/* * Kinetic Model for the Sensory Control of Sporulation in Physarum * polycephalum * * Model Status * * This is the original unchecked version of the model imported * from the previous CellML model repository, 24-Jan-2006. * * Model Structure * * Complementation is the production of a wildtype phenotype when * two recessive mutant alleles are combined in the same genotype. * In fungi complementation can arise when two mutant cells form * to produce a heterokaryon. In such heterokaryons two nuclear * populations mix, providing the biochemical basis for the complementation * effect. * * In the Marwan 2003 publication described here, the author uses * the photosensory control of sporulation in the protist Physarum * polycephalum as an example of how complementation in a heterokaryon * can create a wildtype phenotype. Marwan also investigates how * such a process can depend on the time-dependent physiological * state adopted after pathway activation by one of the mutant * fusion partners. * * The kinetic model of this process can be seen in below. Two * inputs, light of the far-red wavelength and glucose, control * the devlopmental switch network through formation of the sporulation * signal S. Photoreceptor and glucose sensor dependent pathways * are integrated by a mechanism which behaves like a logic AND * gate. Transcription of gene S is repressed by the product of * gene V, while the transcription of gene V is reiprocally repressed * by the product of gene S. * * The model has been described here in CellML (the raw CellML * description of the Marwan 2003 model can be downloaded in various * formats as described in ). * * The complete original paper reference is cited below: * * Theory of Time-Resolved Somatic Complementation and Its Use * to Explore the Sporulation Control Network in Physarum polycephalum * , Wolfgang Marwan, 2003, Genetics, 164, 105-115. PubMed ID: * 12750324 * * reaction diagram * * [[Image file: marwan_2003.png]] * * Schematic diagram of the kinetic model for the sensory control * of sporulation in Physarum polycephalum. */ import nsrunit; // Warning: unit conversion turned off due to unit errors in 4 equation(s) unit conversion off; //Warning: unit hour_ renamed from hour, as the latter is predefined in JSim with different fundamental units. unit hour_=3.6E6 meter^(-3)*second^1; // unit micromolar predefined unit flux=2.7777778E-10 second^(-1)*mole^1; unit first_order_rate_constant=2.7777778E-7 meter^3*second^(-1); unit second_order_rate_constant=2.7777778E-4 meter^6*second^(-1)*mole^(-1); math main { realDomain time hour_; time.min=0; extern time.max; extern time.delta; real Pfr(time) micromolar; when(time=time.min) Pfr=10.0; real Pr(time) micromolar; when(time=time.min) Pr=0.0; real Ifr_sigma_fr_phi_fr dimensionless; Ifr_sigma_fr_phi_fr=0.1; real Ir_sigma_r_phi_r dimensionless; Ir_sigma_r_phi_r=0.0; real kd first_order_rate_constant; kd=0.1; real Xi(time) micromolar; when(time=time.min) Xi=6.0; real Xa(time) micromolar; when(time=time.min) Xa=0.0; real kia second_order_rate_constant; kia=0.1; real kai first_order_rate_constant; kai=0.8; real prepreS(time) micromolar; when(time=time.min) prepreS=200.0; real kx second_order_rate_constant; kx=0.2; real preS(time) micromolar; when(time=time.min) preS=0.0; real Ya(time) micromolar; when(time=time.min) Ya=0.9; real ky second_order_rate_constant; ky=1.0; real S(time) micromolar; when(time=time.min) S=0.0; real alpha1 micromolar; alpha1=30.0; real V(time) micromolar; when(time=time.min) V=50.0; real alpha2 micromolar; alpha2=50.0; real kG second_order_rate_constant; kG=0.1; real glucose micromolar; glucose=1.0; // // Pfr:time=(Ir_sigma_r_phi_r*Pr-Ifr_sigma_fr_phi_fr*Pfr); // Pr:time=(Ifr_sigma_fr_phi_fr*Pr-(Ir_sigma_r_phi_r*Pr+kd*Pr)); // Xi:time=(kai*Xa-kia*Pr*Xi); // Xa:time=(kia*Pr*Xi-kai*Xa); // prepreS:time=((-1)*(kx*Xa*prepreS)); // preS:time=(kx*Xa*prepreS-ky*Ya*preS); // S:time=(ky*Ya*preS+alpha1/(1+V^3)-S); // V:time=(alpha2/(1+S^3)-V); // Ya:time=((-1)*(kG*glucose*Ya)); // }