Author	Topic:   Genetic Engineering
Human/Rabbit Embryos (Moderator)	posted 8/18/03 9:58 AM     New Scientist | AFPFriday August 15, 12:30 PM Human-rabbit embryos intensify stem cell debate By Philip Cohen "Human" embryonic stem cells have been harvested from cloned embryos created by fusing human cells with rabbit eggs, claims a soon-to-be published report by Chinese scientists. The goal of the experiments by Hui Zhen Sheng of Shanghai Second Medical University was to create a new source of embryonic stem cells (ESCs). These have the ability to transform into any tissue, making them potential sources of replacement cells for the treatment of many diseases. However, at present, these can only be derived from fertilised human embryos, resulting in widespread controversy. The embryos must be destroyed to harvest ESCs, which some see as ending a potential human life. In contrast, few experts think the rabbit-human hybrid embryos could be develop beyond the earliest stages. Also, cells from the hybrid contain only a tiny amount of rabbit DNA in mitochondria, structures that supply chemical power to the cell, suggesting the cells might be useful for human therapies. But the immediate reception of Sheng's paper suggests it is unlikely to calm the fierce debate. It has already been hailed as an important advance, questioned for its scientific rigour and sensationalised as a bizarre mixing of human and animal parts. Chinese whispers Rumours of Sheng's work have been circulating for two years in scientific circles and occasional news reports . But she had a hard time finally getting the work accepted by the scientific community. "I was frustrated that it took so long to get the paper published," she told the journal Nature . "And it still may take a while for people to accept the work." One reason for the scepticism is that other researchers have had almost no success in their experiments with interspecies cloning techniques. Interspecies cloning has attracted researchers because eggs from humans, or endangered animals, are hard to obtain. Instead, scientists use eggs from a readily available source, e.g. cattle, empty out their chromosomes, and insert nuclear DNA from a donor, e.g. a human. The process "reprograms" the genetic material and creates an embryo that is the genetic twin of the donor. Except for a few animal cloning experiments where the two species were closely related, all these experiments have failed. But in the August issue of Cell Research (vol 13, p 251), a peer reviewed journal of the Chinese Academy of Sciences, Sheng reports remarkable success. Using donor cells from the foreskins of a five-year old boy and two men, and facial tissue from a woman, her team created hybrid rabbit-human embryos and from them derived ESCs that had the ability to transform into many tissue types. Human reprogramming Some see publication of the work as an important step forward. "This is the first paper to convincingly show that you can get human reprogramming," Robin Lovell-Badge of the National Institute for Medical Research in London told Nature . But others point out shortcomings. ESCs are supposed to be able to reproduce indefinitely, for instance, something the Chinese group did not demonstrate. And that tiny bit of rabbit DNA in the cells could still be a problem for any medical applications. The few rabbit genes present may generate proteins that would be rapidly attacked by the human immune system. Robert Lanza of Massachusetts-based biotech company Advanced Cell Technology says: "If this is true, it's very important. But their results are very hard to believe." Lanza's team has tried and failed to derive ESCs from human-cow and human-rabbit embryos. He is now convinced those experiments are doomed for very basic biological reasons. But Lanza says Sheng could easily win over doubters by supplying their hybrid cells to other ESC labs to test. His own work is now focused on other ways to reprogram cells, partly because of the public reaction to his experiments that mixed human and animal cells. "There is always the yuck factor," he told New Scientist . http://gonow.to/resonance submitters website
First Human Embryos Cloned (Moderator)	posted 8/18/03 10:11 AM     First cloned human embryos created 12:07 26 November 01 The first cloned human embryos have been created, claims a US biotechnology company, as predicted by New Scientist on 13 July. The achievement is a technological feat, but more significantly crosses a major ethical boundary. Advanced Cell Technology (ACT) of Worcester, Massachusetts says its intention is not to produce a cloned baby, but to develop a way of obtaining embryonic stem cells matched to patients. These "pluripotent" cells have the potential to mature into any cell type and are showing great promise in the treatment of diseases including diabetes, stroke and Parkinson's disease. Harvesting the cells from an embryonic clone of a patient would mean the transplant tissue was perfectly matched. But ACT's announcement has provoked, on the one hand, scepticism from some scientists about whether viable cloned embryos had actually been created, and on the other, fury from anti-cloning groups. Ian Wilmut, who cloned Dolly the sheep at the Roslin Institute, said ACT's results were "very preliminary". He said a human embryo is expected to double its number of cells every 24 hours, but even ACT's most developed embryo had not done this: "The furthest it got was to have six cells, at a time it should have had 60, so it had already died." Bruno Quintavalle, of the Pro-Life Alliance, reflected the views of many opponents of cloning when he said ACT's achievement was a "milestone in scientific depravity". David King of Human Genetics Alert told the BBC: "They have done the work for those who do want to clone humans." Legal loophole The work is legal in the US because ACT is a private company, not receiving federal government funds. However, President George W Bush had planned to outlaw cloning before the 11 September attacks and is likely to revive the proposed legislation. Following the announcement on Sunday, Bush said he was "100 per cent oppose to any type of cloning of human embryos". In the UK, a legal loophole exposed on 15 November means cloning is not illegal but a one line bill being presented to parliament on Monday will make "it an offence to place in a woman a human embryo which has been created by a method other than by fertilisation". This would not have ruled out ACT's work, had it been carried in the UK. Most scientists oppose reproductive cloning (producing babies), but are in favour of therapeutic cloning (producing transplant cells) and so will hope that any new laws in the US or UK will be able to separate the two. Twin track approach The researchers from ACT, with colleagues at Duncan Holly Biomedical, used two different techniques to produce the embryos. Both have been successful in previous animal experiments, but had not been performed on human embryos. The first was the nuclear transfer (NT) technique used to produce Dolly, in which the nuclear DNA in an egg is replaced with DNA from an adult cell and then fused. ACT used 19 eggs from seven volunteers. Of these, only three went on to develop to the four or six cell stage. The second technique used is called parthenogenesis and ACT's experiments on this were reported by New Scientist magazine on 6 October. Normally, fertilised egg cells get one set of chromosomes each from the mother and father. But in parthenogenesis, the egg cell duplicates one set of maternal chromosomes. Producing embryos by parthenogenesis is ethically attractive because they never develop into fetuses, meaning they are not "potential people". ACT used 22 eggs for the parthenogenesis experiment, six of which went on to develop blastocoele cavities. This means the embryo has developed an inner and outer group of cells - the inner cells are the potential source of embryonic stem cells. ACT has already obtained embryonic stem cells from parthenogenetic monkey embryos. Weblinks Advanced Cell Technology Journal of Regenerative Medicine Parthenogenesis, New Scientist magazine Cloning, New Scientist Stem cells, NIH ACT's Jose Cibelli, first author of the Journal of Regenerative Medicine paper, accepts the research is at an early stage: "We understand that these are preliminary results, but given the importance of this emerging field of medicine we decided to publish our results now." Michael West, ACT's Chief Executive Officer, adds that, if successful, the approach could provide ways of tackling a "tidal wave of age-related disease that will accompany the aging of the population". "We may have found a means of rebuilding the lifespan of cells," he said. "This would allow us to supply young cells of any kind, identical to the patient." In November 1998, ACT said it had fused the genetic material from a human nuclear DNA with an emptied-out cow's egg to create a hybrid embryo. The following month, researchers at Kyunghee University in South Korea claimed to have produced cloned human embryos, but it was never confirmed. Claims of human cloning experiments by other scientists and religious groups have also never been confirmed - ACT's new research is the first to be published in a scientific journal. Damian Carrington http://gonow.to/resonance submitters website
Ram	posted 4/23/04 2:43 AM     Thursday April 22, 01:30 PM 'Virgin birth' mammal rewrites rules of biology By Sylvia Pagán Westphal A mammal that is the daughter of two female parents has been created for the first time. Until now such a feat had been considered biologically impossible. But the mouse, called Kaguya, was born without the involvement of any sperm or male cell - only female eggs were needed. In the same way that the birth of Dolly the sheep in 1997 shattered the dogma that an adult cell could never be reprogrammed to make a new individual, the fact that Kaguya lives challenges another one of long-held rule: that two mammals of the same sex cannot combine their genomes to give rise to viable offspring. What scientists learn from this remarkable rodent, created in Japan, is likely to have an impact on fields from fundamental embryology to assisted reproduction and even cloning. However, several experts have already warned against assuming the method could be used in humans to help two women have a biological child, not least because the process is extremely inefficient. It would also be highly risky and require a very large number of eggs. "To do this kind of experimentation in humans would be outrageous," says fertility specialist Gianpiero Palermo of Cornell University in New York. Virgin birth Kaguya was created by combining the genetic material of two egg cells. This would not normally work, a fact evidenced by decades of studies into the phenomenon of parthenogenesis, also known as virgin birth. In parthenogenesis, the egg becomes the sole source of genetic material for the creation of an embryo. It is a mode of reproduction in some species, though not in mammals. In mammals parthenogenesis can begin if an egg is accidentally or experimentally activated as if it had been fertilised - but this parthenote never grows past a few days. This is because of there a biological phenomenon known as imprinting. During sperm and egg formation in mammals, certain genes necessary for embryo development are shut down with a series of chemical marks, or imprints, some in the sperm, other in the egg. Only when sperm and egg meet are all of the key genes available, allowing proper development. But Tomohiro Kono and colleagues at the Tokyo University of Agriculture in Tokyo, Japan, circumvented this imprinting barrier by manipulating the nucleus of a female egg to make it more male-like. This was far from simple. Perhaps the most important of the many steps required was the creation of eggs that produced a protein called IGF-2. This is crucial to embryo growth but is normally only produced by sperm-derived DNA. The researchers achieved the trick by using genetically altered mice to provide the donated eggs. The nucleus of such an egg was then transferred into a regular egg that, with the genomes of two females, proceeded to grow and divide. However, Kaguya and one sister were the only live animals resulting from 457 reconstructed eggs. Fertility techniques Although attempting to apply such an approach to humans horrifies experts, that does not mean the technique will not have a big impact in studies of human biology. For example, future experiments of the same kind will allow scientists to learn which other genes can be altered to bypass imprinting defects. This could help optimise fertility techniques, some of which are thought to interfere with imprinting. In addition, the work might provide new hints to make animal cloning more efficient, as many of the failures in cloned animals are thought to come from imprinting defects. While he agrees the creation of the mouse is a major achievement, imprinting expert Azim Surani, at the University of Cambridge, UK, hopes the work will not be misinterpreted to imply that males are somehow redundant. "It shows the opposite - clearly IGF-2 is the key gene," he says. "They managed to get around it but to really get to a situation where the procedure would work as well as [fertilisation with] sperm, you would need to mutate a lot more genes." Journal reference: Nature (vol 428, p 860) http://uk.news.yahoo.com/040422/12/erqei.html 'Virgin birth' mammal rewrites rules of biology
'Virgin birth' mammal rewrites rules of biology	posted 6/8/04 6:05 AM     'Virgin birth' mammal rewrites rules of biology 18:00 21 April 04 NewScientist.com news service A mammal that is the daughter of two female parents has been created for the first time. Until now such a feat had been considered biologically impossible. But the mouse, called Kaguya, was born without the involvement of any sperm or male cell - only female eggs were needed. In the same way that the birth of Dolly the sheep in 1997 shattered the dogma that an adult cell could never be reprogrammed to make a new individual, the fact that Kaguya lives challenges another one of long-held rule: that two mammals of the same sex cannot combine their genomes to give rise to viable offspring. The virgin birth What scientists learn from this remarkable rodent, created in Japan, is likely to have an impact on fields from fundamental embryology to assisted reproduction and even cloning. However, several experts have already warned against assuming the method could be used in humans to help two women have a biological child, not least because the process is extremely inefficient. It would also be highly risky and require a very large number of eggs. "To do this kind of experimentation in humans would be outrageous," says fertility specialist Gianpiero Palermo of Cornell University in New York. Virgin birth Kaguya was created by combining the genetic material of two egg cells. This would not normally work, a fact evidenced by decades of studies into the phenomenon of parthenogenesis, also known as virgin birth. In parthenogenesis, the egg becomes the sole source of genetic material for the creation of an embryo. It is a mode of reproduction in some species, though not in mammals. In mammals parthenogenesis can begin if an egg is accidentally or experimentally activated as if it had been fertilised - but this parthenote never grows past a few days. This is because of there a biological phenomenon known as imprinting. During sperm and egg formation in mammals, certain genes necessary for embryo development are shut down with a series of chemical marks, or imprints, some in the sperm, other in the egg. Only when sperm and egg meet are all of the key genes available, allowing proper development. But Tomohiro Kono and colleagues at the Tokyo University of Agriculture in Tokyo, Japan, circumvented this imprinting barrier by manipulating the nucleus of a female egg to make it more male-like. This was far from simple. Perhaps the most important of the many steps required was the creation of eggs that produced a protein called IGF-2. This is crucial to embryo growth but is normally only produced by sperm-derived DNA. The researchers achieved the trick by using genetically altered mice to provide the donated eggs. The nucleus of such an egg was then transferred into a regular egg that, with the genomes of two females, proceeded to grow and divide. However, Kaguya and one sister were the only live animals resulting from 457 reconstructed eggs. Fertility techniques Although attempting to apply such an approach to humans horrifies experts, that does not mean the technique will not have a big impact in studies of human biology. For example, future experiments of the same kind will allow scientists to learn which other genes can be altered to bypass imprinting defects. This could help optimise fertility techniques, some of which are thought to interfere with imprinting. In addition, the work might provide new hints to make animal cloning more efficient, as many of the failures in cloned animals are thought to come from imprinting defects. While he agrees the creation of the mouse is a major achievement, imprinting expert Azim Surani, at the University of Cambridge, UK, hopes the work will not be misinterpreted to imply that males are somehow redundant. "It shows the opposite - clearly IGF-2 is the key gene," he says. "They managed to get around it but to really get to a situation where the procedure would work as well as [fertilisation with] sperm, you would need to mutate a lot more genes." Journal reference: Nature (vol 428, p 860) Sylvia Pagán Westphal http://www.newscientist.com/news/news.jsp?id=ns99994909
Pig-human chimeras contain cell surprise	posted 6/8/04 6:21 AM     Pig-human chimeras contain cell surprise 13:42 13 January 04 NewScientist.com news service Pigs grown from fetuses into which human stem cells were injected have surprised scientists by having cells in which the DNA from the two species is mixed at the most intimate level. It is the first time such fused cells have been seen in living creatures. The discovery could have serious implications for xenotransplantation - the use of animal tissue and organs in humans - and even the origin of diseases such as HIV. The adult pigs that had received human stem cells as fetuses were found to have pig cells, human cells and the hybrid cells in their blood and organs. "What we found was completely unexpected. We found that the human and pig cells had totally fused in the animals' bodies," said Jeffrey Platt, director of the Mayo Clinic Transplantation Biology Program. Nuclear mix The hybrid cells had both human and pig surface markers. But, most surprisingly, the hybrid cell nuclei were found to have chromosomal DNA that contained both human and pig genes. The researchers found that about 60 per cent of the animals' non-pig cells were hybrids, with the remainder being fully human. Importantly, the team also found that porcine endogenous retrovirus (PERV), which is present in almost all pigs, was also present in the hybrid cells. Previous laboratory work has shown that while PERVs in pig cells cannot infect human cells, those in hybrid cells can. The discovery therefore suggests a serious potential problem for xenotransplantation. The work also suggests a possible route of infection for other viruses that have crossed from animals to humans. "Perhaps HIV managed to jump from primates to humans through infected blood from a bite, which allowed the stem cells from the two species to fuse," Platt told New Scientist. "When the genes recombined, perhaps the virus was reawakened." Body plan Chimeric animals containing human cells have been created before. New Scientist reported in December on the growing of human liver cells in sheep. The work, by Esmail Zanjani and colleagues at the University of Nevada, Reno, aims to provide human tissue for transplantation into people. "The new work is certainly very interesting," Zanjani told New Scientist. "But the question is how widespread and how many of these hybrid cells were found? If they are very rare - and we haven't found any in our experiments - then I don't think it is that important." Zanjani says it is "possible" that HIV had spread to humans through a type of human-primate cell fusion, but adds that much more research needs to be done. In Platt's experiments, the human stem cells were injected into the pig fetuses about a third of the way through gestation. In Zanjani's work, the cells were injected about halfway through. The injections must be given after the body plan of the fetus has developed, but before the immune system is active. The former ensures the animals look like normal pigs and sheep. The latter prevents the human stem cells being rejected. Journal reference: Federation of American Societies for Experimental Biology Journal (DOI: 1096/fj.03-00962fje) Gaia Vince http://www.newscientist.com/news/news.jsp?id=ns99994558
'Humanised' organs can be grown in animals	posted 6/8/04 6:24 AM     'Humanised' organs can be grown in animals 19:00 17 December 03 . It's bad news, says your doctor. Your liver is failing. So he extracts stem cells from your bone marrow and injects them into a sheep fetus while it is still in the womb. When the sheep is born, much of the animal's liver will consist of your own cells - ready to be harvested and given back to you. This dream therapy is still years off, if it happens at all, but the first steps have already been taken by a team led by Esmail Zanjani at the University of Nevada, Reno. "Esmail has some pretty startling results," says Alan Flake of the Children's Hospital of Philadelphia. Zanjani's team hopes the animal-human chimeras they are creating will one day yield new cells genetically identical to a patient's own for repairing damaged organs, and perhaps larger pieces for transplantation. It might even be possible to transfer whole organs, since in some cases having at least a partly human organ would be better than a purely animal xenotransplant. Immune rejection of the animal portion would still be a problem, but it is not insurmountable, says Flake. "I don't think that in 10 to 15 years that's out of the question." Growth factors If perfected, the technique could overcome some of the big stumbling blocks facing researchers who want to make tissues and organs for implants. It might yield significant quantities of just about any kind of cell or tissue, for instance, with no need to fiddle about with different culture conditions or growth factors. Instead, the host animal's own developmental program guides the injected human stem cells into their final roles. "We take advantage of the growing nature of the fetus," Zanjani says. It would also allow doctors to obtain immune-compatible cells without having to create human embryos by therapeutic cloning. Human cells could be separated from the animal ones simply by modifying existing cell-sorting machines. Providing the method really does produce normal human cells, they would not be rejected. And any stray animal cells would be killed off by the recipient's immune system. Of course, the idea of using part-human, part-animal chimeras as living factories for producing cells or organs raises a host of ethical and safety issues. There is the risk of transferring animal diseases to humans, for a start. And the creation of such chimeras has long been controversial. Is a sheep with human cells making up part of its brain no longer just a sheep? Stem cell jab Zanjani's original goal was to see if unborn children with genetic defects could be treated by injecting healthy stem cells into the fetus. This is still his main aim, but while doing animal experiments he realised the technique could also be used to grow "humanised" organs. The first hint this might work came from work done by Flake a few years ago (Nature Medicine, vol 6, p 1282). He showed that when human mesenchymal stem cells extracted from bone marrow are injected into sheep fetuses, the human cells become part of the heart, skin, muscle, fat and other tissues. But the numbers of human cells were very low. Zanjani's team has now managed to produce sheep-human chimeras with a surprisingly high proportion of human cells in some organs. According to results presented at a conference earlier in December, in some cases between seven and 15 per cent of all the cells in the sheep's livers are human. The human cells must be injected around halfway through gestation - before the fetus's immune system has learned the difference between its own and foreign cells, so that the animal does not reject them, but after the body plan has formed. That ensures that the resulting animals look like normal sheep rather than strange hybrids like the "geep", created by fusing the embryos of a sheep and goat. Clustering together In some cases the human liver cells cluster together to form functional, fully human liver units, says Graca Almeida-Porada of the Nevada team. These units could be transplanted whole as auxiliary organs, says Zanjani. What is more, human albumin - a blood protein produced by the liver - has been detected in the host animals' blood. The work has been submitted for publication. Meanwhile, results of similar experiments on the heart will be published early in 2004. "The type of stem cells we use make a lot of heart cells," is all Zanjani will say about these experiments. If he is right, it would be an important advance because it would open the door to creating fetal heart cells for therapy. For example, a kind of fetal heart cell called a cardiomyocyte has been shown to be especially good at repairing hearts in rats or mice, but there is one big obstacle: at the moment the only source of human fetal heart cells is human fetuses. Robert Kloner, a heart expert at the University of Southern California in Los Angeles, says an approach like Zanjani's would get around this ethical issue. Time and place Zanjani says it might also be possible to grow a wide range of other tissues, such as insulin-producing islet cells for treating diabetes. And he hopes it will be possible to increase the proportion of human cells in organs still further. The team is now trying to identify subpopulations of stem cells that might be better at producing one organ or another. Their results also hint that the timing and site of the injection make a difference. But all members of the Nevada team stress that the technique is years, if not decades away from being tested in humans. For starters, it will be crucial to make sure the human cells really are functional. Recent experiments have suggested that some stem cells fuse with other cells when injected, rather than forming normal heart cells or liver cells. A key question is whether the human cells fuse with sheep cells, says Philip Noguchi, head of the Center for Biologics Evaluation and Research at the US Food and Drug Administration. It would not necessarily be the death knell if the cells do fuse, but it would be important to know what problems it presents, Noguchi says. Zanjani is optimistic, however: with human cells making up such a large proportion of some chimera organs, he thinks the sheep would die if these cells were dysfunctional fused cells. Lurking viruses All the same, there is widespread opposition to xenotransplantation in countries such as the UK and Canada. One big worry is that retroviruses lurking in animal DNA could mutate into forms that infect people. The US is more open to the idea, and a few clinical trials are under way, but health concerns mean Zanjani's technique would be expensive to develop. What is more, companies are unlikely to invest in the method because he has not tried to patent it. And it could even be unpatentable: in 1998, the US Patent Office declared it unlikely that it would grant any more patents on part-human inventions. Then there is the moral issue. Some people oppose the creation of all human-animal chimeras on religious grounds, and many more would join them if there were the slightest chance that sheep with human brain cells might be more than just sheep. Zanjani doesn't rule out the possibility entirely. "There is no way for us to know," he says. "But at the level we're working with the animal, it's still a sheep." Sylvia Pagán Westphal, Boston http://www.newscientist.com/news/news.jsp?id=ns99994492
New Genome Test Finds Big Differences Among People	posted 7/23/04 12:55 AM     Science - Reuters New Genome Test Finds Big Differences Among People Thu Jul 22, 4:36 PM ET By Maggie Fox, Health and Science Correspondent WASHINGTON (Reuters) - A new way of comparing DNA has turned up surprising genetic differences among normal, healthy people, researchers said on Thursday. The researchers found -- by accident -- that some people are missing large chunks of DNA, while others have extra copies of stretches of DNA. Writing in the journal Science, the researchers have dubbed these differences "copy number polymorphisms." They are found in genes linked with cancer risk, with how much people eat and with reactions to drugs. "Thus, a relationship between CNPs and susceptibility to health problems such as neurological disease, cancer, and obesity is an intriguing possibility," the researchers wrote in their report. The team at Cold Spring Harbor Laboratory in New York, the Karolinska Institute in Stockholm, Sweden and elsewhere used a new kind of DNA test called Representational Oligonucleotide Microarray Analysis or ROMA. "It can detect differences in DNA from any two sources," said Cold Spring Harbor spokesman Peter Sherwood. The researchers were looking for genetic differences linked with cancer. "As a control in the cancer experiment they compared normal to normal DNA, expecting it to be pretty much the same," Sherwood said in a telephone interview. "They detected more than 70 of these large chunks of DNA that were altered in normal human cells." These were large differences that have not been reported before -- involving much more DNA than so-called single nucleotide polymorphisms, which are well-known single-letter changes in the A, C, T, G nucleotide code that makes up DNA. Other experts praised the work. "PRETTY IMPORTANT" "I think it's pretty important," said Craig Venter, who led the team that first sequenced the complete human genome when at Celera Genomics (news - web sites) Inc . "This helps explain how, with very little sequence differences, how we humans come up with such big differences among us," added Venter, now at the nonprofit Institute for Biological Energy Alternatives. Although genome experts are not done picking out the many genes found in human DNA, they estimate there may be as few as 30,000 different genes -- a far cry from original estimates of 100,000 or more. Venter and others have predicted that patterns of DNA outside the genes will hold much of the secret to human biology. The researchers also found possible mistakes in the map of the human genome published by the Human Genome Project (news - web sites). In 20 people they found a stretch of DNA on chromosome 16 that does not appear there in the published sequence of the human genome -- but rather on chromosome 6. "It is extra copies of a gene that no one knew about," Sherwood said. Comparisons of human to chimpanzee genomes have found similar swaps, when a gene migrates from one chromosome to another. "Just as chromosomal rearrangements have played a significant role in primate evolution and human disease, structural polymorphisms may play an analogous role in determining genetic diversity within the human population," the researchers wrote. Everyone has two copies of each chromosome, except for the X and Y chromosomes that separate men from women. The researchers found that each of their healthy volunteers had just one copy of each CNP. "If they happen to marry and have children with someone who has the same CNP, maybe the children will be affected," Sherwood said. http://story.news.yahoo.com/news?tmpl=story&cid=585&e=2&u=/nm/20040722/sc_nm/science_genome_dc
Scientists Aim to Revive the Woolly Mammoth (Moderator)	posted 5/7/05 7:16 AM     Scientists Aim to Revive the Woolly Mammoth By Bill Christensen posted: 11 April 2005 12:56 pm ET Scientists with the Mammoth Creation Project hope to find a frozen woolly mammoth specimen with sperm DNA. The sperm DNA would then be injected into a female elephant; by repeating the procedure with offspring, a creature 88 percent mammoth could be produced within fifty years. "This is possible with modern technology we already have," said Akira Iritani, who is chairman of the genetic engineering department at Kinki University in Japan and a member of the Mammoth Creation Project. However, the DNA in mammoth remains found to date has been unusable, damaged by time and climate changes. "From a geologist's point of view, the preservation of viable sperm is very unlikely, and this is so far confirmed by the poor condition of cells in the mammoth carcasses," said Andrei Sher, Russian paleontologist and mammoth expert. Woolly mammoths became extinct about 10,000 years ago as warming weather reduced their food sources. Although only about a hundred specimens have been found, as many as ten million mammoths are believed buried in permanently frozen Russian soil. Irtani has already picked out a preserve for living mammoths in northern Siberia; this "Pleistocene Park" would feature extinct species of deer, woolly rhinoceroses and maybe even saber-toothed cats, along with the mammoths. In his novel Jurassic Park, Michael Crichton popularized the idea of using dinosaur DNA taken from mosquito-like insects trapped in amber to create a Jurassic Park of recreated dinosaurs. Unhappily for the Pleistocene Park planners, both books and all three movies ended badly for most of the participants, including the investors. Also, astute scientists are already pointing out that these experiments would merely create mammoth-like creatures, not mammoths themselves. This wasn't pointed out until the third movie in the Jurassic Park series. http://www.livescience.com/scienceoffiction/050412_mammoth_effort.html
Woolly Mammoth Resurrection, "Jurassic Park" Planned (Moderator)	posted 5/7/05 7:25 AM     Woolly Mammoth Resurrection, "Jurassic Park" Planned Stefan Lovgren for National Geographic News April 8, 2005 A team of Japanese genetic scientists aims to bring woolly mammoths back to life and create a Jurassic Park-style refuge for resurrected species. The effort has garnered new attention as a frozen mammoth is drawing crowds at the 2005 World Exposition in Aichi, Japan (see photo). The team of scientists, which is not associated with the exhibit, wants to do more than just put a carcass on display. They aim to revive the Ice Age plant-eaters, 10,000 years after they went extinct. Their plan: to retrieve sperm from a mammoth frozen in tundra, use it to impregnate an elephant, and then raise the offspring in a safari park in the Siberian wild. "If we create a mammoth, we will know much more about these animals, their history, and why they went extinct," said Kazufumi Goto, head scientist at the Mammoth Creation Project. The venture is privately funded and includes researchers from various institutions in Japan. Many mammoth experts scoff at the idea, calling it scientifically impossible and even morally irresponsible. "DNA preserved in ancient tissues is fragmented into thousands of tiny pieces nowhere near sufficiently preserved to drive the development of a baby mammoth," said Adrian Lister, a paleontologist at University College London in England. Furthermore, Lister added, "the natural habitat of the mammoth no longer exists. We would be creating an animal as a theme park attraction. Is this ethical?" Ice Age Giants Mammoths first appeared in Africa about four million years ago, then migrated north and dispersed widely across Europe and Asia. At first a fairly generalized elephant species, mammoths evolved into several specialized species adapted to their environments. The hardy woolly mammoths, for instance, thrived in the cold of Ice Age Siberia. In carvings and cave paintings, Ice Age humans immortalized the giant beasts, which stood about 11 feet (3.4 meters) tall at the shoulder and weighed about seven tons. "It is hard to imagine that woolly mammoths browsed around the places where we live now, and our ancestors saw them, lived with them, and even hunted them," said Andrei Sher, a paleontologist and mammoth expert at the Severtsov Institute of Ecology and Evolution in Moscow, Russia. At the end of the last ice age, about 10,000 years ago, woolly mammoths dwindled to extinction as warming weather diminished their food sources, most scientists believe. There are believed to be ten million mammoths buried in permanently frozen soil in Siberia. Because of the sparse human population in the region, though, only about a hundred specimens have been discovered, including two dozen complete skeletons. Only a handful of complete carcasses have been found. In 2002 hunters stumbled across the mammoth now on display in Japan. After a period of relatively warm weather, the head of the beast had been left protruding through the snow and ice cover. Viable DNA? The scientists with the Mammoth Creation Project are hoping to find a mammoth that is sufficiently well preserved in the ice to enable them to extract sperm DNA from the frozen remains. They will then inject the sperm DNA into a female elephant, the mammoth's modern-day counterpart. By repeating the procedure with offspring, scientists say, they could produce a creature that is 88 percent mammoth within 50 years. "This is possible with modern technology we already have," said Akira Iritani, who is chairman of the genetic engineering department at Kinki University in Japan and a member of the Mammoth Creation Project. In 1986 Iritani's lab successfully fertilized rabbit eggs artificially, employing a technique now used in humans. In 1990 his colleague Goto, the Mammoth Creation Project head scientist, pioneered a breeding plan to save a native Japanese cow species by injecting dead sperm cells into mature eggs. The current challenge, however, is finding viable woolly mammoth DNA. The DNA in mammoth remains found to date has been unusable, damaged by time and climate changes. "From a geologist's point of view, the preservation of viable sperm is very unlikely, and this is so far confirmed by the poor condition of cells in the mammoth carcasses," said Sher, the Russian paleontologist. Current Siberian permafrost temperatures are 10 to 18 degrees Fahrenheit (minus 12 to 8 degrees Celsius), which may not be cold enough for DNA survival. Sperm is not the only possible DNA source, and mammoth-elephant crossbreeding isn't the only potential way to resurrect the woolly mammoth. An alternative method would be to clone a mammoth from DNA found in mammoth muscles or skin. To do this, however, scientists would need preserved cells with some unbroken strands of DNA. "There is no evidence this exists, and even if it did, it is very unlikely to be preserved without significant errors having accumulated—probably leading to birth defects," said Lister, the London paleontologist. Safari Park The Japanese scientists, however, are not deterred. Iritani is planning a summer expedition to Siberia to search for more carcasses. His team has already picked out a home for living mammoths in northern Siberia. The preserve, dubbed Pleistocene Park, could feature not only mammoths, but also extinct species of deer, woolly rhinoceroses, and even saber-toothed cats, he said. "This is an extension of my work for the past 20 years in trying to save endangered species," Iritani said. Other scientists are less enthusiastic about the project. "Even if the cloning experiment is successful, they are not reconstructing the past but rather creating a new mammoth-like creature," said Anatoly Lozhkin, an Ice Age expert at the Northeast Interdisciplinary Scientific Research Institute in Magadan, Russia. "Scientists are always able to learn from every experiment, but I am not sure that cloning a mammoth will help us significantly move forward our understanding of the animal or the conditions under which it lived," Lozhkin said. http://news.nationalgeographic.com/news/2005/04/0408_050408_woollymammoth.html

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