title: Chemical offense by means of toxicysts in the freshwater ciliate, Coleps hirtus.
abstract: Coleps hirtus is a small common freshwater ciliate belonging to the protostomatid group, its body covered by calcified plates assembled to form an armor. Coleps feeds on bacteria, algae, flagellates, living and dead ciliates, animal and plant tissues. To assist its carnivorous feeding the ciliate is equipped with offensive extrusomes (toxicysts), clustering mainly in and around its oral aperture. In this study, we isolated the discharge of the toxicysts from living cells, evaluating its cytotoxic effects against various ciliate species, and demonstrating that it is essential for the effectiveness of Coleps' predatory behavior. The analysis of the toxicyst discharge performed by liquid chromatography-electrospray-mass spectrometry and gas chromatography-mass spectrometry, revealed the presence of a mixture of 19 saturated, monounsaturated and polyunsaturated free fatty acids with the addition of a minor amount of a diterpenoid (phytanic acid).
authors: Laboratory of Protistology and Biology Education, University of Macerata, P.le Bertelli 1, 62100, Macerata, Italy.
authors: Federico
authors: F
authors: Buonanno
authors: Andrea
authors: A
authors: Anesi
authors: Graziano
authors: G
authors: Guella
authors: Santosh
authors: S
authors: Kumar
authors: Daizy
authors: D
authors: Bharti
authors: Antonietta
authors: A
authors: La Terza
authors: Luana
authors: L
authors: Quassinti
authors: Massimo
authors: M
authors: Bramucci
authors: Claudio
authors: C
authors: Ortenzi
mesh_terms: D002853:Chromatography, Liquid; D016798:Ciliophora / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D003603:Cytotoxins / Q000737:chemistry* / Q000302:isolation & purification*; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005227:Fatty Acids / Q000032:analysis*; D005247:Feeding Behavior; D005618:Fresh Water / Q000469:parasitology; D020459:Genes, rRNA; D008853:Microscopy; D008969:Molecular Sequence Data; D010831:Phytanic Acid / Q000032:analysis*; D016053:RNA, Protozoan / Q000235:genetics; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D017422:Sequence Analysis, DNA; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D003603:Cytotoxins; D016054:DNA, Protozoan; D004275:DNA, Ribosomal; D005227:Fatty Acids; D016053:RNA, Protozoan; D012337:RNA, Ribosomal, 18S; D010831:Phytanic Acid
keywords: Extrusomes; PUFAs; cytotoxicity; free fatty acids; predator-prey interactions