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This article was originally written for a paranormal magazine called The Paranormal Journal, it became known as The Underground Files covering ghosts, ufos, cryptozoology, and government conspiracies amongst others. I no longer write for the magazine and it is no longer in existence. Human Cloning Maybe Impossible Cloning humans or any other primate maybe impossible with today’s techniques because of a fundamental molecular obstacle, say scientists trying to understand why attempts to clone monkeys have failed. From the very first step, cloned primate cells don’t divide properly, causing a helter-skelter mix of chromosomes too abnormal for pregnancy to begin, University of Pittsburgh researchers reported Thursday in the journal Science. “Most people in the cloning field will be surprised by this,” said lead researcher Gerald Schatten. “This work demonstrates there’s a pothole in the process. We know now the depth and breadth of the pothole, and we’re designing strategies to get around it.” Dozens of animal clones, including cows, pigs, mice, goats and a cat have been born since Dolly the sheep became the first being created from an adult cell in 1997. But it’s still a very uncertain area. Many are stillborn and others survive with severe defects. A cult group claimed in December to have cloned a human, something never verified. A doctor who is separately pursuing human cloning has reported in an Internet journal preliminary data on an early stage cloned human embryo, but with no chromosome information. Cloning experts worry that attempting human cloning is dangerous not just because of all the barnyard clones with birth defects, but because the attempts with monkeys, much closer genetically to people, using the Dolly technique has so far failed. To clone, scientists harvest an unfertilised egg from a female donor, removing the genetic material and replacing it with DNA from an adult cell of the animal to be cloned. An electric shock coaxes it into dividing. If all goes well, the egg grows into an embryo that can be implanted into a surrogate mother. For cells to divide properly, chromosomes must duplicate themselves and precisely line up along a zipper like structure called a spindle. Once the chromosomes are in place, the spindle helps the cell to pull apart into two. During human reproduction, if the chromosomes do not split correctly, defects such as Down syndrome result, or the pregnancy fails. Schatten wondered if the chromosome abnormalities were behind failed monkey clonings. And inside monkeys, their cloned cells, the Pittsburgh researchers discovered spindles and chaotic chromosome numbers. Eggs harbour proteins that act as molecular motors that are key to spindle formations. In primates, those proteins are so tightly bound to the egg’s DNA that cloning’s first step of DNA removal pulls apart, destroying all hopes of a later pregnancy. In other mammals, enough spindle-forming proteins float in the egg’s remaining fluid for reproduction to take place, Schatten said. The discovery is very important, said Dr. Duane Kraemer, a successful cloner of non-primates at Texas A&M University. “The fact that they don’t get pregnancies at all suggests that there is something different going on there than with other species,” he said. “It points to a potential problem that may have to be solved before the next advance can be made.” It’s not just bad news for reproductive cloning. It also means the related field of therapeutic cloning, using embryonic stem cells to grow to customised tissues for medical treatment, may prove harder too, Schatten said. However, if 95 percent of the cells growing in a lab dish have abnormal chromosomes, the remaining 5 percent could be still be used, he added. His lab is exploring a way to overcome the problem, by combining cloning with old fashion egg fertilisation. The sperm-and-egg joining jump-starts spindle formation. Schatten then pulls out that sperm and egg DNA, leaving just clone DNA in the now growing monkey cells. “The value of this for deriving embryonic stem cells is going to be very attractive,” Schatten said. Human Cloning Maybe Impossible written by Bill Barber |
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