Biochemical clocks are robust to small fluctuations

Many biological mechanisms, such as metabolism, must be synchronized to a diurnal cycle. Organisms use biochemical clocks to achieve this, but these can be affected by internal or environmental factors.

Using a method for determining the period and coherence of oscillations in biological systems, Clara del Junco and Suriyanarayanan Vaikuntanathan demonstrated the robustness of these systems to small deviations.

In their previous work, del Junco and Vaikuntanathan modeled biological oscillators as a biased random walk where each oscillator cycles around roughly the same path and return to its initial chemical state. However, this methodology does not consider potential noise in the oscillators’ period or coherence. For instance, according to del Junco, at the peak of each oscillation, certain parameters might not get up to the same value every time.

By introducing additional small cycles to the topologies of the random walkers at different spatial arrangements, the researchers built upon their old method to include these slight variations, which may be driven by temperature fluctuations or energy transfer between cells.

Even with increasing amounts of randomness introduced into the system, the researchers found their theory to successfully predict the period and coherence of the oscillations. This implies that, as long as the system has a high energy budget, the oscillation parameters are unaffected by the addition of small cycles or their spatial arrangements. Extended to a biological system, these results suggest biological oscillators may be insensitive to small fluctuations.

Next, del Junco and Vaikuntanathan plan to apply this methodology to study a system of photosynthetic bacteria.

Source: “Robust oscillations in multi-cyclic Markov state models of biochemical clocks,” by Clara del Junco and Suriyanarayanan Vaikuntanathan, Journal of Chemical Physics (2020). The article can be accessed at https://doi.org/10.1063/1.5143259 .