EAGER: Development of a Genetic System Directing Multicellular Development of Myxococcales

粘细菌在细菌中的区别在于其生命周期中的多细胞阶段，称为子实体。初步证据表明，这种从单细胞到多细胞子实体的转变是由光调节的。该项目的主要目标是建立一套新的，以前未经测试的，但潜在的变革性的遗传工具，可以广泛应用于细菌的研究，但在这里用来检查光诱导的过渡到多细胞的粘细菌。确定粘细菌中这种多细胞过程的机制可能对理解多细胞真核生物（包括大多数高等生物）中更复杂途径的进化具有重要意义。本科生和研究生将接受多学科最先进的研究方法和技术的培训，包括细菌遗传学和结构生物化学和生物物理学。此外，超过75名学生将在完成生物化学和分子生物学本科课程期间接触到研究经验。子实体形成的遗传机制不保守的粘球菌导致在果实形态和可见光作为一个重要的环境信号的作用的变化。这种相对缺乏保护的原因尚不清楚。开发一种新的遗传系统来检查和测试这种独特的多细胞程序的可塑性，对于回答复杂的发育途径如何响应各种遗传变化至关重要。建议的遗传系统将被用来支持探索性的工作，光如何控制子实体的形成在非光合粘细菌。编码a）感知和响应光的细菌光感受器和B）蓝细菌的生物钟KaiC同源物的基因在粘球菌的所有三个亚目中都被发现，但它们在非光合细菌中的作用在很大程度上仍然未知。遗传学上，最好的特征M。xanthus不含这两个基因，但与M. fulvus有。这两种途径如何适应这些差异？通过对近缘种、不同种的比较分析，对M. xanthus和M. fulvus，研究人员将能够解决这个问题，而没有复杂性与更多样化的粘细菌。基于可用于M. xanthus，将在M.黄色的该遗传系统将允许表征红光光感受器（称为细菌光敏色素）和生物钟KaiC同系物的生化功能，以定义这些蛋白质在粘球菌发育中的作用。此外，还对M. fulvus在光和黑暗中将进行比较沿着与M. fulvus发育转录组与M.该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Myxobacteria are distinguished among bacteria by a multicellular stage in their life cycle known as fruiting bodies. Preliminary evidence suggests that this transition from single cell to multicellular fruiting body is regulated by light. The primary goal of this project is to establish a set of novel, previously untested yet potentially transformative genetic tools that can be applied broadly in bacterial studies but are used here to examine the light induced transition to multicellularity in Myxobacteria. Determining the mechanisms underlying this multicellular process in Myxobacteria could have important implications for understanding the evolution of more complex pathways seen in multicellular eukaryotes, which include most higher organisms. Undergraduate and graduate students will receive training in multidisciplinary state-of-the-art research methods and techniques including bacterial genetics and structural biochemistry and biophysics. In addition, over 75 students will be exposed to research experiences during completion of undergraduate courses in biochemistry and molecular biology.The genetic mechanisms underlying fruiting body formation are not conserved in Myxococcales resulting in variations in the fruiting morphology and the role of visible light as an essential environmental signal. The reasons for this relative lack of conservation are unknown. Development of a novel genetic system for examining and testing the plasticity of this unique multicellular program is vital to answering how a complex developmental pathway responds to various genetic changes. The proposed genetic system will be used to support exploratory work on how light controls fruiting body formation in non-photosynthetic Myxobacteria. Genes that code for a) the bacterial photoreceptors that perceive and respond to light and b) the circadian clock KaiC homolog of cyanobacteria are found across all three suborders of Myxococcales, yet their role in non-photosynthetic bacteria remain largely unknown. Genetically, the best characterized M. xanthus doesn't contain either of these genes, but closely related M. fulvus does. How have the two pathways adapted to these differences? By using a comparative analysis of closely related, yet distinctly different species, M. xanthus and M. fulvus, the investigators will be able to approach this question without the complexity inherent with more diverse Myxobacteria. Insertion mutations via plasmid integration mutagenesis and in-frame deletions using insertion-excision mutagenesis, based on tools available for M. xanthus, will be developed in M. fulvus. This genetic system will allow characterization of the biochemical function of the red-light photoreceptor known as bacteriophytochrome and the circadian clock KaiC homolog, to define the role of these proteins in Myxococcales development. In addition, the developmental transcriptome of M. fulvus in the light and dark will be compared along with a comparison of the M. fulvus developmental transcriptome to that of M. xanthus to determine similarities and differences in developmental gene expression between these two close relatives.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.