Comparative genomics of Arsenophonus, a bacterial symbiont of arthropods

我在大学里学到的第一件事就是细菌可以做惊人的事情。它们可以降解原油。它们可以生活在温泉或盐浓度极高的地方。他们几乎可以适应一切，并在那里谋生。这使它们成为自然环境中过程的重要组成部分，也是潜在的非常有用的新功能来源。细菌也是动物生命中非常重要的一部分。我们的消化功能被益生菌改变，这表明细菌对良好的消化系统健康很重要。在奶牛中，肠道细菌对动物利用草中的营养物质至关重要。更广泛地说，许多昆虫携带遗传细菌。这些物质可以分为三种：a)昆虫生长和繁殖所需要的。在这种情况下，细菌负责合成饮食中没有的营养物质。b)在某些情况下对昆虫有益——例如，它们增强了对病原体和寄生虫的抵抗力。c)寄生，操纵昆虫的生物特性达到自己的目的。细菌如何为昆虫执行功能——以及它们如何操纵它们的生物学——是我们理解昆虫在自然环境中的功能的重要问题——但这些问题还没有很好地解决。在这个项目中，我们研究了有益细菌和寄生细菌是如何不同的，检查了两种不同的细菌的基因组，这两种细菌是相关的，但与宿主的相互作用非常不同。其中一种——鼻arsenophonus nasoniae，是一种寄生虫，之前已经对其进行了测序。在这个项目中，我们将对Arsenophonus triatominarum进行测序，这是一种生活在吸血虫Triatoma infestans中的细菌，它是一种有益的乘客。首先，我们将使用基于萤火虫酶的新技术完成a . triatominarum的基因组序列，该技术可以在一到两周内产生基因组草图。然后，我们将把它的基因组与鼻甲进行比较。这种比较会立即突出基因的重要性。这两种细菌共享的基因在许多宿主-细菌相互作用中可能是必不可少的。在一种细菌中发现而在另一种细菌中没有发现的基因子集，代表了那些可能在寄生/宿主功能（如果仅在寄生虫中）和产生宿主益处（如果仅存在于有益细菌中）中发挥重要作用的基因。三角锥虫的基因组序列也将引起人们的直接兴趣，因为它的宿主——小虫三角锥虫——是恰加斯病的一种媒介，将导致锥虫的疾病传播给人类。在更充分地了解三角蝽蝽的伴侣后，我们可能能够设计出新的方法来控制三角蝽蝽的种群规模，或限制其传播病原体的能力。

One of the first things I learnt at University was that bacteria could do amazing things. They could degrade crude oil. They could live in hot springs, or places with extreme salt concentrations. They could adapt to virtually everything, and make a living there. This makes them a crucial part of the processes in the natural environment, and also potential very useful sources of new capabilities. Bacteria also are a very important part of animal life. Our digestive function is changed by probiotics, indicating bacteria are important in good digestive health. In cows, gut bacteria are of vital importance in making the nutrients in grass usable by the animal. More widely, many insects carry inherited bacteria. These can be of three kinds- a) required by the insect for it to grow and reproduce. In this case, the bacteria are responsible for the synthesis of nutrients not available in the diet. b) Helpful to the insect in some circumstances-for instance, they increase resistance to pathogens and parasites. c) Parasitic, manipulating the biology of the insect to their own ends. How bacteria carry out functions for the insect-and how they manipulate their biology-are issues that are important for our understanding of insect function in the natural environment-but these questions are not well resolved. In this project, we examine how bacteria that are beneficial and parasitic differ, examining the genomes of two different bacteria that are related, but have very different interactions with their host. One of these-Arsenophonus nasoniae, is a parasite, and has been sequenced previously. In this project, we will sequence Arsenophonus triatominarum, a bacterium that lives in a blood sucking bug, Triatoma infestans, where it is a beneficial passenger. First, we will complete the genome sequence of A. triatominarum, using new technology based on firefly enzymes that can produce a draft genome in just one or two weeks. We will then compare its genome to A. nasoniae. This comparison will immediately highlight genes of importance. Genes that are shared by the two bacteria but have diverged significantly are likely essential to many host-bacteria interactions. The subset of genes that are found in one but not the other, represent those likely to be important in parasitism/host function (if in the parasite only) and in producing host benefit (if present in the beneficial bacterium only). The genome sequence of A. triatominarum will also be of direct interest, as its host-the bug Triatoma infestans-is a vector of chagas disease, transferring disease causing trypanosomes to humans. In understanding the partners of the triatomine bug more fully, we may be able to devise new methods to control the triatomine population size, or curtail its ability to transmit pathogens.