Daily rhythms in the transcriptomes of the human parasite Schistosoma mansoni

Abstract

The consequences of the earth’s daily rotation have led to 24-hour biological rhythms in most organisms. Parasites have daily rhythms, which, when in synchrony with host rhythms, optimize their fitness. Using round-the-clock transcriptomics of male and female Schistosoma mansoni blood flukes we have discovered the first 24-hour molecular oscillations in a metazoan parasite, and gained insight into its daily rhythms. We show that expression of ∼2% of its genes followed diel cycles. Rhythmic processes, in synchrony in both sexes, included a night-time stress response and a day-time metabolic ‘rush hour’. These 24hr rhythms may be driven by host rhythms and/or generated by an intrinsic circadian clock. However, canonical core clock genes are lacking, suggesting an unusual oscillatory mechanism or loss of a functional clock. The daily rhythms in biology identified here, may promote within-host survival and between-host transmission, and are important for the development and delivery of therapeutics against schistosomiasis.

Mistimed malaria parasites re‐synchronize with host feeding‐fasting rhythms by shortening the duration of intra‐erythrocytic development

“…Viruses do not appear to have rhythms in their own activities but instead may manipulate host rhythms to facilitate replication 5,17 . Daily rhythms in the feeding‐fasting cycles of hosts appear to drive periodicity in the gene expression patterns of Trypanosoma brucei 9 and Schistosoma mansoni , 18 as well as setting the timing of blood stage replication by Plasmodium spp. (malaria parasites) 19‐21 …”