title: Quantitative analysis of signal transduction in motile and phototactic cells by computerized light stimulation and model based tracking.
abstract: To investigate the responses of Halobacterium salinarum to stimulation with light (phototaxis and photokinesis), we designed an experimental setup consisting of optical devices for automatic video image acquisition and computer-controlled light stimulation, and developed algorithms to analyze physiological responses of the cells. Cells are categorized as motile and nonmotile by a classification scheme based on the square displacement of cell positions. Computerized tracking based on a dynamic model of the stochastic cell movement and a Kalman filter-based algorithm allows smoothed estimates of the cell tracks and the detection of physiological responses to complex stimulus patterns. The setup and algorithms were calibrated which allows quantitative measurements and systematic analysis of cellular sensing and response. Overall, the setup is flexible, extensible, and consists mainly of commercially available products. This facilitates modifications of the setup and algorithms for physiological studies of the motility of cells or microorganisms.
authors.affiliation: Max Planck Institute of Biochemistry, 82152 Martinsried, Germany. streif@mpi-magdeburg.mpg.de
authors.forename: Stefan
authors.initials: S
authors.lastname: Streif
authors.forename: Wilfried Franz
authors.initials: WF
authors.lastname: Staudinger
authors.forename: Dieter
authors.initials: D
authors.lastname: Oesterhelt
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Marwan
mesh_terms: D000465:Algorithms; D001185:Artificial Intelligence; D002465:Cell Movement / Q000502:physiology / Q000528:radiation effects; D003198:Computer Simulation; D006217:Halobacterium / Q000166:cytology* / Q000502:physiology* / Q000528:radiation effects; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008027:Light; D055537:Light Signal Transduction / Q000502:physiology* / Q000528:radiation effects; D018715:Microscopy, Video / Q000379:methods*; D008954:Models, Biological; D010363:Pattern Recognition, Automated / Q000379:methods*; D012815:Signal Processing, Computer-Assisted; D013382:Subtraction Technique