| Comments |
"Another criterion of circadian rhythms is that their period length is approximately constant at different ambient temperatures, a phenomenon known as temperature compensation of the period (refs 1,2). Fig.5 shows that the bioluminescence rhythm of AMC149 meets this criterion: period length was 25.5hr at 25°C, 24hr at 30°C, and 23hr at 36°C. The calculated Q10 Value for frequency (1/period) of this rhythm is 1.1. This value lies within the range for the temperature dependence of circadian rhythms in eukaryotes and is far from that of most biological processes, such as growth or respiration, for which the Q10 Values are usually between 2 and 3. Temperature compensation of the amino acid uptake rhythm has been reported for another cyanobacterium, Synechococcus RF-1(ref 7). Therefore, the rhythms of Synechococcus satisfy the three fundamental criteria for circadian rhythms." A general statement not giving explicit references |