Quantum mechanics predicts Bicoid interpretation times of less than a second

Abstract

The establishment and interpretation of the concentration distribution of the morphogen Bicoid (Bcd) is considered crucial for the successful embryonic development of fruit flies. However, the biophysical mechanisms behind the timely formation and subsequent interpretation of this prototypical morphogenetic system by its target genes are not yet completely understood. Recently a discrete time, one-dimensional quantum walk model of Bcd gradient formation has been successfully used to explain the observed multiple dynamic modes of the Bcd system. However, the question of its precise interpretation by its primary target gene hunchback (hb) remains still unanswered. In this paper it will be shown that the interpretation of the Bcd gradient by its primary target gene hb, with the observed precision of ∼ 10%, takes a time period of less than a second, as expected on the basis of recent experimental observations. Furthermore, the quantum walk model is also used to explain certain key observations of recent optogenetic experiments concerning the time windows for Bcd interpretation. Finally, it is concluded that the incorporation of quantum effects into the treatment of Bcd gradient represents a viable step in exploring the dynamics of morphogen gradients.