Whilst most cells in the body express a circadian rhythm, this is usually transciptionally mediated through expression of genes Per1 and Per2. However, red blood cells (RBCs) have no DNA, yet express rhythms in periredoxins.

 

We showed that the clock mechanism is based on cycling levels of potassium in the cytoplasm, and that interfering with cytosolic potassium changed the clock speed (Nature Communications), but that the clock was nevertheless temperature conserved (Journal of Biological Rhythms) suggesting it is not subject to conventional reaction kinetics.

 

 

We have also shown similar effects in voles, who show an ultradian (2h) clock, using a new technique that avoided the necessity for animal sacrifice (Scientific Reports).  We have also explored the interaction between circadian rhythms and red cell electrophysiological rhythms in malarial infection.  Broadening from blood cells, we have also identified electrophysiological rhythms in both megakaryocytes and adipose cells.