Table 1.

List of independent (dimensionless) parameters involved in our theory.

Parameter	Meaning	Estimate	Value	Ref
ζ	Rescaled pre-rRNA surface density	<0.12	Varied	16
$\frac{{\gamma }_{\mathrm{p}}{b}^2}{N_r{k}_{\mathrm{B}}T}$	Rescaled surface tension per RBP	0.03	0.03
χ	Interaction parameter	>10	12
ϵ	RBP-RNA-binding energy	<−10	−12
${\mu }_{\mathrm{p}}/\left(k_{\mathrm{B}}T\right)$	RBP chemical potential	−10	−10	13

The unit length b of pre-rRNA is estimated as 4 nm (≈12 b) by using the value of single-stranded DNA (23). The absolute temperature T is 300 K. The surface density ${\sigma }_{\mathrm{in}}$ was estimated by the number of Pol I (50 Pol I per rDNA, 300 copies of active rDNA repeat per cell, ~10 FCs per nucleolus, ~2 nucleoli per cell) and the typical radius of FCs $r_{\mathrm{in}}~100\mathrm{nm}$ (3,16). The surface tension ${\gamma }_{\mathrm{p}}$ can be estimated as $~k_{\mathrm{B}}T/b_{\mathrm{p}}^2$ (27,28), where the size $b_{\mathrm{p}}$ of FBL is ≈4 nm (29). The number of units $N_{\mathrm{r}}$ in the FBL-binding region of pre-rRNA is estimated by using its length ∼400 b (2,16). The chemical potential of FBL was estimated by using its concentration ~1 μM (13).