Investigating recurrent cooption of mitochondrial cytochrome c maturation systems in Archaeplastida

趋同进化是同一特征在不同物种中的独立起源。通常，趋同特征的适应性优势是显而易见的，例如鸟类、蝙蝠和昆虫的动力飞行趋同进化。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其作为线粒体电子传递链的一部分的正常功能至关重要，线粒体电子传递链产生并调节细胞内的能量流。两种不同的生化途径被用来实现这种修饰，许多物种已经收敛地在这两种不同的途径之间切换。然而，这两种途径都达到了相同的目标，因此这种途径转换的进化优势尚不清楚。该项目将研究植物和绿藻中的许多趋同通路开关。该项目将结合分子生物学、基因工程、植物生长发育分析和计算生物学来评估这种通路开关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。外展体验将包括公开演讲、演示和实践活动，向公众宣传植物科学研究和应用。该项目将使用转基因方法和功能分析来评估线粒体定位，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，这种酶的获得使不同植物和藻类的趋同途径转换成为可能。该项目还将使用转基因技术在模型工厂中创建人工系统开关。这些转基因植物将使用代谢组学、功能分析和高通量表型来评估这种转换的潜在适应性或有害影响。系统遗传学和比较基因组学将用于评估植物和真核生物细胞色素c成熟的宏观进化模式，通过探索真核生物进化过程中途径开关的数量，评估是否存在其他替代途径来促进这种开关，并评估水平转移在真核生物中传播替代途径的作用。研究结果将扩大对在没有明显适应利益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适应利益明显的平行进化的例子形成对比。该提案由分子和细胞生物科学部的遗传机制组和环境生物学部的进化过程组共同审查并将共同资助。资金也由既定计划提供，以刺激竞争性研究。该奖项反映了美国国家科学基金会的法定使命，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.