Mechanisms to understand the basis of species invasiveness

了解物种入侵基础的机制

• 批准号: RGPIN-2016-04480
• 负责人: MacIsaac, Hugh
• 金额: $ 4.52万
• 依托单位: University of Windsor
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=615089
• 关键词: Mechanisms; understand; basis; species; invasiveness

Biological invasions are a leading source of biodiversity change globally. Understanding the factors that contribute to invasion success at both the establishment-spread stage and impact stage are vital to reducing ecological, economic and health problems associated with introduction of nonindigenous species (NIS). Prior work has determined that some NIS that are introduced to and establish in a new ecosystem will have a greater ecological impact than do complementary native species at the same trophic level, possibly owing to prey naivety. It has proven very challenging to develop generalities to predict NIS impact, though recent work has focused on differences in functional responses - the feeding rate of an animal relative to food density. This work revealed generally higher feeding rates by invasive (i.e. high impact) NIS than their native analogues. However, the underlying basis for these feeding rate differences has not been addressed, nor has the generality of the pattern across different taxonomic groups. In this proposal I will conduct comparative feeding trials of NIS and native species from a broad array of environments - including terrestrial and aquatic environments - and trophic levels - predators versus herbivores - to test for differences in functional responses. Taxa selected will include broadly different taxonomic groups including beetles, mussels, fishes, ascidians and crabs, allowing us to examine the generality of feeding rate differences. Feeding trials of beetles will be videotaped, which will allow us to determine the species' behavioural repertoires (e.g. time budgets, attack rate). Functional responses are expressed through the interaction of an organism’s physiology with its environment. When active, genes produce mRNAs, and up-regulation or down-regulation of these genes produces more or fewer of these molecules. Translation of these molecules into proteins enacts the responses (ie. feeding rate). We will apply transcriptomics using a candidate gene approach, whereby specific genes hypothesized to play a role in the efficiency of predation/herbivory, will be targeted. If invasiveness has a molecular basis, we expect that basic digestive enzymes (e.g. a-amylases), metabolic genes (eg. ATPases), sensory genes (e.g. opsin genes), or muscle genes (e.g. tropomyosin) should be differentially expressed in invasive NIS versus native species. Our studies will also explore the importance of ambient temperature and life stages to these results.

生物入侵是全球生物多样性变化的主要原因。了解在定居传播阶段和影响阶段入侵成功的因素对于减少与引入非本地物种 (NIS) 相关的生态、经济和健康问题至关重要。先前的研究已经确定，一些引入新生态系统并在新生态系统中建立的NIS将比相同营养级的互补本地物种产生更大的生态影响，这可能是由于猎物的幼稚造成的。尽管最近的工作集中在功能反应（动物的摄食率相对于食物密度）的差异上，但事实证明，建立预测 NIS 影响的通用性非常具有挑战性。这项工作表明，侵入性（即高影响力）NIS 的喂养率通常比天然类似物更高。然而，这些进食率差异的根本原因尚未得到解决，不同分类群之间模式的普遍性也尚未得到解决。 在本提案中，我将对来自各种环境（包括陆地和水生环境）和营养水平（捕食者与食草动物）的 NIS 和本地物种进行比较喂养试验，以测试功能反应的差异。所选的分类单元将包括广泛不同的分类群，包括甲虫、贻贝、鱼类、海鞘和螃蟹，使我们能够检查摄食率差异的普遍性。甲虫的喂养试验将被录像，这将使我们能够确定该物种的行为能力（例如时间预算、攻击率）。功能反应通过有机体的生理学与其环境的相互作用来表达。当活跃时，基因会产生 mRNA，这些基因的上调或下调会产生更多或更少的这些分子。这些分子翻译成蛋白质会产生反应（即进食速率）。我们将使用候选基因方法应用转录组学，其中假设在捕食/食草效率中发挥作用的特定基因将成为目标。如果入侵性具有分子基础，我们预计基本消化酶（例如α-淀粉酶）、代谢基因（例如ATP酶）、感觉基因（例如视蛋白基因）或肌肉基因（例如原肌球蛋白）在入侵NIS与本地物种中应该有差异表达。我们的研究还将探讨环境温度和生命阶段对这些结果的重要性。