Modelling genetic regulation of growth and form in a branching sponge

We present a mathematical model of the genetic regulation controlling skeletogenesis and the influence of the physical environment on a branching sponge with accretive growth (e.g.Haliclona oculataorLubomirskia baikalensis). From previous work, it is known that high concentrations of silicate induce spicule formation and upregulate thesilicateingene. The upregulation of this gene activates locally the production of spicules in the sponge and the deposition of the skeleton. Furthermore, it is known that the expression of the geneIroquoisinduces the formation of an aquiferous system, consisting of exhalant and inhalant pores. We propose a model of the regulatory network controlling the separa…