Distributions and dynamics of the signaling molecule in a system with diffusion. Distributions (left column) and dynamics (center column) of c
at steady-state for different values of . The right most column stands for a density plot of the distribution of as a function of for discerning a putative increase in the molecular noise (see text). In all cases the parameters set (, ) is γ2 (see Figure 2B). The production rate is modulated as a function of (, , ) in order to maintain constant the average 〈c
〉 = 25 nM. The histograms obtained in the stochastic simulations (blue bars, left column) are in qualitative agreement with the probability densities from the analytical calculations (blue line, left column). When increasing the diffusion coefficient, the system explores different dynamics as revealed by the trajectories shown in the center column. The grey-shaded background shown in the trajectories of c
indicates the presence of a mRNA molecule in the cell. The density plots (right column) reveals that the diffusion does not contribute to an increase of the intrinsic noise since the spreading of the distributions in a direction perpendicular to the diagonal does not grow.