Concentration gradients of activator and inhibitors of cellular differentiation in a filamentous cyanobacterium

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。蓝藻水藻分化出一种叫做异囊的特殊细胞，这种细胞提供一种氮，这种氮可以用于有机体其余细胞的生长。异囊发生在非分枝细丝上大约每10个细胞位置，长度可达数百个细胞。在这个项目中，分子遗传学方法将用于研究分化激活剂与两种分化抑制剂的相互作用。将测量活化剂对不同浓度抑制剂的降解反应，将确定参与活化剂降解的蛋白酶，将确定两种抑制剂之一的分子活性，并将可视化控制沿着细丝形成异囊模式的活化剂的浓度梯度。激活剂？抑制剂模型已经被提出来描述在各种各样的生物体中看到的许多模式的形成。Anabaena开发系统的简单性使其非常适合测试该模型的许多方面。特别是，该项目将首次证明分化激活剂的抑制剂依赖降解。这个项目是狭隘地集中在蓝藻异囊分化的遗传学上，但更广泛的生物学影响将是在许多生物中控制细胞分化规范的分子机制类型上。除了研究成果，该项目还将通过资助研究生和本科生的研究培训、加强本科生遗传学实验课程的部分内容、为资助的研究生提供教学机会以及允许他们参加国家会议来促进教学、培训和学习。指导本科生获得研究学分将有可能扩大太平洋岛民后裔学生在生物科学领域的参与。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The cyanobacterium Anabaena differentiates specialized cells called heterocysts that supply a form of nitrogen that can be used for growth to the remainder of the cells of the organism. Heterocysts occur at approximately every tenth cell position on unbranched filaments that can be hundreds of cells in length. In this project, a molecular genetic approach will be used to investigate the interactions of an activator of differentiation with two inhibitors of differentiation. Degradation of the activator in response to varying concentrations of the inhibitors will be measured, the protease(s) involved in degradation of the activator will be identified, the molecular activity of one of the two inhibitors will be determined, and concentration gradients of the activator that governs formation of the pattern of heterocysts along filaments will be visualized. The activator ? inhibitor model has been proposed to describe the formation of many patterns seen in a wide variety of organisms. The simplicity of the Anabaena developmental system makes it ideal for testing many aspects of the model. In particular, this project will demonstrate for the first time inhibitor-dependent degradation of the activator of differentiation. This project is narrowly focused on the genetics of heterocyst differentiation in cyanobacteria, but the broader biological impact will be on the types of molecular mechanisms that control specification of cells for differentiation in many organisms. In addition to the research findings, this project will also promote teaching, training and learning by funding the research training of graduate students and undergraduate students, by enhancing sections of an undergraduate genetics laboratory course, by providing funded graduate students with teaching opportunities and by allowing their participation at national meetings. Mentoring of undergraduate students for research credit will potentially broaden the participation of students of Pacific Islander descent in the biological sciences.