How Recruitment mechanism contributes to patterning in Drosophila developing wing

ALVAREZ HUGO ARIEL; MUÑOZ NAVA, LUIS MANUEL; NAHMAD BENSUSAN, MARCOS; CHARA, OSVALDO

Conferencia; XLVII Reunión Anual de la Sociedad Argentina de Biofísica; 2018

How concentration patterns of signals that determine cell fates get established is a fundamental problem in developmental biology. In the developing wing of the fruit fly Drosophila melanogaster (called imaginal wing disc), the wing fate is defined by the expression of the selector gene vestigial (vg). The size of the Vg domain is determined through proliferation of Vg expressing cells near the dorsal-ventral boundary of the wing disc, and also through the propagation of the Vg pattern to neighboring cells by a process known as recruitment. However, the spatiotemporal contributions of these mechanisms to the final size of the wing have not yet been carefully examined. We quantitatively examine Vg expression along the dorsal-ventral (DV) axis in the wing disc and find that the Vg pattern overscales (i.e., it expands more than predicted by tissue size). This overscaling phenotype can be recapitulated from simulations of a mathematical model that explicitly incorporates a recruitment mechanism. We developed a Cellular Potts Model of a growing tissue where the Vg concentration expressed in each cell is assumed as a function of its difference with the neighboring cells and encoded by an Ordinary Differential Equation.The agreement between the experimental data and the modeling results here presented suggests that the proposed recruitment mechanism could, at least in part, explain the spatio-temporal pattern of Vg concentration.