Modularity of gene expression and tradeoffs in the evolution of plasticity

基因表达的模块化和可塑性进化中的权衡

• 批准号: 7405887
• 负责人: Emilie Snell-Rood
• 金额: $ 4.48万
• 依托单位: TRUSTEES OF INDIANA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7405887
• 关键词: Antibiotic Resistance; Architecture; Behavior; Biological Models; Brain; Costs and Benefits; Development; Diabetes Mellitus; Environment; Evolution; Gene Expression; Genes; Genetic; Genetic Drift; Health; Home environment; Horns; Human; Human body; Insecta; Invaded; Learning; Microarray Analysis; Morphology; Mutation; Nutritional; Obesity; Order Coleoptera; Organism; Pattern; Pharmaceutical Preparations; Phenotype; Play; Public Health; RNA Interference; Range; Rate; Research; Role; Specificity; Testing; Time; Variant; Virulence; Work; aging brain; coping; cost; developmental genetics; experience; gene function; knock-down; nutrition; pathogen; pleiotropism; tool; trait

DESCRIPTION (provided by applicant): Plasticity in gene expression underlies much of the ability of organisms to cope with environmental variation. Understanding limits in the ability of organisms to adjust to a range of environments has implications for understanding how pathogens respond to human environments (e.g., antibiotic resistance), and how humans respond, at times inappropriately, to current environments (e.g., obesity). This research tests the hypothesis that the degree of modularity, or environmental specificity, of gene expression has fundamental implications for defining limits in the evolution of plasticity. Highly modular gene expression is assumed to permit adaptation to specific environments because overlap in gene function, and thus pleiotropy, is much reduced. At the same time, highly modular gene expression comes at a potential cost: when alternative environments are experienced infrequently, selection on environment-specific genes is weakened and mutation accumulation can occur. These hypotheses will be tested in a newly emerging model system in evolutionary developmental genetics: homed beetles in the genus Onthophagus. These insects display highly divergent alternative phenotypes depending on larval nutrition. Such alternative morphs develop through expression of genes shared across the development of traits, as well as genes specific to different morphs. This research tests several predictions by contrasting the development of secondary sexual traits (horns) and brains in horned (aggressive fighter) and hornless (non-aggressive sneaker) beetle morphs. This research tests four predictions both within and between species: 1) increased environmentally-specific gene expression will be correlated with the evolution of greater ranges of plasticity, 2) genes specific to the development of morph behavior and morphology will be more genetically variable than those shared between morphs, 3) genes specific to morph development experience higher rates of genetic divergence as a result of weak selection, and 4) morph-specific genes will play functional roles in generating divergence between morphs. This work will use a variety of tools developed for Onthophagus beetles, including transcriptional profiling via microarray analysis, and investigating gene function through RNA interference gene knock-down. Relevance. Understanding evolutionary limits of plasticity in gene expression has implications for public health. If we can curb the ability of pathogens to cope with multiple environments, such as invading the human body or dealing with multiple medications, we may be able to reduce pathogen virulence. We may learn why humans cannot express genes that promote health in a wide range of environments, such as diabetes-inducing nutritional environments or changes in the aging brain.

描述（由申请人提供）：基因表达的可塑性是生物体科普环境变化的能力的基础。了解生物体适应一系列环境的能力的限制对于了解病原体如何对人类环境作出反应具有意义（例如，抗生素耐药性），以及人类对当前环境的反应，有时是不适当的（例如，肥胖症）。这项研究测试的假设，即模块化的程度，或环境特异性，基因表达的定义限制可塑性的进化具有根本意义。高度模块化的基因表达被认为允许适应特定的环境，因为基因功能的重叠，从而多效性，大大减少。与此同时，高度模块化的基因表达也有潜在的代价：当替代环境很少出现时，对环境特异性基因的选择就会减弱，突变就会积累。这些假设将在一个新出现的模型系统在进化发育遗传学测试：在Onthophagus属的甲虫回家。这些昆虫表现出高度不同的替代表型，这取决于幼虫的营养。这种替代变体通过在性状发育过程中共享的基因以及对不同变体特异的基因的表达而发展。这项研究通过对比有角（攻击性战斗机）和无角（非攻击性运动鞋）甲虫变体的第二性征（角）和大脑的发展来测试几个预测。这项研究测试了物种内部和物种之间的四个预测：1）增加的环境特异性基因表达将与更大范围的可塑性的进化相关，2）特异于变体行为和形态发育的基因将比变体之间共享的基因更具遗传变异性，3）特异于变体发育的基因由于弱选择而经历更高的遗传分歧率，（4）形态特异性基因在形态分化中起重要作用。这项工作将使用各种工具开发Onthophagus甲虫，包括通过微阵列分析转录谱，并通过RNA干扰基因敲低调查基因功能。本案无关了解基因表达可塑性的进化极限对公共卫生有重要意义。如果我们能够抑制病原体科普多种环境的能力，比如入侵人体或处理多种药物，我们就有可能降低病原体的毒力。我们可能会了解为什么人类不能在广泛的环境中表达促进健康的基因，例如糖尿病诱导的营养环境或衰老大脑的变化。