Howard Richard D, DeWoody J Andrew, Muir William M
Departments of Biological Sciences, Forestry and Natural Resources, and Animal Sciences, Purdue University, West Lafayette, IN 47907, USA.
Proc Natl Acad Sci U S A. 2004 Mar 2;101(9):2934-8. doi: 10.1073/pnas.0306285101. Epub 2004 Feb 19.
Genetically modified (GM) strains now exist for many organisms, producing significant promise for agricultural production. However, if these organisms have some fitness advantage, they may also pose an environmental harm when released. High mating success of GM males relative to WT males provides such an important fitness advantage. Here, we provide documentation that GM male medaka fish modified with salmon growth hormone possess an overwhelming mating advantage. GM medaka offspring possess a survival disadvantage relative to WT, however. When both of these fitness components are included in our model, the transgene is predicted to spread if GM individuals enter wild populations (because of the mating advantage) and ultimately lead to population extinction (because of the viability disadvantage). Mating trials indicate that WT males use alternative mating tactics in an effort to counter the mating advantage of GM males, and we use genetic markers to ascertain the success of these alternative strategies. Finally, we model the impact of alternative mating tactics by WT males on transgene spread. Such tactics may reduce the rate of transgene spread, but not the outcome.
现在许多生物都有转基因（GM）品系，这为农业生产带来了巨大希望。然而，如果这些生物具有某种适应性优势，那么它们被释放后也可能对环境造成危害。转基因雄性相对于野生型（WT）雄性具有较高的交配成功率，这就是一种重要的适应性优势。在此，我们提供证据表明，用鲑鱼生长激素改造的转基因青鳉雄鱼具有压倒性的交配优势。然而，转基因青鳉后代相对于野生型具有生存劣势。当我们的模型同时考虑这两个适应性组成部分时，预计如果转基因个体进入野生种群（由于交配优势），转基因将会传播，最终导致种群灭绝（由于生存能力劣势）。交配试验表明，野生型雄鱼会采用替代交配策略来对抗转基因雄鱼的交配优势，我们使用遗传标记来确定这些替代策略的成功率。最后，我们模拟了野生型雄鱼的替代交配策略对转基因传播的影响。这种策略可能会降低转基因传播的速度，但不会改变最终结果。
