Cloned Animals Show Grave Health Problems

selectspec writes: "According to this article in the nytimes, scientists are reporting unexpected levels of defects in sheep and other animals cloned in recent years. Apparently, the cloned DNA is more susceptible to damage during the procedure. This pretty much rules out cloning humans for now." The pivotal battle of bioengineering gets a rain delay.

Comments

Corrections...

[Anonymous Coward]

Some corrections to your post:

Telomeres are not just Adenine repeats - you're thinking of the "Poly-A" tails added to mRNA transcripts after DNA transcription. They *are* however, AT rich (i.e. composed of more Adenines and Thiamines than Cytosines and Guanines).

Also, the presence of telomerease in NOT the standard definition of cancer, although cancer cells certainly must have a way of preventing telomere degradation. There is a LOT of other important cellular machinery that also goes wrong in cancer, and thus you simply cannot sum up and "define" cancer so easily.

The effect of telomere maintenence is not fully understood yet. Mouse cells with telomerase expressed when it normally isn't DO live for quite a long time, certainly much longer than normal mice somatic cells, but NOT forever.

In any case, cloning will NOT be the end of the world, nor will genetic engineering, as so many on Slashdot predict. If people are going to make statements about the effects of a field, they'd do best to actually have some knowledge in that field (like the author of the parent post) rather than a bunch of code-monkeys who can hack Perl and then think they know more about nature, genetics and the enivronment than people who've spent most of their lives studying it.

Sincerely,
Kevin Christie
kwchri@wm.edu

Re:Corrections...

[Punto]

they'd do best to actually have some knowledge in that field [...] rather than a bunch of code-monkeys[...]

Ok, for the code monkeys: it's the TTL.
Each cell has a TTL field, just like a network packet. If the TTL hits 0, the cell dies (TTL is set to TTL-1 every time the cell is reproduced). If the TTL gets set to -1 or something, it will never be 0, and the cell will never stop reproducing. That's cancer.

The problem with cloning is that they get the original cell with a low TTL, and use that to create the new individual, who will have less time to live. They can't reset it.

They must have some kind of problem with their routers or something.

--

Thinly-veiled anti-cloning propaganda

[HEbGb]

The article really sounds like it was designed to dissuade people from ever cloning a human. The first page did sound like reasonable scientific presentations, but once I got to the second page, with its grotesque descriptions and subtle language tricks, it really is obvious that this is simple anti-cloning propaganda.

I don't think I buy the argument that it is really the 'rapid' duplication causing the problems, although it can certainly be one source of error. There is already a substantial body of scientific evidence of DNA deteriorating over time within a healthy organism. Every time a cell divides, errors are introduced, and every genetic error increases the possibility of a medical problem.

When you clone an animal, you are starting with 'corrupted' DNA, which understandably causes a lot of problems after further duplication. This was thought to be the source of many of the problems with 'Dolly' the sheep.

This problem could be possibly be solved by using DNA extracted from the very young.

But, of course, the article doesn't want you to consider this as a possibility, and uses subtle language to undermine the credibility of those who may support the cloning of humans.

For example, after decrying the evils of human cloning, they say that there are scientists proposing the cloning of humans (Dr. Zavos and Dr. Antinori) but that "Academic scientists say they would not dare to think of cloning a human at this time." Are these two not academic? Then why was their recent workshop sponsored by a Rome university? Zavos is even a Professor Emeritus from the University of Kentucky. His credentials are solid, but the article attempts to paint him as a quack.

The end of the article reminds us that House hearings will be starting shortly regarding human cloning. Is this a bit of a 'call-to-arms' by the NYTimes?

The telomeres are the interesting bit.

[landley]

At the end of each DNA strand is a region called a telomere, a long repeated sequence of the same nucleic acid (Adenine, I think) that regulates cell division. Cell division starts when the approriate molecule binds to the telomeres. The longer the telomeres are, the more likely the cell is to divide. The shorter it is, the more of a stimulus it needs to get started dividing.

Each time the cell divides, the telomeres get shorter. The the DNA strands aren't copied all the way to the end, and they down like a fuse. Right next to the telomeres is vital metabolic proteins, so when the telomeres are exhausted the next cell division damages those genes and kills the cell. This is, fundamentally speaking, the cell's aging process.

There's an enzyme called telomerase that protects the telomeres during cell division so they don't get shorter. This means cells with this enzyme in them can divide an unlimited number of times. In the body, this is used during early fetal delopent, for the production of sex cells (so the next generation doesn't die sooner than the previous one), and in a few other places like bone marrow stem cells where unlimited cell division is pretty much required to keep the blood supply up.

The presence of telomerase in any other cell is pretty much the definition of cancer. Cancer cells divide an unlimited number of times because they have a genetic flaw that switches on the gene for telomerase, which is present in most cells but not enabled. (This is why testicular cancer and lukemia are so common: those cells use telomerase normally, so if their division process gets damaged and runs out of control they don't die off. There's no such thing as a benign bone marrow tumor, it won't use up all its cell divisions and die off normally.)

The problem with cloning is you're starting from a cell that's already aged, and so has shorter telomeres. The baby starts out with a much shorter lifespan, and a much slower healing process because its cells don't divide as easily (due to shorter telomeres being a smaller target for the division triggering enzymes to find).

What you need to make a good clone is some way to repair the telomeres AFTER they've already partially burned down. Gluing extra AAAAA sequences onto the end of each gene.

Active telomere reconstruction basically requires nanotechnology. On the bright side, it would be about 50% of the way to extending human lifespans indefinitely. (Limited cell division's half the problem. The other half is that our DNA is a recipe, not a blueprint, which means that it lists the steps required to make something but not what the finished product should look like. With a blueprint, you can fix the finished product because you know what it should look like. With a recipe, you have to start over from the beginning and build a new one, and see what you get.)

Now you know where my email address comes from. :)

Rob

redactions

[deran9ed]

The clones that have been produced, they say, often have problems severe enough - developmental delays, heart defects, lung problems and malfunctioning immune systems - to give pause to anyone thinking of cloning a human being. In one example that seems like science fiction come true, some cloned mice that appeared normal suddenly, as young adults, grew grotesquely fat.

Some of the things people tend to either overlook, ignore, or just not know, is that cloning is not creating a perfect replication of life of any form. These findings will now support this.

Misconceptions:
We may be able to cure cancer if cloning leads to a better understanding of cell differentiation. Theories exist about how cloning may lead to a cure for heart attacks, a revolution in cosmetic surgery, organs for organ transplantation, and predictions abound about how cloning technology will save thousands of lives.

Wrong DNA testing will hopefully address issues surrounding health and anyone who uses cloning as an argument is blind to science and the real truth surrounding cloning.

Medical tragedies - Many people have suffered accidental medical tragedies during their lifetimes. Read about a girl who needs a kidney, a burn victim, a girl born with cosmetic deformities, a man who needs a liver, a women who is infertile because of cancer, and a father who lost his only son.

Assumptions and statements such as this are thrown in the loop by those who are in power to gain financially by supporting cloning by attempting to empathize with those suffering.

All these people favor cloning and want the science to proceed. To cure infertility - Infertile people are discriminated against. Men are made to feel like they are not "real men." Women are made to feel as if they are useless barren vessels. Worse, being infertile is often not considered a "real medical problem" and insurance companies and governments are not sympathetic.

Again when dealing with situations like this, people are apt to just fall wholeheartedly into ideas presented by people without knowing underlying factors. No scientist who expects to gain finances will tell someone "We can create a beautiful person who looks like your son, but he will still have all the issues that killed him in the first place for $30,000.00"

Endangered species could be saved - Through the research leading up to human cloning we will perfect the technology to clone animals, and thus we could forever preserve endangered species, including human beings.Animals and plants could be cloned for medical purposes - Through the research leading up to human cloning, we should discover how to clone animals and plants to produce life-saving medications.

Personally I think DNA research is a better solution. Many people think of cloning as something of a Unix command:


for file in * ; do cat TOBECLONED | sort | uniq | grep -v PROBLEMS >> NEWTHING

Samples were taken from HumanCloning.org

crackbabies cloned