The Effect of Temperature on Cell Density of Wild Type and Mutant Chlamydomonas reinhardtii

Abstract

Chlamydomonas reinhardtii is a unicellular green alga, which is used as a model organism in many fields of molecular biology. In order to understand more about the optimum conditions necessary for the growth of C. reinhardtii in a lab setting, we focused on how temperature can affect the abundance of both wild-type and mutant forms. We used the CC-1690 wild-type strain and the CC-3913 - pf9-3 mutant strain. In our experiment, we used three temperature treatments: 11°C, 17°C, 25°C. We had three replicates at each treatment temperature for each and took cell density measurements over ten days. Based on observations and data that we collected, we observed that the wild type generally reaches the greatest cell density at 17°C, where as the mutant type has the highest cell density at 25°C. The results of these data allow us to reject both of our null hypotheses. We suggest that this is because the wild type C. reinhardtii are better capable of accumulating the energy necessary for growth due to the functions of flagella and the presence of certain enzymes, whereas the mutant type lacks these traits beneficial for their living (Falk et al. 2006).