Lectin binding patterns of Scrippsiella lachrymosa (Dinophyceae) in relation to cyst formation and nutrient conditions

Selective feeding behaviour of key free-living protists: avenues for continued study

“…Although molecular mechanisms may be involved, there is no direct experimental evidence to demonstrate this at present. For example, cell surface N-actetyl-glucosamine expression of a photosynthetic dinoflagellate changes with N-status of the cell (Kremp & Anderson 2004). Because cell surface sugar moieties appear to act as ligands for predatory protist lectins (Wootton et al 2007), the variable expression of cell surface carbohydrate residues by the prey may affect cell surface recognition (capture and processing) by the protist predator.…”

Cell surface lectin-binding glycoconjugates on marine planktonic protists

“…2d and e). Con A has been reported to bind to a wide variety of dinoflagellate, diatom, coccolithophore, prymnesiophyte and ciliate species, highlighting that mannose/glucose residues commonly occur on the surface of protozoan cells and their prey (Ramoino, 1997; Cho, 2002; Takahashi et al , 2002; Strom et al , 2003; Kremp & Anderson, 2004; Wootton et al , 2006). The lack of Con A binding to Paraphysomonas vestita could potentially be explained by the presence of silicified scales which cover the cell surface of this species.…”

“…To date, fixing protists before lectin incubation has been the most common method of preparation (e.g. Lueken et al, 1981;Allen et al, 1988;Ramoino, 1997;Strom et al, 2003;Kremp & Anderson, 2004). In general, this method is unsuitable for studying sugar moieties on the cell surface of protozoan and microalgal cells, particularly in flow cytometric applications, where fluorescence intensity is used to quantify relative concentrations of cell surface glycoconjugates.…”

“…In protistan research, plant lectins have been used for a diverse range of applications including the study of conjugation, nuclear division, cellular morphogenesis, trichocyst discharge and as markers of membrane transport (Lueken et al, 1981;Allen et al, 1988;Ramoino et al, 2001). Lectins have also been used to investigate changes in protist surface carbohy-drate expression with differing nutritional status (Ramoino, 1997;Kremp & Anderson, 2004).…”

“…In order to determine the relevance of carbohydrate-protein interactions within microbial food webs, a suitable protocol for studying the presence and localization of cell surface sugar moieties is required. There are a wealth of studies investigating lectin binding to carbohydrates within a broad range of free-living protists, including ciliates, dinoflagellates, diatoms and coccolithophores (Costas & Rodas, 1994;Ramoino, 1997;Cho, 2002;Takahashi et al, 2002;Strom et al, 2003;Kremp & Anderson, 2004;Wilks & Sleigh, 2004). The method of preparation in the majority of studies, however, causes permeabilization of cell walls, resulting in lectins binding to internal cell structures in addition to those on the cell surface (Lueken et al, 1981;Allen et al, 1988;Ramoino, 1997).…”