LTREB: A long-term Study of Host-parasite Interactions

LTREB：宿主-寄生虫相互作用的长期研究

• 批准号: 0128510
• 负责人: Curtis Lively
• 金额: $ 30万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-02-01 至 2008-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0128510&HistoricalAwards=false
• 关键词: LTREB; long; term; Study; Host

Lively0128510Explaining the widespread distribution and maintenance of genetic recombination is widely regarded as one of the most interesting challenges facing evolutionary biologists, and a large number of ecological and genetical hypotheses have been suggested to explain why clonal reproduction has not generally replaced genetically recombining individuals in populations. Contrasting these alternatives has proven difficult, but the effort is greatly aided by studies of populations in which clonal and recombinant individuals coexist. Such mixed populations are common in the freshwater New Zealand snail, Potamopyrgus antipodarum, which has been used as a model system for evaluating different hypotheses. In past studies, no support for the lottery hypothesis, the reproductive assurance hypothesis, or the tangled bank hypothesis has been found. In contrast, past work has shown that the frequency of recombinant individuals is spatially coupled with the prevalence of infection by larval trematodes. This result is consistent with the idea that time-lagged, frequency-dependent selection by parasites prevents the elimination of recombinant hosts by clonal hosts - the Red Queen hypothesis. But, direct tests of this hypothesis are still needed. This LTREB research will allow measurement in mixed populations of the frequency of recombinant and clonal individuals over time. Long-term data will provide a test of the hypothesis that time-lagged selection by parasites prevents the replacement of recombinant individuals by clonal individuals in natural populations.

解释基因重组的广泛分布和维持被广泛认为是进化生物学家面临的最有趣的挑战之一，并且已经提出了大量的生态和遗传学假设来解释为什么无性繁殖没有普遍取代种群中基因重组的个体。对比这些选择已被证明是困难的，但对克隆和重组个体共存的种群的研究极大地帮助了这一努力。这种混合种群在新西兰淡水蜗牛Potamopyrgus antipodarum中很常见，它已被用作评估不同假设的模型系统。在过去的研究中，没有发现支持彩票假说、生殖保证假说或纠结银行假说的证据。相比之下，过去的研究表明，重组个体的频率在空间上与幼虫虫感染的流行程度相关。这一结果与“红皇后假说”一致，即寄生虫的时间滞后、频率依赖的选择阻止了克隆宿主对重组宿主的淘汰。但是，对这一假设的直接检验仍然是必要的。这项LTREB研究将允许在混合群体中随时间测量重组和克隆个体的频率。长期数据将为寄生虫的时间滞后选择阻止重组个体被自然种群中的克隆个体取代的假设提供检验。