THE GENETICS AND EVOLUTION OF MATERNAL EFFECTS ON PARASITE RESISTANCE

不同的母亲会有不同的经历。一些母亲将能够吃更多或更高质量的食物。这不仅会影响他们，而且会影响他们的后代感染传染病或寄生虫的可能性。这对大多数生物都是如此，包括人类。例如，有些动物在某些条件下只会生更大的蛋。在许多动物中，这是当它们有更多的食物时，但不太直观的情况也会发生：一些动物在食物较少时会产生更大的蛋。无论哪种方式，这些卵的较大后代对寄生虫的抵抗力更强。这样一种策略，即母亲为后代准备他们预测的坚韧时期，被称为母性效应。这些是遗传给后代的特征，而不是在他们的基因中编码。然而，独立于这些母体效应，母亲也会将基因传递给她的后代。所以，后代可能仅仅是因为他们的母亲有抵抗力，他们继承了她的基因。因此，有两个原因可能是后代抵抗：母体效应和基因（或两者的组合）。我们想了解这两种效应如何共同作用，使后代对寄生虫感染易感或抵抗，我们想了解种群在这方面如何变化（进化）。这种基础实验很难在人类或老鼠身上进行，所以我们设计了一种小型的、快速进化的甲壳类动物--水蚤。这种甲壳类动物很容易在实验室中工作，但也在世界各地的小池塘和湖泊中发现。因此，在实验室里做的任何实验都可以告诉我们自然界正在发生的事情。我们的实验将：1）说明母体条件（例如，食物的多少）如何影响后代对感染的抵抗力2）确定这些母体效应是否代价高昂，例如，它们是否加速衰老过程3）研究母体效应如何根据母亲的基因而不同4）确定母体效应如何在自然界中作为寄生虫寄生虫的结果而演变尽管拟议研究的要素是好奇心驱动的，但此类基础研究和更多应用领域之间的知识转移是必不可少的。特别是，这些知识可以帮助我们识别，甚至预测疾病爆发可能发生的条件。反过来，最终用户和政策制定者可以发展能力，以控制或避免疾病的爆发，无论是在人类中，还是作为保护脆弱动物种群努力的一部分。

Different mothers will have different experiences. Some mothers will be able to eat more, or higher quality food. This will not only affect them, but also their offspring in how likely they are to contract an infectious disease or parasite. This is true for most organisms, including humans. For example, some animals simply make bigger eggs under certain conditions. In many animals this is when they have more food, but the less intuitive scenario can also occurs: some animals make larger eggs when there is less food. Either way, the bigger offspring from these eggs are more resistant to parasites. Such a strategy, where mothers prepare offspring for what they predict as tough times ahead, are called maternal effects. These are traits passed down to offspring that are not coded in their genes. However, independent of these maternal effects, a mother will also pass genes to her offspring. So, offspring may be resistant simply because their mother was resistant and they inherited her genes. Thus, there are two reasons an offspring could be resistant: maternal effects and genes (or a combination of both). We want to understand how these two effects work together to make offspring either susceptible or resistant to being infected by parasites, and we want to understand how populations might change (evolve) in this regard. The sort of fundamental experiments required would be very difficult to do in a human or a mouse, and so we have designed experiments with a small, rapidly-evolving crustacean, Daphnia. This crustacean is easy to work with in the laboratory, but is also found all over the world in small ponds and lakes. Therefore, any experiments done in the laboratory can inform us about what is happening in nature. Our experiments will:1) illustrate how maternal conditions (say, more or less food) affect how resistant their offspring are to infection2) determine if these maternal effects are costly and for example, whether or not they accelerate the aging process3) study how maternal effects differ depending on the genes of the mother4) determine how maternal effects evolve in nature as a consequence of parasite epidemicsAlthough elements of the proposed research are curiosity-driven, knowledge-transfer between such basic research and more applied realms is essential. In particular, this knowledge can help us to identify, and even predict, the conditions under which disease outbreaks may occur. In turn, end-users and policy-makers can develop the capacity to contain or avert outbreaks of diseases, either in humans, or as part of the effort to conserve vulnerable animal populations.