NSF Postdoctoral Fellowship in Biology FY 2011

Cozy Loralyn M, Bloomington IN

Investigators

Abstract

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.