced into it. The sticking together of the plasmid with the gene inserted into it is catalysed by the enzyme DNA ligase.
4. The plasmid is re-inserted into the bacteria by mixing with calcium chloride (which makes the bacterial membranes more porous) in a test-tube. This is called transformation into bacteria.
5. Once inside the bacterial cells, the plasmids are reproduced when the cell reproduces.
6. The introduced gene will now be expressed by the bacterial cells.

 

[Survivor39]

Dr Doom and .ben, I am surprised that neither of you have answered my "Challenge Questions" posted in the "To Affinity & Beyond" forum.

Come on! I'm sure you know them.

 

[.ben]

Here's a summary I found in the spectrum of life book

Recombinant DNA technology:

1. Gene is cut out of the chromosome of one species using a restriction enzyme.
2. Circular piece of DNA (plasmid), present in bacterial cells is removed from the cells and cut open with the same enzyme. The bacterium Escherichia coli is commonly used as the source of the plasmid.
3. The 'cutout' gene is mixed with the bacterial plasmids. Because they have been cut with the same enzyme, the cut ends of the plasmid and the ends of the gene match. Therefore a plasmid recombines with the gene spliced into it. The sticking together of the plasmid with the gene inserted into it is catalysed by the enzyme DNA ligase.
4. The plasmid is re-inserted into the bacteria by mixing with calcium chloride (which makes the bacterial membranes more porous) in a test-tube. This is called transformation into bacteria.
5. Once inside the bacterial cells, the plasmids are reproduced when the cell reproduces.
6. The introduced gene will now be expressed by the bacterial cells.

Because once you extract the gene using restriction enzymes, you need to copy it over and over to make many copies using PCR. Then once the copies are made you use microinjection, genegun etc to insert all the genes

You've hit the nail on the head this is the thing i don't get. If you've got the bacterial plasmids to replicate and make the recombinant DNA, why do you need PCR to make multiple copoies of the genes?

Also how would you make transgenic species if the organism WASN"t single celled, like a cow or pig etc?

@Survivor39 Dr Doom might he seems smart but not mee i'm a biology retard

 

[Dr_Doom]

What I remember is PCR (Polymerase chain reaction), is used to boost the replication of the bacterial plasmids... Like on their own they will not divide..

Survivor is this right?

 

[Dr_Doom]

I just read PCR is used in DNA fingerprinting when only small amounts of DNA is collected. It is used to multiply the DNA to create more copies.