Investigating recurrent cooption of mitochondrial cytochrome c maturation systems in Archaeplastida

趋同进化是不同物种同一特征的独立起源。通常，趋同特征的适应性益处是显而易见的，例如鸟类、蝙蝠和昆虫的动力飞行的趋同进化。然而，并不是所有的趋同进化都有明显的优势。例如，c型细胞色素的翻译后修饰对于它们作为线粒体电子传递链的一部分的适当功能是必不可少的，线粒体电子传递链产生并调节细胞中的能量流。两种不同的生化途径被用来实现这种修饰，许多物种已经在这两种不同的途径之间收敛地切换。然而，这两种途径都实现了相同的目标，因此这种途径转换的进化优势尚不清楚。本计画将探讨植物与绿色藻类中众多的会聚路径开关。该项目将使用分子生物学，遗传工程，植物生长和发育测定以及计算生物学的组合来评估这种途径转换的机制和进化重要性。项目参与者将接受基因组学研究方面的高级培训。研究成果将通过期刊文章和会议报告传播。该项目将利用转基因方法和功能测定来评估线粒体定位，评估敲除/下调线，并通过关键酶的转化拯救来恢复功能。基于比较基因组学的期望是，这种酶的获得使得在不同的植物和藻类中能够进行会聚途径转换。该项目还将使用转基因技术在一个模型工厂中创建一个人工系统开关。这些转基因植物将使用代谢组学、功能测定和高通量表型分析进行评估，以评估这种转换的潜在适应性或有害影响。系统发育学和比较基因组学将被用来评估跨植物和真核生物的细胞色素c成熟的宏观进化模式，通过探索在真核生物进化过程中的通路开关的数量，评估是否存在其他替代通路，以促进开关，并评估水平转移在真核生物之间传播替代通路的作用。这些结果将拓宽对在没有明显适应性益处的情况下促进趋同进化的过程和影响的理解，这与其他众所周知的平行进化的例子形成对比，因为平行进化的适应性好处是显而易见的。由分子和细胞生物科学部遗传机制组和环境科学部进化过程组资助。生物学该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Convergent evolution is the independent origin of the same feature in different species. Often, the adaptive benefit of a convergent feature is apparent, such as the convergent evolution of powered flight in birds, bats and insects. However, not all cases of convergent evolution have an obvious advantage. For example, the post-translational modification of c-type cytochromes is essential for their proper function as part of the mitochondrial electron transport chain, which produces and regulates energy flow in cells. Two distinct biochemical pathways are used to achieve this modification, and many species have convergently switched between these two distinct pathways. Yet, both pathways achieve the same goal, so the evolutionary advantage of this pathway switch is unknown. This project will investigate the numerous convergent pathway switches in plants and green algae. The project will use a combination of molecular biology, genetic engineering, plant growth and development assays, and computational biology to assess the mechanisms and evolutionary importance of this pathway switch. Project participants will receive advanced training in genomics research. Research results will be disseminated through journal articles and conference presentations. Outreach experiences will include public presentations, demonstrations, and hands-on activities that educate the public on plant science research and applications.The project will use transgenic approaches and functional assays to assess mitochondrial localization, evaluate knock out/down lines, and restore function via transformation rescue of a key enzyme. The expectation, based on comparative genomics, is that the gain of this enzyme has enabled the convergent pathway switch in diverse plants and algae. The project will also use transgenics to create an artificial system switch in a model plant. These transgenic plants will be assessed using metabolomics, functional assays, and high-throughput phenotyping to evaluate the potential adaptive or detrimental effects of this switch. Phylogenetics and comparative genomics will be used to evaluate the macroevolutionary patterns of cytochrome c maturation across plants and eukaryotes by exploring the number of pathway switches during eukaryotic evolution, evaluating whether other alternate pathways exist to facilitate the switch, and assessing the role of horizontal transfer in spreading alternative pathways among eukaryotes. The results will broaden understanding of the processes and influences that promote convergent evolution under a scenario where there is no obvious adaptive benefit, which contrasts with other well-known examples of parallel evolution for which the adaptive benefit is obvious.This proposal was co-reviewed and will be co-funded by the Genetic Mechanisms Cluster in the Division of Molecular and Cellular Biosciences and by the Evolutionary Processes Cluster of the Division of Environmental Biology. Funding was also provided by the Established Program to Stimulate Competitive Research.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.