Inheritance of gene expression in polyploid wheat

确保我们有安全的粮食供应是当今人类面临的最大挑战之一。为了能够应对这一挑战，我们将需要采用广泛的方法来改善作物生产。我们的许多主要作物都是多倍体，这意味着它们所有的DNA都被复制了，每个基因都有多个副本。多倍体在植物中特别常见，我们许多最重要的食物都来自多倍体。很可能你早餐吃的是多倍体，因为这些多倍体包括做吐司的小麦、粥里的燕麦、薯饼里的土豆或健康的香蕉。世界人口正在迅速增长，这意味着我们需要大幅增加粮食产量，以确保每个人都有足够的食物。然而，增加多倍体作物的产量是复杂的，因为它们的DNA中每个基因都有多个拷贝。在非多倍体植物中，我们可以计算出单个基因的功能，从而能够使用该基因来改善作物。例如，我们可能想要确定一种基因，它可以使每株植物产生更多的西红柿。然而，在多倍体中，我们不仅需要了解一个基因的功能，我们还需要知道其他拷贝的功能。在我们的实验室里，我们以小麦为例，开始理解多倍体中基因的多重拷贝。小麦植物中的不同器官和细胞都有相同的DNA，每个基因都有三个副本，但这些基因副本可以独立地打开、关闭或变暗，就像一个房间里有三个独立的灯一样。我们最近发现，在大约三分之一的时间里，基因拷贝在不同程度上被激活。令人惊讶的是，在不同的小麦植株中，这些基因拷贝可以以不同的模式开启。例如，在一个小麦植株中，拷贝1号可能是打开的，但在另一个小麦植株中，拷贝1号是关闭的，拷贝2号是打开的。为了培育小麦的改良植株，我们将不同的小麦植株进行杂交，使种子既有母本的一些性状，又有父本的一些性状，以达到综合改良的目的。我们发现，这种杂交的后代可能会保持与父母相同的基因拷贝模式，或者他们可能会产生新的模式。在这个项目中，我们将发现基因活动的新模式产生的频率以及这些模式是如何控制的。我们获得的知识将用于寻找改变基因活动模式的方法，这将有利于小麦和其他多倍体作物的生产。

Ensuring that we have a secure food supply is one of the biggest challenges facing humankind today. To be able to meet this challenge we will need to use a wide range of approaches to improve crop production. Many of our major crops are polyploid, which means that all their DNA has been duplicated and they have multiple copies of each gene. Polyploidy is particularly common in plants and many of our most important foods come from polyploids. It is likely that you ate a polyploid for breakfast since these include the wheat which made your toast, oats in your porridge, potatoes in your hash browns or that healthy banana. The world's population is increasing rapidly, which means we will need to dramatically increase food production to make sure everyone has enough to eat. However, increasing the production of polyploid crops is complicated by the multiple copies of each gene in their DNA. In a non-polyploid plant we can work out the function of an individual gene, to be able to use that gene to improve the crop. For example we might want to identify a gene which can make more tomatoes per plant. However in a polyploid we don't just need to understand what the function of one gene is, we need to know what the other copies are doing too.In our lab we are using wheat as an example to start understanding the multiple copies of genes in polyploids. The different organs and cells in a wheat plant all have the same DNA with three copies of each gene, but the gene copies can be switched on, switched off or dimmed independently, much like a room with three separate lamps. We recently found that about one third of the time the gene copies are turned on at different levels. Surprisingly in different wheat plants these gene copies can be turned on in different patterns. For example in one wheat plant copy number 1 might be turned on, but in a different wheat plant copy number 1 is turned off and copy number 2 is turned on. To develop improved wheat plants we crossbreed different wheat plants to generate seeds that have some characteristics from the mother and some from the father, aiming for improved characteristics overall. We found that the offspring from such a cross may keep the same pattern of gene copies turned on as their mother or their father, or they may make a new pattern. In this project we will discover how often new patterns of gene activity are generated and how these patterns are controlled. The knowledge we obtain will be used to find ways to change the patterns of gene activity which will benefit the production of wheat and other polyploid crops.