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Follow on Google News | AILESBURY ETHICAL: 'is Parthogenesis an alternative to Cloning?' by Dr. Patrick TreacyStem cells are the holy grail of modern biology. These root cells can, with proper stimulation, be used to produce virtually any type of cell in the body. Until now, the best source of stem cells has been human embryos.
By: Ailesbury Media (1) Somatic Cell Nuclear Transfer: In this technique, commonly known as “Human Therapeutic Cloning” a patient’s body cell is combined with an egg cell that has its DNA removed. As a result the body cell’s DNA is reprogrammed back to an embryonic state, and totipotent stem cells are produced identical to the patient. (2) Ooplasmic Transfer: In the reverse of nuclear transfer, ooplasmic transfer involves the removal of the cytoplasm of an oocyte and transferring it into the body cell of a patient thereby transforming the patient’s cell into a primitive stem cell. (3) Parthenogenesis: Tell us more about the technique of parthenogenesis, which appears to both reduce transplantation problems and possibly be less controversial Parthenogenesis is derived from the Greek words for 'virgin birth'. In modern biology, it refers to a form of reproduction in which an ovum develops into a new individual without having been fertilised. In many social insects, such as the honeybee and the ant, the unfertilised eggs give rise to the male drones and the fertilized eggs to the female workers and queens. Charles Bonnet discovered the phenomenon of parthenogenesis in the 18th century. In 1900, biologists were able to encourage artificial parthenogenesis in some species. Jacques Loeb reported in that year that he was able to induce unfertilised frog eggs to grow by scratching them with a needle. Since that time various chemical and mechanical means have been used to produce artificial parthenogenesis in numerous animals including rabbits. However, in most cases the resulting developments abnormal. In 1936, Gregory Pincus induced parthenogenesis in mammalian (rabbit) eggs by temperature change and chemical agents. No successful experiments with human parthenogenesis have been reported. The phenomenon is rarer among plants (where it is called parthenocarpy) Would parthenogenesis really be ethically acceptable? The parthenogenetic creation of primate embryos with subsequent production of stem cells suggests a new, perhaps somewhat less ethically controversial direction in research aimed at treating human diseases with stem cell-derived therapies. There is no doubt that the Catholic Church would denounce it on the basis of two couples not being involved in the creation of the initial embryo but they would have certain difficulties explaining when exactly a life force actually entered the cell to make it a potential human being. This would become more difficult if human parthenogenesis was found to occur by some simple method such as heating or electrifying the cell, which is one of the reasons that I maintain that life is a continium. Anyway, it is now known that a team of scientists from Mayo Clinic, Sloan Kettering Cancer Centre and Wake Forest University working with a Massachusetts biotechnology company recently managed to create primate embryos parthenogenetically. The research involved stimulating a monkey egg to grow without any help from sperm. The researchers used chemicals to signal the eggs not to eject half of their chromosomes (as they would do in sexual reproduction) How long will it be before human parthenogenesis is achieved? Researchers from the same biotech company that supported the current research, Advanced Cell Technologies, created considerable controversy in November of last year when they announced they had cloned human embryos. The embryos had not grown beyond six cells and had not produced stem cells. While the race is on to create parthenogenetic human embryos, considerable doubts remain regarding the safety and efficacy of this approach. Researchers believe that the male DNA that mixes with the females DNA in the egg probably has an important role to play in gene activation in at least some kinds of stem cells. For example, studies in mice produced parthenogenetically suggest that those stem cells differentiate more readily into neurons than into other cell types such a muscle. The hypothesis that such cells would indeed be immune-privileged also remains unproven. # # # Ailesbury Clinics Ltd is the leading provider of advanced medical aesthetic skin care in Ireland. It was awarded Best Medical Practice in Ireland 2005. Further details WEBSITE http://www.ailesburyclinic.ie PHONE +3531 2692255/ 2133 Fax 2692250 End
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