bluuebunny/crossref_metadata_2025_split huggingface dataset:
PHYTOCHROME‐MEDIATED STIPE ELONGATION IN THE KELP NEREOCYSTIS (PHAEOPHYCEAE)1
Authors: Duncan Mary Jo , Foreman Ronald E. 
Published: August 2007

ABSTRACTPreliminary evidence is presented which indicates that far‐red irradiation promotes and near‐red inhibits rapid stipe elongation in Nereocystis luetkeana (Mertens) Postels & Ruprecht. Laboratory results showed afar‐red reversal of red inhibition, but a red/far‐red reversal was not evident in field experiments. The effects of changing ratios of red and far‐red irradiation brought about by selective water absorption are discussed in relation to stipe elongation of Nereocystis.
PROPOSED NEW IDENTIFICATION CHARACTER FOR THE GENUSCOLACIUM(EUGLENOPHYCEAE)1
Authors: Willey Ruth L. 
Published: August 2007

ABSTRACTCells of the genusColaciumEhrenberg can be distinguished with the light microscope from cells of the genusEuglenaEhrenberg by the presence of basophilic granules in the anterior tip of theColaciumcell which are clustered around the canal opening. The granules exhibit a biphasic pattern of osmiophilia in electron micrographs. Together with the occasionally obscure character of the paramyloncapped, inner pyrenoids, the granules should serve as a useful character to distinguish between the motile, flagellated cells of the two genera whether from laboratory cultures or from field collections of natural populations.
OLISTHODISCUS LUTEUS (CHRYSOPHYCEAE). V. ITS OCCURRENCE, ABUNDANCE AND DYNAMICS IN NARRAGANSETT BAY, RHODE ISLAND1
Authors: Tomas Carmelo R. 
Published: August 2007

ABSTRACTThe distribution and abundance of the flagellate Olisthodiscus luteus Carter were examined over a 17 yr period (1959–75) at one station in lower Narragansett Bay, Rhode Island, and at many stations throughout the Bay during the 1974, 1975 summer bloom periods. A bimodal pattern of maximum abundance characterized the 17 yr data set. Maxima (103–104 cells·ml−1) occurred during June–July and October–November separated by a mid summer (August) minimum of <102 cells·ml−1. This species was also absent from surface waters during the winter months (January–February) of each year. Regional abundances reached maximal densities of >105 cells·ml−1 during June 1974 and were confined to the northern and western regions of Narragansett Bay. Incident light, temperature, salinity and nutrient (NH4+, NO3−, NO2−, PO43‐) levels were also determined. The abundance cycle appears to be strongly effected by temperature, life cycle, motility, excreted substances and, to lesser extent, by light intensity, salinity, and nutrient dynamics. Regional distribution is affected by motility, wind forced water movements and benthic stage formation. The autecological data for O. luteus, pertinent observations of herbivorous zooplankton and the field observations are used to assess causative factors regulating the dynamics of O. luteus populations in Narragansett Bay. Pratt's hypothesis on the interaction between this species and Skeletonema costatum (Grev.) Cleve is reexamined.
MICROSPECTROPHOTOMETRIC ANALYSIS OF MITOSIS AND DNA SNYTHESIS ASSOCIATED WITH COLONY FORMATION IN PEDIASTRUM BORYANUM (CHLOROPHYCEAE)1
Authors: Millington William F. , Rasch Ellen M. 
Published: August 2007

ABSTRACTPatterns of DNA synthesis and mitosis in the coenobial alga Pediastrum boryanum (Turp.) Meneghini were analyzed by cytophotometric measurements of individual, Feulgen‐stained nuclei from swarming zoospores aggregating into colonies, and cells in colonies varying in age from 12 to 96 h after their initial transfer to fresh culture medium. A haploid genome size of 0.2 pg DNA (corresponding to roughly 11 × 1012 daltons, or 1.64 × 105 kb) was estimated by comparative measurements of nuclei from zoospores or young colonies and chicken erythrocyte (RBC) nuclei which were included with each set of Pediastrum slides as an internal reference standard of 2.5 pg DNA/cell. Although nuclear morphology and extent of chromatin condensation vary with different stages of colony development, nuclear division in P. boryanum appears to follow each cycle of DNA replication with no accumulation of DNA beyond the 2C level. Cytoplasmic cleavage resulting in the formation of individual zoospores is delayed until completion of mitosis, as is the demise of the pyrenoid. After 96 h of culture, 40% of all colonies have cells that are 8‐ or 16‐nucleate and some colonies have 32 nuclei/cell. Release of zoospores within vesicles occurs at this time to complete a cycle of asexual reproduction.
HOST‐RANGE, PLAQUE‐MORPHOLOGY STUDIES OF CYANOPHAGE LPP‐11
Authors: Kraus Marjorie P. 
Published: August 2007

ABSTRACTTransduction by temperate cyanophage plays an important role in understanding the effects of environmental pollution on genetic function. Using a new isolate, this paper illustrates the influence of contaminants and the rapid variations that result as a virus particle passes through successive hosts. Host‐range and plaque‐morphology, using an extended range of genetically‐differing hosts, compares archetype LPP‐1 cyanophage cultured on microbially contaminated hosts with bacteria‐free cyanophage cultured on pure host strains. Microbial contamination can alter the host‐range and serology of the cyanophage produced. It is suggested that bacteria are involved in the virus infection of cyanophycean hosts and that the study of host‐range and plaque‐morphology can aid in the biological characterization and segregation of mutants illustrating mechanisms of inter generic transfer of genetic material. It is shown that derivatives of archetype LPP‐1, cultured on axenic hosts, possess a host‐range, plaque‐morphology and serology similar or identical to that of the temperate cyanophage, S3.
ULTRASTRUCTURE CHARACTERISTICS OF MONOSPORE FORMATION IN PORPHYRA GARDNERI (RHODOPHYTA)1
Authors: Hawkes Michael W. 
Published: August 2007

ABSTRACTMonosporogenesis in Porphyra gardneri (Smith & Hollenberg) Hawkes has been examined with the transmission electron microscope. Increased dictyosome activity resulting in the production of small and large fibrous vesicles is a characteristic feature of the developing monospores. Released monospores lack a cell wall. Four of the six Porphyra species commercially cultivated in Japan form monospores. Monospore production is of economic importance because it results in an increased number of foliose thalli.
BACTERIA INDUCED POLYMORPHISM IN AN AXENIC LABORATORY STRAIN OF ULVA LACTUCA (CHLOROPHYCEAE)1
Authors: Provasoli Luigi , Pintner Irma J. 
Published: August 2007

ABSTRACTA laboratory culture of Ulva lactuca L. purified with antibiotics in 1958 can assume different morphologies. In synthetic media of the ASP type it grows as a pin‐cushion composed of uniseriate branching filaments. Only occasionally some finger‐like germlings appear which, after a few millimeters growth, disintegrate and originate the branched uniseriate filaments. Many strains of marine bacteria, isolated from Ulva and other seaweeds collected in nature or from laboratory cultures, when grown together with this axenic Ulva, induced growth of long thin Enteromorpha‐like tubes (active bacteria). Other bacterial strains have no visible morphological effect on the Ulva (inactive). Combinations of several active and inactive bacterial strains result in flat ribbons which can be wide or narrow and with distromatic portions intercalated between tubular portions. No combination has so far induced the axenic Ulva to produce the typical expanded foliose thallus. Bacterial filtrates are inactive; syntrophic growth seems indispensable. The bacterial strains lose the ability to induce morphogenic effects on the axenic Ulva when grown for several transfers in organic marine media and regain it by growing with Ulva for several transfers in synthetic mineral media. Each partner appears therefore to be dependent on the metabolites produced by the other. The perpetuation of a wide morphological versatility of this laboratory strain of Ulva after 15 yr maintenance under under artificial conditions emphasizes the phylogenetic importance of this versatility.
SPHACELARIA LACUSTRIS SP. NOV., A FRESHWATER BROWN ALGA FROM LAKE MICHIGAN1
Authors: Schloesser Robert E. , Blum John L. 
Published: August 2007

ABSTRACTThe growth, reproduction and ultrastructure of a new freshwater phaeophyte, Sphacelaria lacustris sp. nov., are described. The plant occurs as a minute calcified thallus at 5–15 m depth along the western shoreline of Lake Michigan. Both freshly collected and laboratory grown plants show apical growth of erect and basal filaments, intermittent longitudinal divisions in filament segments, vegetative reproduction by propagules, numerous parietal chloroplasts and an absence of pyrenoids, characteristics of Sphacelaria. This material is separated from the only other freshwater species in the genus (S. fluviatilis Jao) at least by differences in longitudinal septation, in branching, in its propagules and in general aspect. Between this plant and marine brown algae there are essential similarities of ultrastructure of cell wall and pores, chloroplasts, mitochondria, nucleus and the production/excretion of physodes.
HISTORICAL BIOGEOGRAPHY OF CHARA (CHAROPHYTA): AN APPRAISAL OF THE BRAUN‐WOOD CLASSIFICATION PLUS A FALSIFIABLE ALTERNATIVE FOR FUTURE CONSIDERATION1
Authors: Proctor Vernon W. 
Published: August 2007

ABSTRACTTo that classification of the genus Chara, first advanced by Braun in 1847 with subsequent reiteration by the same author in 1867 and 1882 and by Wood in 1962 and 1965, an alternative is here proposed. Contended strengths of the present model include: i) a more accurate reflection of the phylogeny of the genus; ii) conformity with current distribution of dioecious taxa assumed consistently ancestral to their monoecious, morphological counterparts; iii) assumption of allopatric speciation primarily as a result of tectonic movement; and, iv) a foundation of underlying conjecture nearly all of which is potentially falsifiable in the Popperian sense as well as predictive with respect to a wide array of features. Deemphasized or rejected are previous assumptions that; i) stipulode, and to a lesser extent cortical, development reflect major evolutionary trends; ii) endemism is rare in the Charophyta; iii) dioecism and monoecism can be accommodated infraspecifically; iv) evolutionarily significant transitions between the preceding occur in both directions; v) hybridization contributed significantly to the phylogeny of the Charophyta; vi) section Grovesia is monophyletic in origin; and, vii) the Chara flora of Australasia arrived via India. The evidence upon which this classification rests is considered primarily with respect to the genus Chara, although the model appears equally applicable to the genus Nitella.
PARAMYLON SYNTHESIS IN HETEROTROPHIC AND PHOTOHETEROTROPHIC EUGLENA (EUGLENOPHYCEAE)1
Authors: Briand Joël , Calvayrac Régis 
Published: August 2007

ABSTRACTGrowth of Euglena gracilis Klebs in medium containing DL‐lactate as sole carbon source results in the synthesis of large quantities of paramylon at the beginning of exponential growth. The accumulation of paramylon grains in the cytoplasm is observable in both dark‐grown and light‐grown cells. Furthermore, the cells fix 14CO2 in darkness. Incorporated CO2 is found in paramylon which is function of the physiological state of the cells, being most intense in exponential phase heterotrophic Euglena. The mitochondria undergo structural modifications in older cultures, i.e., when the exogenous carbon source becomes exhausted. At the beginning of exponential growth, they are swollen and vesiculated with an electrontranslucent matrix containing an extensive internal membrane system. This vesiculated mitochondrial system is correlated with paramylon synthesis, since forming paramylon grains are seen within the vesiculated complex. Stationary phase cells present a compact chondriome with a dense matrix devoid of vesiculation. Membrane‐bound paramylon grains are found in the cytoplasm of these cells.
EFFECT OF GROWTH SUBSTANCES ON “APICAL DOMINANCE” IN SPHACELARIA FURCIGERA (PHAEOPHYTA)1
Authors: Dworetzky Beth , Klein Richard M. , Cook Philip W. 
Published: August 2007

ABSTRACTGibberellic acid (GA), naphthaleneacetic acid (NAA), and kinetin (K) were tested individually and in combinations on the development of filaments of Sphacelaria furcigera Kütz. Unbranched tips from filaments with or without intact apical cells were grown in the presence or absence of growth substances to study their effects on an apical‐dominance‐like response previously observed in this genus. Removal of the apical cell resulted in lateral branches developing significantly closer to the tip than in uninjured controls. GA and K had no effect on location of lateral branches of uninjured filaments, but exerted some control as evidenced by increases in the distance from a punctured apical cell to the nearest lateral branch. NAA had no positive effects and was toxic in even moderate concentrations. The three growth substances in all combinations could not fully replace the apical cell in repressing branch development. GA and K presented simultaneously were no more effective than either presented alone.
MORPHOLOGY AND CHEMICAL COMPOSITION OF A NATURAL POPULATION OF AN ICE‐ASSOCIATED ANTARCTIC DIATOM NAVICULA GLACIEI1
Authors: Whitaker Terence M. , Richardson Michael G. 
Published: August 2007

ABSTRACTDuring winter (1973), a very pure natural population of the diatom Navicula glaciei Van Heurck occurred in dense concentrations (up to 244 mg·m−2 chlorophyll a) in the sea ice at Signy Island, South Orkneys, Antarctica. Samples of algal material were collected for subsequent chemical analysis. The diatom had a composition of 33.77% ash, 21.81% lipid, 25.38% crude, protein, 19.04% crude carbohydrate and an intact calorific value of 15.384 KJ·g−1. Carbon, hydrogen, nitrogen and phosphorus formed 34, 5.3, 4.1 and 0.52% dry wt respectively. The material was analysed for the trace elements Na, K, Fe, Ca, Mg, Al, Zn, Cu, Pb, Mn, 137Cs. Fatty acid composition was dominated by 16:0 palmitic acid (20.46%), 16:1 palmitoleic acid (32.86%), and 20:5 docosahexaenoic acid (19.33%). To supplement a very scanty original description, a full taxonomic description is given in the text.
ECOLOGY AND DEVELOPMENTAL MORPHOLOGY OF MALE PLANTS OF CHONDRUS CRISPUS (GIGARTINALES, RHODOPHYTA)1
Authors: Tveter‐Gallagher Eleanor , Mathieson Arthur C. , Cheney Donald P. 
Published: August 2007

ABSTRACTThe ecology and developmental morphology of the male plants of Chondrus crispus Stackhouse from New England and the Canadian Maritime Provinces are described. The period of maturation and release of spermatia varies spatially; however, the peak discharge generally occurs over a broad period during the summer or fall. Male plants may exhibit comparable abundances to female plants, particularly during periods of maximum spermatial discharge. At maturity, the spermatangial sorus appears as a pink band on dark red terminal branchlets; following spermatial discharge, the sorus becomes white in color. The developmental morphology of spermatia is described from electron microscopic observations.
THE CONTRIBUTION OF ORGANIC SOLUTES TO OSMOTIC BALANCE IN SOME GREEN AND EUSTIGMATOPHYTE ALGAE1
Authors: Brown Lewis M. , Hellebust Johan A. 
Published: August 2007

ABSTRACTSorbitol and proline accumulate to osmotically significant concentrations inStichococcus bacillarisNägeli,Stichococcus chloranthusKrüger andKlebsormidium marinum(Deason) Silva, Mattox & Blackwell. The extent of osmotic balance by these and other organic solutes depends on the isolate for these three species of essentially non‐vacuolate algae. Sucrose, proline and sorbitol accumulate in the lichen algaHyalococcus dermatocarponisWarén, but concentrations on an osmotic basis are low. Sucrose and glutamic acid are significant solutes in the likely non‐vacuolateK. flaccidum(Braun) Silva, Mattox & Blackwell. A similar set of solutes accumulates to an osmotically significant level inUlothrix fimbriataBold, a highly vacuolate alga. Two small eustigmatophycean algae (strains WHOI GSB‐Sticho and WHOI Car‐A) and one small chlorophyte (strain UWASH 20‐2‐2) accumulate organic solutes to a moderate degree during salinity stress; mannitol and proline in the eustigmatophytes and proline in the chlorophyte. The highly vacuolate seaweedEnteromorpha intestinalis(L.) Link accumulates sucrose, but at low levels. Osmotic balance in these algae may also include other solutes, compartmentation (especially in vacuolated forms), or other factors. The role of organic solutes in osmotic balance is variable, and depends on details of physiology and ultrastructure.
PHOTOSYNTHESIS AND TRANSLOCATION STUDIES OF LAURENCIA SPECTABILIS AND ITS SYMBIONT JANCZEWSKIA GARDNERI (RHODOPHYCEAE)1,2
Authors: Court Gary J. 
Published: August 2007

ABSTRACTThe symbiotic association between the supposed parasite Janczewskia gardneri Setchell & Guernsey and its host Laurencia spectabilis Postels & Ruprecht was investigated. Mature plants of J. gardneri were pigmented, contained “typical” red algal chloroplasts when viewed by electron microscopy, and were capable of photosynthesis. Both J. gardneri and L. spectabilis incorporated 14C‐label from NaH14CO3 into similar compounds, including sugars (floridoside, isofloridoside, galactose, glucose) and amino acids (alanine, aspartic acid, glutamic acid, glycine, serine). Translocation of 14C‐labeled photosynthetic products between mature J. gardneri and its host did not occur. This research suggests that mature individuals of J. gardneri are obligate epiphytes.
MICROARCHITECTURE AND ENVELOPE DEVELOPMENT INDYSMORPHOCOCCUS GLOBOSUS(PHACOTACEAE, CHLOROPHYCEAE)1
Authors: Porcella Russell A. , Walne Patricia L. 
Published: August 2007

ABSTRACTThe ultrastructure and development of the envelope (lorica) ofDysmorphococcus globosusBold & Starr are described. This is the first detailed characterization of the envelope of a member of the Phacotaceae. The general ultrastructure and cellular organization of the protoplast are similar to that reported for other volvocalean algae. Transmission electron microscopy (TEM) showed the granular and fibrous components of the immature envelope, the sequential deposition of a mineralized layer, and the presence of perforations in the mineralized layer. Iron is incorporated in the mineralized envelope with55Fe labeling. Experiments with59Fe showed an 86% uptake of available iron by cells in culture, with the label localized to the envelope and envelope‐associated mucilage. Envelope formation is the result of the following phenomena: i) secretion of an immature envelope consisting of an outer fibrous layer and an inner granular layer; ii) sequential precipitation of a mineralized component in the inner layer, during which time pores are formed as part of the developmental process; iii) exudation of mucilaginous materials through those pores; iv) localized secretion and subsequent retention of the secretory product giving rise to the pebbled nature of the envelope surface. In living cells, the envelope surface is coated with mucilaginous secretory products that obscure the pores, which were previously reported to be lacking in this species. Results of acetolysis on aplanospores suggest the presence of a sporopollenin inD. globosus.
ß CARBOXYLATION ENZYMES IN MARINE PHYTOPLANKTON AND ISOLATION AND PURIFICATION OF PYRUVATE CARBOXYLASE FROMAMPHIDINIUM CARTERAE(DINOPHYCEAE)1
Authors: Appleby Geoffrey , Colbeck Jill , Holdsworth Eric S. , Wadman Hugh 
Published: August 2007

ABSTRACTThe diatoms,Phaeodactylum tricornutumBohlin,Cylindrotheca closteriumvar.californica(Meres.) Reim. & Lewin,Thalassiosira pseudonanaHasle & Heimdal and the prymnesiophytePavlova lutheri(Droop), Green, have been shown to contain phosphoenolpyruvate carboxykinase E.C.4.1.1.49. Another diatomChaetoceros calcitrans(Paulsen) Takano, the chlorophyteDunaliella tertiolectaButcher, a rhodophytePorphyridium cruentumNaegeli and the cyanophyteAnabaena cylindricaLemmermann, all possessed phosphoenolpyruvate carboxylases E.G.4.1.1.31, which were stimulated by Mn ions and inhibited by malate and aspartate. Two dinoflagellates,Amphidinium carteraeHulbert andGymnodiniumsp., were shown to contain pyruvate carboxylase E.G.6.4.1.1., not previously reported in plants or marine algae. Pyruvate carboxylase was isolated and purified and found to contain biotin and it was inhibited by avidin and could be distinguished from the other two enzymes by complete inhibition by 5 mM Mn ions. The β carboxylating enzymes account for the anaplerotic formation of amino acids and intermediates of the tricarboxylic acid cycle formed during short‐term fixation of CO2.
BEHAVIOR OF CHLOROPLAST ER DURING CHLOROPLAST DIVISION IN OLISTHODISCUS LUTEUS (CHRYSOPHYCEAE)1
Authors: Magnussen Charlotte , Gibbs Sarah P. 
Published: August 2007

ABSTRACTDuring chloroplast division in Olisthodiscus luteus Carter, the envelope of chloroplast ER may infold either in synchrony with the chloroplast envelope or lag markedly behind the chloroplast envelope giving two different patterns of division. In the first type of division the chloroplast ER infolds in parallel with the chloroplast envelope as the plastid pinches in two. In the second more common type of division, the chloroplast envelope infolds, meets and fuses before the chloroplast ER begins to infold thus producing two plastids in a single sac of chloroplast ER. Separation of these plastids is accomplished by the subsequent infolding of the chloroplast ER.
INSECTICIDAL ACTIVITY OF GONYAULAX (DINOPHYCEAE) CELL POWDERS AND SAXITOXIN TO THE GERMAN COCKROACH1
Authors: Demons Gary P. , Pham Dien V. , Pinion Jack P. 
Published: August 2007

ABSTRACTCrude cell powders prepared from unialgal cultures of Gonyaulax monilata Howell, and G. tamarensis Lebour and saxitoxin were found to be insecticidal against the German cockroach Blatella germanica L., yielding respective LD50 values of 194, 12.50 and 0.7 μg/g insect body weight. Although mice appear more sensitive to saxitoxin than German cockroaches, the insect's small mass and simple rearing requirements favor it as a bioassay organism in analytical situations of limited toxin quantities.
ULTRASTRUCTURE OF THE INFECTION CYCLE OF CYANOPHAGE SM‐2 IN SYNECHOCOCCUS ELONGATUS (CYANOPHYCEAE)1
Authors: Leach Jan E. , Lee Kit W. , Benson Randall L. , Martin Eugene L. 
Published: August 2007

ABSTRACTTransmission electron microscopy was used to examine the ultrastructure aspects of cyanophage SM‐2 replication in its host Synechococcus elongatus Naegeli UTEX 563. Filled virion heads were observed 10 h after infection, correlating well with the 6–8 h eclipse period for the virus. As the infection cycle proceeded from 10–50 h, additional virion heads accumulated at either end of the nucleoplasm. Of the several cyanophage that lyse unicellular bluegreen algae, this is unique to the SM‐2 system. The surrounding photosynthetic lamellae remained intact throughout the infection cycle. The nucleic acid composition of SM‐2 was determined as DNA.
ULTRASTRUCTURAL STUDIES ONSPHAEROPLEA ANNULINA(CHLOROPHYCEAE). VEGETATIVE STRUCTURE AND MITOSIS1
Authors: Cáceres Eduardo J. , Robinson David G. 
Published: August 2007

ABSTRACTThe ultrastructure of the taxonomically disputed filamentous green algaSphaeroplea annulina(Roth) Agardh has been investigated. The filament is a linear coenobium, the individual coenocytes of which are separated by remnants of cytoplasm termed “plugs.” Vegetative growth is coupled with a form of asexual reproduction in which multinucleate autospores are formed but not liberated. Mitosis is of the semi‐open and centric type. A complete disintegration of the nucleolus in metaphase is not seen. A typical phycoplast to which the centriole pairs migrated at the end of telophase was present. Cytokinesis was not coupled with mitosis. These observations rule out possible affinities with the orders Siphonales (sensu lato) and Cladophorales, and, apart from similarities to the filamentous (uninucleate)Microspora,the Ulotrichales as well. Certain similarities with coenocytic chlorococcalean algae occur, but this investigation supports the concept of a separate order: the Sphaeropleales.