where V b and V ex are the concentrations of bound and extracellular virus particles, respectively, t is time, and k b is the apparent rate constant for virus binding. After binding, we assume the bound virus is immediately endocytosed and fused, and its genome and protein components are instantaneously released into the cytoplasm at the expense of the fused virus particle. The protein stoichiometry of a single VSV particle and the lengths of each viral gene and protein are summarized in Table 2 , [28, 29] . Population distribution of polymerases and nucleocapsids. Following the release of the encapsidated genome and proteins into the cytoplasm, VSV transcription is initiated. The viral transcription was assumed to be independent of host-cell functions such as replication [33] . Instead, the viral complex of L and P proteins, with a stoichiometry of 1-3.6, was taken to function as polymerase in transcription and replication [49] . In the absence of P protein, L protein cannot bind to the genome or anti-genome [50] . After binding to the 39 promoter regions of the genomic and anti-genomic templates, the viral polymerase starts to synthesize its own RNA transcription and replication products by elongating along the templates. During transcription a fraction of elongating polymerases terminate transcription by dissociating from the templates as they encounter regulatory signals at intergenic regions [19, 26] . In addition to the regulated polymerase dissociation, time-dependent concentration changes of the polymerases and the viral templates in the cytoplasm influence the distribution of polymerases on the viral templates during transcription and replication. Hence, the distribution of polymerases continuously varies over the viral templates, ultimately determining the relative synthesis levels of mRNAs and genome-size RNAs.