bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Aspect of Morphogenesis in the Ciliate Protozoa*
Authors: CORLISS JOHN O. 
Published: May 2007

SYNOPSIS. Stomatogenesis or new mouth formation sensu lato repnts an explicit example of a major morphogenetic phenomenon le life cycle of most ciliate Protozoa. Investigations of the process a number of approaches may yield data of considerable value. The present paper 3 such approaches are treated in some detail.udies of stomatogenesis can be of importance in providing addial information of significance on the structure and physiology a given organism. Five major types or categories of stomatoesis in ciliates are recognized. These are defined and discussed. search related to such an intrinsic value of the phenomenon the K carried out is generally only descriptive, and the most importechnic employed is some method of silver impregnation.a comparative approach is used, then attention may be focused possible homolegies in stomatogenesis as it occurs in diverse ies of ciliates. Such data are (or potentially are) of value not in the practical taxonomy of the organisms involved but also onsideration of phylogenetic and evolutionary interrelationships ing the higher groups comprising the entire subphylum Ciliophora. Such application of comparative studies may well become a very fruitful approach to certain problems in ciliate phylogeny; 2 examples are discussed briefly. Silver impregnation technics are again indispensable.Perhaps stomatogenesis will prove most valuable in the hands of developmental biologists who are seeking to solve 2 of the most intriguing problems in cell biology today: the exact origin of new kinetosomes (or centrioles), and their precise morphogenetic role in the life cycle of a cell or unicellular organism. Since this third approach to the study of stomatogenesis is of necessity a dynamic one, the researcher must employ sophisticated experimental technics to obtain data at the molecular and macromolecular levels of both organization and function. Some progress in this area has already been made, but the availability of “ideal” organisms has perhaps not been as widely realized as it should. Certain of the “higher” ciliates have a mode of stomatogenesis which would lend itself beautifully to fruitful investigation of problems concerning both replication or neoformation of kinetosomes and their possible role in fibrillogenesis in unicellular organisms.
Nutrition of Volvulina Playfair*
Authors: CAREFOOT J. RUSSEL 
Published: May 2007

SYNOPSIS. Vitamin B12, biotin and thiamine requirements of 10 strains of Volvulina steinii and 1 strain of V. pringsheimii were studied. Vitamin B12 is required for growth of both species, thiamine stimulates growth slightly, and biotin has no discernible effect on growth. The minimum concentration of vitamin B12 giving a growth response in V. steinii, strain SC‐2, was 10−8 g/ml, and maximum growth response was obtained with 1.1 × 10−7 g/ml.An organic carbon source is required for growth of V. steinii but not of V. pringsheimii. Growth of V. steinii, strain SC‐2, occurred in 20 of 21 carbon sources tested. Optimal growth with each carbon source was largely dependent upon pH. Except for pyruvate, acetate, and ethanol, carbon source utilization was light‐dependent, and growth in ethanol was reduced in the dark.Isocitric lyase activity was detected in V. steinii grown on acetate medium.
The Ultrastructure of Crithidia fasciculata and Morphological Changes Induced by Growth in Acriflavin*
Authors: KUSEL J. PETER , MOORE KENNETH E. , WEBER MORTON M. 
Published: May 2007

SYNOPSIS. Crithidia fasciculata is similar to other trypanosomatids in ultrastructure. Of considerable interest is the finding of a lamellar membrane formation attached to the mitochondrion. Some evidence is provided for the tentative hypothesis that this membrane formation is the precursor of mitochondrial membranes. The cellular origin of this structure is unknown.Growth in acriflavin results in a marked alteration of the mitochondrion and kinetoplast. Both structures are deficient in cristae. In addition, the kinetoplast loses its normal fibrillar appearance and becomes a smaller, more electron‐dense organelle. These effects are discussed in relation to the proposed involvement of the kinetoplast in the elaboration of functional mitochondria.
The Structure of Colpoda elliotti n. sp.
Authors: BRADBURY P. C. , OUTKA D. E. 
Published: May 2007

SYNOPSIS. Colpoda elliotti n. sp., found in an enrichment culture from deer droppings, is a small (15–28 by 7.5–17 μ) member of the genus with prominent, rigid, tooth‐like processes set between the kineties in the posterior 2/3 of the body. These “teeth” give it a distinctive outline even when viewed at low magnifications. The usual number of kineties is 12; the number of keel notches is 4. Multiplication occurs in reproductive cysts yielding typically 4 tomites. Thick‐walled, resting cysts are also formed.The nuclear apparatus includes a single, crescentic ***micronucleus and a broadly elliptical macronucleus. The latter contains Feulgen‐positive material in a few large masses, but no central nucleolus.The possibility that this species along with other members of the genas is perhaps more closely related to the Hymenostomatida than to the Trichostomatida as now defined is discussed.
Histomonas meleagridis after One Thousand in vitro Passages
Authors: LUND EVERETT E. , AUGUSTINE PATRICIA C. , CHUTE ANNE M. 
Published: May 2007

SYNOPSIS. During a 7‐year period Histomonas meleagridis survived 1000 passages in Medium 199 fortified with serum and antibiotic‐killed bacteria. The histomonads were originally isolated from a chicken's cecal dropping, and the bacteria were cultivated from the cecal contents of a normal turkey. In many respects, the histomonads remained unchanged during cultivation, but in some other respects they changed considerably, perhaps irreversibly.Morphologically, the histomonads propagated in vitro showed only slight changes. When returned to birds, they resumed the structure characteristic of lumen‐dwelling individuals of this species. However, they had long since lost their ability to produce disease in either chickens or turkeys, and organisms of the tissue‐dwelling type were rarely seen. The long‐cultivated histomonads are actually as nonpathogenic as Histomonas wenrichi, but they have none of the distinguishing morphologic characteristics of the latter.As has been reported elsewhere, H. meleagridis long maintained in the tissue culture medium has also lost much of its ability to immunize either chickens or turkeys against infection with virulent strains of this parasite. Also lost in the process of adaptation to its restricted medium has been the ability to multiply satisfactorily in vitro with the complement of bacteria normal to the ceca of the birds. However, in some instances, histomonads which have become adapted to in vitro cultivation are still able to live in birds with this diversified flora.Activity of the histomonads cultivated in vitro differed but little from that of H. meleagridis freshly isolated from birds, when both were viewed under the same conditions. Histomonads from each of the above sources multiplied most satisfactorily in their accustomed habitat, probably because of a difference in nutritional requirements.
Trichodina (Ciliata: Urceolariidae) of Freshwater Fishes of the Southeastern United States*
Authors: WELLBORN THOMAS L. 
Published: May 2007

SYNOPSIS. Eight new species of Trichodina are described from freshwater fishes of the Southeastern U.S.: T. davisi from Roccus saxatilus (Walbaum), T. funduli from Fundulus notti (Agassiz), T. globosa from Etheostoma radiosum (Hubbs and Black), T. hoffmani from Etheostoma edwini (Hubbs and Cannon), T. hypsilepis from Notropis hypsilepis Suttkus and Raney, T. microdenticula from Dorosoma petenense (Gunther). T. noturi from Noturus leptacanthus Jordan, and T. salmincola from Salmo gairdneri Richardson. Nine species of Trichodina are redescribed: T. californica, T. discoidea, T. fultoni, T. pediculus, T. platyformis, T. reticulata, T. sp. (?T. nigra), T. tumefaciens, and T. vallata. The name T. pediculus is re‐erected for the form that occurs on largemouth bass.Host fish were collected from 36 geographic locations in 10 states (Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, and Tennessee). A total of 939 fish of 46 species was examined for trichodinid parasites.Two methods of impregnating formalin preserved specimens of Trichodina with silver are discussed.A key to the species of Trichodina reported from North American freshwater fishes is given.
Intraclonal Dimorphism of Caudal Cirri in Euplotes vannus: Cortical Determination*
Authors: HUFNAGEL LINDA A. , TORCH REUBEN 
Published: May 2007

SYNOPSIS. Intraclonal variation in number of right caudal cirri (RCC) occurs within some species of the hypotrichous genus Euplotes. Euplotes vannus, a marine species, may have either 2 or 3 RCC. A single clone always contains individuals of both types. The frequency of individuals of each type within a clone was found to be 0.5. This fact suggested that during division each parental cell gives rise to one daughter having 3 RCC and one having 2.Formation of RCC during division was studied in E. vannus and in E. plumipes, a fresh‐water form which always has 2 RCC. The studies were made on living animals and on fixed animals stained with protargol or by the Chatton‐Lwoff method. In both species, the new RCC first appear in the right dorsal kineties and later migrate to the ventral surface. The RCC for the proter develop near the parental equator while those for the opisthe form near the posterior end of the parent cell, both sets developing in close proximity to kinetosomes of the kineties. In both species the 2 dorsal kineties furthest to the right each give rise to 2 RCC, one for the proter and one for the opisthe. In E. vannus, however, the third‐from‐the‐right dorsal kinety also produces one right caudal cirrus for the proter. Therefore, in E. vannus it is the proter which always receives 3 caudal cirri and the opisthe which gets only 2. The role of the cortex in determining these events is discussed.Two cases of abnormal caudal cirrus formation are also described. Other aspects of morphogenesis during division, not previously reported, are also presented and discussed.
Endogenous Stages of the Life Cycle of Isospora rivolta in the Dog
Authors: MAHRT JEROME L. 
Published: May 2007

SYNOPSIS. Coccidia‐free beagle puppies were experimentally infected with a cloned culture of Isospora rivolta oocysts. The endogenous stages were found in the posterior 1/2 of the small intestine, and rarely in the cecum and colon. Maximum numbers of all stages occurred just anterior to the ileocecal valve. Endogenous stages were found in the distal third of the villi, predominantly parasitizing subepithelial cells of the lamina propria; however, stages were occasionally present in epithelial cells. The number of asexual generations could not be determined from their structure, but evidence based on oocyst production suggested that there were at least 2 asexual generations. The schizonts were 17–24 by 12–25 μ and contained 4–24 merozoites, the most common number being 4 or 8. Schizonts with mature merozoites were found as early as 72 hr, but were present in maximum numbers at 96 hr. Merozoites had slender curved bodies and were 10.5–13.4 by 2.3–3.0 μ. Mature gamonts were found by 144 hr. Mature microgametocytes were 13.4 by 8.7 μ and contained 50–70 microgametes. Microgametes had slightly curved tapering bodies (5.8–6.4 by 0.6 μ) with 2 posteriorly directed flagella 11–14 μ long. Mature macrogametes had reticular cytoplasm and a uniformly large nucleus and nucleolus.The prepatent period was 142–146 hr. The patent period was 13–23 days with an average of 19 days.
Trypanosoma avium: Fine Structure of All Developmental Stages*
Authors: BAKER J. R. , BIRD R. G. 
Published: May 2007

SYNOPSIS. Thin sections of the following stages of Trypanosoma avium were examined in the electron microscope: Trypomastigote forms from the blood of a bird, large epimastigote forms developing from the former after 2 hours in vitro, small epimastigote and metacyclic trypomastigote forms developing after longer periods of cultivation in vitro. The general structure of all stages was similar to that which is already well known for the genus, with the following points being of particular interest:(1) In the large trypomastigote and epimastigote forms, and possibly also in the smaller forms, the flagellar sheath was attached to the pellicle, at least in places. In the large trypomastigote forms, this resulted in the drawing out of a “fin” or ridge of cytoplasm, particularly in the mid‐region of the body, to form a true undulating membrane.(2) At least some of the individuals in the blood of a bird have 2 basal bodies, one of which is aflagellate, altho these individuals rarely if ever divide. The large epimastigote forms into which they transform in vitro develop 4 basal bodies (2 flagellate and 2 aflagellate) before dividing.(3) The chondriome is well‐developed in all stages, extending thruout the body, even to the tip of the elongated posterior end of the form in the avian host.(4) A short cytostome, leading from the flagellar pocket, was seen in the hematozoic (blood‐inhabiting) trypomastigote form but not in other stages.(5) It is suggested that the forward movement of the kinetoplast and basal body during the transformation from trypomastigote to epimastigote form is mediated by localized cytoplasmic movement, resulting in the “rolling‐up” of the organism's hind end. It is further suggested that protein synthesis is reduced or even suppressed entirely in the small epi‐ and trypomastigote forms appearing at the end of the developmental cycle in vitro or in the insect host, such synthesis recommencing rapidly after re‐entry into the vertebrate.
Differentiation of Reproductive Cells in Volvox carteri*
Authors: KOCHERT GARY 
Published: May 2007

SYNOPSIS. The life cycle of Volvox carteri was studied in axenic culture using the NB‐3 and the NB‐7 strains isolated from Nebraska. Vegetative colonies of both strains contain 8–12 asexual reproductive cells (gonidia) which divide to form daughter colonies. During daughter colony formation, the reproductive cells of the daughters are delimited at an early stage of cleavage. Gonidia are delimited at the division from 16 to 32 cells, but eggs and male initial cells are not differentiated until the division of the 32‐celled stage. In all instances the reproductive cells are the products of unequal cleavages.Male and female colonies are formed in separate clones. Female colonies contain approximately 20 eggs. Male colonies have approximately 50 male initial cells, each of which forms a sperm bundle containing 64 or 128 sperm. Sperm bundles penetrate female colonies and fertilize the eggs. Zygote formation, zygote germination, and the development of gone colonies is described. Sexual type was inherited in a 1:1 ratio.Male colonies appear spontaneously in the male strain, but female colonies were formed in the female strain only in the presence of a substance produced by colonies from male cultures. This female inducing substance is produced in male cultures primarily, if not exclusively, by male colonies rather than by vegetative colonies. The female inducing substance is heat labile and non‐dialyzable. Activity is destroyed by Pronase, but not by trypsin, chymotrypsin or ribonuclease.Gonidia appear to be most susceptible to female induction during the early stages of their expansion prior to cleavage.
Myxosporidian Parasites from the Fish of the River Lugg
Authors: DAVIES ELIZABETH H. 
Published: May 2007

SYNOPSIS. Six different species of Myxosporidia were recorded from fish of the River Lugg. Myxobolus muelleri, M. artus, M. macrocapsularis, Henneguya zschokkei, H. psorospermica and H. oviperda.Leuciscus cephalus, L. leuciscus and Rutilus rutilus infected with M. muelleri were common; of these 3 hosts, L. cephalus had the highest intensity of infection and the greatest number of infected organs and tissues. M. muelleri was compared from all the different infection sites each month where possible, from the same host (i.e., L. cephalus) and from the same site on different hosts (i.e. from the gills of all 3 hosts). No seasonal variation in occurrence, spore shape or size was found for M. muelleri, but spore size varied depending on the host and site of infection.Tailed and tailless forms of H. zschokkei were found on L. leucicus and H. oviperda on E. lucius. Only tailless H. psorospermica were found.Variations in spore form and size are discussed in relation to their use as taxonomic characters.
Etude de l'Ultrastructure de Gregarina polymorpha (Hamm.) en Syzygie
Authors: DEVAUCHELLE G. 
Published: May 2007

SYNOPSIS. The electron‐microscope study of syzygy in Gregarina polymorpha, shows that this coupling, a prelude to cyst formation and to sexual phenomena, must not be considered as a simple pairing of individuals, but is rather the response of a gamont to a stimulus coming from another individual of a different sex. This response, in the species studied, can be recognized from the modifications that will appear progressively at the contact surfaces of the two gregarines. They affect only the protomerite apex of the posterior individual. There occur: rapid growth of the protomeritic epicyte; separation of this epicyte from the fibrillar zone underneath; formation of a protomeritic cup containing various inclusions; the disappearance of cuticular digitations and the formation of invaginations which become deeper and deeper.All these modifications occur as soon as syzygy starts. They seem to indicate a reaction of the satellite epicyte to a possible stimulus coming from the anterior female gamont. This epicyte could play a different part from the initial one.In the case of association between a primite and several satellites, the posterior gamonts react in a comparable manner but not together.
Effects of Radiation, Antibiotics and Alkylating Agents on Cell Division and Growth in the Ciliate Spathidium spathula*
Authors: WILLIAMS DONALD B. 
Published: May 2007

SYNOPSIS. Spathidium spathula is very sensitive to division inhibition after X‐irradiation. Five kr delivered to animals 1 hr into the cell cycle prolong the period until the next division to about 2 times the normal length. The next 2 cell cycles, however, are shorter than normal, and by the 4th division irradiated cells have recovered the normal division rate. During this division delay, scanning interference microscopy shows that growth in dry mass continues; at the 1st post‐irradiation division the cells average 3 times the normal dry mass. After the 2nd post‐irradiation division, dry mass is 1.5 times the normal amount. Dry mass measurements were not made beyond the 2nd division.Giant cells produced by X‐rays have enlarged macronuclei, indicating that DNA synthesis is not inhibited by a dose of X‐rays that blocks division. Mitomycin C and triethylene melamine, agents which attack or damage DNA, also produce division blockage and giantism in Spathidium. This suggests that damage to DNA in either the macronucleus, the micronucleus or other organelles may be much more effective in delaying cell division than cell growth.
An Analysis of Clumping in the Soil Amoeba Mayorella palestinensis*
Authors: BAND R. NEAL , MOHRLOK SHARON H. 
Published: May 2007

SYNOPSIS. Mayorella palestinensis, a small soil amoeba, clumped during active growth in axenic, fluid culture media. Clumping was not associated with starvation (as in the case of cellular slime molds) or with encystation Hartmannella rhysodes was used as a control amoeba which did not clump to the same extent, but otherwise resembled M. palestinensis. Mixtures of both amoebae formed mixed clumps, without subsequent segregation of amoebae in the clumps.Clumping by M. palestinensis was temperature dependent, localized to the surface of the amoeba and required surface conformation. The requirement for a living system could be separated from the surface specificity of M. palestinensis and satisfied with living amoebae that did not clump by themselves, i.e., H. rhysodes, but did clump with dead M. palestinensis.It is proposed that amoeba‐to‐amoeba adhesion is similar to foreign substrate adhesion, and that M. palestinensis adheres to itself because its surface is more suitable for adhesion than other surfaces present in the culture. A competition for adhesion exists between surfaces so that clumps can be dissociated by providing a foreign surface that is more suitable for adhesion than the surface of the amoeba.
The Physiology of Encystment of Hartmannella castellanii*
Authors: GRIFFITHS A. J. , HUGHES D. E. 
Published: May 2007

SYNOPSIS. Some aspects of the physiology of encystment of the soil amoeba Hartmannella castellanii in a replacement encystment medium consisting of 5 × 10‐2 M MgCl2 have been investigated. It is suggested that measurement of the cellulose produced during encystment in the synthesis of the cyst wall is a more reliable measure of the process than other methods tried.The degree of encystment was dependent on the physiologic state of the amoebae and the composition of the growth medium, but the initial pH of the encystment medium (C. 4.0‐8.5) had little effect on the process. The requirement for Mg during encystment was probably not due to its deficiency during growth. Encystment was inhibited to varying extents by inhibitors of protein synthesis, tetracycline and chloramphenicol and also by arsenate, arsenite and iodoacetate; sodium fluoride, malonate and 2, 4‐dinitrophenol were without marked effect.Addition of glucose and α‐ketoglutarate to the replacement medium led to improvement in the encystment response. The presence of glutamate and histidine during encystment led to cell death. Other carbon and nitrogen sources had no effect.During encystment there was an increase in the metabolic activity of the amoebae, as measured by their oxygen consumption. This was accompanied by a decrease of about 40% in cellular dry weight and protein content. Of the other chemical components, there were marked initial increases in the levels of total carbohydrates and pentose which were followed by their depletion during cellulose synthesis.Encystment was completed after about 64 hr when the synthesis of cellulose was complete and the oxygen uptake of the amoebae fell to an immeasurable level.