COE Study Abroad Project Report


Report on the Poster Presentation at Biophysical Society 49th Annual Meeting(U.S.A.)

Masayuki Sato, Master's course student

Report on participation in Biophysical Society 49th annual meeting

The purposes are to:
1) present my study in poster session.
2) obtain up-to-date information on cell biology and new experimental system.

Meeting report :
In February 11-18, I attended the Biophysical Society 49th Annual Meeting in Long beach, California. This visit aimed at presenting my study in the poster session and obtaining up-to-date information on the study of cell biology and new experimental system related to my study. In February 18, I presented my work about galvanotaxis of Dictyostelium discoideum in poster session. The following were contents ; To investigate the mechanism of directional cell migration to extracellular stimulus, it is important to set up experimental system in which the controlled and uniform gradients of stimulus can be generated precisely in a highly reproducible manner. Directed current electrical fields (dcEF) are useful to generate such gradients of stimulus. A major cellular effect of dcEFs is galvanotaxis, which is directional movement of cells towards the cathode or the anode. Galvanotaxis provide a convenient model system for investigating basic aspects of directional cell motility. We have developed the experimental system which can generate electrical fields at a high speed and low noise and analyze the cell migration. Dictyostelium discoideum is a model organism in which the signaling pathway driving chemotaxis has been well characterized. It has already known that Dictyostelium cell can exhibit galvanotaxis toward cathodal face. (Zhao,2002) We have applied our experimental system to Dictyostelium galvanotaxis. The efficiency of galvanotaxis was voltage dependent, while cell migration speed remained almost constant. We found that the efficiency of galvanotaxis was proportional to the square of the EF strength. Next, the effect of cAMP on galvanotaxis was investigated. cAMP is an attractant of Dictyostelium cells. It has known that cAMP binds to the receptor and activate chemotactic signaling pathway. The galvanotactic efficiency in the presence of cAMP was about 1.6 times larger than that in the absence of cAMP, suggesting that the activation of chemotactic signaling pathway enhance the sensing efficiency of electrical field direction. In my presentation, I discussed about my experimental system and results with some researchers. Then they gave me some suggestions for future direction and informed me some reference works. These were very useful information for me to promote my project. Moreover, This experience stimulated my motivation to my research.
I attended many symposiums and poster sessions to obtain the information related to my research. In this meeting, A large number of study about imaging technique were reported, especially single molecule imaging technique, FRET and AFM. There were also many reports about various type of ion channels and cardiac muscle.