bluuebunny/crossref_metadata_2025 huggingface dataset:
A simple method for large‐scale purification of plasma‐derived apo‐transferrin
Authors: Ascione Ester , Muscariello Livio , Maiello Valentina , Romano Vincenza , Giovacchini Pierangelo , Nardini Ilaria , Farina Claudio
Published: October 2010

We investigated and optimized a purification process, suitable for industrial scale, to obtain pharmaceutical grade apo‐Tf (apo‐transferrin), preserving its physiological properties and functions. Apo‐Tf was obtained from fraction IV subfraction 1 and IV subfraction 4 (fraction IV‐1,4), a waste product of the Cohn fractionation process, performing a single chromatographic run and two viral inactivation/removal steps. The structural integrity and the biological activity of the final product were extensively tested. The yield of apo‐Tf produced was 80% on laboratory scale and 90% in scale‐up lots, and the purity was higher than 95%. The purified protein preserves iron‐ and receptor‐binding activities and shows a normal glycosylation pattern. The single chromatographic step process presented here provides an efficient means to prepare commercial quantities of the protein. The final product is sterile and two viral inactivation/removal steps were introduced into the process.
Production of scFv‐displaying BmNPV in silkworm larvae and its efficient purification
Authors: Dojima Takashi , Nishina Takuya , Kato Tatsuya , Ueda Hiroshi , Park Enoch Y.
Published: October 2010

Baculovirus‐display technology utilizing the gp64 envelope protein has been developed. A simple and efficient process to separate the virus from the majority of the protein contaminants may be needed for the future demand of pure and functional baculovirus vectors ideal for vaccine‐ and gene‐delivery applications. In the present study, using Bombyx mori (silkworm) larvae as a host, scFv (single‐chain variable fragment)‐surface displaying recombinant baculovirus production and its purification from silkworm larval haemolymph by SEC (size‐exclusion chromatography) were demonstrated. The amounts of scFv were 4–8 μg/ml in the haemolymph. The scFv–gp64 fusion protein was confirmed to be incorporated into the cell membrane and the BmNPV (B. mori nucleopolyhedrovirus) surface by immunofluorescence microscopy and Western blotting. rBmNPV (recombinant BmNPV) was purified to higher purity by SEC using Sephacryl S‐1000 column chromatography than by sucrose‐density‐gradient centrifugation. The recovery of purified rBmNPV was 22.2%, and the virus purity in the SEC fraction was increased 269‐fold compared with its purity in haemolymph. Judging from the results of ELISA, approx. 0.9% of the total baculovirus‐particle proteins were occupied by scFv on their surface. A BmNPV‐based silkworm‐larval system is suitable for large‐scale production of baculovirus‐surface‐displayed proteins or peptides in comparison with a cell‐culture system. The present study will be useful for future BmNPV‐application studies for gene delivery and vaccine trials.
Phosphorylation-dependent association of the G4-1/G5PR regulatory subunit with IKKβ negatively modulates NF-κB activation through recruitment of protein phosphatase 5
Authors: Chiang Chao-Wei , Liu Wei-Kuang , Chiang Chi-Wu , Chou Chen-Kung
Published: October 2010

The transcription factor NF-κB (nuclear factor κB) co-ordinates various gene expressions in response to diverse signals and is a critical regulator of inflammation and innate immunity. Several negative regulators of NF-κB have been identified as downstream targets of NF-κB and function as a feedback control of NF-κB activation. A few protein phosphatases have also been shown to inactivate NF-κB activation. However, little is known about how protein phosphatases detect and respond to NF-κB activation. In the present study, we report a regulatory subunit of PP5 (protein phosphatase 5), G4-1, that physically interacts with IKKβ [IκB (inhibitor of NF-κB) kinase β] and negatively regulates NF-κB activation. The association of G4-1 with IKKβ depends on the kinase activity of IKKβ. Mapping of the G4-1-binding domain of IKKβ reveals that the serine-rich domain in the C-terminus of IKKβ is required for G4-1 binding. When seven autophosphorylated serine residues in this domain were mutated to alanine, the mutant form of IKKβ lost its ability to bind G4-1 and was more potent than the wild-type kinase to activate NF-κB. Knockdown of G4-1 enhanced TNFα (tumour necrosis factor α)-induced NF-κB activity, and knockdown of PP5 totally abolished the inhibitory activity of G4-1 on NF-κB activation. The results of the present study suggest that G4-1 functions as an adaptor to recruit PP5 to the phosphorylated C-terminus of activated IKKβ and to down-regulate the activation of IKKβ.
Identification of novel species-selective agonists of the G-protein-coupled receptor GPR35 that promote recruitment of β-arrestin-2 and activate Gα13
Authors: Jenkins Laura , Brea Jose , Smith Nicola J. , Hudson Brian D. , Reilly Graeme , Bryant Nia J. , Castro Marian , Loza María-Isabel , Milligan Graeme
Published: October 2010

The poorly characterized G-protein-coupled receptor GPR35 has been suggested as a potential exploratory target for the treatment of both metabolic disorders and hypertension. It has also been indicated to play an important role in immune modulation. A major impediment to validation of these concepts and further study of the role of this receptor has been a paucity of pharmacological tools that interact with GPR35. Using a receptor–β-arrestin-2 interaction assay with both human and rat orthologues of GPR35, we identified a number of compounds possessing agonist activity. These included the previously described ligand zaprinast. Although a number of active compounds, including cromolyn disodium and dicumarol, displayed similar potency at both orthologues of GPR35, a number of ligands, including pamoate and niflumic acid, had detectable activity only at human GPR35 whereas others, including zaprinast and luteolin, were markedly selective for the rat orthologue. Previous studies have demonstrated activation of Gα13 by GPR35. A Saccharomyces cerevisiae-based assay employing a chimaeric Gpa1–Gα13 G-protein confirmed that all of the compounds active at human GPR35 in the β-arrestin-2 interaction assay were also able to promote cell growth via Gα13. Each of these ligands also promoted binding of [35S]GTP[S] (guanosine 5′-[γ-[35S]thio]triphosphate) to an epitope-tagged form of Gα13 in a GPR35-dependent manner. The ligands identified in these studies will be useful in interrogating the biological actions of GPR35, but appreciation of the species selectivity of ligands at this receptor will be vital to correctly attribute function.
Afterload‐Dependent Flow Fluctuation of Centrifugal Pump: Should it be Actively Fixed?
Authors: Nishida Hiroshi , Akazawa Toshimasa , Nishinaka Tomohiro , Aomi Shigeyuki , Endo Masahiro , Koyanagi Hitoshi
Published: October 2010

Abstract To evaluate the clinical meaning and effects of afterload‐dependent flow fluctuation in a centrifugal pump, concomitant measurement of flow rate and mixed venous oxygen saturation () was performed in 5 cases of open heart surgery in which the patients underwent cardiopulmonary bypass (CPB) with the Terumo Capiox centrifugal pump. Continuous measurement of using the 3M CDI System 100 was performed with a disposable cuvette incorporated into the drainage circuit. After the target flow rate of 2.4 L/min/m2 was obtained under a nonbeating condition, the pump rotational speed was fixed. During the cooling and low temperature period, decreased as the flow rate spontaneously decreased but still stayed around 80% even with a 15–20% decrease in blood flow rate. This indicates that a luxury perfusion condition is ensured as long as the body temperature is kept low. In contrast, during the rewarming period, decreased to around 70–75% despite a 15–25% spontaneous increase in flow rate. Although this level of still indicates adequate systemic perfusion, there is a possibility of regional hypoperfusion in patients with such conditions as cerebrovascular disease. In conclusion, although diligent adjustment of the physiological fluctuating flow rate in the centrifugal pump seems unnecessary during conventional open heart surgery, manual control may be necessary especially during the rewarming period, normothermic surgery, or circulatory assist for shocked patients. From this study, we also conclude that the major benefit of the afterload‐independent autoflow control system of the centrifugal pump is the improvement of safety in terms of the fixed reservoir level and the handling of cardiopulmonary bypass.
HEAVY METAL‐INDUCED INHIBITION OF PHOTOSYNTHESIS: TARGETS OF IN VIVO HEAVY METAL CHLOROPHYLL FORMATION1
Authors: Küpper Hendrik , Šetlík Ivan , Spiller Martin , Küpper Frithjof C. , Prášil Ondřej
Published: October 2010

The targets of heavy metal (here Cu2+ and Zn2+) attack on the photosynthetic apparatus of algae belonging to different phyla were investigated. Experiments with the green alga Scenedesmus quadricauda confirmed previous findings that according to the irradiance level two different phenomena occur, which were further characterized by specific changes in several photosynthetic parameters. The reaction occurring under low irradiance (shade reaction) is characterized by heavy metal substitution of Mg2+ in chl molecules bound predominantly in the light harvesting complex II of Chlorophyta (LHC II). Under high irradiance (sun reaction) the LHC II chls are inaccessible to substitution and the damage occurs in the PSII reaction center instead. Algae with antenna proteins other than the LHC II did not show the two types of heavy metal attack at different irradiances. In red algae (Antithamnion plumula), low Cu2+ concentrations induced the sun reaction even at very low irradiance. In brown algae (Ectocarpus siliculosus) the shade reaction occurred even in saturating irradiance. These results also indicate that despite some similarity in their features, the primary step of the sun reaction and photoinhibition is different.
CLONING, EXPRESSION, AND CHARACTERIZATION OF A HISTONE‐LIKE PROTEIN FROM THE MARINE DINOFLAGELLATE LINGULODINIUM POLYEDRUM (DINOPHYCEAE)1
Authors: Chudnovsky Yakov , Li Joey F. , Rizzo Peter J. , Hastings J. Woodland , Fagan Thomas F.
Published: October 2010

Although nucleosomes and histones are lacking in dinoflagellate nuclei, small basic histone‐like proteins have been reported, but their function(s) is unknown. In this study we cloned and sequenced a gene for a histone‐like protein from the dinoflagellate Lingulodinium polyedrum (Stein) Dodge (HLp) (formerly Gonyaulax polyedra Stein) and investigated its post‐translational modification and DNA‐binding activities. HLp appears to be acetylated in L. polyedrum, and we identified several L. polyedrum proteins that possess histone acetyltransferase activity and may be responsible for this modification. HLp binds weakly to L. polyedrum DNA but to certain specific sequences with higher affinity, consistent with its having a regulatory function.
INFLUENCE OF PHOSPHORUS LIMITATION ON TOXICITY AND PHOTOSYNTHESIS OF ALEXANDRIUM MINUTUM (DINOPHYCEAE) MONITORED BY IN‐LINE DETECTION OF VARIABLE CHLOROPHYLL FLUORESCENCE1
Authors: Lippemeier Sebastian , Frampton Dion M. F. , Blackburn Susan I. , Geier Stephanie C. , Negri Andrew P.
Published: October 2010

The effects of phosphorus (P) limitation on growth, toxicity, and variable chl fluorescence of Alexandrium minutum were examined in batch culture experiments. Cell division was greatly impaired in P‐limited cultures, but P spiking of these cultures after 9 days stimulated high levels of cell division equivalent to P‐replete cultures. The cellular concentration of paralytic shellfish toxins was consistent over the growth cycle of control cultures from lag phase into logarithmic growth phase, with toxins repeatedly lost to daughter cells during division. The low level of cell division in P‐limited cultures resulted in a 10‐fold increase of cellular toxin compared with controls, but this dropped upon P spiking due to increased rates of cell division. The history of phosphorus supply had an important effect on toxin concentration, with the P‐limited and the P‐spiked cultures showing values 2‐fold higher than the P‐replete cultures. Toxin profiles of the A. minutum strain used in these experiments were dominated by the N1‐hydroxy toxins, gonyautoxins (GTX) GTX1 and GTX4, which were approximately 40 times more abundant than their analogues, GTX2 and GTX3, in P‐limited cultures. The dominance of the N1‐hydroxy toxins increased significantly in control cultures as they advanced through logarithmic growth. In‐line measurements of the variable chl fluorescence of light‐adapted cells indicated consistent photochemical efficiency under P‐replete conditions. P limitation induced a drop in fluorescence‐based photochemical efficiency that was reversible by P spiking. There was an inverse linear relationship between in‐line fluorescence and cell toxin quota (r = −0.88). Monitoring fluorescence in‐line may be valuable in managing efficient biotechnological production of toxins.
CHARACTERIZATION OF HaRNAV, A SINGLE‐STRANDED RNA VIRUS CAUSING LYSIS OF HETEROSIGMA AKASHIWO (RAPHIDOPHYCEAE)1
Authors: Tai Vera , Lawrence Janice E. , Lang Andrew S. , Chan Amy M. , Culley Alexander I. , Suttle Curtis A.
Published: October 2010

HaRNAV, a novel virus that infects the toxic bloom‐forming alga Heterosigma akashiwo (Hada) Hada ex Hada et Chihara, was characterized based on morphology, pathology, nucleic acid type, structural proteins, and the range of host strains that it infects. HaRNAV is a 25‐nm single‐stranded RNA (ssRNA) virus with a genome size of approximately 9100 nucleotides. This is the first report of an ssRNA virus that causes lysis of a phytoplankton species. The virus particle is sensitive to chloroform and contains at least five structural proteins ranging in apparent size from 24 to 34 kDa. HaRNAV infection causes swelling of the endoplasmic reticulum and progeny virus particles assemble in the cytoplasm of the host, frequently in crystalline arrays. The infectivity of HaRNAV was tested against 15 strains of H. akashiwo isolated from Japanese waters, the Northeast Pacific, and the Northwest Atlantic. HaRNAV caused lysis of three strains from the Northeast Pacific and two strains from Japan but none from the Northwest Atlantic. The characterization of HaRNAV demonstrates that HaRNAV is a novel type of phytoplankton virus but has some similarities with plant viruses belonging to the Sequiviridae and to other known ssRNA viruses. Further genomic analysis, however, is necessary to determine any phylogenetic relationships. The discovery of HaRNAV emphasizes the diversity of H. akashiwo viral pathogens and, more importantly, algal–virus pathogens and the complexity of virus–host interactions in the environment.
AN EXPERIMENTAL ASSESSMENT OF THE EFFECTS OF NUTRIENT ENHANCEMENT ON THE INTERTIDAL KELP HEDOPHYLLUM SESSILE (LAMINARIALES, PHAEOPHYCEAE)1
Authors: Pfister Catherine A. , Van Alstyne Kathryn L.
Published: October 2010

We tested whether experimentally enhancing nutrients around the kelp Hedophyllum sessile would increase growth, tissue nitrogen, or allocation to phenolic compounds. Packets of time‐released fertilizer were anchored adjacent to fronds in the field, and algae were monitored for several months. Although fertilizer packets increased the concentration of ammonium, nitrate, and phosphorus adjacent to treatment algae by an order of magnitude, there was little evidence that this increased frond growth or size. Hedophyllum individuals showed no tendency to alter allocation patterns in response to nutrient addition. Tissue carbon and nitrogen was unchanged by the nutrient manipulation; most H. sessile had tissue nitrogen concentrations in excess of 2.0% of dry mass. Additionally, the concentration of phloroglucinol equivalents was also unaffected by the presence of increased water column nutrients. Although nutrient concentrations in the water column surrounding the study site show relatively high mean values for ammonium, nitrate, and phosphorus, they are characterized by high spatial and temporal variation. Nonetheless, these data suggest that this intertidal kelp is not limited by nitrogen or phosphorus in wave‐exposed areas in the northeast Pacific Ocean.
GENETIC VARIABILITY AND MOLECULAR PHYLOGENY OF DINOPHYSIS SPECIES (DINOPHYCEAE) FROM NORWEGIAN WATERS INFERRED FROM SINGLE CELL ANALYSES OF rDNA1
Authors: Edvardsen Bente , Shalchian‐Tabrizi Kamran , Jakobsen Kjetill S. , Medlin Linda K. , Dahl Einar , Brubak Sissel , Paasche Eystein
Published: October 2010

The objectives of this study were to determine rDNA sequences of the most common Dinophysis species in Scandinavian waters and to resolve their phylogenetic relationships within the genus and to other dinoflagellates. A third aim was to examine the intraspecific variation in D. acuminata and D. norvegica, because these two species are highly variable in both morphology and toxicity. We obtained nucleotide sequences of coding (small subunit [SSU], partial large subunit [LSU], 5.8S) and noncoding (internal transcribed spacer [ITS]1, ITS2) parts of the rRNA operon by PCR amplification of one or two Dinophysis cells isolated from natural water samples. The three photosynthetic species D. acuminata, D. acuta, and D. norvegica differed in only 5 to 8 of 1802 base pairs (bp) within the SSU rRNA gene. The nonphotosynthetic D. rotundata (synonym Phalacroma rotundatum[Claparède et Lachmann] Kofoid et Michener), however, differed in approximately 55 bp compared with the three photosynthetic species. In the D1 and D2 domains of LSU rDNA, the phototrophic species differed among themselves by 3 to 12 of 733 bp, whereas they differed from D. rotundata by more than 100 bp. This supports the distinction between Dinophysis and Phalacroma. In the phylogenetic analyses based on SSU rDNA, all Dinophysis species were grouped into a common clade in which D. rotundata diverged first. The results indicate an early divergence of Dinophysis within the Dinophyta. The LSU phylogenetic analyses, including 4 new and 11 Dinophysis sequences from EMBL, identified two major clades within the phototrophic species. Little or no intraspecific genetic variation was found in the ITS1–ITS2 region of single cells of D. norvegica and D. acuminata from Norway, but the delineation between these two species was not always clear.
SEX PHEROMONES THAT INDUCE SEXUAL CELL DIVISION IN THE CLOSTERIUM PERACEROSUM–STRIGOSUM–LITTORALE COMPLEX (CHAROPHYTA)1
Authors: Tsuchikane Yuki , Fukumoto Ryo‐hei , Akatsuka Satoko , Fujii Tadashi , Sekimoto Hiroyuki
Published: October 2010

Sexual cell division (SCD) that produces two gametangial cells from one vegetative mother cell is the first step observed morphologically in the sexual reproduction in the Closterium peracerosum–strigosum– littorale complex. SCD‐inducing activities specific for each mating‐type cells were detected in the medium in which both mating type cells has been cocultured. Mating‐type minus (mt−) cells released SCD‐inducing substance specific for mating‐type plus (mt+) cells and were designated as SCD‐ inducing pheromone (IP)‐minus, whereas mt− specific substances released from mt+ cells were designated as SCD‐IP‐plus. Culture medium was subjected to gel filtration, and then SCD‐IP‐plus and SCD‐IP‐minus chemical were found to have the molecular masses of 90–100 kDa and 10–20 kDa, respectively. It was evident that light was imperative for this type of signaling. Gametangial cells of both mating types were obtained from vegetative cells by treatment with SCD‐IPs. Gametangial mt+ cells showed high competency for conjugation with vegetative mt− cells, whereas gametangial mt− cells showed low competency for conjugation with vegetative mt+ cells. These results indicate that SCD in both mating type cells is induced by high molecular weight sex pheromones and that the roles of gametangial cells in the process of conjugation differ by sex.
LESSARDIA ELONGATA GEN. ET SP. NOV. (DINOFLAGELLATA, PERIDINIALES, PODOLAMPACEAE) AND THE TAXONOMIC POSITION OF THE GENUS ROSCOFFIA1
Authors: Saldarriaga Juan F. , Leander Brian S. , “Max” Taylor F. J. R. , Keeling Patrick J.
Published: October 2010

We investigate an organism that closely resembles the nonphotosynthetic dinoflagellate “Gymnodinium elongatum” Hope 1954 using EM and molecular methods. Cells are 20–35 μm long, 10 μm wide, biconical, transparent, and have a faint broad girdle. Thecal plates are thin but present (plate formula Po Pi CP 3′ 1–2A 5″ 3C 6S 4‴ 3″″). With the exception of one feature, the presence of three antapical plates, the amphiesmal arrangement of this species is consistent with that of the order Peridiniales, family Podolampaceae; it is not at all consistent with the characteristics of the genus Gymnodinium. On the basis of these ultrastructural findings, we establish a new genus, Lessardia, and a new species, Lessardia elongata Saldarriaga et Taylor. Molecular phylogenetic analyses were performed using the small subunit rRNA genes of L. elongata as well as Roscoffia capitata, a member of a genus of uncertain systematic position that has been postulated to be related to the Podolampaceae. These analyses place Lessardia and Roscoffia as sister lineages within the so‐called GPP complex. Thecal plate arrangements led us to expand the family Podolampaceae to include the genus Lessardia and, in combination with new molecular results, to propose a close relationship between the Podolampaceae and Roscoffia. Within this lineage, Lessardia and Roscoffia appear to have retained a number of ancestral characters: Roscoffia still has a well‐developed cingulum, a feature absent in all members of the Podolampaceae, and Lessardia has more than one antapical plate, a character reminiscent of some members of the family Protoperidiniaceae.
PHYSICAL AND CHEMICAL CONDITIONS SURROUNDING THE DIURNAL VERTICAL MIGRATION OF CRYPTOMONAS SPP. (CRYPTOPHYCEAE) IN A SEASONALLY STRATIFIED MIDWESTERN RESERVIOR (USA)
Authors: Knapp Charles W. , DeNoyelles Frank , Graham David W. , Bergin Sean
Published: October 2010

Cross Reservoir, a small mesotrophic reservoir located at the University of Kansas Ecological Reserves (Kansas, USA), contained a dense metalimnetic community of algae and photosynthetic bacteria between early July and late October 1997–1999. Within this community, various Cryptomonas species, primarily C. erosa (Ehrenberg), C. erosa var. reflexa (Marsson), and C. rostratisformis (Skuja), diurnally migrated as indicated by in situ fluorescence monitoring and direct phytoplankton enumeration. The Cryptomonas spp. typically resided near the oxic–anoxic boundary of the water column; however, they actively migrated upward during the day and descended to lower anoxic locations at night, apparently responding to diurnal changes in their local habitat. Their nocturnal environment had moderate levels of sulfide, elevated secondary nutrients, and a community of anoxygenic phototrophic bacteria, whereas their daytime environment had higher light, lower nutrients, and no local photosynthetic bacteria. Monitoring indicated that the Cryptomonas spp. migration was generally linked to daily variations in absolute light intensity (e.g. sunny vs. cloudy days) and the level of other potentially growth‐limiting resources, particularly nitrogen and phosphorus. However, further analyses showed that the primary factor that determined whether the Cryptomonas spp. migrated or not on a given day was the slope of the light gradient immediately above the Cryptomonas spp. peak.
CLOSTERIUM MONILIFERUM‐EHRENBERGII(CHAROPHYCEAE, CHLOROPHYTA) SPECIES COMPLEX VIEWED FROM THE 1506 GROUP I INTRON AND ITS2 OF NUCLEAR rDNA
Authors: Denboh Takashi , Ichimura Terunobu , Hendrayanti Dian , Coleman Annette W.
Published: October 2010

To assess phylogenetic relationships and speciation modes inClosterium, we sequenced two noncoding regions of the nuclear ribosomal cistron, the 1506 group I intron in small subunit and the internal transcribed spacer 2, for a total of 58 strains of theClosterium moniliferum‐ehrenbergiispecies complex. These include both homothallic and heterothallicC. moniliferumErenberg ex Ralfs v.moniliferum, heterothallicC. moniliferumv.submoniliferum(Woronichin) Krieger, and heterothallicC. ehrenbergiiMeneghini ex Ralfs that can be divided into several mating groups. We found no or very little sequence divergence within single mating groups ofC. ehrenbergiiand among all heterothallic strains ofC. moniliferumv.moniliferumorC. moniliferumv.submoniliferum.Nevertheless, sequence divergence was much greater between those mating groups ofC. ehrenbergiiand also among the three traditional taxa.Maximum parsimony and maximum likelihood analyses showed that the taxonC. ehrenbergiiwas not monophyletic. The two varieties ofC. moniliferumappeared as a sister clade to certain mating groups ofC. ehrenbergii. Among the clades that were recovered in different trees by maximum parsimony and maximum likelihood analyses, we consistently found two large conspicuous clades: clade I consisted of mating groups A, B, C, H, K, and L ofC. ehrenbergiiwhose zygospores have smooth‐walls, and clade II contained the mating groups D, E, I, J, and S whose zygospores are scrobiculate. Phylogenetic incongruences observed are discussed from the viewpoints of the different molecular nature of the group I intron and internal transcribed spacer 2, as well as putative rapid diversification of the mating groups and probable ancient ancestral hybridization.
PROTOPERIDINIUM BELIZEANUMSP. NOV. (DINOPHYCEAE) FROM MANATEE CAY, BELIZE, CENTRAL AMERICA1
Authors: Faust Maria A.
Published: October 2010

A new marine heterotrophic dinoflagellate species,Protoperidinium belizeanumsp. nov., from a coral reef‐mangrove pond was identified from scanning electron micrographs. Recognition of this new species was based on unique features of the thecal morphology, which included cell size and shape, presence of short and wide postcingular plates, sulcal architecture, antapical spines, and intricate thecal plate patterns of ridged hexagonal depressions. The thecal plate formula is as follows: Po, X, 4′, 3a, 7″, 4C (3+t), 6S, 5‴, 2″″. Species association ofP. be‐lizeanumsp. nov. within the genusProtoperidinium, its habitat, and associated dinoflagellates species are discussed.
ARE “GREEN TIDES” HARMFUL ALGAL BLOOMS? TOXIC PROPERTIES OF WATER‐SOLUBLE EXTRACTS FROM TWO BLOOM‐FORMING MACROALGAE, ULVA FENESTRATA AND ULVARIA OBSCURA (ULVOPHYCEAE)
Authors: Nelson Timothy A. , Lee Dejah J. , Smith Bridget C.
Published: October 2010

Toxic properties are more often associated with microalgal blooms than with macroalgal blooms, although herbivore deterrents are well known in macroalgae, and inhibition of invertebrate larval development by extracts from Ulva spp. has been suggested. This study was prompted from our observation that substantial discoloration of seawater occurred in small bays after mass desiccation‐induced mortality of Ulvaria obscura (Kützing) Gayral. We examined the effects of extracts from Ulva fenestrata Postels et Ruprecht and Ulvaria obscura on Fucus gardneri Silva zygote development, growth of Ulva and Ulvaria, epiphytic algal accumulation, and oyster larval development. Fucus zygote development was inhibited by extracts from both species, although the effects of Ulvaria extracts were significantly greater. Epiphytic algal accumulation and the growth of Ulva and Ulvaria were inhibited by extracts from both species. Oyster larval development was arrested by the presence of extracts from each species. We conclude that extracts from both Ulva fenestrata and Ulvaria obscura have allelopathic properties. The effects are more widespread and occur at lower concentrations for extracts from Ulvaria than Ulva. These properties could alter competitive interactions by inhibiting germination or development of algae and invertebrates.
A TRANSIENT BLOOM OF OSTREOCOCCUS (CHLOROPHYTA, PRASINOPHYCEAE) IN WEST NECK BAY, LONG ISLAND, NEW YORK
Authors: O'Kelly Charles J. , Sieracki Michael E. , Thier Edward C. , Hobson Ilana C.
Published: October 2010

The smallest known eukaryote, Ostreococcus tauri Courties et Chrétiennot‐Dinet, was first reported as the dominant picoplankter in a French lagoon known for its diverse phytoplankton community and high oyster productivity. Long‐term seasonal blooms of this picoeukaryote were observed in association with stable plankton communities. On 5 June 2001, a distinctive monotypic picoplankton bloom was detected by flow cytometry as part of an ongoing study of “brown tide” (Aureococcus anophagefferens) bloom initiation in Long Island bays. The bloom reached a concentration of 5 × 105 cells·mL−1 in West Neck Bay and lasted less than 2 weeks. Epifluorescence microscopy and TEM indicated that the bloom organism was an Ostreococcus‐like picoalga, the first ever observed in a Long Island bay. Many cells of this alga contained numerous virus‐like particles. The Ostreococcus‐like picoalga, which resembles O. tauri, was rare in samples collected the following week. Instead, a substantial increase in the Synechococcus population was observed. Such rapid population changes have not previously been reported for Ostreococcus. Viral lysis and grazing by heterotrophic nanoflagellates may have contributed to the rapid decline of the Ostreococcus‐like cells in West Neck Bay.
COMPARISON OF RNA EXPRESSION PROFILES BETWEEN THE TWO GENERATIONS OF PORPHYRA YEZOENSIS (RHODOPHYTA), BASED ON EXPRESSED SEQUENCE TAG FREQUENCY ANALYSIS
Authors: Asamizu Erika , Nakajima Maiko , Kitade Yukihiro , Saga Naotsune , Nakamura Yasukazu , Tabata Satoshi
Published: October 2010

To identify gene candidates related to the morphological and physiological differences between the gametophytic and sporophytic generations of a marine red alga, Porphyra yezoensis Ueda, large‐scale expressed sequence tag (EST) analysis was conducted. A total of 10,625 5′‐end EST sequences was generated from the sporophyte cDNA library, in addition to the previously published 10,154 ESTs from the gametophyte. A total of 20,779 ESTs was clustered into 4496 nonredundant groups at the criterion of 95% identity for 50 bases. Among the EST groups, only 1013 (22.5%) groups were classified as ESTs that commonly occurred in both generations, whereas a large proportion of EST groups were identified as being unique to either the gametophyte (1940 EST groups = 43.1%) or the sporophyte (1543 EST groups = 34.3%). A statistical significance test revealed 89 and 112 highly expressed gene candidates in the gametophyte and the sporophyte, respectively. Twelve candidate genes were subjected to RT‐PCR analysis, and the differential expression was confirmed. Generation‐specific regulation of alternative splicing of a transcript was demonstrated by RT‐PCR analyses.
CLONING AND CHARACTERIZATION OF A cDNA ENCODING A SEXUAL CELL DIVISION‐INDUCING PHEROMONE FROM A UNICELLULAR GREEN ALGA CLOSTERIUM EHRENBERGII (CHLOROPHYTA)
Authors: Fukumoto Ryo‐hei , Fujii Tadashi , Sekimoto Hiroyuki
Published: October 2010

A full‐length cDNA encoding a sexual cell division‐ inducing pheromone (SCD‐IP) was isolated from a heterothallic green alga, Closterium ehrenbergii Menegh. ex Ralfs, using the rapid amplification of cDNA ends‐PCR method. The cDNA was 907 bp in length and coded for a protein of 209 amino acids with a deduced molecular mass of Mr 23,186. The predicted protein had a possible glycosylation site and a hydrophobic signal peptide for extracellular secretion. Transcripts of the SCD‐IP gene were detected only in mating type minus (mt−) cells and remarkably increased when mt− cells were cocultured with mating type plus (mt+) cells. By contrast, the gene for SCD‐IP was detected in both mating type cells as multicopy genes by Southern blot analysis. Continuous dark conditions and supplementation of a nitrogen source to the culture medium suppressed SCD‐IP expression. The deduced amino acid sequences encoded by genes for SCD‐IP and protoplast‐release‐inducing protein (PR‐IP) Inducer, a sex pheromone isolated from another Closterium species, appeared to share significant homology, suggesting that these sex pheromones were diversified from a single ancestral Closterium pheromone.
CIRCADIAN CHANGES IN RELATIVE ABUNDANCE OF TWO PHOTOSYNTHETIC TRANSCRIPTS IN THE MARINE MACROALGA KAPPAPHYCUS ALVAREZII (RHODOPHYTA)
Authors: Jacobsen Sabine , Lüning Klaus , Goulard Fabienne
Published: October 2010

Circadian regulation of transcriptional gene expression has been shown for a variety of taxa throughout the eukaryotic kingdom and for prokaryotic cyanobacteria but not previously for macroalgae. We reported earlier a strong circadian rhythm of photosynthetic capacity in the red macroalga Kappaphycus alvarezii (Doty) Doty. To determine whether this rhythm is correlated with circadian regulation of steady‐state transcript abundance, we analyzed transcripts of genes whose protein products are involved in photosynthesis. Transcript levels of two plastid‐encoded operons, one for phycoerythrin α and β subunits and another for RUBISCO large and small subunits, were analyzed under light:dark cycles (LD) and under constant illumination (LL) for several days. Both transcripts exhibited diurnal regulation under LD conditions with maximum transcript abundance during early daytime to midday. Under LL conditions, circadian oscillations of steady‐state mRNA abundance were detected for up to three cycles; thus, the analyzed transcripts exhibited diurnal and circadian regulation. Interestingly, peak abundance of the RUBISCO transcript shifted to subjective night under LL. To our knowledge, this is the first report demonstrating that circadian control of steady‐state transcript abundance occurs in a macroalga.
Sterols of the heterotrophic dinoflagellate, pfiesteria piscicida (dinophyceae): is there a lipid biomarker?1
Authors: Leblond Jeffrey D. , Chapman Peter J.
Published: October 2010

Within U.S. waters, blooms of the dinoflagellate, Pfiesteria piscicida, have been recorded on an almost regular basis in the Chesapeake Bay and surrounding mid‐Atlantic regions for the last two decades. Despite the apparent significance of such blooms to the environment and human health and the attendant economic consequences, little work has addressed the physiology and biochemistry, particularly that of sterol composition, of P. piscicida. GC‐MS characterization of trimethylsilyl ether derivatives of sterols from free sterol and sterol ester fractions was performed in an effort to determine whether P. piscicida produces unique sterols that may serve as potential biomarkers. This characterization revealed that like most dinoflagellates, the majority of sterols was present as free sterols. Furthermore, the profile of free sterols was found to resemble those of photosynthetic dinoflagellates, with the dominant compound being the previously reported dinoflagellate sterol, dinosterol. A number of other 4α‐methyl‐substituted sterols and steroidal ketones common to other dinoflagellates were also identified. No strong candidate(s) for a unique sterol biomarker was present.
GENERAL FEATURES OF PHOTOPROTECTION BY ENERGY DISSIPATION IN PLANKTONIC DIATOMS (BACILLARIOPHYCEAE)1
Authors: Lavaud Johann , Rousseau Bernard , Etienne Anne‐Lise
Published: October 2010

Planktonic diatoms (Bacillariophyceae) have to cope with large fluctuations of light intensity and periodic exposure to high light. After a shift to high light, photoprotective dissipation of excess energy characterized by the nonphotochemical quenching of fluorescence (NPQ) and the concomitant deepoxidation of diadinoxanthin to diatoxanthin (DT) were measured in four different planktonic marine diatoms (Bacillariophyceae): Skeletonema costatum (Greville) Cleve, Cylindrotheca fusiformis Reimann et Lewin, Thalassiosira weissflogii (Grunow) Fryxell et Hasle, and Ditylum brightwellii (West) Grunow in comparison to the model organism Phaeodactylum tricornutum Böhlin. Upon a sudden increase of light intensity, deepoxidation was rapid and de novo synthesis of DT also occurred. In all species, NPQ was linearly related to the amount of DT formed during high light. In this report, we focused on the role of DT in the dissipation of energy that takes place in the light‐harvesting complex. In S. costatum for the same amount of DT, less NPQ was formed than in P. tricornutum and as a consequence the photoprotection of PSII was less efficient. The general features of photoprotection by harmless dissipation of excess energy in planktonic diatoms described here partly explain why diatoms are well adapted to light intensity fluctuations.
REPRODUCTIVE COMPATIBILITY AND RDNA SEQUENCE ANALYSES IN THE SELLAPHORA PUPULA SPECIES COMPLEX (BACILLARIOPHYTA)1
Authors: Behnke Anke , Friedl Thomas , Chepurnov Victor A. , Mann David G.
Published: October 2010

We tested whether internal transcribed spacer (ITS) rDNA sequence differences are correlated with sexual compatibility in the Sellaphora pupula complex, a model system for investigations of the species concept and speciation in diatoms. The phylogenetic relationships among the demes and the systematic position of the genus within the raphid diatoms were also investigated. The division of clones of S. pupula and S. laevissima into groups, based on sequence similarities and phylogenetic analyses, resembled groupings based on sexual compatibility: A high ITS sequence divergence, making full alignment difficult or impossible, was found among clones whose gametangia do not interact, whereas there was little sequence divergence among interfertile clones. This is clearly consistent with the idea that “Z clades” exhibit less intraclade than interclade variation in ITS and, as comparisons of secondary structure models for the RECT and PSEUDOCAP clones showed, that there is an equivalence of “CBC” and Z clades in the rectangular and pseudocapitate demes of S. pupula, as earlier hypothesized for chlorophytes. Intraclonal, presumably intraindividual, variation in ITS was found in S. pupula, though with a degree of variation less than that found within a single Z clade; it was too minor to affect the interclonal relationships in the ITS phylogeny. Sellaphora, which appears monophyletic in 18S phylogenies, with Pinnularia and “Navicula”pelliculosa as its closest allies, may also include some species currently classified in Eolimna. The S. pupula–S. laevissima group began to diversify in or before the Miocene.
INDUCED DIMORPHIC LIFE CYCLE OF A COCCOLITHOPHORID,CALYPTROSPHAERA SPHAEROIDEA(PRYMNESIOPHYCEAE, HAPTOPHYTA)1
Authors: Nöel Mary‐Hélène , Kawachi Masanobu , Inouye Isao
Published: October 2010

The holococcolithCalyptrosphaera sphaeroideaSchiller was collected at Miyake‐jima Island, Japan and unialgal cultures established. Alternation of the holococcolith and heterococcolith phases was induced using new culture media (MNK, TR, and LO). Cells synchronized in the holococcolith phase were transferred into TR medium to induce a life cycle change. The heterococcolith phase, which has never been reported before, appeared after more than 40 days. The heterococcoliths were very small elliptical discs, about 0.5 μm wide and 1 μm long. Typical diploid‐type organic scales on the cell surface were observed. This phase was very stable in culture and was tolerant of unfavorable conditions. To reverse the life phase, cells in the heterococcolith phase were transferred into cold LO medium and exposed to low temperature (4°C) and low light (2 μmol photons·m−2·s−1) for 30 min before culturing at normal conditions (22.5°C and 20 μmol photons· m−2·s−1). The swimming behavior of the holococcolith cells seemed to be an indicator of the life cycle phase transition. This article reports for the first time a set of conditions that could control the transition of a coccolithophorid from one life phase to the other. Selected vitamins and trace metals induced the heterococcolith phase, whereas a slightly higher concentration of components in the basic medium along with concomitant stresses of light and temperature induced the holococcolith phase. Based on the results, we propose a hypothesis that the alternation of coccolithophorid life phases is regulated by changes between pelagic and coastal environments coupled with changes in seasonal conditions.
New Systematic Insights in the Ceramium Sinicolacomplex: Resurrection of C. Interruptum S. & G. (Ceramiaceae, Rhodophyta)
Authors: Cho T. O. , Fredericq S. , Murray S. N. , Boo S. M.
Published: October 2010

Setchell & Gardner (1924) provided a taxonomic treatment for the genus Ceramium from lower California and the Gulf of California, Mexico, in which they described several new species, including C. sinicola S. & G. described from Ensenada, BCN and C. interruptum S. & G. described from the vicinity of La Paz, BCS. The latter was later reduced to variety rank in C. sinicolaby Dawson (1950), a taxonomic decision that has subsequently been widely adopted. Phylogenetic analyses inferred from three molecular markers (chloroplast‐encoded rbcL, the RUBISCO spacer, and nuclear encoded SSU rDNA) from recent collections from the Pacific North‐west (California, Oregon) and the Gulf of California reveal a well supported assemblage of three corticated taxa: C. codicolaJ. Ag. 1894, C. sinicola and C. sinicola var. interruptum. Sequence divergence values among the three taxa are sufficient to warrant separate species ranking; hence, we reinstate C. interruptum as a widely distributed epiphyte for the region. C. sinicolais more closely related to C. codicolathan to C. interruptum, with the former two restricted to the host Codium. The molecule‐based relationships are congruent with evolutionary trends in cortication pattern and attachment mode.
Comparative Phylogeography of Reticulate Cladophoralean Algae
Authors: Wysor B. , Kooistra Wiebe H. C. F. , Fredericq Suzanne
Published: October 2010

The study of species distributions requires well‐defined species concepts and well‐resolved species relationships. Ideally, the biogeography of taxa will be concordant with their genetic signatures identified by molecular markers. For groups with poorly defined species (or generic) concepts, taxon sampling can be highly problematic because morphological plasticity may deter sample collection of a species when it expresses alternative morphologies. This may give the impression of a disjunct species distribution when it is actually continuous across a particular geographic range. Likewise, morphological convergence can obscure biogeographic patterns, but with the opposite effect. To avoid taxon sampling problems in a phylogeographic study of the green alga Phyllodictyon anastomosans (Harv.) Kraft et Wynne, a species known for its morphological variability, we included taxa across four genera (Boodlea G. Murray & De Toni, Cladophoropsis Børgesen, Phyllodictyon J. E. Gray, Struveopsis Rhyne et H. Robinson) often characterized by overlapping character states. The inclusion of isolates outside the taxonomic boundaries of P. anastomosans allowed us to extend earlier phylogeographic studies of the closely related C. membranacea (C. agardh) Børgesen and compare patterns between two closely related taxa. Results suggest that the Central American Isthmus represents a formidable but permeable barrier to dispersal.
The Monophyletic Origin of the Peridinin‐, and Fucoxanthin‐Containing Dinoflagellate Plastid Through Tertiary Replacement
Authors: Yoon H. S. , Hackett J. D. , Bhattacharya D.
Published: October 2010

The dinoflagellates contain diverse plastids of uncertain origin. To determine the origin of the peridinin‐ and fucoxanthin‐containing dinoflagellate plastid, we sequenced the plastid‐encoded psaA, psbA, and rbcL genes from various red and dinoflagellate algae. The psbA gene phylogeny, which was made from a dataset of 15 dinoflagellates, 22 rhodophytes, five cryptophytes, seven haptophytes, seven stramenopiles, two chlorophytes, and a glaucophyte as the outgroup, supports monophyly of the peridinin‐, and fucoxanthin‐containing dinoflagellates, as a sister group to the haptophytes. The monophyletic relationship with the haptophytes is recovered in the psbA + psaA phylogeny, with stronger support. The rubisco tree utilized the ‘Form I’ red algal type of rbcL and included fucoxanthin‐containing dinoflagellates. The dinoflagellate + haptophyte sister relationship is also recovered in this analysis. Peridinium foliaceum is shown to group with the diatoms in all the phylogenies. Based on our analyses of plastid sequences, we postulate that: (1) the plastid of peridinin‐, and fucoxanthin‐containing dinoflagellates originated from a common ancestor; (2) the ancestral dinoflagellate acquired its plastid from a haptophyte though a tertiary plastid replacement; (3) ‘Form II’ rubisco replaced the ancestral rbcL after the divergence of the peridinin‐, and fucoxanthin‐containing dinoflagellates; and (4) we confirm that the plastid of P. foliaceum originated from a Stramenopiles endosymbiont.
Biodiversity and Potential Use of Marine Macroalgae From the Offshore Oil Platforms in the Gulf of Mexico
Authors: Lopez‐Bautista J. M. , Fredericq S. , Chapman R. L. , Waters D. A.
Published: October 2010

In the north‐western Gulf of Mexico, more than 3000 oil and gas platforms are supporting a significant community of marine organisms in an area wherein natural hard substrata are scarce. This preliminary study is designed to provide information on the algal component in terms of species diversity of marine red, brown and green macroalgae and cyanobacteria colonizing these artificial reefs. The vertical, horizontal and seasonal distribution and relative abundance are being documented. Taxonomic results are being evaluated for potential use of some of the algae present as sources of natural products for the biotechnological industry. The island character of this steel archipelago in the north‐western Gulf of Mexico provides an ideal environment to test biogeographical relationships with adjacent floras. This research is supported in part by the Minerals Management Service, US Department of the Interior.
Quantum mechanics based force field for carbon (QMFF-Cx) validated to reproduce the mechanical and thermodynamics properties of graphite
Authors: Pascal Tod A. , Karasawa Naoki , Goddard William A.
Published: October 2010

As assemblies of graphene sheets, carbon nanotubes, and fullerenes become components of new nanotechnologies, it is important to be able to predict the structures and properties of these systems. A problem has been that the level of quantum mechanics practical for such systems (density functional theory at the PBE level) cannot describe the London dispersion forces responsible for interaction of the graphene planes (thus graphite falls apart into graphene sheets). To provide a basis for describing these London interactions, we derive the quantum mechanics based force field for carbon (QMFF-Cx) by fitting to results from density functional theory calculations at the M06-2X level, which demonstrates accuracies for a broad class of molecules at short and medium range intermolecular distances. We carried out calculations on the dehydrogenated coronene (C24) dimer, emphasizing two geometries: parallel-displaced X (close to the observed structure in graphite crystal) and PD-Y (the lowest energy transition state for sliding graphene sheets with respect to each other). A third, eclipsed geometry is calculated to be much higher in energy. The QMFF-Cx force field leads to accurate predictions of available experimental mechanical and thermodynamics data of graphite (lattice vibrations, elastic constants, Poisson ratios, lattice modes, phonon dispersion curves, specific heat, and thermal expansion). This validates the use of M06-2X as a practical method for development of new first principles based generations of QMFF force fields.