Michael R. Gretz's research while affiliated with Michigan Technological University and other places

... The flagella of the green alga Chlamydomonas have been used as a model of flagellar structure. Flagella structure has been highly conserved throughout evolution, images from Chlamydomonas are virtually indistinguishable from flagella (or cilia -a term for a short flagellum) of mammalian cells including human sperm and certain epithelia (Johnson, 1995). Chlamydo monas has been chosen because of the ease of growing the organism and because the flagella can be detached from the cells by pH shock or blending. ...

... The most common form of motility in pennate diatoms is known as "gliding," consisting in directed cell movement, typically along the direction parallel to the longitudinal axis of the cell, and when the cell is in close contact with hard surfaces (Edgar and Pickett-Heaps 1984). Directed motility, for example, toward a stimulus, is achieved by varying the time between the reversal of direction, causing forward progression when the movement in the direction of the stimulus lasts longer than away from it (Cohn et al. 2004;Apoya-Horton et al. 2006). Diatom gliding is a complex process, involving the extrusion of adhesive, mucilaginous extracellular polymeric substances (EPS) through the raphe. ...

... Considering the characteristics described above, the production and application of original polysaccharides as therapeutic agents have become increasingly important topics of research. Unfortunately, the SPs of green seaweeds are structurally diverse and heterogeneous [31,32], which makes studies on their structures challenging and hinders their development as therapeutic agents [33]. The production of a standardized commercial product based on green algal SP constituents is expected to be a significant endeavor because the structural and pharmacological features of these components may vary according to the species and location and time of harvest [34][35][36][37][38]. ...

... It produced negative ecological and economic consequences (Alpert et al. 2000;Beville et al. 2012;Taylor and Bothwell 2014). Considerable attention has been paid to this D. geminata problem, as it has invaded more than 187 rivers in many other countries (Blanco and Ector 2009;Gretz et al. 2007). This benthic diatom has been declaring an invasive species in Southern Hemisphere countries such as New Zealand (Kilroy and Unwin 2011), Argentina and Chile (Reid and Torres 2014) since 2010 (Segura 2011). ...

... Bourrelly 1966;Fott 1972;Prescott 1962;Smith 1950). In a strain of S. gelatinosa isolated from Kansas, USA, Wujek (1968) and Wujek & Gretz (1977) described vague pseudoflagella and stalked, oblong, bulb-shaped pyrenoids in cup-shaped chloroplasts in multinucleate vegetative cells. My observations on unauthentic S. gelatinosa SAG 66.94 did not agree with most features described in the literature. ...

... During the period 1982-1986 alone there were 50 new species and varieties of Mallomonas discovered and described in the journal literature (Asmund, Cronberg & D/irrschmidt, 1982;Kristiansen, 1982;Nicholls, 1982Nicholls, , 1984bNicholls, , 1987aD/irrschmidt 1982a, b, 1983a, b, c, 1984Croome & Tyler, 1983a, b, c;Wujek 1984;Cronberg & Hickel, 1985;Dfirrschmidt & Croome, 1985;Gretz, Sommerfeld & Wujek, 1985;Cronberg, 1986). This paper describes three new members of the genus Mallomonas, recently discovered in Ontario, Canada. ...

... These results can be an asset to improve risk assessment frameworks for salinized freshwater environments, considering that most of the prevention measures are no longer suitable, so directional mitigation or restoration actions can be complemented and/or substantially enriched by the results presented here. Adeyemi and Klerks, 2013;Araújo et al., 2012;Araújo et al., 2013;Fogels and Sprague, 1977;Griffith, 2017;Guan and Wang, 2006;Hintz et al., 2019;Lopes et al., 2004;Lopes et al., 2005;Moreira-Santos et al., 2008;Muyssen and Janssen, 2004;Oliveira-Filho et al., 2004;Osundeko et al., 2014;Shaw et al., 2019;Vousdoukas et al., 2020;Yan et al., 2015. ...

... Elaiosome lipid chemistry has been well described (Boulay, Coll-Toledano, & Cerdá, 2006; Boulay, Coll-Toledano, Manzaneda, & Cerdá, 2007;Bresinsky, 1963;Brew et al., 1989;Fischer et al., 2008;Gammans, Bullock, Gibbons, & Schönrogge, 2006;Hughes & Westoby, 1994;Kusmenoglu, Rockwood, & Gretz, 1989;Lanza, Schmitt, & Awad, 1992;Leal et al., 2014;Lisci et al., 1996;Skidmore & Heithaus, 1988;Wu, Peng, Dong, Xia, & Zhao, 2019) and is known to influence both the quantitative and qualitative aspects of seed dispersal effectiveness (sensu Schupp, 1993;Schupp et al., 2010) by ants. Seed-dispersing ants display a preference for food items containing high concentrations of oleic acid, an important signaling compound that stimulates foraging behavior, and thus select for seeds containing high concentrations of this compound (Boulay et al., 2006(Boulay et al., , 2007Brew et al., 1989;Fischer et al., 2008;Lanza et al., 1992;Pfeiffer, Huttenlocher, & Ayasse, 2010;Turner & Frederickson, 2013). ...

... Additionally, the growth phase influences EPS composition for marine diatoms (Penna et al., 1999) and the red microalga Porphyridium purpureum (Li et al., 2020), highlighting the flexibility of the EPSrelated pathways (Aslam et al., 2018). In the case of Phaeodactylum tricornutum, the EPS monosaccharide composition can change depending on the physiological state of the diatom (Willis et al., 2013) and growth phase (Bellinger et al., 2005;Underwood et al., 2004). Our results suggest that P. tricornutum modulates its polysaccharide biosynthesis machinery to adapt to the different cultural conditions, thereby influencing its bioactivity. ...

... The modern concept that all red algae should be grouped into a single class is supported by the occurrence of cellulose in the conchocelis phases of Bangia atropurpurea as well as Porphyra tenera (Gretz et al., 1982). Cellulose was also later found in the conchocelis phases of Porphyra leucostica and Porphyra umbilicalis; the quantities reported were 3.8%, 5%, and 11.8% for the Porphyra species investigated (Gretz et al., 1986;Mukai et al., 1981). It may be concluded that the cellulose from red algae is present in much lower amounts and is less crystalline than from other sources. ...