The lengthscale and timescale of the gradient of the transcription factor, Bicoid, in Drosophila melanogaster embryos

PEREZ IPIÑA EMILIANO; PONCE DAWSON SILVINA

Conferencia; III Dynamics Days South America; 2014

During early development of embryos, cell differentiation is carried out by transcriptional regulation of gene expression. The establishment of gradient of transcriptional factors, determine the patterning of cell fates. The case of Bicoid (Bcd) in Drosophila melanogaster embryos, is very well documented and studied, yet there is still controversy of which are the mechanism that can explain all the gradient characteristics. The Bcd gradient is observed in embryos that express Bcd-GFP. These measures cannot differentiate if Bcd is freely diffusing or bound to any molecular trap, in which the information of the free Bcd will be hinder by the bound ones. In this work, we introduce a SSD model in which Bcd is synthesized at the anterior pole and then diffuses to the posterior pole, while they interact with binding sites. We found that the gradient formed by the Bcd that is unbind, decays early than the gradient form by Bcd bind and unbind. Moreover, the time that take the gradient to be established is consistent with experimental reports, and are in agreement with effective diffusion coeficient that depends on the concentration of Bcd and binding sites.