Published in:
Proceedings: Biological Sciences, 279 (2012) 1732, Seite 1351-1358
Language:
English
ISSN:
0962-8452
Origination:
Footnote:
Description:
Jellyfish, hydras, corals and sea anemones (phylum Cnidaria) are known for their venomous stinging cells, nematocytes, used for prey and defence. Here we show, however, that the potent Type I neurotoxin of the sea anemone Nematostella vectensis, Nvl, is confined to ectodermal gland cells rather than nematocytes. We demonstrate massive Nvl secretion upon encounter with a crustacean prey. Concomitant discharge of nematocysts probably pierces the prey, expediting toxin penetration. Toxin efficiency in sea water is further demonstrated by the rapid paralysis offish or crustacean larvae upon application of recombinant Nvl into their medium. Analysis of other anemone species reveals that in Anthopleura elegantissima. Type I neuro toxins also appear in gland cells, whereas in the common species Anemonia viridis, Type I toxins are localized to both nematocytes and ectodermal gland cells. The nematocyte-based and gland cell-based envenomation mechanisms may reflect substantial differences in the ecology and feeding habits of sea anemone species. Overall, the immunolocalization of neuro toxins to gland cells changes the common view in the literature that sea anemone neurotoxins are produced and delivered only by stinging nematocytes, and raises the possibility that this toxin-secretion mechanism is an ancestral evolutionary state of the venom delivery machinery in sea anemones.