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 oculata or Lubomirskia baikalensis). From previous work, it is known that high concentrations of silicate induce spicule formation and upregulate the silicatein gene. 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 gene Iroquois induces the formation of an aquiferous system, consisting of exhalant and inhalant pores. We propose a model of the regulatory network controlling the separation in time and space of the skeletogenesis and the formation of the aquiferous system. The regulatory network is closely linked with environmental influences. In building a skeleton, silicate is absorbed from the environment. In our model, silicate is transported by diffusion through the environment and absorbed at the surface of a geometric model of the sponge, resulting in silicate gradients emerging in the neighbourhood of the sponge. Our model simulations predict sponge morphology and the positioning of the exhalant pores over the surface of the sponge.
Kaandorp
Jaap A
JA
Section Computational Science, University of Amsterdam, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands. j.a.kaandorp@uva.nl
Blom
Joke G
JG
Verhoef
Jozef
J
Filatov
Max
M
Postma
M
M
Müller
Werner E G
WE
D000818:Animals; D005786:Gene Expression Regulation / Q000502:physiology*; D008954:Models, Biological; D011161:Porifera / Q000235:genetics* / Q000254:growth & development*; D011506:Proteins / Q000235:genetics / Q000378:metabolism
D011506:Proteins