Amoeba proteus expresses a single AQP that is present in the contractile vacuole complex required for osmoregulation, whereas Dictyostelium discoideum expresses four AQPs, of which two are present in the single-celled amoeboidal stage and two more in the later multicellular stages preceding spore formation.
With respect to the extent and promptness of adaptation, the highest demands are probably imposed on free-living protozoa such as Amoeba proteus (Nishihara et al., 2004) and Dictyostelium discoideum (Plattner, 2013), which encounter severe changes in osmotic conditions, e.g., due to rainfall or drought.
AQPs also have been found in the contractile vacuole complexes of Amoeba proteus (Nishihara et al., 2008) and Dictyostelium discoideum (Nolta and Steck, 1994) and are addressed below.
Amoeba proteus lives unsheltered in freshwater and, as such, faces much harsher environmental challenges than protozoa within a human host (Couillard et al., 1989).
We have discussed protozoan AQPs with regard to three different types of lifestyles: human-pathogenic parasites that live a sheltered life inside other cells (Plasmodia:, Toxoplasma gondii, and Trypanosoma cruzi), parasites that swim freely in the blood of their human host (Trypanosoma brucei), and amoebae that are directly exposed to a changing environment (Amoeba proteus and Dictyostelium discoideum).
Morphological alterations in the mitochondria of Amoeba proteus
induced by uncoupling agents.
Camera (Deluxe Toronto color prints), Matthew Libatique; editor, Jay Rabinowitz; music, Clint Mansell; string quartets performed by Kronos Quartet; production designer, James Chinlund; art director, Judy Rhee; set decorator, Ondine Karaky; costume designer, Laura Jean Shannon; sound (Dolby Digital), Ken Ishii; supervising sound editor, Nelson Emerson, special visual effects, Amoeba Proteus
. Reviewed at Cannes Film Festival (noncompeting), May 14, 2000.
Although substantially smaller than Tyrannosaurus rex, Amoeba proteus
terrorizes the cell-eat-cell jungle of a drop of pond water.
A kairomone ("A-factor") from the freshwater predator Amoeba proteus was shown to induce avoidance behavior in certain ciliates of the genus Euplotes (Kusch 1993a).
Amoeba proteus was cultivated at 20 [degrees] C in a synthetic medium ("SM"; 1.5 mmol/L NaCl, 0.05 mmol/L KCl, 0.4 mmol/L Ca[Cl.sub.2], 0.05 mmol/L Mg[Cl.sub.2], 0.05 mmol/L MgS[O.sub.4], 2.0 mmol/L sodium phosphate buffer, pH 6.8).
Isolation of A-factor from culture medium of Amoeba proteus
Thereafter 25 Amoeba proteus were mixed with 2500 of the beads in a total volume of 50 [[micro]liter] in three-spot depression slides for 90 min at 20 [degrees] C.