Comparing the effect of heat shock on locomotion, posture and head oscillation of wild-type (N2 strain) and mutant (VC854 strain) Caenorhabditis elegans

Abstract

In response to extreme temperatures, Caenorhabditis elegans combat cellular stress through activation of a heat shock transcription factor (HSF-1). The downstream effects of HSF-1 can lead to a sleep-like state in nematodes, characterized by decreased feeding and locomotion. Our objective was to compare sleep-state responses exhibited by the wild-type (N2) and mutant (VC854) strains during heat shock. Our experiment implemented an air incubation technique, exposing the nematodes to 35ºC for 30 minutes in the heat shock treatment and a control treatment at 15ºC. The mean number of head oscillations in a 30 second interval, posture and locomotion were measured and recorded for each replicate. Following heat shock treatment, the average number of head oscillations by the mutants was 4 ± 2 (SD: 3.32), while the average number of head oscillations by the wild-type was 9 ± 3 (SD: 5.88). Our results suggest that the effect of heat shock at 35˚C on the activity of mutants (VC854) was not greater than the effects seen on wild-type C. elegans. A possible explanation for this phenomenon is the restricted locomotive potential conferred by the unc-2 gene deletion mutation in the VC854 strain.