Table 2.

Translating qualitative phenotype observations into quantitative constraints.

Phenotypic constraint (CRi)		Mathematical interpretation	Percent of sampled parameter sets that satisfice criterion
CR1	Prior to signal perturbation, the system should exhibit a stable steady state.	$d/d{t}_{\mathrm{a}\mathrm{l}\mathrm{l}\mathrm{s}\mathrm{p}\mathrm{e}\mathrm{c}\mathrm{i}\mathrm{e}\mathrm{s}}\le {10}^{-8}$	56.4
CR2	PI3P depletion induces fusion.	$\frac{\int {[Sec17:SNARE]}_{\mathrm{P}\mathrm{I}3\mathrm{P}\mathrm{d}\mathrm{e}\mathrm{p}\mathrm{l}\mathrm{e}\mathrm{t}\mathrm{i}\mathrm{o}\mathrm{n}}dt}{\int {[Sec17:SNARE]}_{\mathrm{n}\mathrm{o}\mathrm{p}\mathrm{e}\mathrm{r}\mathrm{t}\mathrm{u}\mathrm{r}\mathrm{b}\mathrm{a}\mathrm{t}\mathrm{i}\mathrm{o}\mathrm{n}}dt}\le 0.1$	9.7
CR3	Trigger activation induces fusion.	$\frac{\int {[Sec17:SNARE]}_{\mathrm{t}\mathrm{r}\mathrm{i}\mathrm{g}\mathrm{g}\mathrm{e}\mathrm{r}\mathrm{a}\mathrm{c}\mathrm{t}\mathrm{i}\mathrm{v}\mathrm{a}\mathrm{t}\mathrm{i}\mathrm{o}\mathrm{n}}dt}{\int {[Sec17:SNARE]}_{\mathrm{n}\mathrm{o}\mathrm{p}\mathrm{e}\mathrm{r}\mathrm{t}\mathrm{u}\mathrm{r}\mathrm{b}\mathrm{a}\mathrm{t}\mathrm{i}\mathrm{o}\mathrm{n}}dt}\le 0.1$	24.0
CR4	Fusion due to PI3P depletion should be faster than that due to trigger activation.	$\frac{\int {[Sec17:SNARE]}_{\mathrm{t}\mathrm{r}\mathrm{i}\mathrm{g}\mathrm{g}\mathrm{e}\mathrm{r}\mathrm{a}\mathrm{c}\mathrm{t}\mathrm{i}\mathrm{v}\mathrm{a}\mathrm{t}\mathrm{i}\mathrm{o}\mathrm{n}}dt}{\int {[Sec17:SNARE]}_{\mathrm{P}\mathrm{I}3\mathrm{P}\mathrm{d}\mathrm{e}\mathrm{p}\mathrm{l}\mathrm{e}\mathrm{t}\mathrm{i}\mathrm{o}\mathrm{n}}dt}\le 0.5$	20.2
CR5	In the absence of an external signal, spontaneous fusion events should be rare.	${[Sec17:SNARE]|}_{\mathrm{n}\mathrm{o}\mathrm{p}\mathrm{e}\mathrm{r}\mathrm{t}\mathrm{u}\mathrm{r}\mathrm{b}\mathrm{a}\mathrm{t}\mathrm{i}\mathrm{o}\mathrm{n}}\le {10}^{-6}$	6.9
All criteria satisficed concurrently			0.1