Parasite ecology, evolution and population genetics: the evolutionary ecology of epidemiological triangles

寄生虫生态学、进化和群体遗传学：流行病学三角的进化生态学

• 批准号: 298374-2009
• 负责人: Chilton, Neil
• 金额: $ 1.38万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=526004
• 关键词: Parasite; ecology; evolution; population; genetics

There is a lack of knowledge regarding the evolutionary ecology of vector-borne diseases, that is, the ecological and historical interactions, and changes in the population genetic structure of the three groups of organisms that make up an 'epidemiological triangle'; vectors (e.g. mosquitoes & ticks), hosts (vertebrates), and pathogens (e.g., bacteria & viruses) transmitted by vectors to hosts. Ticks are the most important reservoirs and vectors of human infectious diseases in North America, and they are responsible for transmitting pathogenic agents to domestic animals and wildlife. There are over 30 tick species that occur in Canada, yet for many species, we know very little of the types (i.e. species and strains) of bacteria they contain. Over the next 5 years, graduate and undergraduate students in my research group will conduct innovative and exciting research projects on the population genetics and coevolution of organisms in epidemiological triangles, in which the vectors are different species of tick that differ in their life cycles, types of hosts used and/or their relative host specificity. Molecular techniques will be used to quantify the population genetics of ticks, bacteria and small mammals for multiple genetic markers. Spatial and temporal changes in the genetic structure of tick populations and of different bacterial strains will also be explored. Detailed knowledge of the population genetics and coevolutionary relationships of ticks, their bacteria and hosts, permits an understanding of anomalies in the epidemiology of vector-borne diseases, which might otherwise go explained. Our findings will provide key insights into the ecological and evolutionary factors influencing the population genetic structure of epidemiological triangles, and provide critical information for the construction of ecological epidemiological models of microbial transmission and the population dynamics of vector-borne diseases. Such work is also of importance because some tick species are expanding their geographical ranges in Canada, which poses an increased threat to human and animal health.

对媒介传播疾病的进化生态学，即构成“流行病学三角”的三类生物的生态和历史相互作用以及种群遗传结构的变化缺乏了解；媒介（例如蚊子和蜱虫）、宿主（脊椎动物）以及由媒介传播给宿主的病原体（例如细菌和病毒）。蜱是北美人类传染病最重要的宿主和媒介，它们负责将病原体传播给家畜和野生动物。加拿大有超过 30 种蜱虫，但对于许多物种，我们对其所含细菌的类型（即物种和菌株）知之甚少。在接下来的五年里，我的研究小组的研究生和本科生将针对流行病学三角中的群体遗传学和生物体共同进化开展创新且令人兴奋的研究项目，其中媒介是不同种类的蜱，其生命周期、类型不同使用的宿主和/或其相对宿主特异性。分子技术将用于量化蜱虫、细菌和小型哺乳动物的群体遗传学的多个遗传标记。还将探讨蜱种群和不同细菌菌株的遗传结构的空间和时间变化。对蜱、其细菌和宿主的群体遗传学和共同进化关系的详细了解，有助于了解媒介传播疾病的流行病学异常现象，否则这些现象可能会得到解释。我们的研究结果将为影响流行病学三角群体遗传结构的生态和进化因素提供重要见解，并为构建微生物传播的生态流行病学模型和媒介传播疾病的群体动态提供关键信息。此类工作也很重要，因为一些蜱虫物种正在扩大其在加拿大的地理范围，这对人类和动物健康构成了更大的威胁。