Effects of the Presence of Oxygen on the Morphology and Ultrastructure of Mitochondria in Yeast Cells

Student’s name: Sadie Meyer Home institution: Syracuse University NNCI site: SHyNE @ Northwestern University REU Principal Investigator: Dr. Reiner Bleher, PhD REU Mentor: Eric W. Roth Abstract: The ultrastructure of yeast mitochondria provides valuable insight for exploring various aspects of mitochondrial biology, contributing to our understanding of cellular function, health, and evolution. Regardless of the presence of oxygen, certain cells can take anaerobic pathways of growth where most glucose is converted to lactate; this is referred to as the Warburg Effect. Cancer cells will often rely on such anaerobic pathways for growth. The anaerobic pathway results in a lower return of ATP/mol Glucose than aerobic pathways, and due to the need for energy for cancer cells to thrive, this phenomenon seems impractical. There remains a need to evaluate the pathways taken by cancer cells in growth through models mimicking such environments. Thus, we have investigated yeast cells as a model system for cancer research to study the Warburg Effect. This work focuses on the investigation of yeast mitochondria to gain insight in eukaryotic cell morphology and ultrastructure when grown in either aerobic or anaerobic conditions. Through ex-situ transmission electron microscopy (TEM) imaging of the yeast cells’ mitochondria, we hope to reveal insight into their morphology and potential changes caused by the different growth conditions. In addition to analyzing mitochondria and their cristae (structures formed by the inner mitochondrial membrane), we may investigate the interactions and spatial relationships between mitochondria and other yeast cell organelles such as the endoplasmic reticulum.