The genomics of thermal adaptation in a model pest insect

每年有六分之一的世界农作物因病虫害而损失。全球气温上升预计将导致粮食害虫的范围和数量发生巨大变化，可能给全球粮食供应带来令人担忧的后果。因此，为了在气候变化的背景下保护粮食安全，需要从分子生物学、遗传学、生态学和进化生物学等领域对有害生物物种如何适应其环境进行多学科研究。了解生物体如何适应高温尤为重要，因为温度升高会以广泛的方式影响生物体，从它们的DNA到它们复杂的社会行为。将达尔文进化论原理与DNA测序相结合，是研究害虫如何适应温度的绝佳方法。害虫物种通常有很短的生命周期，因此可以迅速进化以应对不断变化的温度。利用DNA测序来研究害虫如何进化以应对温度是一种很有前途的方法，因为i)许多被认为对害虫如何适应温度很重要的特征和过程，如体型、发育和应激反应，都有遗传基础；ii)它将使我们能够识别与适应气候有关的新基因和新生物过程。然而，目前我们对哪些基因参与适应温度知之甚少，更不知道这些基因能多快地进化并允许害虫传播。我将研究食物害虫如何适应温度。我研究的生物将是红粉甲虫，这是储存谷物的一种主要害虫，每年都会导致大量的小麦、水稻和玉米被丢弃。它也是DNA研究的“模式物种”，具有详细的遗传信息，并且易于在实验室中饲养和研究。我将研究红粉甲虫是如何在极端温度下实时进化的，使用在实验室高温下维持60代的复制种群。通过对适应极端温度生活的面粉甲虫个体的基因组进行测序，我将确定控制对温度适应的基因和生物过程，并找出这些基因如何相互作用。此外，因为我有自这个实验建立以来每一代的样本，我将能够看到参与适应温度的基因如何随着时间的推移而进化，并以此确定这些重要基因对温度变化的反应速度有多快。拟议中的研究将使我们更好地了解DNA是如何使个人和群体适应环境的。而且，重要的是，它将帮助我们更好地预测，随着全球气候的不断变化，食物害虫可能在何时何地传播。

One sixth of the world's crop production is lost to pests and diseases each year. Rises in global temperatures are expected to cause dramatic shifts in the range and abundance of food pests, with potentially alarming consequences for global food supplies. To protect food security in the context of a changing climate therefore requires multidisciplinary research into how pest species adapt to their environments, drawing from the fields of molecular biology, genetics, ecology and evolutionary biology. Understanding how organisms adapt to high temperature is especially important, as temperature increases affect organisms in a wide range of ways, from their DNA to their complex social behaviours.Combining the principles of Darwinian evolution with DNA sequencing is an excellent way of studying how pests adapt to temperature. Pest species usually have very short life-cycles, so can evolve rapidly in response to changing temperatures. Studying how pests evolve in response to temperature using DNA sequencing is a promising way forward because i) many of the characteristics and processes thought to be important for how pests adapt to temperature, such as body size, development and stress response, have a genetic basis; and ii) it will enable us to identify new genes, and new biological processes, involved in adapting to climate. At present, however, we know very little about what kinds of genes are involved in adapting to temperature, and less still about how rapidly these genes can evolve and allow pests to spread.I will study how food pests adapt to temperature. My study organism will be the red flour beetle, a major pest of stored grain that causes enormous amounts of wheat, rice and corn to be discarded each year. It is also a "model species" for DNA research, with detailed genetic information available, and is easy to rear and study in the laboratory. I will study how red flour beetles evolve in response to extreme temperatures in real time, using replicated populations that have been maintained in the laboratory at high temperature for 60 generations. By sequencing the genomes of individual flour beetles adapted to living at extreme temperatures, I will identify the genes and biological processes that govern adaptation to temperature, and find out how these genes interact with one another. Additionally, because I have samples available from every generation since this experiment was set up, I will be able to look at how genes involved in adaptation to temperature evolve over time, and in doing so determine how rapidly these important genes can respond to changing temperature.The proposed research will give us a better understanding of how DNA enables individuals and populations adapt to their environments. And, importantly, it will help us generate better predictions of where and when food pests are likely to spread as the global climate continues to change.