Effect of temperature on distance travelled in wild-type and mutant Chlamydomonas reinhardtii

Abstract

The objective of our study was to investigate the effects of elevated temperatures on the mean distances travelled by wild-type (CC-1690) and mutant (CC-3913) strains of Chlamydomonas reinhardtii. The average motility of the wild-type and mutant strains were measured at temperatures of 20°C, 25°C, and 30°C, with n=4. Movement of the cells were filmed using a DinoXcope camera connected to a Zeiss Axio compound microscope. Each replicate was observed and the length of movement was calculated during a five-second interval using ImageJ with MTrackJ plugin. A two-way ANOVA test was used to analyze the results, which indicated statistical significance with respect to the effect of increased temperature on the mobility of wild-type C. reinhardtii compared to pf9-3 mt- mutants (p=0.01). In addition, wild-type C. reinhardtii showed a general trend of increased movement with higher temperatures (p=0.000001) whereas the presence of the mutation pf9-3 mt- in the mutant C. reinhardtii had a negative effect on their overall movement (p=0.007). Overall, wild-type organisms travelled farther than pf9-3 mt- mutants did, which was likely due to defective inner dynein arms in mutant C. reinhardtii flagella. The findings from our study can be used in further studies to understand the movement of C. reinhardtii.