“…In Drosophila, BMP diffusion occurs within a thin, bounded compartment surrounding a roughly ellipsoidal embryo; DV gradient formation is readily simulated as a reaction-diffusion problem in one dimension, with little loss of accuracy (Eldar et al, 2002;Lander et al, 2002;Eldar et al, 2003;Lander et al, 2006;Lou et al, 2004;Lander et al, 2005Lander et al, , 2007Lou et al, 2005;Mizutani et al, 2005;Shimmi et al, 2005). In view of the more complex arrangement of the zebrafish embryo, we chose here to carry out fully three-dimensional simulations, which are computationally much more costly.…”