Figure 3.

Mean to variance correlation. (A) The noise strength (Fano factor) ν of simulated Bicoid molecular number gradient is defined as molecular variance $\mathrm{var}({\widehat{n}}_j)$ divided by molecular mean $\langle {\widehat{n}}_j\rangle$. The key indicates that parameters were obtained from (1) the high-variance ensemble of 89 embryos, (2) the low-variance ensemble of 17 embryos, and (3) the extreme condition of high diffusion rate D = 7890 (μm²/s), decay rate ω = 1.0 (s^-1) and synthesis rate J = 70000 (molecules/s). (B) As shown in the key, noise strength of simulated fluorescence intensity ${\widehat{I}}_j=[\stackrel{\_}{\alpha n\beta }]$ and rescaled gradient $[\widehat{n}]$ were obtained using parameters from (1) the high-variance ensemble of 89 embryos and (2) the low-variance ensemble of 17 embryos.