Mechanisms to understand the basis of species invasiveness

生物入侵是全球生物多样性变化的主要来源。了解在建立-传播阶段和影响阶段促成入侵成功的因素对于减少与非本地物种引入相关的生态、经济和健康问题至关重要。先前的研究已经确定，一些引入并在新的生态系统中建立的NIS将比在相同营养水平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。尽管最近的工作集中在功能性反应的差异上，即动物相对于食物密度的摄食率，但事实证明，要发展出预测NIS影响的概论是非常具有挑战性的。这项工作表明，入侵性（即高影响）NIS的摄食率通常高于其原生类似物。然而，这些摄食率差异的潜在基础尚未得到解决，也没有在不同分类类群之间的模式的普遍性。***在本提案中，我将对来自广泛环境（包括陆地和水生环境）和营养水平（食肉动物与食草动物）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。所选择的分类群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。甲虫的进食试验将被录像，这将使我们能够确定物种的行为规律（例如时间预算，攻击率）。功能反应是通过生物体的生理与环境的相互作用来表达的。激活时，基因会产生mrna，这些基因的上调或下调会产生或多或少的mrna分子。将这些分子翻译成蛋白质就会产生反应。喂养率)。我们将使用候选基因方法应用转录组学，即假设在捕食/食草效率中发挥作用的特定基因将成为目标。如果侵袭性具有分子基础，我们预计基本的消化酶（如-淀粉酶），代谢基因(如。atp酶)、感觉基因（如视蛋白基因）或肌肉基因（如原肌球蛋白）在侵袭性NIS与本地物种中的表达应该是不同的。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。*** *** *** **

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. -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. *** *** *** **