where r asso,M and r asso,pol are the rates of the associations of M protein and polymerase with the genomic nucleocapsid, respectively, and k M and k pol are the rate constants for each association reaction, respectively. S cond denotes the ratio of the two rate constants (¼k M / k pol ). Unlike L protein, 10% of synthesized M proteins are associated with the plasma membrane [51] . In Equation 3, cond M is the fraction of M proteins associated with the plasma membrane, trans is the fraction of L proteins satisfying the polymerase stoichiometry with P protein, pol total is the total concentration of polymerases associated at the time with nucleocapsids, and M and L are the total concentrations of M and L proteins not assembled into viral progeny. If the concentration of P protein (P) is larger than 3.6-fold concentration of L protein, then trans is equal to 1. Otherwise, trans is equal to P/(3.6L). In our model, M and L proteins compete for free genomic nucleocapsids, and the condensed nucleocapsids, owing to their association with M proteins, cannot be utilized for transcription or replication [19] . From Equations 2 and 3, the newly occupied nucleocapsids by polymerases ((-)nc pol,new ) can be calculated: