13th International Conference on Membrane Computing - MTA Sztaki

<strong>13th</strong> <strong>International</strong> <strong>Conference</strong> on Membrane Computing, CMC13,
Budapest, Hungary, August 28 - 31, 2012. Proceedings, pages 221 - 242.
Maintenance of Chronobiological Information by
P System Mediated Assembly of Control Units
for Oscillatory Waveforms and Frequency
Thomas Hinze 1,2 , Benjamin Schell 2 ,
Mathias Schumann 2 , and Christian Bodenstein 2
1 Brandenburg University of Technology
Institute of Computer Science and Information and Media Technology
Postfach 10 13 44, D-03013 Cottbus, Germany
2 Friedrich Schiller University Jena
School of Biology and Pharmacy, Department of Bioinformatics
Ernst-Abbe-Platz 1–4, D-07743 Jena, Germany
thomas.hinze@tu-cottbus.de, benjamin.schell@uni-jena.de
{mathias.schumann,christian.bodenstein}@uni-jena.de
Abstract. 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 which can significantly improve
the overall signal quality in comparison to individual clocks.
1 Introduction
When spectating at macroscopic as well as microscopic phenomena of life, it becomes
obvious that periodically recurrent behavioural patterns are essential for
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