thanks for the excellent reply. don't you think that injecting say an
enucleated cow egg with the nucleus of the desired patient together
with cdna would lead to selective developmental inhibition. thereby we
may grow organs, tissues etc without the possibility of the egg ever
differentiating into a living human embryo. cdnas i suspect would be
replicated during the cell cycle.
http://answers.google.com/answers/threadview?id=583825

This is a question that is likely to take quite a bit of time and
specialized knowledge to answer. With all due respect, I doubt that
you will receive an answer for $2. If you seek a serious response from
a Google Answers Researcher, I suggest that you raise your price
considerably.

i had offered 50 dollars for the previous question but the commenters
chose to ignore this. ok heres 50. is this enough?

I am not sure what your cDNA would consist of: which genes are you
trying to add more of, and why do youu think this would lead to the
selective production of specific organs?

hi. as i mentioned in the previous question (see link), the target
gene is dkk1, so complimentary dna would produce inhibitory rna
throughout the body of cells as opposed to a select location. although
this would be a permanent change in the genome, the cloned organs
harvested in this way will be a temporary solution because they will
continuously need to be replaced as the body ages. this antigene does
not code for receptor proteins but serves to inhibit gene function and
as such will not result in immunological rejection. instead of growing
all organs simultaneously, this method may be applied to the
production of individual organs and tissues once the correct cdnas are
established.

Part of the confusion is that cDNA does not stand for complementary
(NOT COMPLIMENTARY) DNA, but copy DNA, which is derived by using
reverse transcriptase on an purified mRNA

ok. the coding sequence for the dkk1 gene is known. how difficult is
it to produce its complimentary antigene for the purpose described?

i think i spelled complementary wrongly again. ok so if not cDNA how
about aDNA for antisense DNA? i understand there are machines that can
synthesise DNA to order.

cDNA wouldn't be replicated during the cell cycle.  Furthermore, DNA
synthesis in vitro is limited in lenght. Furthermore, you don't want
cDNA, you want siRNA or aRNA - which would bond to its complementary
strand of RNA, blocking translation of the protein encoded by the
message.  Furthermore, the notion of injecting a cow egg with a human
nucleus isn't exactly the way things are done. Somatic cell nuclear
transfer uses host ova and an entire somatic cell.  These should be
species identical to avoid differences in mitochondrial DNA.

--

The practical side of it all....what you are suggesting is just not
the way a question like this would be appraoched.  If we want to
inhibit the fx of ddk1 and we want to do this through recombinant DNA,
we would knock out the gene for dkk1.

---

As I attempted to explain in the last answer, I do not know of any
evidance in humans of dkk1 having been shown to organize the head.

---

The problem we run into is that if we knock out dkk1 function we do
not know what other developmental problems might occur. Tissue
related, and more generally, related to the fact that this
anencephalic fetus will probably die.

---

the cloned organs harvested in this way will be a temporary solution
because they will
continuously need to be replaced as the body ages.

-- Could you please clarify your menaning and logic in the above statement?

---

 this antigene does not code for 
receptor proteins but serves to inhibitfgene function and as such will
not result in
immunological rejection. instead of growing all organs simultaneously, this method 
may be applied to the production of individual organs and tissues once
the correct cdnas are
established. 

Okay, my eyes are starting to droop, but feel free to comment and I'll
be glad to answer what else I can.  Thoughts mikewa?

I think pforcelli has it right: the better way is to go for a
knock-out. RNAi still is not not understood enough to be the method of
choice. Even if a knock out of dkk1 DID manage to inhibit head
formation, I have doubts if this method would be approved: there are
occasional acephalus fetuses, but I doubt if there would be support
for producing them as organ banks.

In addition to the science being fraught with holes, you'd never be
able to get governmental permission for human trials for the types of
experiment you propose on ethically grounds (and rightfully so I
believe)!  Think about it; there are issues with even getting tissues
from aborted fetuses and you want to create headless ones for harvest.
While I think scientific discourse is important and beneficial to
propose conducting such experiments  is irresponsible.

The other major problem that you'd have is:  

"i am not a rich man but i feel i share an interest with the rest of mankind
in trying to save lives and so i want to put an open offer to any
experts out there who would like to work on this project for a few
years."

You haven't even been able to distinguish between commenters and
google answerers and you  intend to engage experts in research.
Likewise the fact that you aren't a rich man  is also a problem, since
just a few years of research, which is not likely to get you very far
will cost millions of dollars.

Its ultimately bad science, bad ethics, bad PR for the scientific community.

I think I suggested in my previous answer that there are many lines of
research going on with regards to tissue engineering in vitro, and
using in vivo animal hosts.  This is an area of research which has
support, has results, and has nothing close to the ethical problems
suggested in your proposal.  I applaud your desire to help humanity.

dops has it right, when he said, you are looking at many millions of
dollars, plenty just in start up costs.  Furthermore, you are looking
at salaries for several research scientists, including someone
specialized in transgenesis (expensive and time consuming -- think at
least a million to get a dkk1 knockout strain, IF the ko wasn't
lethal). We then are faced with the usual problems encountered in
somatic cell nuclear transfer, a low sucess rate, the need for large
numbers of oocytes, the expertise to execute the technique which is
really localized in only a handful of labs throughout the world.  The
sheer logistical nightmares should be enough to dissaude you.  The
nightmare of PR and poor ethics should likewise do so, and the bad
science, because ultimately thats what this is, should also disaude
you.

If you are passionate about regenerative medicine, think about the
other options out there. Tissue culture, organ development, any of the
work being done w/ stem cells to regenerate tissue.  There is a lot of
promise in the field, just not along this line of hypothesis testing.
Mikewa was correct, this is important dialouge, but ultimately that is
where this line of thought will end.



All the best;

Patrick

how can something be unethical when it harms noone and benefits the
world? the egg will never develop sentience. it is as alive as a
cucumber. but unlike a cucumber you will not eat it but use cloned
cells, tissues, organs and limbs to sustain life. presumably you have
no problems with organ donations from a random doner so why have
problems with organs generated from your own flesh? it is similar in
ethical terms to grafting skin from the leg onto your arm. the cells
taken are 'alive' to the extent that they are functional, just as many
cells remain functionally 'alive' long after you have 'gone to meet
your maker in the clouds'.

how can something be unethical when it harms noone and benefits the
world?

-- Setting personal beliefs aside, experimentation on human
subjects/tissue raises serious ethical concerns, the definition of
what is life, and what is human life is a grey area, and from a PR
standpoint alone, it is a nightmare.  Look at the restrictions on Stem
Cell research.  Look at the recent scandal from WooSuk Wongs lab, with
regards to obtaining oocytes.  It does harm, it harms the reputation
of the scientific community.  We already fight the image battle - do
you have any idea how many people out there think that we are a bunch
of nut-jobs running around with crazy hair and lab coats doing what
ever we want with no regard for morals? This is blissfully not true,
but we needn't perpetuate the image.


 the egg will never develop sentience. it is as alive as a
cucumber. but unlike a cucumber you will not eat it but use cloned
cells, tissues, organs and limbs to sustain life.

-- Again, the egg will never develop sentience, but an egg fertalized
by SCNT could. The question boils down to this...If we can persue the
end of this research through different means (which we can and
currerntly doing) why chose a path that is less promising, more
convoluted, and ethically in debate.

If you really want to get into the ethics of it all, there is
something perverse, IMHO about creating an organism for the sole
purpose of harvesting tissue.  It evokes science fiction, it makes my
stomach turn, and I have yet to meet a scientist in the field who
would be a proponent of "organ banking".


presumably you have no problems with organ donations from a random
doner so why have
problems with organs generated from your own flesh? it is similar in
ethical terms to grafting skin from the leg onto your arm.

-- I personally have no problems with SCNT, Organ donation, Abortion,
stem cell harvesting, but I am a man who is dedicating his life to
science.  I am an individual who doesn't want to see progress hindered
by bad science, and even worse, bad controversial science.


 the cells
taken are 'alive' to the extent that they are functional, just as many
cells remain functionally 'alive' long after you have 'gone to meet
your maker in the clouds'.

-- Im not sure what you mean by this comment. Following the
termination of cardiac function cells die. Rather quickly in fact. 
Several minutes without oxygenation is enough to cause ischemic injury
leading to necrosis.

---- Final point with regards to the utility of this proposal.  The
full function of dkk1 is not known.  Even if it was mapped out, there
is still the problem of transplanting an organ or tissue that is
modified in such a manner, the only feasable way through knockouts. 
We would be transplanting an "abnormal" tissue, which would most
likely never get past the FDA.


--- Dops, mikewa; I don't know if you are with me on this, but feel
free to chime in! I enjoy the back and forth we have via these
postings.

Hi Patrick,

I completely agree with you. What I'd add is that science is a process
of trial and error often with many unexpected results. What do you do
when your mouse model doesn't translate well into human trials and you
wind up engineering a severely damaged person? This is not something
I'm willing to risk.

the other advantage of this technique is that it can be applied to the
production of ethical food. we no longer need to kill animals for food
because we can engineer 'animals' to be grown in vertical factories
without heads and thereby produce endless quantities of meat, milk,
wool, etc. i have contacted government with this proposal but without
responce. my campaigning on the internet appears to generate little
interest. i am slowly coming to the conclusion that the only life i
can save is my own. over the years, no action has been taken on this
issue by private or public bodies. i cannot measure the amount of
lives needlessly lost as a result. i am proposing a share of profits
in this food production/life-extension business in return for services
rendered. we can negotiate terms. google answers appears to be against
the idea of my being able to contact anyone in this forum so please
suggest an alternative means of communicating. you may respond in
google groups sci.life-extension under immortality4 posting.