The Impact of Genetic Recombination on Adaptation

基因重组是几乎所有复杂的多细胞生物的一个显著特征。然而，一些植物和动物物种缺乏这种遗传特征，包括许多农业上重要的物种，如果树、葡萄品种等。提出的研究测试了关于基因重组重要性的流行理论之一，即它加快了对环境变化的有益适应的速度。常见的果蝇（Drosophila melanogaster）被用作模型系统，因为它的培养成本低，世代时间短，并且可以获得许多对多代实验操作至关重要的遗传工具。利用赖斯实验室最近开发的一种新菌株，他将通过实验改变不同人群中基因重组的数量。然后，他将用一个新的环境（低等级的热应力）挑战这些种群，因为这可能发生在全球快速变暖的时期。接下来，他将测量适应的速度，并将其与实验控制的基因重组水平联系起来。目前的理论预测，基因重组将大大提高种群适应新环境的能力。由于人类活动引起的环境迅速变化，快速适应能力正变得越来越重要。这些实验的结果将有助于对植物和动物育种计划的基本了解，并将有助于预测不同生命形式适应人类引起的环境变化的能力。

9509101 RICE Genetic recombination is a prominent feature of virtually all complex, multicellular organisms. Yet some species of plants and animals lack this genetic feature, including many agriculturally important species like fruit trees, grape varieties, etc. The proposed research tests one of the prevailing theories about the importance of genetic recombination, i.e., it accelerates the rate of beneficial adaptation in response to environmental change. 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 critical for the operation of multi-generation experiments. Using a new strain recently developed in Dr. Rice's laboratory, he will experimentally vary the amount of genetic recombination in different populations. He will then challenge these populations with a new environment (low grade thermal stress), as it might occur during a period of rapid global warming. Next he will measure the rate of adaptation 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 adapt to the new environment. The capacity for rapid adaptation is becoming increasingly important owing to the rapid environmental change induced by human activities. Results from these experiments will contribute to basic understanding of plant and animal breeding programs, and will help to predict the capacity of different life forms to adapt to human-induced environmental change.