Meeting Abstract
Nematostella vectensis, a burrowing estuarine anemone, exhibits 24 hour rhythmic cycles in behavior and gene expression. This cycling may be a direct photoresponse to the exposure of light, a molecular circadian clock, or a combination of these two factors. Although N. vectensis, like all organisms inhabiting shallow aquatic environments, experience diurnal lighting conditions, the relative roles of the circadian clock and the photoresponse in driving gene expression remain poorly understood. Here, we compare gene expression from N. vectensis under 12:12 light:dark (LD – diel) and 12:12 dark:dark (DD – disrupted) conditions. Our analysis measured transcriptome-wide oscillations in gene expression to identify genes exhibiting cyclic expression and allowed us to determine which of these continue to have differential expression after removal of the light cue. Comparisons of LD and DD exposed animals revealed approximately 700 genes with significant differences in expression in LD cultured animals, with more than 97% of these losing differential expression after removal of light cue. The analyses of differentially expressed genes revealed an abundance of signal transduction pathways and regulation of transcription processes upregulated during the daytime hours of the LD cycle. This analysis provides a powerful resource to evaluate the impact of light cycling on various molecular pathways in cnidarians, only a portion of which may be regulated by a circadian clock.
