Uncovering the circadian transcriptome of Nasonia vitripennis: insights into a non-canonical insect model

The study of the circadian clock has greatly benefited from using Drosophila as a model system. Yet accumulating evidence suggests that the fly might not be the canonical insect model. Here, I have analysed the circadian transcriptome of the jewel wasp Nasonia vitripennis by using RNA-seq in both constant darkness and constant light (in contrast to flies, the wasps are rhythmic under continuous light). I identify approximately 6% of the transcriptome as cycling under constant conditions, revealing a bimodal distribution of phases and low cycling amplitude. I examine the biological processes under circadian control in Nasonia, identifying clock control of functions such as metabolism, light response and a variety of neural processes, drawing comparisons between Nasonia and Drosophila. Although there was little similarity between cycling genes in Drosophila and Nasonia, the functions fulfilled by cycling transcripts were similar in both species. Interestingly, of the known Drosophila core clock genes, only Pdp1e, shaggy and Clock showed significant cycling in Nasonia, highlighting the potential diversity in molecular clock mechanisms across insect species.