What Are Examples Of Performance Locomotion Growth Genetic Makeup

Gene doping could stretch the physical limits of man strength and endurance. What are the consequences of gene therapy in sports competition, and more, importantly, is it safe?

Gene doping.

© 2003 Nature Publishing Group Murray, T. An Olympic tail? Nature Reviews Genetics 4, 494 (2003). All rights reserved.

Gene doping is an outgrowth of gene therapy. However, instead of injecting DNA into a person'southward trunk for the purpose of restoring some office related to a damaged or missing gene, every bit in gene therapy, gene doping involves inserting DNA for the purpose of enhancing athletic performance. The World Anti-Doping Agency (WADA), an international organization created in 1999 to "promote, coordinate, and monitor the fight against doping in sport in all its forms," defines gene doping as the "nontherapeutic use of cells, genes, genetic elements, or modulation of gene expression, having the capacity to enhance operation" (Earth Anti-Doping Agency, 2008).

One of the first issues that comes up when considering whether, when, and how results from genetic studies will exist exploited for gene doping purposes is whether gene doping is "correct." While many people agree with WADA's position that gene doping threatens the integrity of sports competition, others call up differently. For example, Julian Savulescu, professor of ethics at the University of Oxford, England, argues that "[g]enetic enhancement is not confronting the spirit of sport; information technology is the spirit of sport" (Skipper, 2004). Whether or not it is right to use Deoxyribonucleic acid for enhanced athletic performance will probable be a subject of fiery debate for years to come.

The Science Behind Factor Doping

While gene doping has yet to become a reality, H. Lee Sweeney, a professor of physiology at the Academy of Pennsylvania Schoolhouse of Medicine and ane of the leading researchers in the field of gene therapy, has already been inundated with requests for such doping from professional weight lifters and numerous other athletes, according to an article in Science News (Brownlee, 2004). Sweeney has garnered this attending because of his discovery of a way to potentially reverse muscle degeneration acquired by diseases like Duchenne muscular dystrophy (DMD), a sex-linked genetic disorder. In patients with DMD, a critical muscle poly peptide chosen dystrophin gradually becomes dysfunctional over the first few years of an affected person's life, leading to a loss of muscle fiber, an increment in fibrosis, and eventually consummate loss of musculus function. Working with a mouse breed that had a mutation in the dystrophin factor and thus displayed a DMD-like phenotype (mdx mice), Sweeney and his colleagues observed that when a protein called insulin-like growth factor i (IGF-1) interacted with the cells on the outside of muscle fibers, information technology acquired the cells to grow. In add-on, the research squad adamant that inserting the gene that encodes IGF-1 into muscle cells produced the aforementioned effect.

Sweeney and his colleagues further constitute that when the muscle fibers of mdx mice were exposed to IGF-1, not only did fibrosis decrease as the mice aged, simply muscle mass actually increased by about 40% (Barton et al., 2002). Sweeney told Science News that when the mice became the equivalent of senior citizens (which for mice is almost 20 months of historic period), they were still as strong and fast equally they had been when they were young. After these and subsequent studies, the IGF-1-endowed mice became known as "Schwarzenegger mice." While groundbreaking, Sweeney's enquiry is still experimental, and the findings take yet to be tested on DMD patients or other humans.

Meanwhile, a group of scientists headed by Ronald Evans of the Salk Institute in La Jolla, California, demonstrated that injecting mice with the factor that encodes a fatty-burning protein called PPAR-δ enabled the animals to run up to twice the distance of their wild-type littermates (Wang et al., 2004). Although genetic applied science of these and then-called "marathon mice" could potentially be exploited to enhance able-bodied operation (in long-distance runners or swimmers, for case), Evans's reason for pursuing this line of enquiry was to see whether information technology might accept therapeutic value. Specifically, he wanted to test whether increasing PPAR-δ expression would transform muscle fibers in a mode that might protect confronting obesity and type II diabetes, as previous studies had shown that many obese and type II diabetic patients accept fewer type 1 muscle fibers. Evans and his team thus determined that increasing PPAR-δ expression effectively increased the number of type 1 musculus fibers in mice.

Would Gene Doping Be Safe?

More than important than the ethical implications of gene doping, some experts say, is the fact that gene doping could exist unsafe, and perhaps fifty-fifty fatal. Consider the protein erythropoietin (EPO), a hormone that plays a primal function in red claret cell production. EPO is often administered (as a hormone, not via gene therapy) to patients suffering from anemia as a event of kidney failure or chemotherapy. Scientists are hopeful that they tin can anytime develop a gene therapy method of delivering the gene for EPO instead of administering the protein itself. The hormone EPO is likewise used equally a highly controversial functioning-enhancing substance by athletes every bit a mode to optimize oxygen delivery to musculus cells (past increasing the number of cherry blood cells). Like IGF-ane and PPAR-δ, the EPO gene is considered by some experts to be a potential candidate for gene doping (Azzazy et al., 2005).

But scientists withal have much work to reach before EPO gene delivery, whether for the purpose of factor therapy or the more than controversial purpose of cistron doping, is considered safety. In the same Science News article, the reporter relays a story by Jim Wilson, a professor of medicine at the Academy of Pennsylvania and a leading researcher in the field of gene therapy. When Wilson and colleagues injected macaque monkeys with viral vectors carrying the EPO gene, the host cells ended upward producing and so many blood-red blood cells that the macaques' blood initially thickened into a deadly sludge. The scientists had to draw claret at regular intervals to keep the animals alive. Over time, as the animals' immune systems kicked in, the situation reversed and the animals became severely anemic (Rivera et al., 2005).

The field of cistron therapy, and by extension, factor doping, is full of unpredictable and dangerous results like this, which is why Sweeney, Evans, and other researchers who accept identified DNA targets that could potentially be exploited for gene doping are the first to emphasize that the research is still at only an experimental stage. The therapies need to be proven rubber in some of the larger animal models, not simply mice, before they can even be tested in humans, let lone used for therapy or, as Savulescu says, "in the spirit of sport."

References and Recommended Reading

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Azzazy, H. M. E., et al. Doping in the recombinant era: Strategies and counterstrategies. Clinical Biochemistry 38, 959–965 (2005)

Barton, East. R., et al. Muscle-specific expression of insulin-like growth gene 1 counters muscle reject in mdx mice. Journal of Prison cell Biological science 157, 137–148 (2002)

Brownlee, C. Factor doping: Will athletes get for the ultimate loftier? Science News 166, 280 (2004)

Murray, T. An Olympic tail? Nature Review Genetics 4, 494 (2003) doi:10.1038/nrg1135 (link to article)

Rivera, 5. M., et al. Long-term pharmacologically regulated expression of erythropoietin in patients post-obit AAV-mediated gene transfer. Blood 105, 1424–1430 (2005)

Skipper, M. Gene doping: A new threat for the Olympics? Nature Reviews Genetics 5, 720 (2004) doi:10.1038/nrg1461 (link to article)

Wang, Y. X., et al. Regulation of muscle fiber type and running endurance past PPAR-δ. PLoS Biology two, e294 (2004) (link to article)

Globe Anti-Doping Agency Dwelling house Folio. (accessed June 27, 2008).

Source: http://www.nature.com/scitable/topicpage/sports-gene-doping-and-wada-764

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