Mapping triclabendazole resistance in Fasciola hepatica using next generation sequencing technologies

肝片吸虫病是一种常见而重要的家畜疾病。在英国，它是最常见的与反刍动物消化道有关的感染报告。它是由肝片吸虫引起的，肝片吸虫是一种在肝脏中发现的扁虫，通过泥螺传播。衣原体感染主要通过药物治疗得到控制，最常用的药物是三氯苯达唑(TCBZ)。这是唯一一种对寄生虫的未成熟阶段有效的药物，这些阶段是导致急性、通常是致命的疾病的原因。它也是治疗由同一寄生虫引起的人类肝片吸虫病的首选药物。对TCBZ的耐药性于1995年在澳大利亚首次报告，目前被认为在全球范围内普遍存在。关于肝片吸虫耐药的机制，哪些基因参与，以及耐药性是如何演变的，人们知之甚少。这项提议旨在利用我们创造抗病和敏感肝片吸虫的克隆的能力；在绵羊中产生基因相同的TCBZ敏感和抗药分离株感染，我们将从中产生第二代种群。这些群体将被用来识别标记，在这种情况下，在DNA水平上的单个突变与抗病和感病克隆杂交期间的抗病基因有关。我们将使用快速、高通量的下一代测序技术，这将使我们能够制作出初步的肝片吸虫基因组图谱。抗性标记将被映射到这个初步的基因组上，并使我们能够识别基因组中负责编码抗性的一个或多个基因的区域。在该项目结束时，我们将拥有抗药性的遗传标记，可用于检测和跟踪英国自然感染的羊和牛中肝片吸虫种群中抗药性的出现，但重要的是，它们还将用于未来的项目，以开始定位和识别抗药性编码基因。该项目还将为更广泛的科学界提供其他重要成果，例如寄生虫的基因组数据库和抗药性状况得到很好描述的寄生虫克隆。基因组数据将通过一个可公开访问的网站提供，寄生虫克隆将通过寄宿给我们的工业合作伙伴Ridgeways Research Ltd.向其他群体提供。

Fasciolosis is a common and important disease of livestock. In the UK it is the most commonly reported infection associated with the digestive tract of ruminants. It is caused by Fasciola hepatica, a flatworm found in the liver and transmitted by a mud snail. Fasciolosis is controlled predominantly using drug treatment and the most commonly used drug is triclabendazole (TCBZ). This is the only drug that is effective against the immature stages of the parasite that are responsible for acute, often fatal disease. It is also the drug of choice for human fasciolosis, caused by the same parasite. Resistance to TCBZ was first reported in Australia in 1995 and is now thought to be widespread worldwide. Very little is known about mechanisms of drug resistance in F. hepatica, which genes are involved and how resistance is evolving. This proposal aims to exploit our ability to create clones of resistant and susceptible F. hepatica; to derive genetically identical infections of TCBZ-susceptible and TCBZ-resistant isolates in sheep, from which we will generate second generation populations. These populations will be used to identify markers, in this case single mutations at the DNA level that associate with resistance genes during the crossing of resistant and susceptible clones. We will use rapid, high throughput, next generation sequencing technologies, which allow us to produce a preliminary F. hepatica genome map. The resistance markers will be mapped onto this preliminary genome and allow us to identify regions of the genome where the gene or genes responsible for encoding resistance are found. At the end of the project we will have genetic markers for resistance that could be used to detect and track the emergence of resistance in populations of F. hepatica in naturally infected sheep and cattle in the UK, but, importantly they will also be used in future projects to start to home in and identify genes encoding resistance. There will be other important outputs for the wider scientific community from the project, such as a bank of genome data for the parasite and clones of the parasite whose resistance status is well characterised. Genome data will be made available through a publicly accessible website and the parasite clones will be made available to other groups by lodging them with our industrial partner, Ridgeways Research Ltd.