Systematics of medically important Dermacentor tick vectors

描述（由申请人提供）：蜱是专性吸血动物，也是陆生脊椎动物的临时体外寄生虫。在节肢动物中，蜱虫是仅次于蚊子的第二大传播病原体给人类、宠物、牲畜和野生动物的动物。从医学和兽医的角度来看，某些种是最重要的蜱病媒介；例如，它们是引起落基山斑疹热的立克次体载体；引起北亚蜱斑疹伤寒的西伯利亚立克次体；引起布顿内热的立克次体；引起人类土拉菌病的土拉菌；以及在动物中引起无形体病、巴贝虫病及其菌痢的病原体。这些物种还传播几种导致人类疾病的病毒。在北美，某些种类的革螨叮咬可导致人类和家畜瘫痪。正确识别蜱虫种类，特别是在未成熟阶段，对于流行病学、预防和治疗蜱传疾病至关重要。然而，由于我们对它们的系统分类没有全面的研究，鉴定革螨属的物种是具有挑战性的；由于缺乏分类工作，鉴定若虫和幼虫阶段几乎是不可能的。该项目的总体目标是开发一种全球范围的、全面的、有效的工具来鉴定革螨种，包括其未成熟阶段。这一目标将通过四个具体目标实现：目标1。建立一种全球尺度的皮足属的分类修订；目标2。整合所有可能的证据，开发工具来识别皮肤发育不成熟阶段；目标3。开发一种皮肤蚤的DNA条形码系统；和Aim 4。目的：利用线粒体和核基因重建革螨种的系统发育。的影响。蜱的种类鉴定是研究和管理蜱传疾病的第一步也是必不可少的一步。对革螨蜱的分类学进行研究将有助于更好地了解其生态和地理分布，从而有助于建立和改进控制这些蜱病媒介的适当方法。研究蜱类的进化历史将有助于我们了解媒介能力的演变，并为建立有意义的分类体系提供有力的依据。我们的调查将是同类调查中的第一次，对实现我们的长期目标至关重要，该目标是为伊蚊科所有蜱类提供全面的鉴定工具。

DESCRIPTION (provided by applicant): Ticks are obligate blood-feeders and temporary ectoparasites of terrestrial vertebrates. Among arthropods, ticks are second only to mosquitoes in transmitting pathogens to humans, pets, livestock, and wild animals. Certain species of the genus Dermacentor are the most important tick-vectors from both the medical and veterinary perspectives; for example, they are vectors of Rickettsia rickettsii causing Rocky Mountain spotted fever; Rickettsia sibirica causing North Asian tick typhus; Rickettsia conori causing Boutenneuse fever; Francisella tularensis causing tularemia in humans; and pathogens causing anaplasmosis, babesioses, and theileriosis in animals. These species also transmit several viruses that cause human diseases. In North America, the bites of some species of Dermacentor can result in paralysis in humans and domestic animals. Correct identification of tick species, particularly in the immature stages, is essential for epidemiology, prevention, and treatment of tick-borne diseases. However, identifying Dermacentor species is challenging because we have no comprehensive work on their systematics; identifying the nymphal and larval stages is almost impossible due to the lack of taxonomic work. The overall objective of the proposed project is to develop a global-scale, comprehensive, and effective tool for identification of Dermacentor species, including their immature stages. This objective will be achieved through four specific aims: Aim 1. To produce a global-scale taxonomic revision of the genus Dermacentor; Aim 2. To produce tools to identify the immature stages of Dermacentor integrating all possible evidence; Aim 3. To develop a DNA barcode system for Dermacentor species; and Aim 4. To reconstruct a phylogeny for Dermacentor species using mitochondrial and nuclear genes. Impact. Identification of tick species is the first and essential step of study and management of tick- borne diseases. Conducted research on systematics of the Dermacentor ticks will allow better understanding of their ecology and geographic distribution which in turn will help in establishing and improving adequate methods of control these tick-vectors. Investigation of the evolutionary history of these ticks will help us to understand the evolution of vector competence and provide a strong basis for establishing a meaningful classification system. Our investigation will be the first of its kind and is fundamental to fulfilling our long-term goals, which are to produce comprehensive identification tools for all tick species of the family Ixodidae. PUBLIC HEALTH RELEVANCE: Ticks in the genus Dermacentor are important vectors of the organisms causing Rocky Mountain spotted fever (Rickettsia rickettsii), North Asian tick typhus (Rickettsia sibirica), Boutenneuse fever (Rickettsia conori), tularemia (Francisella tularensis), Omsk hemorrhagic fever, Colorado tick fever, and Crimean-Congo hemorrhagic fever in humans. Identifying tick species correctly is an essential task for the study of tick vector biology and for the prevention and treatment of tick-borne diseases, but often a challenge work even for a well trained expert. This grant proposal is to develop effective identification tools for the Dermacentor ticks, which intergrade molecular, morphological, host, ecological, geographic, and vector information together and can be used by scientists and professionals in the fields of vector biology and tick-borne diseases.