NSF Postdoctoral Fellowship in Biology FY 2011

本行动资助2011年度美国国家科学基金会生物学博士后研究奖学金，扩大参与。该奖学金支持奖学金获得者在主办实验室的研究和培训计划，该奖学金获得者还提出了扩大生物学参与的计划。Loralyn Cozy奖学金的研究和培训计划的标题是“连接Anabaena的细胞分裂和发育”。主办机构是夏威夷大学，赞助科学家是肖恩·卡拉汉博士。形成不同细胞类型的多细胞生物必须严格调节生长细胞和分化细胞之间的过渡。多细胞蓝藻蓝藻为研究发育过程中生长抑制的遗传和分子机制提供了一个简单、易于处理的模型。在营养充足的条件下，水藻生长为活跃分裂细胞的长多细胞细丝。然而，当固定氮变得有限时，大约十分之一的丝细胞最终分化成一个非分裂的特化细胞，称为异囊，它具有固定氮的能力。本研究探讨了异囊细胞分裂和分化过程中细胞分裂的调控。这将决定细胞分裂被抑制的阶段，并确定增殖到非增殖过渡的调节因子。此外，它使用细胞学、遗传学和生物化学技术来表征一种被称为异囊模式蛋白的蛋白质的作用。虽然模式形成和异囊生物化学已经被详细地研究过，但还没有人以彻底、系统的方式研究过分化过程中生长的停止。培训目标包括学习遗传和微观技术，以研究这个简单而进化上古老的发育系统。这项工作广泛地影响了发育生物学、细胞分裂、氮代谢和生物燃料生产等不同的科学领域。此外，主办机构还提供了一个特殊的机会，招收来自科学领域代表性不足的群体的本科生，尤其是来自太平洋岛国的本科生。

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2011, Broadening Participation. The fellowship supports a research and training plan in a host laboratory for the Fellow who also presents a plan to broaden participation in biology. The title of the research and training plan for this fellowship to Loralyn Cozy is "Connecting cell division and development in Anabaena." The host institution is University of Hawaii and the sponsoring scientist is Dr. Sean Callahan.Multicellular organisms that develop distinct cell types must tightly regulate the transition between growing and differentiated cells. The multicellular cyanobacterium Anabaena provides a simple, tractable model for studying the genetic and molecular mechanisms of growth inhibition during development. Under nutrient replete conditions, Anabaena grows as long multicellular filaments of actively dividing cells. However, when fixed nitrogen becomes limiting, approximately every tenth cell of the filament terminally differentiates into a non-dividing specialized cell called a heterocyst, which is capable of nitrogen fixation. This research explores the regulation of cell division in dividing and differentiated heterocyst cells. This will determine the stage at which cell division is inhibited and identify regulators of the proliferating to non-proliferating transition. Further, it uses techniques of cytology, genetics, and biochemistry to characterize the role of a protein known as the heterocyst patterning protein. Although pattern formation and heterocyst biochemistry have been studied in detail, no one has yet examined the cessation of growth during differentiation in a thorough, systematic fashion.Training objectives include learning genetic and microscopic techniques to study this simple and evolutionarily ancient developmental system. The work broadly impacts scientific areas as diverse as developmental biology, cell division, nitrogen metabolism, and biofuel production. In addition, the host institution affords a special opportunity to include undergraduates from groups that are underrepresented in science, especially those of Pacific Island descent.