title: Period doubling induced by thermal noise amplification in genetic circuits.
abstract: Rhythms of life are dictated by oscillations, which take place in a wide rage of biological scales. In bacteria, for example, oscillations have been proven to control many fundamental processes, ranging from gene expression to cell divisions. In genetic circuits, oscillations originate from elemental block such as autorepressors and toggle switches, which produce robust and noise-free cycles with well defined frequency. In some circumstances, the oscillation period of biological functions may double, thus generating bistable behaviors whose ultimate origin is at the basis of intense investigations. Motivated by brain studies, we here study an "elemental" genetic circuit, where a simple nonlinear process interacts with a noisy environment. In the proposed system, nonlinearity naturally arises from the mechanism of cooperative stability, which regulates the concentration of a protein produced during a transcription process. In this elemental model, bistability results from the coherent amplification of environmental fluctuations due to a stochastic resonance of nonlinear origin. This suggests that the period doubling observed in many biological functions might result from the intrinsic interplay between nonlinearity and thermal noise.
authors.affiliation: 1] PRIMALIGHT, Faculty of Electrical Engineering; Applied Mathematics and Computational Science, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia [2] Sapienza University of Rome, Department of Physics, Piazzale Aldo Moro 5, 00185 Rome, Italy [3] Center for Life Nano Science@Sapienza, Istituto Italiano di Tecnologia, Viale Regina Elena 291, 00161, Rome, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Ruocco
authors.affiliation: PRIMALIGHT, Faculty of Electrical Engineering; Applied Mathematics and Computational Science, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
authors.forename: A
authors.initials: A
authors.lastname: Fratalocchi
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001419:Bacteria / Q000235:genetics; D003198:Computer Simulation; D004560:Electricity; D053263:Gene Regulatory Networks; D006801:Humans; D008957:Models, Genetic; D009419:Nerve Tissue Proteins / Q000235:genetics; D010507:Periodicity; D013269:Stochastic Processes; D013696:Temperature; D014158:Transcription, Genetic
chemical_list: D009419:Nerve Tissue Proteins