Bursting on a two state stochastic model for gene transcription inDrosophilaembryos

Abstract

Recent experimental data on the transcription dynamics of eve gene stripe two formation of Drosophila melanogaster embryos occurs in bursts of multiple sizes and durations. That has motivated the proposition of a transcription model having multiple ON states for the promoter of the eve gene each of them characterized by different synthesis rate. To understand the role of multiple ON states on gene transcription we approach the exact solutions for a two state stochastic model for gene transcription in D. melanogaster embryos and derive its bursting limit. Simulations based on the Gillespie algorithm at the bursting limit show the occurrence of bursts of multiple sizes and durations. Based on our theoretical approach, we interpret the aforementioned experimental data as a demonstration of the intrinsic stochasticity of the transcriptional processes in fruit fly embryos. Then, we conceive the experimental arrangement to determine when gene transcription has multiple ON promoter state in a noisy environment.

Binary Expression Enhances Reliability of Messaging in Gene Networks

“…As expected, a very fast switching gene will generate a message with entropy approaching that of the constitutive gene with the same average expression levels. An additional regime is the bursting that takes place when we have and [ 52 ]. This regime leads to a strong reduction on the entropy of the message but its mutual information is low.…”

“…Hence, we interpret this limit as the translational bursting and as the translational burst size. Note, however, that in literature it has also been interpreted as the transcriptional bursting size [ 44 , 46 , 50 , 51 , 52 ]. Here, the burst size coincides with the noise increment in relation to the noise in the expression of the constitutive gene.…”

“…Once the promoter switches ON, n increases towards as if it were a time-dependent Poissonian process because the promoter state remains stable for a sufficiently long time interval. For the case of a fast growth of n in comparison with the remaining time scales of the system, one might take it as a burst which size would not correspond to the increment in noise, , but to , and an analysis of the full trajectory would be necessary to understand this noise regime [ 22 , 52 ].…”

Modelos binários estocásticos para a expressão gênica: uma análise comparativa das propriedades de ruído e uma investigação de respostas a terapias gênicas

“…Perceba que a taxa de síntese é centenas de vezes maior que a degradação, o que pode ser considerado um processo de produção de proteína bastante eficiente. Nesse limite, o promotor permanece principalmente OFF e a distribuição se aproxima de uma binomial negativa como ocorre em síntese de proteínas em regime de burst (YVINEC et al, 2017).…”

“…O gráfico A mostra que o fator de Fano assintótico ocorre para pequenos valores de p s α combinados com grandes valores para a taxa de síntese. Este regime de parâmetros do GAR é qualitativamente distinto do GER, pois o último estaria no limite de burst da expressão gênica (YVINEC et al, 2017).…”