Limits of the Mitochondria-to-Cell Size Scaling Relationship in Budding Yeast
Author: Aya Alkabbani
Faculty Supervisor: Mark Chan
Department: Biology
Saccharomyces cerevisiae, a model organism in biotechnology research, is valued for its flexibility in experimental environments. Mitochondria, which are organelles responsible for energy production, exhibit dynamic behaviors like growth, fusion and fission that are influenced by their environment. For example, it has been shown that mitochondrial size depends on the carbon source present, with cells grown in raffinose showing denser mitochondrial networks compared to glucose. The size of these organelles shows a scaling relationship with overall cell size, and previous results indicate that mitochondrial network density also increases with increasing cell size. We test the limits of this scaling relationship using an optogenetic strain of yeast that can be grown to larger-than-normal sizes when triggered with exposure to the appropriate wavelengths of light, as well as inducing mitochondrial growth using raffinose-containing media. Optimizing cell size & growth medium composition could enhance the use of the organelle for biosynthesis efficiency for molecules ranging from biopharmaceuticals to biofuels. This study’s insight on environmental factors’ influence on cellular physiology contributes to diverse research areas, promising advancements in cellular biology understanding and biotechnology developments. Future research will explore the influence of media composition and cell size on mitochondrial and vacuole performance, further aiming to uncover how different organelles’ size regulations are coordinated.