Pelomyxa Carolinensis Research Articles

The Effect of Surface‐active Agents on the Permeability, Survival, and Pseudopod Formation of Pelomyxa carolinensis

SUMMARY. The effect of surface‐active agents on the permeability, survival, and pseudopod formation of the rhizopod, Pelomyxa carolinensis, was studied. Surfactants increased the rate of uptake of Na22 in almost all instances. Tweens which lower surface tension, stimulated or caused pseudopod formation; Tween 80 was the least toxic. The fatty acid component as well as the hydrophile‐lipophile balance of the surfactant may influence the rate.

Cytological Studies on Pelomyxa carolinensis with Special Reference to the Mitochondria*

SUMMARY. The mitochondria of living, unstained Pelomyxa carolinensis are homogeneous, nonrefractile bodies and occur as spheres, short rods, dumbbell forms or elongated rods. All forms are distributed uniformly throughout the cytoplasm, except for characteristic accumulations around the contractile vacuoles and small food vacuoles. Mitochondria were never observed within food vacuoles, nor in intimate contact with large food vacuoles containing recently ingested paramecia.Aqueous solutions (1:200,000) of Janus green B, Janus blue, and Janus red stained the mitochondria. After 12 hours in Janus green B and Janus blue or 24 hours in Janus red, the mitochondrion appears as a differentiated structure with the stain localized in eccentric granules or crescentic areas. Aqueous solutions of Janus black (1:200,000), amethyst violet (1:200,000) and Rhodamine B (1:50,000) stained only food vacuoles within the organisms.Dumbbell forms and elongated rods, often interpreted as division stages, were continuously observed in the living organism. These observations failed to reveal any division process.Sectioned material was prepared from animals fixed in Champy's, Regaud's, Altmann's and Helly's fluids, as well as in a fixative composed of equal parts of 1% (w/v) chromic acid and 2% (w/v) osmium tetroxide. Excellent results were obtained with Champy and chrom‐osmic fixation, while the other fixatives proved to be of little value.

Cell division in the giant amoeba, pelomyxa carolinensis, following x‐irradiation. II. Analysis of therapeutic effects after fusion with nonirradiated cell portions

Cell division in the giant amoeba, pelomyxa carolinensis, following x‐irradiation. II. Analysis of therapeutic effects after fusion with nonirradiated cell portions

Distribution of some enzymes in the cytoplasm of amoebae.

The main object of our cytochemical studies at the Carlsberg Laboratory for some time has been the amoeba Chaos chaos (Pelomyxa carolinensis) . This organism has certain properties that make it a good object for cytochemical experimentation. It is closely related, both morphologically and physiologically, to the well-known Amoeba proteus , but differs from the latter in that it is multinuclear and correspondingly larger. Its average size is about 0⋅03 μ 1., which is the right order of magnitude for work with the quantitative enzymatic micromethods at our disposal. Another important property is the ease with which the cytoplasmic components can be separated by centrifugation of the living cell. Floating in a density gradient of gum-arabic solution and in centrifugal fields of about 1000 to 2000 g a stratification of the cellular contents takes place (figure 1). When the amoeba is removed from the centrifuge, remixing of the strata by cytoplasmic currents begins immediately, and if the amoeba is kept at room temperature, after 30 to 60 min it will appear perfectly normal, not only with regard to microscopical appearance but also in motility, oxygen consumption, etc. In other words the stratification brought about by a centrifugal force of 1000 to 2000 g is perfectly reversible by all the criteria that we have been able to apply. This indicates that the separation of cytoplasmic constituents by centrifugal stratification of the living cell must be a rather mild procedure. If the remixing is retarded, e. g. by chilling the amoeba, one can separate by means of microneedles cell fragments which contain concentrates of the various cytoplasmic constituents, isolated from each other by this mild and essentially reversible procedure.

Experimental approaches to the evaluation of fractionation media. I. The action of ions on the protoplasm of Amoeba proteus and Pelomyxa carolinensis

Experimental approaches to the evaluation of fractionation media. I. The action of ions on the protoplasm of Amoeba proteus and Pelomyxa carolinensis

Cell division in the giant amoeba, pelomyxa carolinensis, following x‐irradiation. I. Therapeutic effects after fusion with either nonirradiated light or heavy halves of centrifuged amoebae immediately following exposure

Journal of Experimental ZoologyVolume 120, Issue 3 p. 525-545 Article Cell division in the giant amoeba, pelomyxa carolinensis, following x-irradiation. I. Therapeutic effects after fusion with either nonirradiated light or heavy halves of centrifuged amoebae immediately following exposure† Edward W. Daniels, Edward W. Daniels USAF Radiation Laboratory and Department of Physiology, University of ChicagoSearch for more papers by this author Edward W. Daniels, Edward W. Daniels USAF Radiation Laboratory and Department of Physiology, University of ChicagoSearch for more papers by this author First published: August 1952 https://doi.org/10.1002/jez.1401200308Citations: 9 † This investigation was carried out under a research contract between the University of Chicago and the United States Air Force. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume120, Issue3August 1952Pages 525-545 RelatedInformation

Some effects on cell division in Pelomyxa carolinensis following x‐irradiation, treatment with bis (β‐chloroethyl)‐methyl amine and experimental plasmogamy (fusion)

Journal of Experimental ZoologyVolume 120, Issue 3 p. 509-523 Article Some effects on cell division in Pelomyxa carolinensis following x-irradiation, treatment with bis (β-chloroethyl)-methyl amine and experimental plasmogamy (fusion)† Edward W. Daniels, Edward W. Daniels USAF Radiation Laboratory and Department of Physiology, University of ChicagoSearch for more papers by this author Edward W. Daniels, Edward W. Daniels USAF Radiation Laboratory and Department of Physiology, University of ChicagoSearch for more papers by this author First published: August 1952 https://doi.org/10.1002/jez.1401200307Citations: 16 † This investigation was supported by a research grant from the Atomic Energy Commission. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume120, Issue3August 1952Pages 509-523 RelatedInformation

THE EFFECTS OF ETHYL ALCOHOL ON GROWTH AND RESPIRATION IN PELOMYXA CAROLINENSIS

1. Specimens of Pelomyxa carolinensis were exposed to various concentrations of ethyl alcohol and observations made upon their rate of growth and respiration. The following concentrations were tested: 0, 0.001 M, 0.005 M, 0.01 M, 0.05 M, 0.1 M, and 0.5 M and 1.0 M.2. In 1.0 M (4.6%) alcohol all the organisms were dead within 24 hours. In 0.5 M (2.3%), although most of them died early, some lived for a 10-day period.3. Growth was accelerated in 0.005 M, 0.01 M, and 0.05 M alcohol; the greatest acceleration was a 30% increase over the control in 0.005 M.4. In the higher concentrations of alcohol (0.5 M and 0.1 M) the pelomyxae do not feed and show considerable decrease in size; the hyaline layer becomes very large.5. Rate of respiration was found to be much greater in 0.01 M and 0.005 M alcohol than in the controls without alcohol. It was greatest in 0.01 M, especially when the organisms were put into the alcohol solution for 24 hours before the tests were run, in which case respiration was 318% greater tha...

The Effect of Ultra Violet Light on the Protoplasm in Pelomyxa carolinensis

The Effect of Ultra Violet Light on the Protoplasm in Pelomyxa carolinensis

Studies on the effect of x‐irradiation upon Pelomyxa carolinensis with special reference to nuclear division and plasmotomy

Journal of Experimental ZoologyVolume 117, Issue 1 p. 189-209 Article Studies on the effect of x-irradiation upon Pelomyxa carolinensis with special reference to nuclear division and plasmotomy† Edward William Daniels, Edward William Daniels University of Illinois Fellow in Zoology during the academic year 1949–50 at the University of Illinois; now research associate in the Department of Physiology and Toxicity Laboratory, University of Chicago.Search for more papers by this author Edward William Daniels, Edward William Daniels University of Illinois Fellow in Zoology during the academic year 1949–50 at the University of Illinois; now research associate in the Department of Physiology and Toxicity Laboratory, University of Chicago.Search for more papers by this author First published: June 1951 https://doi.org/10.1002/jez.1401170110Citations: 28 † Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Zoology in the Graduate College of the University of Illinois, 1950. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume117, Issue1June 1951Pages 189-209 RelatedInformation

Effects of low concentration of cyanide on growth and respiration in Pelomyxa carolinensis-Wilson.

Summary1. Concentrations of KCN from 10−7M and higher cause inhibition of growth in Pelomyxa carolinensis. 2. In solutions containing 10−9M KCN there is on the average approximately a 50% increase in growth in “young” Pelomyxa and a 17% increase in “old” Pelomyxa. 3. These effects are not caused by increase or decrease in potassium concentration. Potassium, alone, has very little effect, if any, in very low concentration. 4. Concentrations of KCN from 10−9M and higher cause inhibition of respiration in Pelomyxa. 5. In solutions containing 10−11M KCN, there is an approximate 32 and 50% increase in rate of respiration in “young” and “old” pelomyxae respectively, as compared to controls without cyanide.

Observations on the reaction of Pelomyxa carolinensis subjected to a direct-current electric field.

Previous articleNext article No AccessObservations on the Reaction of Pelomyxa carolinensis Subjected to a Directcurrent Electric FieldGeorge E. Daniel and Garnett H. MayGeorge E. Daniel Search for more articles by this author and Garnett H. May Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Volume 23, Number 3Jul., 1950 Article DOIhttps://doi.org/10.1086/physzool.23.3.30152080 Views: 1Total views on this site Citations: 6Citations are reported from Crossref Journal History This article was published in Physiological Zoology (1928-1998), which is continued by Physiological and Biochemical Zoology (1999-present). PDF download Crossref reports the following articles citing this article:Albert W. Friend, E. D. Finch, H. P. Schwan Low Frequency Electric Field Induced Changes in the Shape and Motility of Amoebas, Science 187, no.41744174 (Jan 1975): 357–359.https://doi.org/10.1126/science.1111109EUGENE C. BOVEE, THEODORE L. JAHN Taxonomy and Phylogeny, (Jan 1973): 37–82.https://doi.org/10.1016/B978-0-12-384850-5.50008-7EUGENE C. BOVEE, THEODORE L. JAHN Locomotion and Behavior, (Jan 1973): 249–290.https://doi.org/10.1016/B978-0-12-384850-5.50014-2THEODORE L. JAHN, EUGENE C. BOVEE Effects of Environmental Conditions on the Motile Behavior of Amebas* *Supported by NIH Research Grant 6462, NSF Grant 5573, and ONR Contract NONR 4756., (Jan 1971): 1–35.https://doi.org/10.1016/B978-0-12-011504-4.50007-3THEODORE L. JAHN, EUGENE C. BOVEE MOTILE BEHAVIOR OF PROTOZOA, (Jan 1967): 41–200.https://doi.org/10.1016/B978-0-08-011846-8.50005-0Theodore L. Jahn Contraction of protoplasm. II. Theory: Anodal vs. Cathodal in relation to calcium, Journal of Cellular Physiology 68, no.22 (Oct 1966): 135–148.https://doi.org/10.1002/jcp.1040680208

Notes on Locomotion in Pelomyxa carolinensis

Wilson (1900) described in a general way the movement in Pelomyxa carolinensis. Mast (1926, 1931, 1934) made a detailed study of the process of locomotion in Amoeba proteus and in Pelomyxa palustris. During the course of a study on the function of the protoplasmic constituents in Pelomyxa carolinensis, the author made numerous observations on the process of locomotion in this species. In view of the fact that practically nothing has been published concerning details of locomotion in Pelomyxa carolinensis, it seems desirable to present the following notes.

Relation Between Metabolic Activity and Cyanide Inhibition in Pelomyxa carolinensis Wilson.

SummaryOxygen consumption and carbon dioxide elimination in Pelomyxa caro-linensis was ascertained by means of a Bar-croft-Warburg micro-respirometer. The total average oxygen consumption was found to be 2442 mm3, SS94 mm3, 11,664 mm3 and 26,971 mm3 per hour per million organisms (or 0.07, 0.16, 0.33, and 0.76 mm3 per hour per cubic millimeter cell substance) at 10°, 20°, 30°, and 35°C., respectively.The respiratory quotient varies directly with the temperature. It was found to be 0.45 at 10°C and 0.94 at 30°C. Consequently, carbohydrate metabolism is evidently greater at higher than at lower temperatures.Respiration is inhibited by potassium cyanide (10-4 M) and the degree of inhibition varies directly with the temperature.From the evidence presented, it can be concluded that a cytochrome-cytochrome oxidase system is the mechanism chiefly involved in oxidation of carbohydrate in Pelomyxa and that as carbohydrate metabolism is reduced in its extent, this mechanism becomes less and less active.

PELOMYXA CAROLINENSIS (WILSON) OR CHAOS CHAOS (LINNAEUS)?

1. Since it is impossible to ascertain the exact structure of Roesel's "der kleine Proteus" from his description and figures, it is impossible to identify this organism. 2. P. carolinensis (W.) and A. proteus (L.) differ in characters of such importance that they must be considered members of different genera. 3. The valid scientific name of Wilson's organism is Pelomyxa carolinensis Wilson because he discovered, accurately described, and properly named it.

THE EFFECTS OF POTASSIUM CYANIDE, POTASSIUM ARSENITE, AND ETHYL URETHANE ON RESPIRATION IN PELOMYXA CAROLINENSIS

1. In 10–5 M KCN respiration in Pelomyxa carolinensis is inhibited by 63 per cent. In much higher concentrations of KCN, up to 10–2 M, only slightly greater inhibition occurs.2. Pelomyxae which have been exposed to potassium cyanide (10–5 to 10–2 M), for 12 to 24 hours, show many changes in protoplasmic structure.3. In 5 x 10–3 M potassium arsenite the maximum inhibition of respiration in Pelomyxa carolinensis is 35 per cent; this effect, however, is only temporary.4. In 0.17 M (1.5 per cent) ethyl urethane the respiration of Pelomyxa carolinensis is inhibited by 65 per cent.5. Respiration in Pelomyxa carolinensis appears to occur chiefly through a cytochrome-cytochrome oxidase system, and partly through a mechanism involving glutathione.6. The respiratory mechanism of Pelomyxa carolinensis, a rhizopod, differs considerably from that of a number of the ciliates.

THE EFFECT OF FOOD CONTENT AND TEMPERATURE ON RESPIRATION IN PELOMYXA CAROLINENSIS WILSON

1. The rate of respiration in Peolmyxa carolinensis at 25° C. is closely correlated with the amount of food material present in the cytoplasm.2. The rate of oxygen consumption at 25° C. was found to be 0.244 ± 0.028 mm.3 per hour per mm.3 cell substance and does not differ greatly from that of Amoeba proteus and Actinosphaerium eichhornii. The rates were less at low temperatures (15° C.) and greater at high temperatures (35° C.).3. Temperatures above 35° C. are usually lethal to Pelomyxa, although in several tests the oxygen consumption at 40° C. for one hour was obtained.4. The respiratory quotient is much lower for starved specimens (R.Q.: 0.56) than for well-fed specimens (R.Q.: 0.87) and is approximately equal to that of other free-living Protozoa.5. As the temperature is increased, the rate of oxygen consumption increases, but the rate of increase becomes progressively greater.6. The temperature coefficient for the rate of respiration in Pelomyxa carolinensis is nearly the same as that in Paramecium,...

I. THE RELATION BETWEEN ATTACHMENT TO THE SUBSTRATUM AND INGESTION BY AMEBA IN STRYCHNINE SULFATE SOLUTION AND CONDITIONED MEDIA

1. Strychnine sulfate 0.000069 M decreased percentage attachment to the substratum by Amoeba proteus in 0.0029 M NaCl from 77.3 to 1.3, in 0.0029 M KCl from 40.8 to 2.5, in 0.002 M CaCl(2) from 73.3 to 68.0, in 0.002 M MgCl(2) from 85.5 to 83.3. 2. Frequency of ingestion of chilomonads by Amoeba proteus is increased by adding strychnine sulfate to solutions of NaCl, KCl, or CaCl(2). Frequency of ingestion is increased in NaCl solution from 1.3 to 2.3, in KCl from 0.75 to 2.25, and in CaCl(2) from 1.1 to 1.9 chilomonads per minute. Ingestion is not significantly increased by the addition of strychnine to MgCl(2) solution. 3. Frequency of ingestion of food by Amoeba proteus is not closely correlated with attachment to the substratum in NaCl and KCl solutions to which strychnine sulfate is added. 4. Chilomonads adhere to the plasmalemma of Amoeba proteus in solutions of NaCl, KCl, or CaCl(2) containing strychnine, but in MgCl(2) plus strychnine only a few adhere to it. Strychnine appears to make the surface of the amebae and chilomonads sticky in the former but not in the latter. Frequency of ingestion is apparently correlated with adherence of chilomonads to the plasmalemma. 5. Attachment to the substratum and ingestion by Pelomyxa carolinensis is increased by dead Chilomonas, Colpidium, and Paramecium in aqueous solutions, by materials obtained from paramecia by alcoholic-ether extraction, and by solutions in which these organisms have lived. 6. Attachment to the substratum by Pelomyxa carolinensis is not closely correlated with kind or concentration of inorganic salts used in this study. 7. Materials were found in extracts of paramecia which had certain characteristics in common with choline esters. There is no reason to doubt that under certain conditions materials are present in aqueous and alcoholic extracts which are pharmacologically similar to choline and acetylcholine. 8. Aqueous suspensions of paramecia when subcutaneously injected into young mice for 21 days inhibit the gonadotropic luteinizing hormone of the pituitary. Ovaries from injected mice showed no corpora lutea, and the seminal vesicles from injected males were smaller and contained less fluid than those of the controls.

DIGESTION OF FAT IN THE RHIZOPOD, PELOMYXA CAROLINENSIS

1. If Pelomyxa carolinensis, which contains no fat ingests Colpidium striatum, containing fatty acid, the fatty acid in the food vacuoles disappears and simultaneously globules of a mixture of neutral fat and fatty acid appear in the cytoplasm of Pelomyxa. This indicates that fatty acid passes out of the food vacuoles into the cytoplasm and that some of it there combines with glycerine to form neutral fat. 2. If droplets of olive oil (neutral fat) are injected into the cytoplasm of pelomyxae, which contain no fat, the injected droplets gradually decrease in volume and finally disappear and numerous globules of a mixture of neutral fat and fatty acid appear in the cytoplasm. This indicates that the neutral fat in the injected droplets hydrolyzes and passes out into the cytoplasm.

Correction

I AM indebted to Eugene S. McCartney for calling attention to an error in my article on "The use of generic names as common nouns," SCIENCE, Vol. 96, p. 252. " Pelomyxa carolinensis ," line 13, should be omitted, for "carolinensis" is not a noun in the genitive case, but an adjective in the nominative case.