Based on the light-reactive behavior of siliceous sponges, their intriguing
quartz glass-based spicular system and the existence of a light-generating
luciferase [Mu ¨ller WEG et al.(2009) Cell Mol Life Sci66, 537–552], a pro-tein potentially involved in light reception has been identified, cloned and
recombinantly expressed from the demosponge Suberites domuncula.
Selenium is a trace element found in freshwater and the marine environ-ment. We show that it plays a major role in spicule formation in the demo-sponge Suberites domuncula. If added to primmorphs, an in vitro sponge
cell culture system, it stimulates the formation of siliceous spicules. Using
differential display of transcripts, we demonstrate that, after a 72-h expo-sure of primmorphs to selenium, two genes are up-regulated; one codes for
selenoprotein M and the other for a novel spicule-associated protein....
Sponges (phylum Porifera) live in a symbiotic relationship
with microorganisms, primarily bacteria. Until now, mole-cular proof for the capacity of sponges to recognize fungi in
the surroundingaqueousmilieuhas not beenavailable.Here
we demonstrate, for the demospongeSuberites domuncula
(Porifera, Demospongiae, Hadromerida), a cell surface
receptor that recognizes (1fi3)-b-D-glucans, e.g. curdlan or
laminarin. This receptor, the (1fi3)-b-D-glucan-binding
protein, was identified and its cDNA analysed.
Recent studies have shown that the Porifera, with the
examples of the demosponges Suberites domunculaand
Geodia cydonium, comprise a series of pathways found also
in the immune systemofDeuterostomia, suchas vertebrates,
but are absent in Protostomia, with insects or nematodes as
examples. One pathway is the (2¢)5¢)oligoadenylate syn-thetase [(2±5)A synthetase] system.