Today there were two symposia devoted to better understandimg the powers of the circadian molecular machinery. The first talk given by Joe Takahashi from the Howard Hughes Institute focused on body temperature rhythms and reaching an understanding as to why the master SCN clock does not molecularly or physiologically respond to abrupt temperature changes whereas the peripheral clocks in the liver and lungs do. The Okam’s Razor explanation is that the clock regulates internal rhythms of core body temperature and if the clock is the least bit sensitive to external temperature changes then thermoregulation by the central nervous system can easily go awry. So the body relies on peripheral organs to attend to temperature changes. And of course using circadian clock genetic knockouts has helped circadian biologist target the genes responsible.

In the second circadian talk of the day, Paulo Cassone_Corsi disscussed epigenetic influences on the circadian system. Epigenetics alter gene activity by means of perturbing DNA winding/unwinding from chromatin. Kinases and phosphatases can act as writers and erasers respectively causing severe alternations in DNA. Many disorders of addiction metabolism neurodegeneration and cancer have been linked to such modifications.

This may be the first occassion in which circadian rhythms have become a featured topic of the meeting for not one but many symposia. I hope that the trend continues….