Over the course of this semester, we have examined random and directed motion in a variety of situations. Many of our investigations have been investigating principles with glass beads, while the last lab involved examining motion inside of onion skin cells. Both random and directed motion occur all over nature, from the micro-scale we investigated all the way up to the macro-scale. In this lab, you will take one final look at this phenomenon.
Materials and Methods
In these two videos, Dictyostelia (slime molds) are shown moving on a slide while exposed to an electric field. The first video (sm1) shows wild-type Dictyostelia. In the second video (sm3), the Dictyostelia have been exposed to a chemical, LY294002, which is an inhibitor of PI3K (PI3 kinase is an essential signaling molecule for directional cell movement).
- Size Scaling: Scale Bar Provided 50 um (gray bar in lower left corner of video)
- Time Scaling: 5 seconds / frame
Plot <x>, <y>, <x2> and/or <y2> to reveal whether motion is random or directed.
Question to be answered
- Does the chemical change the behavior of the Dictyostelia? Compare behavior with and without the kinase inhibitor and support your conclusion with quantitative results.