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Hello friends, the following is an article and abstract detailing a recent study carried out Purdue University on the impacts of transgenic fish on wild populations. Using a tiny fish called a medaka as their model organism, the researchers found that males carrying a gene modified for increased growth (gene construct containing human growth hormone driven by Atlantic salmon growth promoter) were much more successful than non-transgenic males in obtaining mates. The authors concluded that "transgenic fish are typically larger than the native stock, and that can confer an advantage in attracting mates". However, this genetic change also reduced the survivability of the offspring of transgenic males. On the basis of these results, the researchers predicted that transgenic fish could bring a wild population to extinction in 40 generations. I've included the aricle and abstract of the study below. This information was published originally by the Purdue University Press and released to the world using the on-line Ecolog Listserv of the Ecological Society of America. http://news.uns.purdue.edu/html4ever/0002.Muir.trojan.html cheers Faisal Moola Ph.D.. candidate Dalhousie University Halifax, N.S. Purdue News February 2000 Transgenic fish could threaten wild populations WEST LAFAYETTE, Ind. Purdue University researchers have found that releasing a transgenic fish to the wild could damage native populations even to the point of extinction. A transgenic organism is one that contains genes from another species. The Purdue research is part of an effort by Purdue and the U.S. Department of Agriculture to assess the risks and benefits of biotechnology and its products, such as genetically modified fish. The study was published in November in the Proceedings of the National Academy of Science. [. . .] Sources: Bill Muir, (765) 494-8032; bmuir@purdue.edu Rick Howard, (765) 494-8136 Writer: Chris Sigurdson, (765) 494-8396; sig@aes.purdue.edu Purdue News Service: (765) 494-2096; purduenews@uns.purdue.edu ABSTRACT Possible ecological risks of transgenic organism release when transgenes affect mating success: Sexual selection and the Trojan gene hypothesis William M. Muir and Richard D. Howard. Widespread interest in producing transgenic organisms is balanced by concern over ecological hazards, such as species extinction if such organisms were to be released into nature. An ecological risk associated with the introduction of a transgenic organism is that the transgene, though rare, can spread in a natural population. An increase in transgene frequency is often assumed to be unlikely because transgenic organisms typically have some viability disadvantage. Reduced viability is assumed to be common because transgenic individuals are best viewed as macromutants that lack any history of selection that could reduce negative fitness effects. However, these arguments ignore the potential advantageous effects of transgenes on some aspect of fitness such as mating success. Here, we examine the risk to a natural population after release of a few transgenic individuals when the transgene trait simultaneously increases transgenic male mating success and lowers the viability of transgenic offspring. We obtained relevant life history data by using the small cyprinodont fish, Japanese medaka (Oryzia= s latipes) as a model. Our deterministic equations predict that a transgene introduced into a natural population by a small number of transgenic fish will spread as a result of enhanced mating advantage, but the reduced viability of offspring will cause eventual local extinction of both populations. Such risks should be evaluated with each new transgenic anim= al before release. -*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*- The preceding message was posted on Sustainable Maritimes (sust-mar) -*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*- Looking for an old message? You'll find it in the sust-mar ARCHIVES ... http://www.chebucto.ns.ca/lists/sust-mar
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