Moulting and hatching in nematodes; the role of astacin metalloproteases as potential anti-nematode targets

寄生线虫是植物和动物的主要害虫。大约有10亿人（主要在发展中国家）携带可导致慢性和衰弱性疾病的寄生线虫。此外，线虫对农业造成重大经济负担，影响全世界的作物和牲畜。控制线虫的方法相对有限，而且耐药性正在变得普遍。所有线虫都有一个共同的生命周期，从卵到4个未成熟的幼虫阶段，再到性成熟的成虫阶段。从卵到幼虫的过程包括一个孵化过程，从个体幼虫阶段到成年阶段包括一个被称为蜕皮的重复过程，在这个过程中，外部骨架脱落并合成一个新的骨架。换羽过程有利于生长。星酸酶是参与孵化、骨架合成和蜕皮过程的催化剂。这类酶所起的特殊作用已在模型实验系统中得到证实，现在将在一种重要的兽医寄生虫中进行检查和表征。弯曲血蜱是绵羊和山羊的一种常见的、具有重要经济意义的寄生虫。在该系统中获得的信息也将与其他动物和植物寄生虫有关。该项目的目的是确定、研究和利用这些酶，其总体目标是确定疫苗和药物靶点，以治疗和控制线虫感染。

Parasitic nematodes are a major pest of plants and animals. Around 1 billion people, predominantly in the developing world, harbour parasitic nematodes that cause chronic and debilitating diseases. In addition, nematodes cause a significant economic burden to agriculture, affecting crops and livestock throughout the world. Methods to control nematodes are relatively limited, and drug resistance is becoming common. All nematodes share a common lifecycle growing from an egg through 4 immature larval stages before reaching the sexually mature adult stage. Progression from egg to larvae involves a hatching process, and from individual larval stages to adulthood involves a repeated process termed moulting, where the external skeleton is shed and a new one synthesised. The moulting process allows growth. The astacin enzymes are catalysts that are involved in the processes of hatching, skeleton synthesis and moulting. The specific roles played by this class of enzymes have been confirmed in a model experimental system and will now be examined and characterized in an important veterinary parasite. The nematode Haemonchus contortus is a common and economically significant parasite of sheep and goats. Information gained in this system will also be of relevance in other parasites of animals and plants. The project aims are to identify, study and exploit these enzymes with the overall goal of identifying vaccine and drug targets to treat and control nematode infections.