IFLP   13074
INSTITUTO DE FISICA LA PLATA
Unidad Ejecutora - UE
artículos
Título:
Delay model of circadian gene expression with two negative feedback loops
Autor/es:
A BOHN,; J.R. LOPES; L. DIAMBRA; L. MENNA-BARRETO
Revista:
BIOLOGICAL RHYTHM RESEARCH
Editorial:
Taylor & Francis
Referencias:
Año: 2006 vol. 37 p. 405 - 417
ISSN:
0929-1016
Resumen:
In this theoretical paper we propose a quantitative minimal model for circadian gene expression based on two negative feedback loops. We perform numerical simulations to analyse its dynamics and parameter sensitivities in free-running conditions, and verify the entrainability by a single periodic driver. We furthermore apply two simultaneously acting external drivers, leading to aperiodic oscillations in the case of a single-loop system. These can be turned into regular periodic oscillations by introduction of a second loop. Our studies confirm the increasing evidence that multiple feedback loops increase the robustness of regulatory systems, and stress the particular situation of systems that are close to transition from freerunning oscillation to steady-state behaviour. We discuss possible molecular realisations of the featured feedback loops and suggest the application of complex patterns of external stimulation as a generallyuseful approach to assess the functionality of models of circadian systems.