Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Stochastic Simulation of Gene Expression in a Single Cell   In this paper, we consider two stochastic models of gene expression in
prokaryotic cells. In the first model, sixteen biochemical reactions involved
in transcription, translation and transcriptional regulation in the presence of
inducer molecules are considered. The time evolution of the number of
biomolecules of a particular type is determined using the stochastic simulation
method based on the Gillespie Algorithm. The results obtained show that if the
number of inducer molecules, N(I), is greater than or equal to the number of
regulatory molecules, N(R), the average protein level is high in the steady
state (state 2). The magnitude of the level is the same as long as N{I) greater
than or equal to N(R). When N(I) is very very less than N(R), the average
protein level is low, practically zero (state 1). As N(I) increases, the
protein level continues to remain low. When N(I)becomes close to N(R), protein
levels in the steady state are intermediate between high and low.In the
presence of autocatalysis, a cell mostly exists in either state 1 or state 2
giving rise to a bimodal distribution in the protein levels in an ensemble of
cells. This corresponds to the "all or none'' phenomenon observed in
experiments. In the second model, the inducer molecules are not considered
explicitly. An exhaustive simulation over the parameter space of the model
shows that there are three major patterns of gene expression, Type A, Type B
and Type C. The effect of varying the cellular parameters on the patterns, in
particular, the transition from one type of pattern to another, is studied.
Type A and Type B patterns have been observed in experiments. Simple
mathematical models of transcriptional regulation predict Type C pattern of
gene expression in certain parameter regimes.

13
The categories of this paper are: quant-ph
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
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The categories of this paper are: q-fin
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
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The categories of this paper are: hep-lat
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The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
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The categories of this paper are: funct-an
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The categories of this paper are: comp-gas