Maintenance of Chronobiological Information by P System Mediated Assembly of Control Units for Oscillatory Waveforms and Frequency

摘要

Oscillatory signals turn out to be reliable carriers for efficient processing and propagation of information in both spheres, life sciences and engineering. Each living organism typically comprises a variety of inherent biological rhythms whose periodicities cover a widespread range of scales like split seconds, minutes, or hours, and sometimes even months or years. Due to different molecular principles of generation, those rhythms seem to persist independently from each other. Their combination and assembly in conjunction with recurrent environmental changes can lead to astonishing capabilities and evolutionary advantages. Motivated by the question on how populations of cicadas, an insect species living in the soil, sustain a synchronous life cycle of 17 years away from any known external stimulus of this duration, we aim at exploring potential underlying mechanisms by P system mediated assembly of a set of chemical control units. To this end, we identify a collection of core oscillators responsible for sinusoidal, spiking, and plated waveforms along with pass filters, switches, and modulators. Considering these units as genotypic elementary components, we utilise P system control for selection and (re-)assembly of units towards complex phenotypic systems. Two simulation case studies demonstrate the potential of this approach following the idea of artificial evolution. Our first study inspired by the cicadas converts a chemical frequency divider model 1:17 into counterparts of 1:3, 1:5, and 1:6 just by exchange of single units. In the second study adopted from the mammalian circadian clock system residing within the suprachiasmatic nucleus, we illustrate the stabilisation of the overall clock signal by addition of auxiliary core oscillators.