Supplement request for 1F32GM116361-01

1F32GM116361-01 的补充请求

基本信息

批准号：
9403361
负责人：
Justin C Havird
金额：
$ 0.06万
依托单位：
COLORADO STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-07-01 至 2018-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9403361
关键词：
Address Affect Age of Onset Aging Animals Backcrossings Bacteria Biological Assay Categories Cell Nucleus Cell physiology Cells Characteristics Chloroplast DNA Complement Complex DNA Disease Distant Droughts Ecology Environment Eukaryota Evolution Exhibits Female Fertility Fertilization in Vitro Financial compensation Gene Expression Genes Genome Genomics Glycolysis Growth Health Human Hybrids Individual Inherited Lead Life Metabolic Metabolic Pathway Mitochondria Mitochondrial DNA Modeling Mutate Mutation Nuclear Organelles Organism Oxidative Phosphorylation Parents Pattern Phenotype Photosynthetic Complexes Physiology Plants Population Population Sizes Production Published Comment Regulation Replacement Therapy Research Severities Silene Symbiosis System Testing Time Tissue-Specific Gene Expression Tissues Work age related base biological adaptation to stress complex IV differential expression environmental stressor falls fitness functional genomics insight male metabolic rate mitochondrial DNA mutation mitochondrial genome oxidative damage public health relevance response sex theories transcriptome sequencing virtual

项目摘要

DESCRIPTION (provided by applicant): All eukaryotes have or once had mitochondria. These organelles are the remains of an ancient symbiosis with a bacterium early in eukaryotic evolution some 2 billion years ago. As such, mitochondria retain their own genome (mtDNA). Although it only encodes a small fraction of the genes encoded by nuclear DNA (nucDNA), its products must interact closely with their nucDNA-encoded counterparts in order to generate the energy needed for maintaining eukaryotic cellular functions. Mutations in mtDNA can lead to a breakdown in this interaction, with dire consequences for organismal health. Mutations in mtDNA accumulate rapidly compared to nucDNA in animals, and one general theory of ageing posits that the accumulation of somatic mtDNA mutations leads to ageing and the onset of age-related diseases. However, not all eukaryotes have elevated mtDNA mutation rates. To understand how underlying mtDNA mutations influence organismal health and fitness, the proposed research will examine mito-nuclear mismatch in the plant genus Silene, which occurs when mtDNA from one population/species is expressed against the nuclear background of a distant relative. Silene contains species with both slowly and rapidly evolving mtDNA, making it an ideal model for this research. The overarching question addressed by the proposed research is to determine how mito-nuclear interactions influence organismal physiology, ecology, and evolution. Silene species and populations with varying degrees of evolutionary relatedness will be crossed in order to produce progeny with a range of predicted mito-nuclear mismatch severities. Standard growth phenotypes, metabolic rates, and fecundities will be assayed in these hybrids. Oxidative phosphorylation (OXPHOS) proficiency will be assessed in both control and mismatched individuals by assessing OXPHOS complex II and IV activity. Complex IV consists of both mtDNA and nucDNA-ecoded subunits and should show reduced activity in mismatched individuals, while complex II serves as a negative control, since it is composed solely of nucDNA-encoded subunits. Furthermore, differential gene expression will be assessed between a subset of control and mismatched individuals via RNA-Seq to test between several alternative hypotheses for how mismatch affects organismal function. Finally, control and mismatched individuals will be assessed under variable drought regimes to determine if specific mito-nuclear backgrounds may be adapted to particular environments. This work will extend our understanding of mito-nuclear genomic interactions by utilizing a well- suited model that complements previous studies. Its results will be relevant to ongoing issues in human health including advancing theories of ageing and commenting on ongoing debates regarding the long-term consequences of mitochondrial replacement therapy (aka, "three-parent" in-vitro fertilization).

描述（由申请人提供）：所有真核生物都具有或曾经具有线粒体。这些细胞器是大约 20 亿年前与细菌共生的遗迹，因此，线粒体保留了自己的基因组 (mtDNA)。只编码核 DNA (nucDNA) 编码基因的一小部分，其产物必须与其 nucDNA 编码分子密切相互作用，以产生维持维持所需的能量。与动物体内的 nucDNA 相比，mtDNA 的突变会导致这种相互作用的破坏，从而对机体健康造成可怕的后果，并且一种普遍的衰老理论认为，体细胞 mtDNA 突变的积累会导致衰老。然而，并非所有真核生物的 mtDNA 突变率都会升高。为了了解潜在的 mtDNA 突变如何影响生物健康和健康，拟议的研究将进行研究。 Silene 植物属中的线粒体核不匹配，当来自一个种群/物种的 mtDNA 在远亲的核背景下表达时，Silene 包含具有缓慢和快速进化 mtDNA 的物种，使其成为这项研究的理想模型。拟议研究解决的首要问题是确定线粒体-核相互作用如何影响生物生理学、生态学和进化，具有不同程度进化相关性的沉默物种和种群将进行杂交，以产生具有不同进化相关性的后代。将通过评估 OXPHOS 复合物 II 和 IV 活性，对这些杂种中的一系列预测的线粒体核错配严重程度进行分析。复合物 IV 由 mtDNA 和 nucDNA 编码的亚基组成，在不匹配的个体中应表现出降低的活性，而复合物 II 作为阴性对照，因为它此外，将通过 RNA-Seq 评估对照个体和不匹配个体之间的差异基因表达，以测试不匹配如何影响生物功能的几种替代假设。在不同的干旱条件下进行评估，以确定特定的线粒体核背景是否可以适应特定的环境。这项工作将通过利用补充先前研究的合适模型来扩展我们对线粒体核基因组相互作用的理解。与人类健康中持续存在的问题相关，包括新兴的衰老理论，并对有关线粒体替代疗法（又名“三亲”体外受精）的长期后果的持续辩论进行评论。