Sherry, Tim, Lam, Brian, Kao, Michelle, Nowak, Nate, Mendoza, Steve, Kim, Taejoon, Arisaka, Katsushi, Madruga, Blake, Jiang, Karen
[
International Worm Meeting,
2015]
Worm tracking of freely moving worms is essential to study the connection between behavior and neural activity. However, these microscopes are often limited in their ability to track worms under various behavioral simulations. We present a fluorescence worm tracking microscope that has an open geometry and thus can track worms even if the behavioral platform is difficult or impossible to move via a motorized stage. As opposed to other automated worm tracking systems, our microscope is fully mobile-where all the optical components are mounted on top of a motorized xy stage-while the sample stage where C. elegans rests is stationary. This platform allows for ratiometric calcium imaging while also tracking a dark field worm image for behavioral analysis, running at 15 frames per second. The current configuration has three cameras, two for each of the YFP and CFP channels, and a dark field image showing the worm body, under a 10x magnification; the microscope can also be adjusted to image at 20x. Being able to track freely moving worms without moving the sample stage, allows our microscope to perform worm tracking in experimental conditions that similar systems have not been able to achieve. In addition, since the sample is stationary, we also avoid introducing confounding effects on the worms due to stage acceleration. To test this novel hardware, we run a thermotaxis experiment tracking a worm without moving the temperature platform. Our worm was labeled with AIY::CAM and we find a correlation between the AIY activity and the temperature of the head location during isothermal behavior. Our methodology could also apply to other behavioral experiments where an external stimulus would be hard to move via a motorized stage, such as an electrotaxis experiment.
[
Worm Breeder's Gazette,
1975]
This group works on C. elegans for about two years. Our main interest is the development of this organism. We are serial sectioning eggs in various cleavage stages to trace the cell lineage. Completed so far: 1 egg, 2 two-cell stages, 1 four- cell stage, 1 bretzel-stage. An assembly line is being organized and hopefully the turnout will speed up. Nomarski studies on cleaving eggs supplement the EM studies. A detailed study of the ultrastructure of the cleavage furrow and the formation of cell membranes at early cleavage stages has been initiated. We are reconstructing 3-D pictures using a PDP 11/45 computer with a Vector General Graphics Display. Work has been started to accumulate a set of cleavage-deficient mutants for morphological analysis. In addition some preliminary experiments show that eggs can be opened by treatment with a variety of proteolytic enzymes. In this way suspensions of embryonal cells can be obtained. Ruth Pertel is spending 4 months as a guest in the lab to teach us axenic cultivation and replica plating. She also is interested in defining differences between the two strains of C. elegans Bristol N2 and NIH that have been kept separate for a number of years. Jerzy Nowak from Poland worked 4 months on proteolytic enzymes in cleavage stages. He also started using the O'Farrell technique (J.B.C. 250, 4007-4021, 1975) for high resolution two-dimensional electrophoresis of proteins from eggs and worms. Randy Cassada will join the group as a staff member starting December 1975.