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

该奖项根据2009年《美国复苏和再投资法案》(公法111-5)提供资金。蓝藻鱼腥藻分化出称为异形囊的特殊细胞，提供一种形式的氮，可用于生长生物体的其余细胞。在长度可达数百个细胞的未分枝细丝上，杂胞体大约每10个细胞位置就会出现一次。在这个项目中，将使用分子遗传学方法来研究分化激活剂和两种分化抑制物之间的相互作用。将测量激活剂对不同浓度的抑制剂的降解，将鉴定参与激活剂降解的蛋白酶(S)，将确定两种抑制剂之一的分子活性，并将可视化控制沿细丝的异质囊图案形成的激活剂的浓度梯度。激活剂？抑制物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成为测试该模型的许多方面的理想选择。特别是，该项目将首次展示依赖于抑制剂的分化激活剂的降解。该项目狭隘地集中在蓝藻异胞分化的遗传学上，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的类型。除研究成果外，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室课程的章节，为受资助的研究生提供教学机会，并允许他们参加国家会议，来促进教学、培训和学习。为本科生提供研究学分的辅导可能会扩大太平洋岛民后裔学生对生物科学的参与。

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.