A New model System to Test the Adaptive Significance of Recombination

测试重组适应性意义的新模型系统

• 批准号: 9806917
• 负责人: William Rice
• 金额: $ 9.6万
• 依托单位: University of California-Santa Cruz
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-15 至 1999-02-22
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9806917&HistoricalAwards=false
• 关键词: New; model; System; Test; Adaptive

Rice9806917 Reproduction in plants and animals can occur with or without genetic recombination, yet most multicellular organisms utilize genetic recombination when producing offspring. In contrast, many agriculturally important crops such as nut trees, fruit trees, grapes, berries, etc. are propagated clonally, i.e., without genetic recombination. What are the costs of bypassing the normal recombining mode of sexual reproduction? The proposed research creates a new model system that permits a truly definitive test of most of the current theories concerning the adaptive significance of genetic recombination. The model system will be used to test the hypothesis that new beneficial mutations are incorporated into recombining populations at a far greater rate than clonal populations. The capacity for rapid adaptive evolution is becoming increasingly important owing to the rapid environmental change induced by human activities, e.g. global warming, habitat fragmentation, introduction of exotic species and disease organisms. The common fruit fly (Drosophila melanogaster) is used as a model system owing to its inexpensive culturing, short generation time, and availability of numerous genetic tools which are critical for the operation of these multi-generation experiments. Using a new clone-generator technology recently developed in our laboratory, we will experimentally introduce new beneficial mutations into populations with low vs. high levels of genetic recombination. Next we will measure the probability of accumulation of these beneficial mutations and relate this to the experimentally controlled level of genetic recombination. Current theory predicts that genetic recombination will greatly enhance the capacity of the populations to incorporate new beneficial mutations, and to purge deleterious mutations. Results from these experiments will contribute to our basic understanding of plant and animal breeding programs, long and short-term evolution, and will help us to predict the capacity of different life forms to adapt to human-induced environmental change.

植物和动物的繁殖可以有或没有基因重组，但大多数多细胞生物利用基因重组产生后代。 相反，许多农业上重要的作物如坚果树、果树、葡萄、浆果等是无性繁殖的，即，没有基因重组。 绕过正常的有性生殖重组模式的代价是什么？拟议的研究创建了一个新的模型系统，允许一个真正明确的测试大多数目前的理论有关的适应意义的遗传重组。 该模型系统将被用来测试的假设，新的有益的突变被纳入重组人口在一个更大的速度比克隆人口。由于人类活动引起的环境迅速变化，例如全球变暖、生境破碎化、引进外来物种和致病生物，迅速适应性进化的能力变得越来越重要。常见的果蝇（果蝇）被用作模型系统，由于其廉价的培养，世代时间短，和许多遗传工具的可用性，这是至关重要的操作这些多代实验。 使用我们实验室最近开发的一种新的克隆发生器技术，我们将实验性地将新的有益突变引入具有低水平与高水平遗传重组的人群中。 接下来，我们将测量这些有益突变的累积概率，并将其与实验控制的遗传重组水平相关联。 目前的理论预测，基因重组将大大提高人口的能力，纳入新的有益的突变，并清除有害的突变。 这些实验的结果将有助于我们对动植物育种计划、长期和短期进化的基本理解，并将帮助我们预测不同生命形式适应人类引起的环境变化的能力。