Using PCR to change DNA sequenes is only practical if the change you want to make is minimal (say a few bases) and the primers have to be big to avoid nonspecificity or incidental reactions.
genetics...
- Thread starter Dash
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I lied, this is last post. Was indeed plasmid work..... first you crawl, then you walk, then you run. Genetics is just starting to walk. Learing that you can crawl is the hard part.frankcastle said:
You can also use viruses that can introduce DNA sequences into host DNA but difficult to target to the right spot effectively.
Hey my point is that it's not as easy as people are trying to make it sound.
Like I said technically it's possible but not really feasible. That's the take home message that readers should be getting from this.
Like I said technically it's possible but not really feasible. That's the take home message that readers should be getting from this.
As for Sanger's sequencing isn't that just for determining the sequence of nucleotides? Doesn't directly allow us to change sequences.
Anyways I hope you don't think I'm trying to be a jerk it's just that with all the jargon/lingo/concepts that people who didn't study this area wouldn't know I like to be very specific and I found there were a number of inaccuracies in what you were saying. It's like saying I can fix a lawnmower so I can fix the space shuttle.
This thread just raised the overall intellectual level of the board to a statistically signficant degree.
Sorry to drop the debate, wanted to work the next day.....
Using your analogy of fixing the lawnmower then the space shuttle.....if you gain enough knowledge in the process yes you will be able to fix the shuttle eventually, not straight from lawnmowers but eventually.....
I agree that it is technically not feasible right now, but I feel that in 10 to 15 years it will be more feasible, then within 50 years designer DNA, designer people.
Sanger is used for determining the sequence of polypeptides by using restriction enyzmes as cutters. Then identifying the amino acid removed.
By building a polypeptide, you can make an RNA template for a DNA strand to be built, via the magic of reverse transcriptase. Building a polypetide is simple organic chemistry, but with the size involved it would take a long time to synthesize a strand of the necessary length, that is where the advance in technology is needed.....almost a reverse Sanger machine. Once you have the polypeptide the rest is lightning fast.
As for the histones, just strip DNA from natural ones, then add your own strand, instant nuclear material. I know that is over simplifying a very complex process, but something that should be viable as the cell does it itself naturally to an extent during replication.
Using your analogy of fixing the lawnmower then the space shuttle.....if you gain enough knowledge in the process yes you will be able to fix the shuttle eventually, not straight from lawnmowers but eventually.....
I agree that it is technically not feasible right now, but I feel that in 10 to 15 years it will be more feasible, then within 50 years designer DNA, designer people.
Sanger is used for determining the sequence of polypeptides by using restriction enyzmes as cutters. Then identifying the amino acid removed.
By building a polypeptide, you can make an RNA template for a DNA strand to be built, via the magic of reverse transcriptase. Building a polypetide is simple organic chemistry, but with the size involved it would take a long time to synthesize a strand of the necessary length, that is where the advance in technology is needed.....almost a reverse Sanger machine. Once you have the polypeptide the rest is lightning fast.
As for the histones, just strip DNA from natural ones, then add your own strand, instant nuclear material. I know that is over simplifying a very complex process, but something that should be viable as the cell does it itself naturally to an extent during replication.
Okay now we are closer in agreement. From the way I was reading your posts you were making it sound like this stuff could be accomplished today. My point is that we are not at that stage. I agree we have some of the basic tools but none of them are efficient enough to do the job properly.DistantVoyeur said:
I couldn't agree more that some time down the line it's possible. But the original poster was wondering if it could be done TODAY. The answer to that is NO.
Well the Sanger method you speak of has one major flaw you can make the sequence that produces the protein but what about all the regulatory sequences? Those can't be gleaned from the protein. Considering that gene expression is far from being fully understood (the general topic of my MSc thesis) there are too many obstacles at this point.
As for the histones. I'd have to check my old textbooks to see if you drop DNA into a mixture of histones if they will automatically fall into place. I'm leaning towards no.
Not to mention using the reverse transcriptase approach there is still the problem of inserting the gene into the proper spot..... and what problems will occur since many genes are not continuous and are interrupted with various spacers, and regulatory sequences and what not?
Anyways, I'm not trying to argue that it's impossible but demonstrate that there are too many problems at this point and that is why it can't be done. Otherwise someone would have done it already. Years from now yes I think it's safe to say that designer babies will be available to the rich.
Anyways, the point is we agree that there is a lot that has to happen between working on the old two stroke lawnmower and firing up a space shuttle.
Two stroke?? I thought you meant 4 stroke.....geeze never get to the shuttle working on 2 strokes......frankcastle said:
Was fun dredging up genetics.....one of the reasons I'm a believer in the rapidity of progress is that due to medical reasons I had 2 kicks at the can with biochemistry. In the mid 80's what was touted as cutting edge was either false, redundant, or common knowledge by the late 90's (2nd kick). Remember going into way more detail in an "introductory" 2nd year course than was taught in a cutting edge 4th year course in a newly evolving area of bio-inorganic chemistry. Plus technology is even more advanced now, and more dollars are finally getting put into research.
Will be interesting to see when developments happen, but yes as of yet it is not possible in anyway shape or form to make designer DNA with any accuracy. As far as the US Military is telling us anyways......
I wonder how the short bald men out there like being described as having hereditary flaws?Dash said:
Anyway, genetic manipulation may allow the faulty genes to be removed and the correct ones to be inserted, resulting in the normal expression of the genes, and prhaps the elimination of the abnormal conditions.
The adult human body is estimated to consist of 10-20th body cells or somatic cells. In addition, the ova or sperm cells, known as germ cells, allow for the reproduction of the species. Genetic manipulation can be applied to either of the somatic or germ line cells. This in itself raises ethical questions for it can be argued that any changes made to somatic cells are restricted to one individual, whereas changes to germline cells have the potential to be passed onto future generations and thus may have effects on the whole of humanity as an evolving species.
The indiscriminate use of genetic modification may have the potential to do irreparable harm to the individual and society as a whole.
Still think its a good idea?
Sure it might have effects later on down the line but assuming there were the tools to do it in the first place then the same tools could fix the problem.
Besides we've been doing all sorts of selective breeding anyways.
Yes I agree that there could be unforseen problems but that risk shouldn't prevent us from trying to use this technology in the future. Isn't that what life is all about a cycle of problems and solutions?
Besides we've been doing all sorts of selective breeding anyways.
Yes I agree that there could be unforseen problems but that risk shouldn't prevent us from trying to use this technology in the future. Isn't that what life is all about a cycle of problems and solutions?
I think there are many more pressing problems that are facing us as it is. The biggest is probably the limited resources of the planet.
