Involvement of contractile vacuoles in the osmoregulation process of the marine parasitic amoeba Neoparamoeba perurans

2015 ◽  
Vol 39 (5) ◽  
pp. 629-633 ◽  
Author(s):  
P C Lima ◽  
R S Taylor ◽  
M Cook
Keyword(s):  
Contractile Vacuoles

Morphology and description of infraciliary bands pattern in four Metadinium Awerinzew & Mutafowa, 1914 species (Ciliophora, Entodiniomorphida, Ophryoscolecidae) with taxonomic notes on the genus

Zootaxa ◽  
2018 ◽  
Vol 4500 (4) ◽  
pp. 574 ◽  
Author(s):  
FRANCIANE CEDROLA ◽  
MARIANA FONSECA ROSSI ◽  
ISABEL MARTINELE ◽  
MARTA D’AGOSTO ◽  
ROBERTO JÚNIO PEDROSO DIAS
Keyword(s):  
Host Species ◽  
Morphological Similarity ◽  
Type Pattern ◽  
Anterior Body ◽  
Contractile Vacuoles ◽  
Geographical Locations

The genus Metadinium includes ophryoscolecid ciliates, with two retractile ciliary zones in the anterior body portion, two broad skeletal plates, a lobed macronucleus and two contractile vacuoles. Species belonging to this genus were recorded in several geographical locations and in different host species. However, they were mostly described based on a single ciliatological technique, and until now, there is only one description of the infraciliary pattern in Metadinium ciliates (Metadinium medium). The present study performs the morphological and infraciliature characterization of four species belonging to Metadinium: M. esalqum, M. minorum, M. rotundatum and M. ypsilon; and presents taxonomic notes on the genus. The oral infraciliature in these four Metadinium species corresponds to the Diplodinium-type, pattern shared with genera Diplodinium, Diploplastron, Eudiplodinium, Eremoplastron and Polyplastron. A brief review conducted highlights the difficulty of delimiting Metadinium species due to the morphological similarity among them. 

The Physiology of Contractile Vacuoles

1960 ◽  
Vol 37 (1) ◽  
pp. 73-82
Author(s):  
J. A. KITCHING ◽  
J. E. PADFIELD ◽  
M. H. ROGERS
Keyword(s):  
Body Surface ◽  
Normal Activity ◽  
The Body ◽  
Contractile Vacuole ◽  
Diffusion Constants ◽  
Contractile Vacuoles

1. The suctorian Discophrya collini (Root) has been subjected to D2O-H2O mixtures containing up to 99.7% D2O. 2. In 25% D2O or over there is a rapid but temporary shrinkage of the body. This shrinkage is difficult to estimate owing to the wrinkling of the body surface, but amounts to at least 10% in the undiluted (99.7%)D2O. 3. During the period of temporary shrinkage the contractile vacuole ceases activity. Normal activity is resumed when the normal volume is regained. In concentrations of D2O too low to cause shrinkage there is a temporary fall in the rate of vacuolar output. 4. Return to H2O leads to a brief but often very considerable rise in vacuolar output. 5. It is concluded that D2O penetrates less rapidly than H2O. A difference of at least 10% in the diffusion constants in the membrane would be required to explain our results. We cannot exclude this as unreasonable from our data, although an explanation based on differences in the equilibrium properties of D2O and H2O might also be invoked.

Benthic ciliates from Sepetiba Bay (Rio de Janeiro, Brazil) with description of Pseudokeronopsis sepetibensis n. sp. (Spirotrichea: Urostylida)

Zootaxa ◽  
2004 ◽  
Vol 587 (1) ◽  
pp. 1 ◽  
Author(s):  
Rodrigo C. Wanick ◽  
Inácio D.D. Silva-Neto
Keyword(s):  
Rio De Janeiro ◽  
Unique Combination ◽  
Constant Number ◽  
The South ◽  
Sepetiba Bay ◽  
Oral Region ◽  
Water And Sediment ◽  
Contractile Vacuoles ◽  
Janeiro State ◽  
Benthic Ciliates

During the period from 2001 to 2002, we examined samples of water and sediment from five stations in Sepetiba Bay, located in the south region of Rio de Janeiro state, Brazil. We identified 32 species of ciliate protists representing seven classes: Karyorelictea, Heterotrichea, Spirotrichea, Litostomatea, Phyllopharyngea, Protostomatea and Oligohymenophorea. Among the Spirotrichea, we discovered Pseudokeronopsis sepetibensis n. sp., characterized by a unique combination of three features: 3 contractile vacuoles, an inconspicuous mid-ventral row, and 4 5 frontoterminal cirri. It showed yellow-greenish coloration and elongated body outline (100 140 m x 20 26 m). On average, there were 44 adoral membranelles, 50 left marginal cirri, 48 right marginal cirri and 41 mid-ventral cirri disposed in a straight row past the level of the oral region. Other features include 4 frontoterminal cirri and a constant number of 3 transverse cirri; 8 frontal cirri (4 anterior and 4 posterior arranged as an atypical bicorone).

scholarly journals Proton pumps populate the contractile vacuoles of Dictyostelium amoebae.

1993 ◽  
Vol 121 (6) ◽  
pp. 1311-1327 ◽  
Author(s):  
J Heuser ◽  
Q Zhu ◽  
M Clarke
Keyword(s):  
Pure Water ◽  
Video Recording ◽  
Freeze Fracture ◽  
Time Lapse ◽  
Contractile Vacuole ◽  
Proton Pumps ◽  
Fluid Accumulation ◽  
Styryl Dyes ◽  
B Subunit ◽  
Contractile Vacuoles

Amoebae of the eukaryotic microorganism Dictyostelium discoideum were found to contain an interconnected array of tubules and cisternae whose membranes were studded with 15-nm-diameter "pegs." Comparison of the ultrastructure and freeze-fracture behavior of these pegs with similar structures found in other cells and tissues indicated that they were the head domains of vacuolar-type proton pumps. Supporting this identification, the pegs were observed to decorate and clump when broken amoebae were exposed to an antiserum against the B subunit of mammalian vacuolar H(+)-ATPase. The appearance of the peg-rich cisternae in quick-frozen amoebae depended on their osmotic environment: under hyperosmotic conditions, the cisternae were flat with many narrow tubular extensions, while under hypo-osmotic conditions the cisternae ranged from bulbous to spherical. In all cases, however, their contents deep etched like pure water. These properties indicated that the interconnected tubules and cisternae comprise the contractile vacuole system of Dictyostelium. Earlier studies had demonstrated that contractile vacuole membranes in Dictyostelium are extremely rich in calmodulin (Zhu, Q., and M. Clarke, 1992, J. Cell Biol. 118: 347-358). Light microscopic immunofluorescence confirmed that antibodies against the vacuolar proton pump colocalized with anti-calmodulin antibodies on these organelles. Time-lapse video recording of living amoebae imaged by interference-reflection microscopy, or by fluorescence microscopy after staining contractile vacuole membranes with potential-sensitive styryl dyes, revealed the extent and dynamic interrelationship of the cisternal and tubular elements in Dictyostelium's contractile vacuole system. The high density of proton pumps throughout its membranes suggests that the generation of a proton gradient is likely to be an important factor in the mechanism of fluid accumulation by contractile vacuoles.

scholarly journals PARAMECIA WITH EXTRA CONTRACTILE VACUOLES

Science ◽  
1918 ◽  
Vol 48 (1238) ◽  
pp. 295-296 ◽  
Author(s):  
R. T. Hance
Keyword(s):  
Contractile Vacuoles
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