Biology PhD Defense Proposal by Abdurrahman ElZafarany
Advisor: Katrina Velle
Committee members:
- Professor Pia Moisander
- Professor Erin Bromage
- Asst. Professor Hangjian Ling
Abstract:
The brain-eating amoeba, Naegleria fowleri, thrives in warm freshwater environments, but these cells can cause a deadly infection if they are inhaled, as they can crawl from the upper sinuses into the brain. To infect, Naegleria must navigate through a complex three-dimensional environment and generate traction to the extracellular matrix, making processes like pathfinding and adhesion critical to pathogenesis. Despite the importance of cell crawling to disease, little is known about the mechanisms behind it. To investigate these mechanisms, I use Naegleria gruberi—a nonpathogenic model for N. fowleri. Using custom designed microchannels with specific obstacles, I am using live imaging microscopy to quantify pathfinding decisions. I will pair this imaging with nuclear staining and targeted perturbations of actin machinery to assess how the nucleus and cytoskeleton contribute to pathfinding. Preliminary data shows a bias for the wider of two paths, rapid repolarization, and successful crawling through extreme confinement. Simultaneously, I am testing adhesion strength on different surface coatings with distinct chemical properties using microscopy and adhesion assays such as shaking. Preliminary data shows Naegleria amoebae form different adhesion strengths depending on the environment. Learning how Naegleria crawls is an essential first step to allow the identification of potential drug targets.
Library - Grand Reading Room
Katrina Velle
508 999-8206
kvelle@umassd.edu