Ultrastructural localization of chitin in the cystic wall of Euplotes muscicola Kahl (ciliata, hypotrichia)

Abstract

SummaryThe ultrastructural localization of chitin in the cyst walls of Euplotes muscicola was carried out after deproteinization and by specific labelling with WGA-gold complex. The overall ectocyst contains chitin that alone can sustain the exact profile of this cystic layer. In the endocyst, electron clear sublayers include chitin and alternate with other sublayers probably of proteic nature.

Ultrastructure, Eneystment and Cyst Wall Composition of the Resting Cyst of the Peritrich Ciliate Opisthonecta henneguyi

“…The mesocyst of Opisthonecta henneguyi is a chitinous layer. Chitin polymerization and secretion probably takes place on the outer cell membrane, as has been described in most chitin‐secreting systems, such as fungi, yeasts, arthropods, flagellates, and some ciliated protozoa with chitinous cyst wall, such as Euplotes muscicola (Greco et al 1990) and Hyalophysa chattoni (Landers 1991a). Chitin secretion also occurs by chitosomes (vesicles that transport chitin synthetase to the cell surface in fungi).…”

“…The presence of chitin has been reported in the cyst wall of Hyalophysa chattoni (Landers 199la, b), Cyclogramma blochmanni, Cli‐macostomun virens, Phacodinium metschnikoff, Euplotes inky‐stans , and Telotrochidium henneguyi (Bussers and Jeuniaux 1974). Chitin has been identified in the mesocyst and endocyst of Nassula picta, Fabrea salina, Bursaria truncatella, Pseu‐domicrothorax agilis , and Pseudomicrothorax dubius (Bussers 1976), and in the endocyst and ectocyst of Blepharisma undu‐lans (Mulisch and Hausmann 1989) and Euplotes muscicola (Greco et al 1990). However, chitin appears to be absent in the resting cyst of Bresslaua, Woodruffia, Didinium , tintinnids, col‐podid ciliates (except Bursaria), Dileptus , and stichotrichs (Bussers 1976; Bussers and Jeuniaux 1974).…”

“…The nature of glycoprotein carbohydrate moieties has been investigated using different lectins in Histriculus cav‐icola (Calvo and De Miguel 1996). The presence of chitin in the resting cysts of ciliates has been investigated using treatment with chitinase (Bussers 1976; Bussers and Jeuniaux 1974) and WGA lectin (Greco et al 1990; Mulisch and Haustnann 1989). Chitin appears in the walls of the resting cysts, often associated with organic or inorganic substances, such as proteins, polysaccharides, and silica (Bussers 1976; Mulisch 1993).…”

2 Genomics to Study Basal Lineage Fungal Biology: Phylogenomics Suggests a Common Origin

“…Despite their unconventional feeding habits, chitin was observed in the inner layer of resting spores and in immature resting spores for some species of Rozella, as indicated with calcofluorwhite staining, as well as the presence of a fungal-specific chitin synthase (CHS) gene (James and Berbee 2011). However, genes encoding fungal-like CHSs are abundant in members of many non-fungal lineages, such as amoebozoans (Entamoeba), trichomonads (Trichomonas and Tritrichomonas) and diatoms (Thalassiosira), stramenopiles and chromalveolates (Campos-Góngora et al 2004;Kneipp et al 1998;Durkin et al 2009;Greco et al 1990). …”

Microbial colonization of copepod body surfaces and chitin degradation in the sea

“…Apart from the shells of crustaceans, sources of chitin also include molluscs and fungi, the egg shells of nematodes and rotifers, cuttlefish bone, squid pen, coelenterates, diatoms and protozoans (ZoBell & Rittenberg, 1937;Dunn & Liberman, 1983;Smucker & Dawson, 1986;Gooday, 1990;Greco et al, 1990). According to Johnstone (1908), the production of chitin by copepods alone is estimated at several million tons annually.…”