DISSERTATION RESEARCH: Epigenetic Effects of an Invasive Parasite on an Avian Host

论文研究：入侵寄生虫对鸟类宿主的表观遗传效应

• 批准号: 1701006
• 负责人: Dale Clayton
• 金额: $ 1.94万
• 依托单位: University of Utah
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2019-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1701006&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Epigenetic; Effects; Invasive

The goal of this research is to understand how processes that modify the function of genes without changing the DNA sequence affect the defense of Galapagos mockingbirds against an introduced and sometimes lethal parasitic fly. This modification may enable the host to respond quickly to parasitism and reduce its negative effects. The parasite lives in the nests of this and other species of birds in the Galapagos and feeds on nestlings, and is a threat to their survival. Studying how this modification acts as a rapid defense against parasites will provide insights into how animals adapt to new environmental threats. This project will involve training undergraduates in field biology techniques and scientific writing. It will also incorporate workshops for Galapagos National Park rangers and tour guides to help develop strategies for monitoring and controlling this pest species in the Galapagos.This project will analyze DNA methylation patterns of mockingbirds studied during four field seasons: two in which mockingbirds were tolerant to the fly parasite, P. downsi, and two in which the fly caused high mortality. During the field study, mockingbird nests were either fumigated with permethrin, a dilute insecticide, that killed the parasite, or sham-fumigated as a control, that let the nests be naturally infested. Growth, health and fledging success of parasitized and non-parasitized nestlings were compared and nestlings were sampled for blood twice during the nestling period. These blood samples, along with samples collected from study birds later recaptured as adults, will be analyzed for variation in methylation patterns. DNA methylation analysis will allow the researchers to identify genes that are affected by parasitism in tolerant vs. non-tolerant years as well as to investigate whether methylation alterations persist to adulthood and are potentially even heritable. The results of this research will provide new insights into epigenetic mechanisms of rapid adaptation in wild populations.

这项研究的目标是了解在不改变DNA序列的情况下修改基因功能的过程如何影响加拉帕戈斯群岛加拉帕戈斯嘲鸟对引入的有时是致命的寄生蝇的防御。这种修饰可以使宿主对寄生反应迅速，减少其负面影响。这种寄生虫生活在加拉帕戈斯的这种鸟类和其他鸟类的巢穴中，以雏鸟为食，对它们的生存构成威胁。研究这种修饰如何作为对寄生虫的快速防御，将有助于了解动物如何适应新的环境威胁。本计画将训练本科生野外生物技术与科学写作。该项目还将为加拉帕戈斯国家公园的护林员和导游举办讲习班，以帮助制定监测和控制加拉帕戈斯这种害虫的战略。该项目将分析四个野外季节中研究的嘲鸟的DNA甲基化模式：两个季节中嘲鸟对苍蝇寄生虫P. downsi具有耐受性，两个季节中苍蝇造成高死亡率。在实地研究中，模仿鸟巢要么用氯菊酯（一种稀释的杀虫剂）熏蒸，杀死寄生虫，要么用假熏蒸作为对照，让鸟巢自然感染。比较了被寄生和未被寄生雏鸟的生长、健康和羽化成功率，并在雏鸟期内两次采血。将分析这些血液样本以及沿着从研究鸟中采集的样本（这些鸟后来作为成年鸟重新捕获）的甲基化模式变化。DNA甲基化分析将使研究人员能够识别在耐受与非耐受年份受寄生虫影响的基因，并调查甲基化改变是否持续到成年，甚至可能是遗传的。这项研究的结果将为野生种群快速适应的表观遗传机制提供新的见解。

项目成果

Alien Invasion: Biology of Philornis Flies Highlighting Philornis downsi, an Introduced Parasite of Galápagos Birds

外星人入侵：菲洛尼斯蝇的生物学突出了菲洛尼斯·唐西（Philornis downsi），一种加拉帕戈斯鸟类的引进寄生虫

• DOI: 10.1146/annurev-ento-020117-043103
• 发表时间: 2018
• 期刊: Annual Review of Entomology
• 影响因子: 23.8
• 作者: McNew, Sabrina M.;Clayton, Dale H.
• 通讯作者: Clayton, Dale H.

Annual environmental variation influences host tolerance to parasites

年度环境变化影响宿主对寄生虫的耐受性

• DOI: 10.1098/rspb.2019.0049
• 发表时间: 2019
• 期刊: Proceedings of the Royal Society B: Biological Sciences
• 作者: McNew, Sabrina M.;Knutie, Sarah A.;Goodman, Graham B.;Theodosopoulos, Angela;Saulsberry, Ashley;Yépez R., Janai;Bush, Sarah E.;Clayton, Dale H.
• 通讯作者: Clayton, Dale H.