| | | Syed Salahuddin Qadri & Aleem Ahmed CLONING EMBRYOThe major problem in mammalian cloning is to obtain working egg cells. It becomes even more difficult in humans. An ordinary woman can produce 1-2 egg cells at a time. For in vitro fertilization (IVF) - commonly known as the procedure of "test tube babies" - a number of human egg cells are required. Using hormonal doses, a maximum of 12 to 15 eggs are produced at a time; later they are separated by surgery. Embryonic cloning by ACT, (Advanced Cell Technology) involved 7 women to get 71 egg cells. Another crucial stage after obtaining egg cells is to successfully get a human embryo. ACT team could make only eight embryos out of 71 egg cells. Only two out of the eight embryos could reach the four-celled stage while only one of them could grow to the six-celled stage. It is important to mention here that the embryonic cloning effort from ACT only partially succeeded - even after third attempt. On the other hand, to be completely successful, an embryo must reach the blastocyst stage - that is, an embryonic stage consisting of 100 to 200 cells. In the experiments of Dolly (the first successfully cloned mammal), only 29 successful embryos could be obtained out of 277 egg cells. Later, in the year 2000 (during the first cross-species cloning experiments resulting in the birth of a cloned gaur - Asian bull) only 42 healthy embryos could be obtained out of 692 egg cells. So it is obvious that mammalian cloned embryos have an extremely low rate of success. General success rate remains only one per cent while the best ratio is 5 per cent (in mouse cloning). BIRTH RATE AND DEATH After the successful cloning of embryo, the next thorny stage is the transfer of embryo in the uterus, having pregnancy and finally having a birth. Even in assisted reproduction (in vitro fertilization), most of the embryos are wasted during the process of transplantation. The bleak picture emerges from the experiments of mammalian cloning. Most of the cloned pregnancies, soon or later, are aborted. A survey of mammalian cloning efforts reveals that, back in 1998, only 31 living mice were obtained out of 2468 embryos, which is by far the largest number of born-cloned mammals in any experiment. It makes the success rate only 1.3 per cent. Furthermore, 20 mice died when they were young. Similarly, in early 2001, cloned gaur died only two days after its birth. In March 2001, three cloned calves were born. First calf died only 12 days later, second one died after 15 days while the third calf (which was apparently healthy) could survive only a couple of days more than other two clones. According to the mammalian cloning experts, early deaths of cloned mammals are very common. For the various reasons, they can't survive longer. IMMUNE SYSTEM AND HEALTH As we have seen above, despite the apparently good health conditions, a cloned mammal faces a number of complications such as problems in respiratory and blood circulation systems, weaknesses in immune system, kidney failure, immune deficiencies, retarded brain growth, etc. Scientists have identified some genes that influence normal biological systems in mammals and cause the problems mentioned above. But there are other factors as well. For example, Telomeres (molecular caps on the tips of chromosomes, which become thinner and thinner as a mammal grows old) have a pivotal role in the process of aging. Dolly faced arthritis when she was only two years old, while the disease strikes a normal sheep at the age of about five to seven years - that is, at the old age from a sheep's point of view. Put in easier words, one can say that Dolly was five years old at the time of her birth (because she was cloned from an adult sheep with the age of five years). In the light of these facts, if Clonaid's claim were correct, then the newly born baby girl would be 30 years old at the time of her birth - because she is a clone of a 30-year-old woman. And, if she lives to maturity - biologically speaking - she will actually be in her 50s despite having been born twenty years ago. It is also important to note that a genetic change in body cells may result in some unknown deficiency, or a horrible disease. What will happen in future, no one really knows at the moment! EVOLUTION SUPPRESSION It is said that cloning will give us more capable plants and animals in a greater quantity. In other words, cloning may give us a sort of "quality control" over the flora and fauna. But, on the other hand, it will also suppress the process of evolution. Every new living organism (from single-celled microbes to multi-cellular and complex mammals) produced through the natural means of reproduction contains different order of genes in it. Therefore, it may also have positive or negative characteristics as well. On the contrary, a clone will have very similar genes and characteristics to that of its original. It is now known that the new genetic makeup, resulting from the natural process of reproduction, also causes better brain-related abilities. These abilities are very important for the survival in the present age. One can easily conclude that cloning will stop the process of natural selection and resulting evolution. SPREADING EPIDEMICS Last, but not the least, because of suppressed evolution, cloned humans will have a lesser potential to fight new diseases. Their immune system will be quite weak to stand attack from an ordinary ailment. The situation might get even worse with the developments in transgenic technology. (Using this technology, genes taken from one species are put in another, different species. For example, scientists are now trying to grow cows, sheep and goats that will contain certain human genes.) It may familiarize non-human proteins and viruses to human proteins and there is a great risk of new epidemics associated with transgenic technology. Normal humans have an adaptive immune system, which has a great potential to fight new diseases. But, as we have seen, cloned humans will certainly become a vulnerable target of such epidemics with, perhaps, no hope of survival.
Syed Salahuddin Qadri, lecturer in Biology at Jamia Millia Govt Degree College, Malir, Karachi; Aleem Ahmed is a science journalist and editor, monthly Global Science, Karachi.
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