1. Myxobacteria movement Cell Tracking Tanya Kazakova University of Notre Dame Advisor: Dr. Mark Alber

2. About Myxobacteria The myxobacteria are Gram- negative organisms (0.5 x 5-7 mm rods) that are capable of multicellular, social behavior. In the presence of nutrients, swarms of myxobacteria feed cooperatively. If the food supply is limited, the myxobacteria form aggregates called “fruiting bodies.”

3. Developmental Cycle for Myxobacteria COUPLING CELL MOVEMENT TO MULTICELLULAR DEVELOPMENT IN MYXOBACTERIA by Dale Kaiser Nature Reviews Microbiology 1, 45-54 (2003)

4. AS Two engines of motility: A and S A+S+A+S+ A+S-A+S- A-S+A-S+ A Adventurous S Social Cells move as a groupCells move alone A - S - cells are unable to swarm or form fruiting bodies.

5. Two engines of motility (cont) S-motility The pilus extends ahead of a cell, adheres to the fibrils on the cells ahead of it and then retracts, pulling the leading end of the piliated cell forward. A-motility Cell is pushed by slime secretion. At any instant, only one end secretes slime and only one end assembles pili. One end cannot do both at the same time.

6. Scenario Suppose we have an image produced to exhibit the results of a biology experiment. In most cases, we will have a black and white drawing such as one exhibited on the left.

7. Goals General: Get the most information from the image Specific: –Track individual cells –Make cell density more obvious –Show the boundaries of expanding front –Get rid of noise

8. About Scion Image National Institutes of Health Package http://rsb.info.nih.gov/nih-image/

9. Using SI: Options -> Color Tables 8 Grays 8 Grays->Fire 1 Original Image Fire 1

10. Example

11. Cell Tracking Features

12. MATLAB

13. Example

14. Possible Directions for Future Work