Samuel Bowser OPP97-25830 Abstract A dominant member of cold, deep-sea sediments is a group of giant protozoa, the aggulatinated foraminifera, also known as forams. For protection, these single-celled organisms encase themselves in architecturally-elegant shells that they construct by collecting, sorting, and cementing together sediment grains. The unique occurrence of these giant cells (greater than one millimeter in size) in the shallow waters of McMurdo Sound, Antarctica allows for the study of the cellular and molecular aspects of shell constructions. This project will use novel light microscopic methods to examine how agglutinated forams secrete and sculpt the adhesive matrix that binds sediment particular in their shells. Comparative time-lapse photography of different foram species constructing shells will identify key steps in the processes that lead to the various shell morphologies. Peptide sequence analyses of the elastic proteins of the shells will provide valuable insight into the chemical nature of foram bioadhesives. From a practical standpoint, these cements have important biotechnological and medical applications. This project will also continue a study of the effects of collection activities, as well as natural physical disturbances, in this unique environment. This interdisciplinary project has implications in a number of fields, including cellular development, evolution, paleontology, marine products chemistry, and ecosystem management.
