Cold Adaptation and Mitochondrial Function in S. cerevisiae

A major theory concerning the origin of life proposes that the first cells arose in cold, rather than hot, conditions. Regardless of its origin, life today can be found throughout the entire globe, even at the poles. Consequently, for survival to be possible, organisms must be capable of energy production under extreme temperatures. The main focus of this study is to determine the genetic basis of the ability of cells to grow at low temperatures. Yeasts are capable of fermentation in cold environments, but the effect of extreme temperatures on respiration is still under investigation. The objective of the experiment was to determine if S. cerevisiae mitochondrial function is important for growth at low temperatures. To test this hypothesis, we screened cold-sensitive mutants for their ability to grow on media that can only be metabolized via respiration. If the mutant gene is important for mitochondrial biogenesis or function, then its deletion may also hinder oxidative phosphorylation. Yeast mutants were grown in conditions at permissive and cold temperatures to observe differences in growth patterns. Our preliminary results suggest that most genes required for growth at low temperature do not affect mitochondrial function. Thus, most cold-sensitive mutants have robust mitochondrial function indicating that their inability to grow at low temperatures does not reflect an underlying mitochondrial defect