Extrusomes

Extrusomes are membrane-bound structures in some eukaryotes which, under certain conditions, discharge their contents outside the cell. There are a variety of different types, probably not homologous, and serving various functions.

Notable extrusomes include mucocysts, which discharge a mucous mass sometimes used in cyst formation, and trichocysts, which discharge a fibrous rod. The stinging found in Cnidarian animals may be regarded as extrusomes as well. Extrusomes found in dinoflagellates are important in the formation of red and black tides.

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