Response to climate warming in a tropical ectotherm: an investigation of epigenetic and mitochondrial haplogroup effects

热带变温带对气候变暖的响应：表观遗传和线粒体单倍群效应的研究

• 批准号: 1656670
• 负责人: Jeanne Zeh
• 金额: $ 80.83万
• 依托单位: Board of Regents, NSHE, obo University of Nevada, Reno
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-15 至 2022-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1656670&HistoricalAwards=false
• 关键词: Response; climate; warming; tropical; ectotherm

A central premise of modern biology has been that inheritance and individual variation are ultimately controlled by the sequence of DNA bases in the genome. However, discoveries in molecular genetics are revealing a more complex reality in which an array of heritable chemical signals determine when, where and in what environmental contexts genes are turned on or turned off. Such control of gene expression is much more sensitive to environmental influences than DNA sequence, and environmentally-induced changes can be transmitted across generations to effect changes in offspring growth, metabolism, neurological development and fertility. A major unresolved question is whether transmission of acquired information across generations enables organisms to respond to environmental challenges or not. This project exploits the unique reproductive characteristics of a model arthropod species, in which embryos develop in an external, transparent brood sac and can be monitored and manipulated, to determine whether environmentally-induced epigenetic effects play a causal role in the transmission of altered gene expression patterns from parents to offspring. The project will provide training for K-12 instructors, high school students, undergraduates, graduate students and a postdoctoral scholar and will include high school outreach in the form of museum exhibits, internships, presentations, training in molecular techniques, advising in science project competitions and assistance with curriculum development. The impact of naturally occurring mitochondrial variation on the epigenetic regulation of nuclear gene expression by small noncoding RNAs (sncRNAs) and its effects on evolutionary responses to environmental challenges are poorly understood. This project will exploit two highly divergent mitochondrial haplogroups (A, B2) that co-occur in populations of the pseudoscorpion, Cordylochernes scorpioides, to determine whether selection acting on this pool of genetic diversity can enable this tropical arthropod to respond to temperature-induced physiological stress through adaptation and/or environmentally-induced epigenetic changes. The project will include: (1) a multi-generation experiment to examine the response of A and B2 haplogroups to incrementally increasing temperatures; (2) an epigenetic response experiment in which replicates of the haplogroups will be reared as split broods at control and elevated temperatures, and offspring assayed from the control and elevated temperature treatment crosses, and (3) a study in which differentially-expressed sncRNAs will be microinjected into early-stage embryos to assess possible causal epigenetic effects on elevated temperature response. Taken together, these experiments will address the potential for an adaptive evolutionary response to environmental challenges, and will determine whether: (1) divergent mitochondrial haplogroups differ in their responses; (2) epigenetic effects are adaptive or pathological; (3) epigenetic effects are transmitted paternally or maternally, and (4) differentially expressed sncRNAs play a causal role in the transmission of environmentally-induced epigenetic modifications.

现代生物学的主要前提是，遗传和个体变异最终受基因组中的DNA碱基序列控制。然而，分子遗传学中的发现揭示了一个更复杂的现实，在这种现实中，一系列可遗传的化学信号决定了何时，何时何地和在哪些环境环境中打开或关闭了什么。 这种对基因表达的控制对环境影响比DNA序列更为敏感，并且可以在各个一代传播环境引起的变化，以影响后代生长，代谢，神经系统发育和生育能力的变化。一个尚未解决的主要问题是，在世代相传的获得信息是否能够应对环境挑战。该项目利用了模型节肢动物物种的独特生殖特征，其中胚胎在外部，透明的育雏囊中发展并可以受到监测和操纵，以确定环境诱导的表观遗传效应是否在转移的基因表达模式传播父母从父母到后代的传播中起因果关系。该项目将为K-12讲师，高中生，大学生，研究生和博士后学者提供培训，并将包括博物馆展览，实习，演讲，分子技术培训的高中宣传，在科学项目竞赛方面提供咨询和课程开发方面的援助。对小型非编码RNA（SNCRNA）（SNCRNA）及其对环境挑战的进化反应的影响，天然存在的线粒体变异对核基因表达的表观遗传调节的影响。该项目将利用两个高度不同的线粒体单倍型（A，B2），它们在伪镜的种群中共同发生，即孢子虫星菌，以确定在这种热带促进的遗传多样性上的选择是否能够通过温度诱导的物理学和//或环境化的适应性响应。该项目将包括：（1）多代实验，以检查A和B2单倍群对逐步升高温度的响应； （2）一个表观遗传反应实验，其中将作为对照和温度升高时的育雏饲养的单倍群的重复，并根据对照和温度治疗越高的升高进行测定，（3）一项研究将对早期的启动进行差异表达的SNCRNA，以评估较早的鼻部效应，以评估递增的启动。综上所述，这些实验将解决对环境挑战的适应性进化反应的潜力，并确定：（1）线粒体单倍群的反应不同； （2）表观遗传作用是自适应或病理； （3）表观遗传效应是亲子或母亲传播的，（4）差异表达的SNCRNA在环境诱导的表观遗传修饰的传播中起因果作用。

项目成果

Sperm competitive advantage of a rare mitochondrial haplogroup linked to differential expression of mitochondrial oxidative phosphorylation genes

• DOI: 10.1111/jeb.13536
• 发表时间: 2019-09
• 期刊: Journal of Evolutionary Biology
• 影响因子: 2.1
• 作者: J. A. Zeh;Maya A Zawlodzki;Melvin M. Bonilla;Eleanor Su-Keene;Michael V. Padua;D. W. Zeh

Simulated climate warming and mitochondrial haplogroup modulate testicular small non-coding RNA expression in the neotropical pseudoscorpion, Cordylochernes scorpioides

• DOI: 10.1093/eep/dvy027
• 发表时间: 2018-10
• 期刊: Environmental Epigenetics
• 影响因子: 3.8
• 作者: Eleanor Su-Keene;Melvin M. Bonilla;Michael V. Padua;D. W. Zeh;J. A. Zeh