Blepharisma Undulans Research Articles

Some properties of a photodynamic pigment from Blepharisma.

1. A pigment can be extracted from Blepharisma undulans by heat treatment of a concentrated suspension of the deeply pigmented animals. 2. In the presence of this pigment, various colorless protozoans are sensitized to light and killed if exposed long enough. The protozoans show a differential sensitivity, some being much more sensitive than others. 3. Bleached colorless blepharismas are not sensitized to their own pigment even after prolonged exposure in the most concentrated solutions available. 4. Blepharisma is also less sensitive than any of the protozoans tested to such photodynamic dyes as rose bengal. 5. The pigment is not extracted from wet blepharismas by non-polar solvents, but is readily extracted into such polar organic solvents as the alcohols. 6. When the alcohol extract is dried, the amorphous residue is readily soluble in a variety of organic solvents, but not in the most non-polar. 7. The pigment is highly stable in alcohol extract and has been kept in the dark for years. 8. The pigment is bleached by light in a photooxidation. 9. Absorption maxima are found at wave lengths 5800, 5400, 4800, and 3300 A, the latter being the largest. Similar peaks are found in alcohol and water solutions, although the heights are not exactly the same. In both alcoholic and aqueous solutions pH had an effect on the absorption spectrum. Heat has little effect but illumination with intense visible light or exposure to ultraviolet light bleaches the pigment with decreases in the characteristic peaks. 10. Preliminary absorption column experiments indicate a single pigment in the alcohol extract. 11. Experiments on the migration of zoopurpurin in agar and gelatin gels indicate that it diffuses at about the same rate as eosin and is therefore probably not a large molecule.

Ultraviolet radiation effects on growth processes of Blepharisma undulans

1. 1. The effect of selected dosages of monochromatic ultraviolet light of wavelengths 238, 245, 253, 265, 280, 302, 313, 366 mμ were studied on the following: 1) regeneration of cut Blepharisma; 2) division rate; 3) conjugation; 4) survival of colored and bleached individuals. 2. 2. No evidence for photoreactivation could be demonstrated in the ultraviolet injured animals. 3. 3. Fission was most delayed at wavelength 280 mμ at the first division, but a somewhat longer delay was observed at 254 and 265 mμ for the third division. 4. 4. The action spectrum for survival after large dosages of ultraviolet light best fits a curve that is a composite for a mixture of nucleic acid and protein, rather than either substance alone.

On the morphogenetic role of the macronucleus during conjugation in Blepharisma undulans

On the morphogenetic role of the macronucleus during conjugation in Blepharisma undulans

Multiconjugation in blepharisma.

A cytological and experimental study was carried out on conjugations involving more than two individuals of Blepharisma undulans. Attachment of the participants in a conjugating group occurs in a number of characteristic patterns. Regardless of the attachment pattern, nuclear changes occur in all members of a multiconjugant system. These changes are identical in nature and duration to those observed in normal paired conjugation, and occur synchronously in all participants of the system. The stocks of B. undulans used are found to be selfing, physiologically not differentiated into mating types. Multiconjugation can be induced by varying food supply and population density. The probability of autogamous processes in connection with multiconjugation is discussed.

The role of the macronucleus in the differentiation of blepharisma undulans

The role of the macronucleus in the differentiation of blepharisma undulans

PHOTOOXIDATIONS IN PIGMENTED BLEPHARISMA

1. Blepharisma undulans, a protozoan with a reddish pigment, shows increased oxygen consumption under the influence of light. 2. If the light intensity is high, the animals are killed during a burst of oxygen consumption. 3. If the blepharismas are first bleached by exposure to light of low intensity they show only slightly increased oxygen consumption under the influence of light and they are not killed. 4. A preparation in which the animals are killed by heat still shows the increase in oxygen consumption on illumination with brilliant light. The supernatant solution does so as well, as does an alcohol extract of the dye. 5. The conclusion is drawn that the blepharismas are killed during photooxidation of the pigment, but the mechanism of action is not clear. Several possibilities are considered in the discussion.

The Culture and Division Rate of Stentor coeruleus.

Due to the difficulty of carrying on isolation cultures of Stentor coeruleus,1 this protozoan has not been much used in pedigreed culture work. Hetherington2 has recently published a culture method for this organism. He did not, however, continue the culture of Stentor for longer than 7-day periods, and also found some difficulty in keeping Stentor alive, using different types of Protozoa as food, and various media as the basis of his cultures. Beers34 has shown that Didinium can be cultured at a constant division rate if fed on a superabundant diet of Paramecium. At the suggestion and with the advice of Dr. J. A. Dawson, the writer began experiments to determine a suitable method of culturing Stentor coeruleus using Blepharisma undulans as the source of food.A pure line of Stentor coeruleus was begun by isolating a single individual. As a result of 2 successive divisions four individuals were isolated and used to begin a pedigree culture of 4 lines. Each individual was placed in a separate culture dish c...

Physiological significance of conjugation in Blepharisma undulans

Physiological significance of conjugation in Blepharisma undulans

Morphology of the contractile vacuole and cloacal region in Blepharisma undulans

Journal of Experimental ZoologyVolume 69, Issue 1 p. 59-104 Article Morphology of the contractile vacuole and cloacal region in Blepharisma undulans† Imogene Moore, Imogene Moore Osborn Zoölogical Laboratory, Yale UniversitySearch for more papers by this author Imogene Moore, Imogene Moore Osborn Zoölogical Laboratory, Yale UniversitySearch for more papers by this author First published: October 1934 https://doi.org/10.1002/jez.1400690105Citations: 10 † A dissertation presented to the faculty of the Graduate School of Yale University, in candidacy for the degree of doctor of philosophy, 1931. 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 Volume69, Issue1October 1934Pages 59-104 RelatedInformation

Reaction of Blepharisma to Golgi Impregnation Methods.

From a study of the normal and regenerating contractile vacuoles in vivo, evidence was obtained that the normal contractile vacuole in Blepharisma undulans is not a permanent cell organ, but a system of temporary, potentially independent fluid vacuoles.1 In view of the fact that conflicting opinions concerning the permanence of contractile vacuoles have arisen from the failure of investigators to study both living and stained preparations, the above conclusions have been tested by a study of fixed material, derived from the pedigreed cultures. The Nassanov methods and the original Kolatschev technique were employed, not only because of their proved success in demonstrating contractile vacuole structure, but also because by their use the Blepharisma vacuole could be examined in the light of the Nassanov homology.In the several series of preparations which were made, Paramecia, mixed with the Blepharisma prior to fixation and treated identically step by step, were used as controls. Although the contractile ...

NOTES ON THE LOSS AND REGENERATION OF THE PELLICLE IN BLEPHARISMA UNDULANS

1. It has been observed, that when Blepharisma undulans is treated with strychnine sulphate, morphine sulphate and several other chemicals the pellicle is shed. The pellicle and the naked animal have been studied.2. The pink color so characteristic of this animal is restricted to the pellicle.3. The pellicle is not essential for life, division or motion and its character is dependent on the amount of food available.4. Under favorable conditions the pellicle is easily regenerated.

THE CORRELATION OF THE AMOUNT OF SUNLIGHT WITH THE DIVISION RATES OF CILIATES

1. Previous analysis of the division rates of Paramecium aurelia (mutant), Blepharisma undulans, and Histrio complanatus grown separately in pedigree isolation culture, under as nearly identical conditions as possible, for a period of 3 years, disclosed a secular trend and a seasonal rhythm for each organism. The seasonal rhythm has a maximum in July.2. This seasonal rhythm is shown to be related to the amount of sunshine reaching the locality of the cultures. The maximum amount of sunshine is received in July also.3. After the effect of trend and the influence of the amount of sunlight are removed from the division rates, they show no relation to each other except for deviations caused by known changes in the culture technique. Each organism has a division rate varying independently of the others, when the effect of external unifying influences are removed.4. Consequently, the amount of sunlight, other conditions held constant, seems to determine the similarity of the division rate of these diverse organisms. The temperature is a secondary determining factor which has apparently less influence than sunlight when both variables are present in these experiments. Data from other investigations supports these conclusions.5. It is suggested that the downward trend of the rates and the diminution of seasonal cycle which continue under laboratory conditions may be due to an accumulative deficiency of light of the shorter wave lengths which is absorbed by the containers, and that this effect be evaluated in studies made with more nearly constant environments.

Cannibalism in a Ciliate, Blepharisma.

In mass cultures of several different races of Blepharisma undulans, including one which has been cultured by the writer for several years and used in connection with other investigations, cannibalism has occurred frequently. This phenomenon has not been very generally noted among ciliate protozoans, as the writer found in reporting a similar case in the Hypotrichida,1 and there are certain aspects of this process in Blepharisma which promise to add to the knowledge of digestive processes in ciliate protozoa.Cannibalism takes place in mass cultures in which growth has been rapid and large numbers of Blepharisma are present. The animal about to become a cannibal is always considerably larger than the individual that is ingested. The process of ingestion is relatively slow, requiring several minutes for completion. Ingested animals are not readily killed by the cannibal but show movements for varying periods, in one case as high as 8 hours. Ingestion is not always followed by digestion of ingested individua...

THE ANALYSIS OF THE DIVISION RATES OF CILIATES

1. Analysis of the division rates of Paramecium aurelia (mutant), Blepharisma undulans, and Histrio complanatus grown separately in pedigree isolation culture with the same culture medium, and in the same room at any given time, for a period of 3 years, discloses a secular trend and a seasonal rhythm for each organism. The seasonal rhythm is a yearly cycle with a maximum during July. 2. After removal of the effects of trend and seasonal rhythm, no correlation is found between the division rates of the several organisms. The distribution of the division rates is then one of chance order, except for large deviations known to be associated with changes in the culture technique. Each organism has a division rate varying independently of the others. 3. Consequently, seasonal rhythm alone has forced similar variations in the division rates of these three protozoans. The seasonal effect is gradually lost when the animals are raised for several years under laboratory conditions. Examination of the literature discloses other similar cases. 4. It is clear that unless all of the conditions of experiment are kept constant, one must analyze all protozoan division rate data in some such manner as that here presented before any conclusions may be drawn as to the existence of "cycles" or "rhythms."

Studies on the Life History of Blepharisma undulans.

Studies on the life history of Blepharisma undulans have been in progress for over five and a half years, all the animals employed being the progeny of a single individual isolated November, 1921. The work was planned to determine, in particular, the viability of this infusorian in the absence of fertilization, and the effects of fertilization on the rate of reproduction, in an attempt to broaden the results from our earlier studies on Paramecium aurelia1 and Spathidium spatula.2 A preliminary statement of the characteristics of this race of Blepharisma undulans was presented in 1922.4Whereas earlier workers on this organism found that conjugation occurred rather infrequently and invariably was followed by death, conjugation was readily induced in our pedigree cultures, and the exconjugants proved to be viable in nearly every case. Accordingly excellent material was afforded for the problem at hand.Two conclusions may be emphasized from the data secured to date:(1) The animals of this race of Blepharisma ...

THE STRUCTURE OF THE UNDULATING MEMBRANE IN THE CILIATEBLEPHARISMA

It has for long been generally accepted' that the undulating membrane of ciliates is composed of a serried row of fine cilia fused into a homogeneous-appearing membrane. This conception has been based largely on the fact that the membrane, when treated with fixatives, resolves itself into a linear series of very fine fibrilla@. Moreover, several investigators have remarked on the occasional appearance of delicate striations in the living mem brane of certain ciliates. In addition to this Maier reports having noticed, in the living specimen an actual breaking down of the membrane into fibrilke for some distance inward from its free border. It was thought of interest to study the behavior of the undu lating membrane in Blepharisma undulans by subjecting it to manipulaton with the microdissection needle. A single blepharisma, in a shallow hanging drop in a Barber's moist chamber, was held stationary by means of a microneedle

Regeneration at various phases in the life‐history of Spathidium spathula and Blepharisma undulans

Regeneration at various phases in the life‐history of Spathidium spathula and Blepharisma undulans

Regeneration in Spathidium spathula and Blepharisma undulans

In a study of regeneration of form and function at various phases in the life history of the infusorians Spathidium spathula and Blepharisma undulans, it has been determined that the power of restoring lost parts and of continuing normal existence is in all cases dependent upon the same factor, the nuclear content of the fragment. Individuals of known pedigree were cut transversely, and the behavior or the fragments observed until regeneration and division or regeneration and death had occurred. During the vegetative state, regenerative power is highly developed in both ciliates, but because of the more distributed condition of the nucleus in Spathidium than in Blepharisma relatively smaller fragments from either extremity of the former are capable of complete regeneration. All fragments which continue to divide contain both macro and micronuclear material. It has been impossible to produce an amicronucleate race by artificial means. In Spathidium, where the two nuclear elements extend throughout the cell both during and after fission, there is no difference in the regenerative power at any peroid of asexual life. In Blepharisma, however, where large amacronucleate fragments may be obtained during the process of division, it has been found that temporary restoration of external organelles is possible in the absence of nuclear material, if the formation of a new peristome has already been started. Dedifferentiation immediately follows and death occurs in a few days. The presence of micronuclei in such fragments, moreover, is not sufficient for continued existence. During conjugation, complete regeneration in Spathidium is less frequent than during asexual life. Portions containing the synkaryon regenerate and divide; other pieces remain unchanged or undergo only temporary restoration of form. Fragments obtained from starved Spathidia prior to encystment either fail to regenerate, or regain normal form and subsequently encyst.

Racial variations in Blepharisma undulans

Studies on Blepharisma undulans and Blepharisma lateritia Stein, have emphasized the impossibility or great difficulty of observing the micronuclei, and also the inevitable death of ex-conjugants without dividing. Thus Butschli1 was unable to identify micronuclei in vegetative specimens of B. lateritia though he found them in conjugants. Exconjugants invariably died. Calkins2 did not find micronuclei in non-dividing B. undulans, but discovered them during division within the macronuclear membrane, and described their emergence and activities during conjugation. He likewise was unsuccessful in obtaining a single viable exconjugant.During the past five months we have had under observation a pedigree culture of Blepharisma undulans which emphasizes racial differences within the species. The animals of this race possess from four to fourteen relatively conspicuous micronuclei, all of which are free in the cytoplasm during every stage of the life of the cell; and all the exconjugants thus far secured proved to...

The effect of chemicals on the division rate of protozoa

These experiments have been carried out during the past year for the purpose of finding out whether the products of nucleoproteid breakdown have any effect upon the division rate of free-living cells, the ultimate aim being to get some light on the controlling factors of cell division. Two ciliated protozoa were used. One, Actinobolus radians Stein, lives exclusively on a diet of Halteria grandinella, another ciliate. The other, Blepharisma undulans Stein, lives on bacteria. Four control lines of each have been watched, fed, and the number of divisions recorded daily, and curves based upon the averaged division rates for five day periods, give the fluctuations in vitality of the organisms as measured by the division rates. Periods of depression, and of decreasing and increasing vitality have been clearly marked. Individuals for experimentation were in all cases sister cells of the control lines of the same dates. The results show that amino acids and their derivatives have but slight effect on the division rate at any period of vitality. The purins and their derivatives have but a slight effect on the division rate when vitality is very low or very high, but a marked effect of increasing the rate when vitality is decreasing (allantoin) or increasing (hypoxanthin, xanthin).