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Sample records for galaxaura marginata rhodophyta

  1. Unusual C,O-Fused Glycosylapigenins from Serjania marginata Leaves.

    PubMed

    Heredia-Vieira, Silvia C; Simonet, Ana M; Vilegas, Wagner; Macías, Francisco A

    2015-01-23

    A phytochemical study of a Serjania marginata leaf extract with antiulcer activity afforded 15 compounds, including the new 3-O-α-l-arabinopyranosyl(1→3)-α-l-rhamnopyranosyl(1→2)[β-d-glucopyranosyl(1→4)]-α-l-arabinopyranosyloleanolic acid (1) and 7,5″-anhydroapigenin 8-C-α-(2,6-dideoxy-5-hydroxy-ribo-hexopyranosyl)-4'-O-β-d-glucopyranoside (4). The structures of the new compounds were determined by spectroscopic analysis, including 1D and 2D NMR techniques, mass spectrometry, and chemical methods. Compound 4 is a C-hexopyranosylapigenin with an unusual cyclic ether linkage between C-5″ and C-7 of apigenin. The isolated proanthocyanidins have high antioxidant activities, and these compounds are probably responsible for the gastroprotective effect of the extract.

  2. Polyploid evolution and Pleistocene glacial cycles: A case study from the alpine primrose Primula marginata (Primulaceae)

    PubMed Central

    2012-01-01

    Background Recent studies highlighted the role of Pleistocene climatic cycles in polyploid speciation and of southern Alpine refugia as reservoirs of diversity during glacial maxima. The polyploid Primula marginata, endemic to the southwestern Alps, includes both hexaploid and dodecaploid cytotypes that show no ecological or morphological differences. We used flow cytometry to determine variation and geographic distribution of cytotypes within and between populations and analyses of chloroplast (cp) and nuclear ribosomal (nr) DNA sequences from the Internal Transcribed Spacer (ITS) region to infer the evolutionary history of the two cytotypes and the auto- vs. allopolyploid origin of dodecaploid populations. Results We did not detect any intermediate cytotypes or variation of ploidy levels within populations. Hexaploids occur in the western and dodecaploids in the eastern part of the distributional range, respectively. The cpDNA and nrDNA topologies are in conflict, for the former supports shared ancestry between P. marginata and P. latifolia, while the latter implies common origins between at least some ITS clones of P. marginata and P. allionii. Conclusions Our results suggest an initial episode of chloroplast capture involving ancestral lineages of P. latifolia and P. marginata, followed by polyploidization between P. marginata-like and P. allionii-like lineages in a southern refugium of the Maritime Alps. The higher proportion of ITS polymorphisms in dodecaploid than in hexaploid accessions of P. marginata and higher total nucleotide diversity of ITS clones in dodecaploid vs. hexaploid individuals sequences are congruent with the allopolyploid hypothesis of dodecaploid origin. PMID:22530870

  3. Ancestor-descendant relationships in evolution: origin of the extant pygmy right whale, Caperea marginata.

    PubMed

    Tsai, Cheng-Hsiu; Fordyce, R Ewan

    2015-01-01

    Ancestor-descendant relationships (ADRs), involving descent with modification, are the fundamental concept in evolution, but are usually difficult to recognize. We examined the cladistic relationship between the only reported fossil pygmy right whale, †Miocaperea pulchra, and its sole living relative, the enigmatic pygmy right whale Caperea marginata, the latter represented by both adult and juvenile specimens. †Miocaperea is phylogenetically bracketed between juvenile and adult Caperea marginata in morphologically based analyses, thus suggesting a possible ADR-the first so far identified within baleen whales (Cetacea: Mysticeti). The †Miocaperea-Caperea lineage may show long-term morphological stasis and, in turn, punctuated equilibrium.

  4. Comparative proteomic analysis of hemocyanins in Dinocras cephalotes and Perla marginata (Plecoptera).

    PubMed

    Amore, V; García, M A Puig; Timperio, A M; Egidi, G; Ubero-Pascal, N; Fochetti, R

    2011-02-01

    Hemocyanins are large oligomeric respiratory proteins found in many arthropods and mollusks. The overall expression of hemocyanin mRNA, revealed by studies on Plecoptera hemocyanin sequencing, has raised the question of whether the protein is expressed or not. In fact, the presence of expressed hemocyanin has only been reported in the literature for one species, Perla marginata (Panzer, 1799). In this paper, we report the presence of hemocyanin and hexamerin proteins in Dinocras cephalotes (Curtis, 1827), a species closely related to P. marginata. To assess the presence of hemocyanin, we used a reproducible and highly sensitive method based on liquid chromatography tandem mass spectrometry. We conclude that regardless of its putative function (respiratory, immune defense, storage protein), the hemocyanin is actually expressed in species in which its mRNA is present.

  5. Can Dufour's gland compounds honestly signal fertility in the primitively eusocial wasp Ropalidia marginata?

    NASA Astrophysics Data System (ADS)

    Mitra, Aniruddha; Gadagkar, Raghavendra

    2011-02-01

    Unlike queens of typical primitively eusocial species, Ropalidia marginata queens are docile and non-interactive, and hence cannot be using dominance to maintain their status. It appears that the queen maintains reproductive monopoly through a pheromone, of which the Dufour's gland is at least one source. Here, we reconfirm earlier results showing that queens and workers can be correctly classified on a discriminant function using the compositions of their respective Dufour's glands, and also demonstrate consistent queen-worker differences based on categories of compounds and on single compounds also in some cases. Since the queen pheromone is expected to be an honest signal of the fecundity of a queen, we investigate the correlation of Dufour's gland compounds with ovarian activation of queens. Our study shows that Dufour's gland compounds in R. marginata correlate with the state of ovarian activation of queens, suggesting that such compounds may portray the fecundity of a queen, and may indeed function as honest signals of fertility.

  6. Attractiveness of fruit and flower odorants detected by olfactory receptor neurons in the fruit chafer Pachnoda marginata.

    PubMed

    Larsson, Mattias C; Stensmyr, Marcus C; Bice, Shannon B; Hansson, Bill S

    2003-05-01

    We studied the attraction of the African fruit chafer Pachnoda marginata Drury (Coleoptera: Scarabaeidae) to banana and 34 synthetic plant compounds previously shown to be detected by P. marginata olfactory receptor neurons. The behavioral studies were carried out in a two-choice olfactometer, where the attraction of beetles to lures and controls was monitored in 30-min intervals during whole days. Monitoring of the attraction over time gave additional information when comparing relative attractiveness of different compounds. Seventeen of the test compounds, primarily phenylic compounds, fruit esters, isovaleric acid, acetoin, and some floral or fruit terpenes, were attractive to P. marginata. Compounds showing no attractiveness included green leaf volatiles, lactones. and several alcohols, but also phenylic compounds and esters. One case of blend synergism was demonstrated, as well as some examples of sexual dimorphism in attraction. The significance of certain compounds and receptor neurons for olfactory-guided behavior of phytophagous scarabs is discussed.

  7. Growth responses and accumulation of soluble sugars in Inga marginata Wild. (Fabaceae) subjected to flooding under contrasting light conditions.

    PubMed

    Bender, B; Capellesso, E S; Lottici, M E; Sentkovski, J; Mielniczki-Pereira, A A; Rosa, L M G; Sausen, T L

    2016-08-15

    Flood events in riparian forests of southern Brazil, can be characterized as unpredictable and of low magnitude with an average duration of less than 15 days. Inga marginata is an evergreen tree which grows in Southeast South America on a wide range of environments, including riparian forests. In this paper, the interactive effects of the light environment and soil flooding on morphological parameters of I. marginata were examined. Seedlings were acclimated in two contrasting light conditions: sun or shade for 30 days. Sun and shade plants were subjected to soil flooding for two periods; five or 15 days. After 5 days, the interaction between flooding and light did not affect growth, chlorophyll content and dry mass or the root-shoot ratio. After 15 days, flooded plants from the sunny treatment had a lower shoot dry mass compared to control sun plants and flooded plants from the shaded treatment. Moreover, the higher dry mass observed for shade plants compared to sun plants, following flooding, can also be directly associated with a higher content of soluble sugars. Shade plants of I. marginata showed a greater acclimation to soil waterlogging. This acclimation appears to be associated with a larger accumulation of soluble sugars compared to non-flooded plants. The responses observed on the shade plants appear to be decisive to indicate the use of I. marginata in degraded areas.

  8. Unusual occurrence of cocoons in population of Haplodiplosis marginata (Diptera: Cecidomyiidae) in Belgium.

    PubMed

    Censier, F; Chavalle, S; Knor, S; De Proft, M; Bodson, B; Skuhravá, M

    2014-01-01

    The saddle gall midge, Haplodiplosis marginata (von Roser) (Diptera: Cecidomyiidae), is a phytophagous species that develops in saddle-shaped galls on stems of wheat Triticum vulgare, barley Hordeum sativum, rye Secale cereale, and some other species of Poaceae. Only one generation develops per year. Full-grown larvae leave galls and drop onto the soil where they remain up to the springtime of the following year. Larvae do not usually spin cocoons. However, formation of cocoons by larvae was observed in populations developing in western Europe: in England in 1954, in the Netherlands in the 1960s, and in Belgium in 2011. On the basis of our analysis, a part of the larval population forms cocoons as protection against unfavorable weather conditions, especially drought.

  9. Unusual Occurrence of Cocoons in Population of Haplodiplosis marginata (Diptera: Cecidomyiidae) in Belgium

    PubMed Central

    Censier, F.; Chavalle, S.; Knor, S.; De Proft, M.; Bodson, B.; Skuhravá, M.

    2014-01-01

    The saddle gall midge, Haplodiplosis marginata (von Roser) (Diptera: Cecidomyiidae), is a phytophagous species that develops in saddle-shaped galls on stems of wheat Triticum vulgare, barley Hordeum sativum, rye Secale cereale, and some other species of Poaceae. Only one generation develops per year. Full-grown larvae leave galls and drop onto the soil where they remain up to the springtime of the following year. Larvae do not usually spin cocoons. However, formation of cocoons by larvae was observed in populations developing in western Europe: in England in 1954, in the Netherlands in the 1960s, and in Belgium in 2011. On the basis of our analysis, a part of the larval population forms cocoons as protection against unfavorable weather conditions, especially drought. PMID:25525104

  10. Developmental abnormalities in Glomeris marginata (Villers 1789) (Myriapoda: Diplopoda): implications for body axis determination in a myriapod

    NASA Astrophysics Data System (ADS)

    Janssen, Ralf

    2013-01-01

    Abnormally developing embryos (ADEs) of the common pill millipede Glomeris marginata have been investigated by means of nuclear staining and mRNA in situ hybridization. It showed that all ADEs represent cases of Duplicitas posterior, which means that the posterior body pole is duplicated. The severity of the duplication ranges from duplicated posterior trunk segments in one specimen to an almost completely duplicated specimen that only shares the very anterior head region. Remarkably, none of the encountered ADEs represents a case of Duplicitas anterior (duplicated anterior pole) or a case of Duplicitas cruciata (cruciate duplication with two anterior and two posterior poles). This observation is discussed in the light of earlier reports on G. marginata ADEs that claim to have found these abnormalities. The lack of any other axial abnormality aside from D. posterior implies that early axis determination in G. marginata, and possibly myriapods in general, underlies the developmental mechanisms that prevent the formation of any other type of axial duplication. It is proposed that the formation of D. posterior-type embryos could be caused by the formation of two instead of only one posterior cumulus early during development.

  11. Developmental abnormalities in Glomeris marginata (Villers 1789) (Myriapoda: Diplopoda): implications for body axis determination in a myriapod.

    PubMed

    Janssen, Ralf

    2013-01-01

    Abnormally developing embryos (ADEs) of the common pill millipede Glomeris marginata have been investigated by means of nuclear staining and mRNA in situ hybridization. It showed that all ADEs represent cases of Duplicitas posterior, which means that the posterior body pole is duplicated. The severity of the duplication ranges from duplicated posterior trunk segments in one specimen to an almost completely duplicated specimen that only shares the very anterior head region. Remarkably, none of the encountered ADEs represents a case of Duplicitas anterior (duplicated anterior pole) or a case of Duplicitas cruciata (cruciate duplication with two anterior and two posterior poles). This observation is discussed in the light of earlier reports on G. marginata ADEs that claim to have found these abnormalities. The lack of any other axial abnormality aside from D. posterior implies that early axis determination in G. marginata, and possibly myriapods in general, underlies the developmental mechanisms that prevent the formation of any other type of axial duplication. It is proposed that the formation of D. posterior-type embryos could be caused by the formation of two instead of only one posterior cumulus early during development.

  12. Insect herbivores associated with an evergreen tree Goniorrhachis marginata Taub. (Leguminosae: Caesalpinioideae) in a tropical dry forest.

    PubMed

    Silva, J O; Neves, F S

    2014-08-01

    Goniorrhachis marginata Taub. (Leguminosae: Caesalpinioideae) is a tree species found in Brazilian tropical dry forests that retain their leaves during the dry season. That being, we addressed the following question: i) How do insect diversity (sap-sucking and chewing), leaf herbivory and defensive traits (tannin and leaf sclerophylly) vary on the evergreen tree species G. marginata between seasons? The abundance of sap-sucking insects was higher in the dry season than in the rainy season. However, we did not verify any difference in the species richness and abundance of chewing insects between seasons. Leaf herbivory was higher in the rainy season, whereas leaf sclerophylly was higher in the dry season. However, herbivory was not related to sclerophylly. Insect herbivores likely decrease their folivory activity during the dry season due to life history patterns or changes in behaviour, possibly entering diapause or inactivity during this period. Therefore, G. marginata acts as a likely keystone species, serving as a moist refuge for the insect fauna during the dry season in tropical dry forest, and the presence of this evergreen species is crucial to conservation strategies of this threatened ecosystem.

  13. Production of 15N-labeled α-amanitin in Galerina marginata

    PubMed Central

    DuBois, Brandon; Sgambelluri, R. Michael; Angelos, Evan R.; Li, Xuan; Holmes, Daniel

    2015-01-01

    α-Amanitin is the major causal constituent of deadly Amanita mushrooms that account for the majority of fatal mushroom poisonings worldwide. It is also an important biochemical tool for the study of its target, RNA polymerase II. The commercial supply of this bicyclic peptide comes directly from A. phalloides, the death cap mushroom, which is collected from its natural habitat. Isotopically labeled amanitin could be useful for clinical and forensic applications, but α-amanitin has not been chemically synthesized and A. phalloides cannot be cultured on artificial medium. Using Galerina marginata, an unrelated saprobic mushroom that grows and produces α-amanitin in culture, we describe a method for producing 15N-labeled α-amanitin using growth media containing 15N as sole nitrogen source. A key to success was preparing 15N-enriched yeast extract via a novel method designated “glass bead-assisted maturation.” In the presence of the labeled yeast extract and 15N-NH4Cl, α-amanitin was produced with >97% isotope enrichment. The labeled product was confirmed by HPLC, high-resolution mass spectrometry, and NMR. PMID:26100667

  14. Production of (15)N-labeled α-amanitin in Galerina marginata.

    PubMed

    Luo, Hong; DuBois, Brandon; Sgambelluri, R Michael; Angelos, Evan R; Li, Xuan; Holmes, Daniel; Walton, Jonathan D

    2015-09-01

    α-Amanitin is the major causal constituent of deadly Amanita mushrooms that account for the majority of fatal mushroom poisonings worldwide. It is also an important biochemical tool for the study of its target, RNA polymerase II. The commercial supply of this bicyclic peptide comes from Amanita phalloides, the death cap mushroom, which is collected from the wild. Isotopically labeled amanitin could be useful for clinical and forensic applications, but α-amanitin has not been chemically synthesized and A. phalloides cannot be cultured on artificial medium. Using Galerina marginata, an unrelated saprotrophic mushroom that grows and produces α-amanitin in culture, we describe a method for producing (15)N-labeled α-amanitin using growth media containing (15)N as sole nitrogen source. A key to success was preparing (15)N-enriched yeast extract via a novel method designated "glass bead-assisted maturation." In the presence of the labeled yeast extract and (15)N-NH4Cl, α-amanitin was produced with >97% isotope enrichment. The labeled product was confirmed by HPLC, high-resolution mass spectrometry, and NMR.

  15. Homing abilities of the tropical primitively eusocial paper wasp Ropalidia marginata.

    PubMed

    Mandal, Souvik; Gadagkar, Raghavendra

    2015-08-01

    Compared to our extensive knowledge about the navigation and homing abilities of ants and bees, we know rather little about these phenomena in social wasps. Here, we report the homing abilities of the tropical primitively eusocial wasp Ropalidia marginata and the factors that affect their homing success. To determine from how far these wasps can return to their nests, we transported foragers blindfold and released them at gradually increasing distances from their nests in four cardinal directions. Their homing success was determined by checking their presence on their nests on three consecutive nights. All foragers (56 individuals, 115 releases) returned back from an area of 0.73 ± 0.25 km(2) on the day of release (minimal homing area), whereas 83.8 % of the foragers (217 individuals, 420 releases) returned when we enlarged the area of release to 6.22 ± 0.66 km(2) around their nests (maximal homing area). Of 66 releases, no wasps returned from beyond the maximal homing area. The minimal homing area might be familiar to the foragers because they probably routinely forage in this area and the maximal homing area represents the maximum distances from which the wasps are capable of returning to their nests, with or without familiarity.

  16. The pygmy right whale Caperea marginata: the last of the cetotheres.

    PubMed

    Fordyce, R Ewan; Marx, Felix G

    2013-02-22

    The pygmy right whale, Caperea marginata, is the most enigmatic of the living baleen whales (Mysticeti). Its highly disparate morphology and the virtual absence of a described fossil record have made it extremely difficult to place Caperea into a broader evolutionary context, and molecular and morphological studies have frequently contradicted each other as to the origins and phylogenetic relationships of the species. Our study of a wealth of material from New Zealand collections, representing a wide range of ontogenetic stages, has identified several new features previously unreported in Caperea, which suggest that the pygmy right whale may be the last survivor of the supposedly extinct family Cetotheriidae. This hypothesis is corroborated by both morphology-based and total evidence cladistic analyses, including 166 morphological characters and 23 taxa, representing all the living and extinct families of toothless baleen whales. Our results allow us to formally refer Caperea to Cetotheriidae, thus resurrecting the latter from extinction and helping to clarify the origins of a long-problematic living species.

  17. Dracaena marginata biofilter: design of growth substrate and treatment of stormwater runoff.

    PubMed

    Vijayaraghavan, K; Praveen, R S

    2016-01-01

    The purpose of this research was to investigate the efficiency of Dracaena marginata planted biofilters to decontaminate urban runoff. A new biofilter growth substrate was prepared using low-cost and locally available materials such as red soil, fine sand, perlite, vermiculite, coco-peat and Sargassum biomass. The performance of biofilter substrate was compared with local garden soil based on physical and water quality parameters. Preliminary analyses indicated that biofilter substrate exhibited desirable characteristics such as low bulk density (1140 kg/m(3)), high water holding capacity (59.6%), air-filled porosity (7.82%) and hydraulic conductivity (965 mm/h). Four different biofilter assemblies, with vegetated and non-vegetated systems, were examined for several artificial rain events (un-spiked and metal-spiked). Results from un-spiked artificial rain events suggested that concentrations of most of the chemical components in effluent were highest at the beginning of rain events and thereafter subsided during the subsequent rain events. Biofilter growth substrate showed superior potential over garden soil to retain metal ions such as Al, Fe, Cu, Cr, Ni, Zn, Cd and Pb during metal-spiked rain events. Significant differences were also observed between non-vegetated and vegetated biofilter assemblies in runoff quality, with the latter producing better results.

  18. Production of terpenes in the culture of Chlorophyceae and Rhodophyta

    NASA Astrophysics Data System (ADS)

    Abe, M.; Hashimoto, S.

    2014-12-01

    Terpenes show high reactivity in the troposphere, contributing to organic aerosol reactions with OH radicals. One of the main sources of terpenes in the atmosphere is terrestrial plants. It has been recently reported that marine phytoplankton also produce monoterpenes (Yassaa et al: 2008). Because aerosol production of natural origin affects the cloud cover over the open ocean, it is important to investigate the origin of aerosol generation in the open ocean. In this study, we investigated the production of terpenes and isoprene with a focus on Chlamydomonas (Chlorophyceae) and Rhodella maculata (Rhodophyta). Concentrations of terpenes and isoprene were measured using a dynamic headspace (GERSTEL DHS)—gas chromatograph (Agilent 6890N)—mass spectrometer (Agilent 5975C). In addition, chlorophyll a was measured using a fluorometer (Turner TD-700). The results showed that isoprene, α-pinene, and β-pinene were produced by Chlamydomonas sp. and that isoprene, limonene, and camphene were produced by Rhodella maculata. Chlamydomonas sp. produced α-pinene and β-pinene, similar to land plants. The ratio of the pinene/isoprene concentrations in the atmosphere over seawater where phytoplankton are blooming has been reported as approximately 0.7 (Yassaa et al: 2008). In this experiment, the pinene/isoprene concentration ratios in the cultures were approximately 0.1. This result indicates that marine phytoplankton may not be ignored in the marine atmosphere chemistry of terpenes.

  19. Kalkbohrende Mikrothalli bei Helminthocladia und Scinaia (Nemaliales, Rhodophyta)

    NASA Astrophysics Data System (ADS)

    Kornmann, P.; Sahling, P.-H.

    1980-03-01

    Shell-boring microthalli in Helminthocladia and Scinaia (Nemaliales, Rhodophyta). Spores shed from pink mussel shells were shown to develop into branched monosiphonous thalli, their filaments penetrating into shell fragments. Isolates from four single germlings were cultivated. Two of these produced gametophytes of Helminthocladia and Scinaia; the others have so far only reproduced by tetraspores or monospores. Evidently the microthalli of some genera of the Nemaliales — which are, with the exception of Nemalion multifidum, known only from cultures — are shell-inhabiting and have therefore not been found in nature. The adult algae occur mainly on shells and CaCO3 substrates. Until the beginning of the century, Helminthocladia and Scinaia frequently occurred at Helgoland, but they have not been found there for more than 50 years. Their microthalli, however, are still present as shell-boring algae. This study is intended to stimulate similar ones in other genera of the Nemaliales so as to obtain a broader basis for discussion of systematic and phylogenetic relationships.

  20. Reproductive queue without overt conflict in the primitively eusocial wasp Ropalidia marginata

    PubMed Central

    Bang, Alok; Gadagkar, Raghavendra

    2012-01-01

    Colonies of the primitively eusocial wasp Ropalidia marginata consist of a single egg layer (queen) and a number of non–egg-laying workers. Although the queen is a docile individual, not at the top of the behavioral dominance hierarchy of the colony, she maintains complete reproductive monopoly. If the queen is lost or removed, one and only one of the workers [potential queen (PQ)] becomes hyperaggressive and will become the next queen of the colony. The PQ is almost never challenged because she first becomes hyperaggressive and then gradually loses her aggression, develops her ovaries, and starts laying eggs. Although we are unable to identify the PQ when the queen is present, she appears to be a “cryptic heir designate.” Here, we show that there is not just one heir designate but a long reproductive queue and that PQs take over the role of egg-laying, successively, without overt conflict, as the queen or previous PQs are removed. The dominance rank of an individual is not a significant predictor of its position in the succession hierarchy. The age of an individual is a significant predictor, but it is not a perfect predictor because PQs often bypass older individuals to become successors. We suggest that such a predesignated reproductive queue that is implemented without overt conflict is adaptive in the tropics, where conspecific usurpers from outside the colony, which can take advantage of the anarchy prevailing in a queenless colony and invade it, are likely to be present throughout the year. PMID:22908278

  1. The Dufour's gland and the cuticle in the social wasp Ropalidia marginata contain the same hydrocarbons in similar proportions.

    PubMed

    Mitra, A; Gadagkar, R

    2014-01-23

    Queens in many social insects are known to maintain their status through chemicals (pheromones) and cuticular hydrocarbons and have been the focus of many investigations that have looked at the chemicals involved in queen signaling. In the primitively eusocial wasp Ropalidia marginata Lepeletier (Hymenoptera: Vespidae), the Dufour's gland has been shown to be involved in queen signaling, and Dufour's gland hydrocarbons have been found to be correlated with fertility. Hence, this study analyzed the cuticle of R. marginata along with the Dufour's gland in order to compare their hydrocarbon profiles. The results show that the Dufour's gland and cuticle contained the same set of hydrocarbons in similar proportions (for the majority of compounds). Patterns pertaining to fertility signaling present in cuticular hydrocarbons were also similar to those present in the Dufour's gland hydrocarbons. Furthermore, the haemolymph contained the same hydrocarbons as found in the Dufour's gland and cuticle in similar proportions, thereby providing an explanation as to why the hydrocarbon profiles of the Dufour's gland and cuticle are correlated.

  2. Comparative evaluation of haemagglutination potential of haemolymph from two species of giant African land snails (Archachatina marginata and Achatina achatina).

    PubMed

    Abiona, John Adesanya; Akinduti, Paul Akinniyi; Oyekunle, Mufutao Atanda; Osinowo, Olusegun Ayodeji; Onagbesan, A Okanlawon Mohammed

    2014-05-01

    A comparative study was conducted to evaluate haemagglutination potential in the haemolymph of two species of giant African land snails (Archachatina marginata and Achatina achatina). Three liveweight groups of snails (<100 g, 101-150 g and >150 g) were used with 4 replicates per liveweight per species for haemagglutination assay (HA). The effect of aestivation on haemagglutination potential was also evaluated. Erythrocytes (2%) from cattle, sheep, goat and chicken were used for HA assay. Results showed that agglutinin-like substances that agglutinate erythrocytes of sheep, goat, cattle and chicken were present in the haemolymph of the two species of giant African land snails. Effect of species was found to be significant (P < 0.001) on haemagglutination titre. Haemolymph of A. marginata, had higher haemagglutination titre than that of A. achatina across the three liveweight groups used in this study. Snail liveweight had no significant effect (P > 0.05) on agglutinin content of the haemolymph in both species. Agglutination level depended on the source of erythrocyte used. Sheep erythrocyte recorded the highest haemagglutination titre, followed by goat, cattle, and chicken in that order. To our knowledge, this is the first evidence that Giant African land snails (GALS) haemolymph contain agglutinins as previously reported for Helix species. This evidence may be the basis for its survivability in the wild and thus establish the use of GALS for African herbal medicinal applications.

  3. Topical anti-inflammatory activity of a monofloral honey of Mimosa scabrella provided by Melipona marginata during winter in southern Brazil.

    PubMed

    Borsato, Débora M; Prudente, Arthur S; Döll-Boscardin, Patrícia M; Borsato, Aurélio V; Luz, Cynthia F P; Maia, Beatriz H L N S; Cabrini, Daniela A; Otuki, Michel F; Miguel, Marilis D; Farago, Paulo V; Miguel, Obdulio G

    2014-07-01

    Melipona marginata is an endangered species of stingless bee from Brazil that produces honey with particular physicochemical features and a remarkable exotic flavor. To the best of our knowledge, this is the first report devoted to exploring the medicinal potential of this honey. Thus, the aim of this paper was to investigate the potential anti-inflammatory activity of honey extract from M. marginata on skin inflammation. The honey sample was classified as a monofloral honey of Mimosa scabrella. The presence of 11 phenolic compounds as kaempferol and caffeic acid was detected using the high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-UV-ESI-MS) method. The anti-inflammatory activity was measured using a 12-O-tetradecanoylphorbol-13-acetate-induced ear edema model of inflammation in mice. The topical application of the M. marginata honey extract (1.0 mg/ear) was able to reduce ear edema with an inhibitory effect of 54 ± 5%. This extract decreased the myeloperoxidase activity in 75 ± 3%, which suggests a lower leucocyte infiltration that was confirmed by histological analysis. This extract also provided a reduction of 55 ± 14% in the production of reactive oxygen species. This anti-inflammatory activity could be due to a synergic effect of the phenolic compounds identified in the honey sample. Taken together, these results open up new possibilities for the use of M. marginata honey extract in skin disorders.

  4. The expression pattern of genes involved in early neurogenesis suggests distinct and conserved functions in the diplopod Glomeris marginata.

    PubMed

    Pioro, Hilary L; Stollewerk, Angelika

    2006-01-01

    We have shown recently that the expression and function of proneural genes is conserved in chelicerates and myriapods, although groups of neural precursors are specified in the ventral neuroectoderm of these arthropod groups, rather than single cells as in insects and crustaceans. We present additional evidence that the pattern of neurogenesis seen in chelicerates and in previously analyzed myriapod species is representative of both arthropod groups, by analysing the formation of neural precursors in the diplopod Archispirostreptus sp. This raises the question as to what extent the genetic network has been modified to result in different modes of neurogenesis in the arthropod group. To find out which components of the neural genetic network might account for the different mode of neural precursor formation in chelicerates and myriapods, we identified genes in the diplopod Glomeris marginata that are known to be involved in early neurogenesis in Drosophila and studied their expression pattern. In Drosophila, early neurogenesis is controlled by proneural genes that encode HLH transcription factors. These genes belong to two major subfamilies, the achaete-scute group and the atonal group. Different proneural proteins activate both a common neural programme and distinct neuronal subtype-specific target genes. We show that the expression pattern of homologs of the Drosophila proneural genes daughterless, atonal, and Sox B1 are partially conserved in Glomeris mariginata. While the expression of the pan-neural gene snail is conserved in the ventral neuroectoderm of G. marginata, we found an additional expression domain in the ventral midline. We conclude that, although the components of the genetic network involved in specification of neural precursors seem to be conserved in chelicerates, myriapods, and Drosophila, the function of some of the genes might have changed during evolution.

  5. Roughness-dependent friction force of the tarsal claw system in the beetle Pachnoda marginata (Coleoptera, Scarabaeidae).

    PubMed

    Dai, Zhendong; Gorb, Stanislav N; Schwarz, Uli

    2002-08-01

    This paper studies slide-resisting forces generated by claws in the free-walking beetle Pachnoda marginata (Coleoptera, Scarabaeoidea) with emphasis on the relationship between the dimension of the claw tip and the substrate texture. To evaluate the force range by which the claw can interact with a substrate, forces generated by the freely moving legs were measured using a load cell force transducer. To obtain information about material properties of the claw, its mechanical strength was tested in a fracture experiment, and the internal structure of the fractured claw material was studied by scanning electron microscopy. The bending stress of the claw was evaluated as 143.4-684.2 MPa, depending on the cross-section model selected. Data from these different approaches led us to propose a model explaining the saturation of friction force with increased texture roughness. The forces are determined by the relative size of the surface roughness R(a) (or an average particle diameter) and the diameter of the claw tip. When surface roughness is much bigger than the claw tip diameter, the beetle can grasp surface irregularities and generate a high degree of attachment due to mechanical interlocking with substrate texture. When R(a) is lower than or comparable to the claw tip diameter, the frictional properties of the contact between claw and substrate particles play a key role in the generation of the friction force.

  6. Evolution of social behaviour in the primitively eusocial wasp Ropalidia marginata: do we need to look beyond kin selection?

    PubMed

    Gadagkar, Raghavendra

    2016-02-05

    Ropalidia marginata is a primitively eusocial wasp widely distributed in peninsular India. Although solitary females found a small proportion of nests, the vast majority of new nests are founded by small groups of females. In such multiple foundress nests, a single dominant female functions as the queen and lays eggs, while the rest function as sterile workers and care for the queen's brood. Previous attempts to understand the evolution of social behaviour and altruism in this species have employed inclusive fitness theory (kin selection) as a guiding framework. Although inclusive fitness theory is quite successful in explaining the high propensity of the wasps to found nests in groups, several features of their social organization suggest that forces other than kin selection may also have played a significant role in the evolution of this species. These features include lowering of genetic relatedness owing to polyandry and serial polygyny, nest foundation by unrelated individuals, acceptance of young non-nest-mates, a combination of well-developed nest-mate recognition and lack of intra-colony kin recognition, a combination of meek and docile queens and a decentralized self-organized work force, long reproductive queues with cryptic heir designates and conflict-free queen succession, all resulting in extreme intra-colony cooperation and inter-colony conflict.

  7. Evolution of social behaviour in the primitively eusocial wasp Ropalidia marginata: do we need to look beyond kin selection?

    PubMed Central

    Gadagkar, Raghavendra

    2016-01-01

    Ropalidia marginata is a primitively eusocial wasp widely distributed in peninsular India. Although solitary females found a small proportion of nests, the vast majority of new nests are founded by small groups of females. In such multiple foundress nests, a single dominant female functions as the queen and lays eggs, while the rest function as sterile workers and care for the queen's brood. Previous attempts to understand the evolution of social behaviour and altruism in this species have employed inclusive fitness theory (kin selection) as a guiding framework. Although inclusive fitness theory is quite successful in explaining the high propensity of the wasps to found nests in groups, several features of their social organization suggest that forces other than kin selection may also have played a significant role in the evolution of this species. These features include lowering of genetic relatedness owing to polyandry and serial polygyny, nest foundation by unrelated individuals, acceptance of young non-nest-mates, a combination of well-developed nest-mate recognition and lack of intra-colony kin recognition, a combination of meek and docile queens and a decentralized self-organized work force, long reproductive queues with cryptic heir designates and conflict-free queen succession, all resulting in extreme intra-colony cooperation and inter-colony conflict. PMID:26729933

  8. Daily and annual patterns of thermoregulation in painted turtles (Chrysemys picta marginata) living in a thermally variable marsh in Northern Michigan.

    PubMed

    Rowe, John W; Converse, Paul E; Clark, David L

    2014-02-01

    The capacity for an ectothermic reptile to thermoregulate has implications for many components of its life history. Over two years, we studied thermoregulation in a population of Midland painted turtles (Chrysemys picta marginata) in a shallow, thermally variable wetland during summer in Northern Michigan. Mean body temperature (Tb) of free-ranging turtles was greater in 2008 (25.8 °C) than in 2010 (19.7 °C). Laboratory determined thermoregulatory set point (Tset) ranged from 25 °C (Tset-min) to 31 °C (Tset-max) and was lower during the fall (17-26 °C). Deviations of Tb distributions from field measured operative temperatures (Te) and indices of thermoregulation indicated that C. picta marginata were capable of a limited degree of thermoregulation. Operative temperatures and thermal quality (de=|Tset-min-Te| and |Te-Tset-max|) cycled daily with maximal thermal quality occurring during late morning and late afternoon. The accuracy of thermoregulation (db=|Tset-min-Tb| and |Tb-Tset-max|) was maximal (db values were minimal) as Tb declined and traversed Tset during the late afternoon-early evening hours and was higher on cloudy days than on sunny days because relatively low Te values decreased the number of Tb values that were above Tset. Our index of thermal exploitation (Ex=frequency of Tb observations within Tset) was 36%, slightly lower than that reported for an Ontario population of C. picta marginata. Regression of db (thermal accuracy) on de (thermal quality) indicated that turtles invested more in thermoregulation when thermal quality was low and when water levels were high than when they were low. There were no intersexual differences in mean Tb throughout the year but females had relatively high laboratory determined Tb values in the fall, perhaps reflecting the importance of maintaining ovarian development prior to winter.

  9. Ecto- and arbuscular mycorrhizal symbiosis can induce tolerance to toxic pulses of phosphorus in jarrah (Eucalyptus marginata) seedlings.

    PubMed

    Kariman, Khalil; Barker, Susan J; Finnegan, Patrick M; Tibbett, Mark

    2014-10-01

    In common with many plants native to low P soils, jarrah (Eucalyptus marginata) develops toxicity symptoms upon exposure to elevated phosphorus (P). Jarrah plants can establish arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) associations, along with a non-colonizing symbiosis described recently. AM colonization is known to influence the pattern of expression of genes required for P uptake of host plants and our aim was to investigate this phenomenon in relation to P sensitivity. Therefore, we examined the effect on hosts of the presence of AM and ECM fungi in combination with toxic pulses of P and assessed possible correlations between the induced tolerance and the shoot P concentration. The P transport dynamics of AM (Rhizophagus irregularis and Scutellospora calospora), ECM (Scleroderma sp.), non-colonizing symbiosis (Austroboletus occidentalis), dual mycorrhizal (R. irregularis and Scleroderma sp.), and non-mycorrhizal (NM) seedlings were monitored following two pulses of P. The ECM and A. occidentalis associations significantly enhanced the shoot P content of jarrah plants growing under P-deficient conditions. In addition, S. calospora, A. occidentalis, and Scleroderma sp. all stimulated plant growth significantly. All inoculated plants had significantly lower phytotoxicity symptoms compared to NM controls 7 days after addition of an elevated P dose (30 mg P kg(-1) soil). Following exposure to toxicity-inducing levels of P, the shoot P concentration was significantly lower in R. irregularis-inoculated and dually inoculated plants compared to NM controls. Although all inoculated plants had reduced toxicity symptoms and there was a positive linear relationship between rank and shoot P concentration, the protective effect was not necessarily explained by the type of fungal association or the extent of mycorrhizal colonization.

  10. Sensitivity of jarrah (Eucalyptus marginata) to phosphate, phosphite, and arsenate pulses as influenced by fungal symbiotic associations.

    PubMed

    Kariman, Khalil; Barker, Susan J; Jost, Ricarda; Finnegan, Patrick M; Tibbett, Mark

    2016-07-01

    Many plant species adapted to P-impoverished soils, including jarrah (Eucalyptus marginata), develop toxicity symptoms when exposed to high doses of phosphate (Pi) and its analogs such as phosphite (Phi) and arsenate (AsV). The present study was undertaken to investigate the effects of fungal symbionts Scutellospora calospora, Scleroderma sp., and Austroboletus occidentalis on the response of jarrah to highly toxic pulses (1.5 mmol kg(-1) soil) of Pi, Phi, and AsV. S. calospora formed an arbuscular mycorrhizal (AM) symbiosis while both Scleroderma sp. and A. occidentalis established a non-colonizing symbiosis with jarrah plants. All these interactions significantly improved jarrah growth and Pi uptake under P-limiting conditions. The AM fungal colonization naturally declines in AM-eucalypt symbioses after 2-3 months; however, in the present study, the high Pi pulse inhibited the decline of AM fungal colonization in jarrah. Four weeks after exposure to the Pi pulse, plants inoculated with S. calospora had significantly lower toxicity symptoms compared to non-mycorrhizal (NM) plants, and all fungal treatments induced tolerance against Phi toxicity in jarrah. However, no tolerance was observed for AsV-treated plants even though all inoculated plants had significantly lower shoot As concentrations than the NM plants. The transcript profile of five jarrah high-affinity phosphate transporter (PHT1 family) genes in roots was not altered in response to any of the fungal species tested. Interestingly, plants exposed to high Pi supplies for 1 day did not have reduced transcript levels for any of the five PHT1 genes in roots, and transcript abundance of four PHT1 genes actually increased. It is therefore suggested that jarrah, and perhaps other P-sensitive perennial species, respond positively to Pi available in the soil solution through increasing rather than decreasing the expression of selected PHT1 genes. Furthermore, Scleroderma sp. can be considered as a fungus with

  11. Detection and characterization of Mycoplasma spp. and Salmonella spp. in free-living European tortoises (Testudo hermanni, Testudo graeca, and Testudo marginata).

    PubMed

    Lecis, Roberta; Paglietti, B; Rubino, S; Are, B M; Muzzeddu, M; Berlinguer, F; Chessa, B; Pittau, M; Alberti, A

    2011-07-01

    Free-living and captive chelonians might suffer from upper respiratory tract disease (URTD), a pathology primarily caused by Mycoplasma agassizii. Wild tortoises can also be an important reservoir of Salmonella spp., which are commensal in the host reptile but are potential zoonotic agents. Between July 2009 and June 2010, we screened free-living European tortoises (spur-thighed tortoises Testudo graeca, Hermann's tortoises Testudo hermanni, marginated tortoises Testudo marginata) temporarily housed in a wildlife center in Italy. We molecularly characterized 13 Mycoplasma isolates detected in all Testudo spp. studied, and three PCR-positive animals showed typical URTD clinical signs at the time of sampling. Three Salmonella enterica serotypes (Abony, Potsdam, Granlo), already related to reptile-associated human infections, were also identified. These results highlight the potential role played by wildlife recovery centers in the spread and transmission of pathogens among wild chelonians and to humans.

  12. Insight into glucosidase II from the red marine microalga Porphyridium sp. (Rhodophyta).

    PubMed

    Levy-Ontman, Oshrat; Fisher, Merav; Shotland, Yoram; Tekoah, Yoram; Malis Arad, Shoshana

    2015-12-01

    N-glycosylation of proteins is one of the most important post-translational modifications that occur in various organisms, and is of utmost importance for protein function, stability, secretion, and loca-lization. Although the N-linked glycosylation pathway of proteins has been extensively characterized in mammals and plants, not much information is available regarding the N-glycosylation pathway in algae. We studied the α 1,3-glucosidase glucosidase II (GANAB) glycoenzyme in a red marine microalga Porphyridium sp. (Rhodophyta) using bioinformatic and biochemical approaches. The GANAB-gene was found to be highly conserved evolutionarily (compo-sed of all the common features of α and β subunits) and to exhibit similar motifs consistent with that of homolog eukaryotes GANAB genes. Phylogenetic analysis revealed its wide distribution across an evolutionarily vast range of organisms; while the α subunit is highly conserved and its phylogenic tree is similar to the taxon evolutionary tree, the β subunit is less conserved and its pattern somewhat differs from the taxon tree. In addition, the activity of the red microalgal GANAB enzyme was studied, including functional and biochemical characterization using a bioassay, indicating that the enzyme is similar to other eukaryotes ortholog GANAB enzymes. A correlation between polysaccharide production and GANAB activity, indicating its involvement in polysaccharide biosynthesis, is also demonstrated. This study represents a valuable contribution toward understanding the N-glycosylation and polysaccharide biosynthesis pathways in red microalgae.

  13. Cloning and analysis of calmodulin gene from Porphyra yezoensis Ueda (Bangiales, Rhodophyta)

    NASA Astrophysics Data System (ADS)

    Wang, Mengqiang; Mao, Yunxiang; Zhuang, Yunyun; Kong, Fanna; Sui, Zhenghong

    2009-09-01

    In order to understand the mechanisms of signal transduction and anti-desiccation mechanisms of Porphyra yezoensis, cDNA and its genomic sequence of Calmodulin gene (CaM) was cloned by the technique of polymerase chain reaction (PCR) based on the analysis of P. yezoensis ESTs from dbEST database. The result shows that the full-length cDNA of CaM consists of 603 bps including an ORF encoding for 151 amino acids and a terminate codon UGA, while the length of genomic sequence is 1231 bps including 2 exons and 1 intron. The average GC content of the coding region is 58.77%, while the GC content of the third position of this gene is as high as 82.23%. Four Ca2+ binding sites (EF-hand) are found in this gene. The predicted molecular mass of the deduced peptide is 16688.72 Da and the pI is 4.222. By aligning with known CaM genes, the similarity of CaM gene sequence with homologous genes in Chlamydomonas incerta and Chlamydomonas reinhardtii is 72.7% and 72.2% respectively, and the similarity of the deduced amino acid sequence of CaM gene with homologous genes in C. incerta and C. reinhardtii are both 71.5%. This is the first report on CaM from a species of Rhodophyta.

  14. DNA barcode assessment of Ceramiales (Rhodophyta) in the intertidal zone of the northwestern Yellow Sea

    NASA Astrophysics Data System (ADS)

    Du, Guoying; Wu, Feifei; Guo, Hao; Xue, Hongfan; Mao, Yunxiang

    2015-05-01

    A total of 142 specimens of Ceramiales (Rhodophyta) were collected each month from October 2011 to November 2012 in the intertidal zone of the northwestern Yellow Sea. These specimens covered 21 species, 14 genera, and four families. Cluster analyses show that the specimens had a high diversity for the three DNA markers, namely, partial large subunit rRNA gene (LSU), universal plastid amplicon (UPA), and partial mitochondrial cytochrome c oxidase subunit I gene (COI). No intraspecific divergence was found in our collection for these markers, except for a 1-3 bp divergence in the COI of Ceramium kondoi, Symphyocladia latiuscula, and Neosiphonia japonica. Because short DNA markers were used, the phylogenetic relationships of higher taxonomic levels were hard to evaluate with poor branch support. More than half species of our collection failed to find their matched sequences owing to shortage information of DNA barcodes for macroalgae in GenBank or BOLD (Barcode of Life Data) Systems. Three specimens were presumed as Heterosiphonia crispella by cluster analyses on DNA barcodes assisted by morphological identification, which was the first record in the investigated area, implying that it might be a cryptic or invasive species in the coastal area of northwestern Yellow Sea. In the neighbor-joining trees of all three DNA markers, Heterosiphonia japonica converged with Dasya spp. and was distant from the other Heterosiphonia spp., implying that H. japonica had affinities to the genus Dasya. The LSU and UPA markers amplified and sequenced easier than the COI marker across the Ceramiales species, but the COI had a higher ability to discriminate between species.

  15. Growth of gametophytes and sporophytes of Grateloupia subpectinata (Rhodophyta) in culture

    NASA Astrophysics Data System (ADS)

    Adharini, Ratih Ida; Kim, Hyung Geun

    2016-09-01

    Comparison of growing thalli in alternating haploid and diploid phases of Grateloupia subpectinata (Rhodophyta) was studied. Fertile thalli from gametophyte and tetrasporophyte of G. subpectinata were collected from Yangyang, on the eastern coast of Korea. The size of the released tetraspores and carpospores was measured; the spores were then incubated at the temperature of 20°C, irradiance of 40 μmol photon m-2s-1 and photoperiod of 12L and 12D. Carpospores were also cultivated in the same conditions as the tetraspores culture. The crusts were subsequently transferred to a tank culture after six months. The specific growth rate (SGR) was measured by observing 50 crusts and 30 thalli. The released carpospores had a larger diameter (9.98 μm) than the tetraspores (9.38 μm). The crusts from the carpospores also show a higher specific growth rate (14.04% d-1) than tetraspores (13.39% d-1). After being transferred and cultured in a tank, the upright thalli grew slowly in May-June (13-15°C) and rapidly in July-September (17-22°C). The length of growing thalli of sporophyte from carpospores also revealed a higher specific growth rate (2.83% d-1) than gametophytic thalli (2.38% d-1). The specific growth rate of crusts and thalli developed from carpospores was higher than that of the crusts developed from tetraspores. This result suggests that the cultivation of sporophytes may be more profitable than gametophytes because harvesting can be done more efficiently.

  16. Inhibition of photosynthesis in the microalga Chaetoceros curvisetus (Bacillariophyta) by macroalga Gracilaria lemaneiformis (Rhodophyta)

    NASA Astrophysics Data System (ADS)

    Ye, Changpeng; Zhang, Mengcheng; Yang, Yufeng

    2013-11-01

    We investigated the effects of dried macroalga Gracilaria lemaneiformis (Rhodophyta) on photosynthesis of the bloom-forming microalga Chaetoceros curvisetus. C. curvisetus was cultured with different amounts of dried G. lemaneiformis under controlled laboratory conditions. We measured the photosynthetic oxygen evolution rate and established the chlorophyll a fluorescence transient (OJIP) curve coupled with its specific parameters. We observed concentration-dependent and time-dependent relationships between dried G. lemaneiformis and inhibition of photosynthesis in C. curvisetus. Co-culture with dried G. lemaneiformis also resulted in a decrease in the light-saturated maximum photosynthetic oxygen evolution rate ( P max) in C. curvisetus, and a decrease in the OJIP curve along with its specific parameters; the maximum photochemical efficiency of PSII ( F v / F m), the amount of active PSII reaction centers per excited cross section at t=0 and t= t FM (RC/CS0 and RC/CSm, respectively), the absorption flux per excited cross section at t =0 (ABS/ CS0), and the efficiency with which a trapped exciton moves an electron into the electron transport chain ( ψ 0). The dark respiration rate ( R d) increased in C. curvisetus co-cultured with dried G. lemaneiformis. The JIP-test and the oxygen evolution results indicated that dried G. lemaneiformis decreased the number of active reaction centers, blocked the electron transport chain, and damaged the oxygen-evolving complex of C. curvisetus. This result indicated that dried fragments of G. lemaneiformis could effectively inhibit photosynthesis of C. curvisetus, and thus, could serve as a functional product to control and mitigate C. curvisetus blooms.

  17. Micromechanical properties of consecutive layers in specialized insect cuticle: the gula of Pachnoda marginata (Coleoptera, Scarabaeidae) and the infrared sensilla of Melanophila acuminata (Coleoptera, Buprestidae).

    PubMed

    Müller, Martin; Olek, Maciej; Giersig, Michael; Schmitz, Helmut

    2008-08-01

    Insect cuticle is a highly adaptive material that fulfils a wide spectrum of different functions. Cuticle does not only build the exoskeleton with diverse moveable parts but is also an important component of a stunning variety of mechanosensory receptors. Therefore, the mechanical properties of these specialized cuticular systems are of crucial importance. We studied the different cuticular layers of the head part (gula) of the head-to-neck ball articulation of Pachnoda marginata and of the photomechanic infrared (IR) sensilla of Melanophila acuminata on the basis of cross sections. In our study, we combined histological methods (i.e. detection of the different types of cuticle by specific staining) with measurements of hardness (H) and reduced elastic modulus (E(r)) by nanoindentation technique. In the gula of Pachnoda we found an unusual aberrance from the well-known layering. Between the epi- and exocuticle, two meso- and one endocuticular layers are deposited which are softer and more elastic than the underlying exo- and mesocuticular layers. The hardest of all examined materials is the cuticle of the exocuticular shell of the internal sphere of the Melanophila IR sensillum with H=0.53GPa whereas the inner mesocuticular core of the sensillum represents the most elastic and softest layer with values of H=0.29GPa and E(r)=4.8GPa. Results are discussed with regard to the proposed functions.

  18. Development of Angiostrongylus costaricensis Morera and Céspedes 1971 (Nematoda: Angiostrongylidae) larvae in the intermediate host Sarasinula marginata (Semper 1885) (Mollusca: Soleolifera).

    PubMed

    Mendonça, Cristiane L G F; Carvalho, Omar S; Mota, Ester M; Lenzi, Henrique L

    2008-04-01

    In life cycle of Angiostrongylus costaricensis, veronicellidae mollusks participate as the invertebrate host while rodents as the main vertebrate host. The current work shows a sequential larval development of A. costaricensis in Sarasinula marginata, individually killed and digested from day 1 to 43, post infection. Some larvae, recovered from sedimentation, were submitted to selective staining after paraffin embedded or inclusion in JB-4 to study inner structures. As control, four slugs were used, two killed at the beginning of infection and the others at the end of the experiment. At day 2 post infection, larvae were motionless and thick, presenting initial retention of granules. At day 4, L2 were detected, persisting until 43 days post infection. Larvae L2 displayed a large amount of granules rich in lipids and carbohydrates through its overall body, with more accumulation at the medial third corresponding to the esophagus-intestine transition site. Lipid granules, the main energetic source, were located at the basal and apical regions of intestinal cells. Both L1 and L3 presented bilateral alae, which is also common in other nematodes. Transition forms between L2 to L3 molts were also observed.

  19. Thermal pollution and settlement of new tropical alien species: The case of Grateloupia yinggehaiensis (Rhodophyta) in the Venice Lagoon

    NASA Astrophysics Data System (ADS)

    Wolf, M. A.; Sfriso, A.; Moro, I.

    2014-06-01

    The Venice Lagoon has become increasingly affected by the introduction of allochthonous macroalgae mainly coming from the Indo-Pacific area. In consequence to the recent climate changes and temperature increase, such species could simply find numerous habitats suitable for their growth. One local process that contributes to water temperature changes is thermal pollution. In this study we used the DNA barcoding method to identify a new alien macroalgal species, Grateloupia yinggehaiensis Wang et Luan (Rhodophyta), found near the industrial area of Porto Marghera (Venice, Italy) hosting the Fusina thermoelectric power plant. The microclimate of this area has enabled the spread of this species native of the tropical area of the Hainan Province (China) and probably introduced in the Mediterranean Sea via shellfish transfers.

  20. Effects of seawater salinity and temperature on growth and pigment contents in Hypnea cervicornis J. Agardh (Gigartinales, Rhodophyta).

    PubMed

    Ding, Lanping; Ma, Yuanyuan; Huang, Bingxin; Chen, Shanwen

    2013-01-01

    This study simulated outdoor environmental living conditions and observed the growth rates and changes of several photosynthetic pigments (Chl a, Car, PE, and PC) in Hypnea cervicornis J. Agardh (Gigartinales, Rhodophyta) by setting up different ranges of salinity (25, 30, 35, 40, 45, and 50) and temperature (15, 20, 25, and 30°C). At conditions of culture, the results are as follows. (1) Changes in salinity and temperature have significant effects on the growth of H. cervicornis. The growth rates first increase then decrease as the temperature increases, while growth tends to decline as salinity increases. The optimum salinity and temperature conditions for growth are 25 and 25°C, respectively. (2) Salinity and temperature have significant or extremely significant effects on photosynthetic pigments (Chl a, Car, PE, and PC) in H. cervicornis. The results of this study are advantageous to ensure propagation and economic development of this species in the southern sea area of China.

  1. Effects of Seawater Salinity and Temperature on Growth and Pigment Contents in Hypnea cervicornis J. Agardh (Gigartinales, Rhodophyta)

    PubMed Central

    Ding, Lanping; Ma, Yuanyuan; Huang, Bingxin; Chen, Shanwen

    2013-01-01

    This study simulated outdoor environmental living conditions and observed the growth rates and changes of several photosynthetic pigments (Chl a, Car, PE, and PC) in Hypnea cervicornis J. Agardh (Gigartinales, Rhodophyta) by setting up different ranges of salinity (25, 30, 35, 40, 45, and 50) and temperature (15, 20, 25, and 30°C). At conditions of culture, the results are as follows. (1) Changes in salinity and temperature have significant effects on the growth of H. cervicornis. The growth rates first increase then decrease as the temperature increases, while growth tends to decline as salinity increases. The optimum salinity and temperature conditions for growth are 25 and 25°C, respectively. (2) Salinity and temperature have significant or extremely significant effects on photosynthetic pigments (Chl a, Car, PE, and PC) in H. cervicornis. The results of this study are advantageous to ensure propagation and economic development of this species in the southern sea area of China. PMID:24350276

  2. Occurrence of aluminum in chloride cells of Perla marginata (Plecoptera) after exposure to low pH and elevated aluminum concentration

    SciTech Connect

    Guerold, F.; Giamberini, L.; Pihan, J.C.; Tourmann, J.L.; Kaufmann, R.

    1995-04-01

    As a consequence of acid depositions on poorly buffered catchments underlain by hard rocks, aluminum is mobilized and transported from terrestrial systems to the aquatic environment. Loss of fishes has been related to low pH and elevated aluminum concentrations in surface waters which present a low ionic content especially during acid stress such as snowmelt and heavy rainfalls. Among the causes of fish population decline in acid waters, aluminum is considered a toxic cofactor. Different studies have clearly shown that aluminum is accumulated in different organs such as kidneys, liver and gills. Research on fish has demonstrated that aluminum may be toxic, but the toxicity is markedly influenced by the pH, organic compounds and calcium content of the water. Field surveys have shown clearly that macroinvertebrates are also affected by surface-water acidification. However, little is know about the possible effects of aluminum on aquatic invertebrates and, particularly, on aquatic insects exposed to acidic conditions. Hall et al. have shown that the whole-body concentration of aluminum decreases in blackflies and mayflies transplated from neutral water to acid water. Similar results have been reported for Daphnia and chironomid. On the contrary, Ormerod et al. demonstrated the absence of relationship between water pH and insect aluminum concentrations. When aluminum occurs in aquatic insects, it has been shown that it is primarily adsorbed on the external surface and/or accumulates in gut contents. To our knowledge, the subcellular location as well as the toxicity of aluminum to acid-sensitive aquatic insects remains unclear and existing hypotheses are often based on research on fish. In this content the purpose of this study was to investigate the presence of aluminum at a subcellular level in the acid-sensitive species of stonefly, Perla marginata, after exposure to low pH and elevated aluminum concentrations. 18 refs., 1 fig., 1 tab.

  3. Visualization of DNA-containing structures in various species of Chlorophyta, Rhodophyta and Cyanophyta using SYBR Green I dye.

    PubMed

    Vítová, M; Hendrychová, J; Cepák, V; Zachleder, V

    2005-01-01

    We developed an alternative method of staining cell nuclei and chloroplast nucleoids of algal cells using SYBR Green I (the fluorescent dye used commonly for detecting dsDNA in agarose and polyacrylamide gels as an alternative to highly mutagenic ethidium bromide and for DNA staining of viruses and bacteria followed by flow cytometry, digital image analysis or real-time PCR), which enabled routine staining in vivo. Cells do not need to be fixed or treated chemically or physically before staining, thus the shape, size and position of DNA-containing structures are not affected. The fluorescence signal is sharp and reproducible. Examples of application of the method are shown in color microphotographs for representatives of eukaryotic algae from the taxa Chlorophyta, Rhodophyta and the prokaryotic Cyanophyta. The method is also useful for studying progress of the cell cycle in algal cells dividing by multiple fission, as shown by observation of changes in nuclear number during the cell cycle of the green alga Chlamydomonas reinhardtii and Scenedesmus quadricauda. Staining with SYBR Green I can be recommended as a fast, safe and efficient method for the detection of DNA-containing structures in vivo.

  4. A molecular phylogeny of the marine red algae (Rhodophyta) based on the nuclear small-subunit rRNA gene.

    PubMed Central

    Ragan, M A; Bird, C J; Rice, E L; Gutell, R R; Murphy, C A; Singh, R K

    1994-01-01

    A phylogeny of marine Rhodophyta has been inferred by a number of methods from nucleotide sequences of nuclear genes encoding small subunit rRNA from 39 species in 15 orders. Sequence divergences are relatively large, especially among bangiophytes and even among congeners in this group. Subclass Bangiophycidae appears polyphyletic, encompassing at least three lineages, with Porphyridiales distributed between two of these. Subclass Florideophycidae is monophyletic, with Hildenbrandiales, Corallinales, Ahnfeltiales, and a close association of Nemaliales, Acrochaetiales, and Palmariales forming the four deepest branches. Cermiales may represent a convergence of vegetative and reproductive morphologies, as family Ceramiaceae is at best weakly related to the rest of the order, and one of its members appears to be allied to Gelidiales. Except for Gigartinales, for which more data are required, the other florideophyte orders appear distinct and taxonomically justified. A good correlation was observed with taxonomy based on pit-plug ultrastructure. Tests under maximum-likelihood and parsimony of alternative phylogenies based on structure and chemistry refuted suggestions that Acrochaetiales is the most primitive florideophyte order and that Gelidiales and Hildenbrandiales are sister groups. PMID:8041780

  5. Prediction of mono-, bi-, and trivalent metal cation relative toxicity to the seaweed Gracilaria domingensis (Gracilariales, Rhodophyta) in synthetic seawater.

    PubMed

    Mendes, Luiz Fernando; Zambotti-Villela, Leonardo; Yokoya, Nair Sumie; Bastos, Erick Leite; Stevani, Cassius Vinicius; Colepicolo, Pio

    2013-11-01

    The present study reports a 48-h aquatic metal-toxicity assay based on daily growth rates of the red seaweed Gracilaria domingensis (Gracilariales, Rhodophyta) in synthetic seawater. The median inhibitory concentration (IC50) for each metal cation was experimentally determined, and the ratios of free ions (aqueous complex) were calculated by software minimization of the total equilibrium activity (MINTEQA2) to determine the free median inhibitory concentration (IC50F). A model for predicting the toxicity of 14 metal cations was developed using the generic function approximation algorithm (GFA) with log IC50F values as the dependent variables and the following properties as independent variables: ionic radius (r), atomic number (AN), electronegativity (Xm ), covalent index (Xm (2) r), first hydrolysis constant (|log KOH |), softness index (σp ), ion charge (Z), ionization potential (ΔIP), electrochemical potential (ΔEo ), atomic number divided by ionization potential (AN/ΔIP), and the cation polarizing power for Z(2) /r and Z/AR. The 3-term independent variables were predicted as the best-fit model (log IC50F: -23.64 + 5.59 Z/AR + 0.99 |log KOH | + 37.05 σp ; adjusted r(2) : 0.88; predicted r(2) : 0.68; Friedman lack-of-fit score: 1.6). This mathematical expression can be used to predict metal-biomolecule interactions, as well as the toxicity of mono-, bi-, and trivalent metal cations, which have not been experimentally tested in seaweed to date. Quantitative ion-character relationships allowed the authors to infer that the mechanism of toxicity might involve an interaction between metals and functional groups of biological species containing sulfur or oxygen.

  6. Variations in morphology and PSII photosynthetic capabilities during the early development of tetraspores of Gracilaria vermiculophylla (Ohmi) Papenfuss (Gracilariales, Rhodophyta)

    PubMed Central

    2010-01-01

    Background Red algae are primitive photosynthetic eukaryotes, whose spores are ideal subjects for studies of photosynthesis and development. Although the development of red alga spores has received considerable research attention, few studies have focused on the detailed morphological and photosynthetic changes that occur during the early development of tetraspores of Gracilaria vermiculophylla (Ohmi) Papenfuss (Gracilariales, Rhodophyta). Herein, we documented these changes in this species of red algae. Results In the tetraspores, we observed two types of division, cruciate and zonate, and both could develop into multicellular bodies (disks). During the first 84 hours, tetraspores divided several times, but the diameter of the disks changed very little; thereafter, the diameter increased significantly. Scanning electron microscopy observations and analysis of histological sections revealed that the natural shape of the disk remains tapered over time, and the erect frond grows from the central protrusion of the disk. Cultivation of tissue from excised disks demonstrated that the central protrusion of the disk is essential for initiation of the erect frond. Photosynthetic (i.e., PSII) activities were measured using chlorophyll fluorescence analysis. The results indicated that freshly released tetraspores retained limited PSII photosynthetic capabilities; when the tetraspores attached to a substrate, those capabilities increased significantly. In the disk, the PSII activity of both marginal and central cells was similar, although some degree of morphological polarity was present; the PSII photosynthetic capabilities in young germling exhibited an apico-basal gradient. Conclusions Attachment of tetraspores to a substrate significantly enhanced their PSII photosynthetic capabilities, and triggered further development. The central protrusion of the disk is the growth point, may have transfer of nutritive material with the marginal cells. Within the young germling, the

  7. Grateloupia ramosa Wang & Luan sp. nov. (Halymeniaceae, Rhodophyta), a new species from China based on morphological evidence and comparative rbcL sequences

    NASA Astrophysics Data System (ADS)

    Cao, Cuicui; Liu, Miao; Guo, Shaoru; Zhao, Dan; Luan, Rixiao; Wang, Hongwei

    2016-03-01

    Grateloupia ramosa Wang & Luan sp. nov. (Halymeniaceae, Rhodophyta) is newly described from Hainan Province, southern China. The organism has the following morphological features: (1) purplish red, cartilaginous and lubricous thalli 5-10 cm in height; (2) compressed percurrent axes bearing abundant branches with opposite arrangement; (3) claw-like apices on top, constricted to 2-4 cm at the base; (4) cortex consisting of 3-6 layers of elliptical or anomalous cells and a medulla covered by compact medullary filaments; (5) reproductive structures distributed throughout the thallus, especially centralized at the bottom of the end portion of the branches; and (6) 4-celled Carpogonial branches and 3-celled auxiliary-cell branches, both of the Grateloupia-type. The morphological diff erences were supported by molecular phylogenetics based on ribulose-1, 5-bisphosphate carboxylase/oxygenase ( rbcL) gene sequence analysis. There was only a 1 bp divergence between specimens collected from Wenchang and Lingshui of Hainan province. The new species was embedded in the large Grateloupia clade of the Halymeniaceae. The pairwise distances between G. ramosa and other species within Grateloupia ranged from 26 to 105 bp, within pairwise distances of 13-111 bp between species of the large genus Grateloupia in Halymeniaceae. Thus, we propose this new species as G. ramosa Wang & Luan sp. nov.

  8. Crouania pumila sp. nov. (Callithamniaceae: Rhodophyta), a new species of marine red algae from the Seaflower International Biosphere Reserve, Caribbean Colombia.

    PubMed

    Gavio, Brigitte; Reyes-Gómez, Viviana P; Wynne, Michael J

    2013-09-01

    In the Colombian Caribbean, the marine macroalgal flora of the Seaflower International Biosphere Reserve has been little studied, despite its ecological importance. Historical records have reported only 201 macroalgae species within its area of almost 350,000 km2. However, recent surveys have shown a diversity of small algae previously overlooked. With the aim to determine the macroalgal diversity in the Reserve, we undertook field surveys in different ecosystems: coral reefs, seagrass beds, and rocky and sandy substrates, at different depths, from intertidal to 37 m. During these field surveys, we collected a small described species belonging to the genus Crouania (Callithamniaceae, Rhodophyta), Crouania pumila sp. nov. that is decribed in this paper. This new species was distinguished from other species of the genus by a distinctive suite of traits including its diminutive size (to only 3.5 mm in length), its decumbent, slightly calcified habit (epiphytic on other algae), its ramisympodial branching, the ecorticate main axes, and the elongate shape of the terminal cells of the cortical filaments. The observations were provided for both female (cystocarpic) and tetrasporangiate thalli; however, male thalli were not seen. Further studies have to be undertaken in this Reserve in order to carry out other macroalgal analysis and descriptions.

  9. Preliminary study on the responses of three marine algae, Ulva pertusa (Chlorophyta), Gelidium amansii (Rhodophyta) and Sargassum enerve (Phaeophyta), to nitrogen source and its availability

    NASA Astrophysics Data System (ADS)

    Liu, Dongyan; Amy, Pickering; Sun, Jun

    2004-04-01

    An experiment was designed to select economically valuable macroalga species with high nutrient uptake rates. Such species cultured on a large scale could be a potential solution to eutrophication. Three macroalgae species, Ulva pertusa (Chlorophyta), Gelidium amansii (Rhodophyta) and Sargassum enerve (Phaeophyta), were chosen for the experiment because of their economic values and availability. Control and four nitrogen concentrations were achieved by adding NH{4/+} and NO{3/-}. The results indicate that the fresh weights of all species increase faster than that of control after 5 d culture. The fresh weight of Ulva pertusa increases fastest among the 3 species. However, different species show different responses to nitrogen source and its availability. They also show the advantage of using NH{4/+} than using NO{3/-}. U. pertusa grows best and shows higher capability of removing nitrogen at 200µmolL-1, but it has lower economical value. G. amansii has higher economical value but lower capability of removing nitrogen at 200 µmolL-1. The capability of nitrogen assimilation of S. enerve is higher than that of G. amansii at 200µmolL -1, but the former’s increase of fresh weight is lower than those of other two species. Then present preliminary study demonstrates that it is possible to use macroalgae as biofilters and further development of this approach could provide biologically valuable information on the source, fate, and transport of N in marine ecosystems. Caution is needed should we extrapolate these findings to natural environments.

  10. Increased iron availability resulting from increased CO2 enhances carbon and nitrogen metabolism in the economical marine red macroalga Pyropia haitanensis (Rhodophyta).

    PubMed

    Chen, Binbin; Zou, Dinghui; Yang, Yufeng

    2017-04-01

    Ocean acidification caused by rising CO2 is predicted to increase the concentrations of dissolved species of Fe(II) and Fe(III), leading to the enhanced photosynthetic carbon sequestration in some algal species. In this study, the carbon and nitrogen metabolism in responses to increased iron availability under two CO2 levels (390 μL L(-1) and 1000 μL L(-1)), were investigated in the maricultivated macroalga Pyropia haitanensis (Rhodophyta). The results showed that, elevated CO2 increased soluble carbonhydrate (SC) contents, resulting from enhanced photosynthesis and photosynthetic pigment synthesis in this algae, but declined its soluble protein (SP) contents, resulting in increased ratio of SC/SP. This enhanced photosynthesis performance and carbon accumulation was more significant under iron enrichment condition in seawater, with higher iron uptake rate at high CO2 level. As a key essential biogenic element for algae, Fe-replete functionally contributed to P. haitanensis photosynthesis. Increased SC fundamentally provided carbon skeletons for nitrogen assimilation. The significant increase of carbon and nitrogen assimilation finally contributed to enhanced growth in this alga. This was also intuitively reflected by respiration that provided energy for cellular metabolism and algal growth. We propose that, in the predicted scenario of rising atmospheric CO2, P. haitanensis is capable to adjust its physiology by increasing its carbon and nitrogen metabolism to acclimate the acidified seawater, at the background of global climate change and simultaneously increased iron concentration due to decreased pH levels.

  11. Spreading and autoecology of the invasive species Gracilaria vermiculophylla (Gracilariales, Rhodophyta) in the lagoons of the north-western Adriatic Sea (Mediterranean Sea, Italy)

    NASA Astrophysics Data System (ADS)

    Sfriso, A.; Wolf, M. A.; Maistro, S.; Sciuto, K.; Moro, I.

    2012-12-01

    Gracilaria vermiculophylla (Ohmi) Papenfuss, an invasive Rhodophyta recently recorded in the Po Delta lagoons (May 2008), was also found in the Venice lagoon in March 2009 and successively in Pialassa della Baiona (Emilia-Romagna Region) in May 2009. The species has colonized the eutrophic and confined areas of Venice by pleustophytic tangled populations (5-15 kg fwt m-2), replacing the allochthonous species whereas it is absent in the areas characterized by low nutrient availability and high water exchange. In contrast, in the Po Delta lagoons and in Pialassa della Baiona it is present everywhere, also with high water renewal, because of the eutrophication caused by the Po river and the industrial area of Ravenna. This study presents the autoecology and distribution of G. vermiculophylla in the above environments, according to their different eutrophication status, showing its relationship with physico-chemical parameters and nutrient concentrations in water column, pore-water, surface sediments and particulate matter collected by traps in a station of the Venice lagoon (Teneri) sampled monthly during one year. Furthermore, we give new information on its morphology and the high dimorphism between female and male gametophytes and tetrasporophytes.

  12. Morphological study of the genus Herposiphonia (Rhodophyta, Rhodomelaceae) on the coast of eastern Guangdong, China, with a description of H. pinnata sp. nov.

    NASA Astrophysics Data System (ADS)

    Ding, Lanping; Tan, Huaqiang; Zhang, Quanliang; Zeng, Lingzhao; Huang, Bingxin

    2016-03-01

    We present a taxonomic study of taxa of the red algae genus Herposiphonia (Rhodophyta, Rhodomelaceae), collected from the coast of eastern Guangdong, China. We made detailed morphological studies and considered recent taxonomic criteria for species delimitation, and are making the first report of five different species on the coast of Guangdong, including a new species. The species identified were H. caespitosa Tseng, H. hollenbergii Dawson, H. pecten - veneris (Harvey) Falkenberg, H. subdisticha Okamura and H. pinnata Ding and Tan sp. nov. H. pinnata sp. nov. is characterized by bright green thalli; most parts of the feathery thalli are free of the substratum; determinate branches and indeterminate branches are arranged in a chaotic sequence; the primary axis has bare segments; the determinate branch has 9-11 periaxial cells per segment; vegetative trichoblasts are abundant; and tetrasporangia are formed on the middle of the determinate branch with 1-8 successive segments in a single rectilinear series. This paper is also the first record of sporophyte plants of H. pecten-veneris.

  13. Use of Galerina marginata genes and proteins for peptide production

    DOEpatents

    Hallen-Adams, Heather E.; Scott-Craig, John S.; Walton, Jonathan D.; Luo, Hong

    2017-03-21

    The present invention relates to compositions and methods comprising genes and peptides associated with cyclic peptides and cyclic peptide production in mushrooms. In particular, the present invention relates to using genes and proteins from Galerina species encoding peptides specifically relating to amatoxins in addition to proteins involved with processing cyclic peptide toxins. In a preferred embodiment, the present invention also relates to methods for making small peptides and small cyclic peptides including peptides similar to amanitin. Further, the present inventions relate to providing kits for making small peptides.

  14. Use of Galerina marginata genes and proteins for peptide production

    DOEpatents

    Hallen-Adams, Heather E.; Scott-Craig, John S.; Walton, Jonathan D.; Luo, Hong

    2016-03-01

    The present invention relates to compositions and methods comprising genes and peptides associated with cyclic peptides and cyclic peptide production in mushrooms. In particular, the present invention relates to using genes and proteins from Galerina species encoding peptides specifically relating to amatoxins in addition to proteins involved with processing cyclic peptide toxins. In a preferred embodiment, the present invention also relates to methods for making small peptides and small cyclic peptides including peptides similar to amanitin. Further, the present inventions relate to providing kits for making small peptides.

  15. Der Lebenszyklus von Porphyrostromium obscurum (Bangiophyceae, Rhodophyta)

    NASA Astrophysics Data System (ADS)

    Kornmann, P.

    1987-06-01

    Studies on the sexuality and the heteromorphous life cycle of Erythrotrichia ciliaris provided decisive criteria for the establishment of the genus Erythrotrichopeltis (Kornmann, 1984). This genus was transferred by Wynne (1986) to Porphyrostromium Trevisan 1848. In the present study Erythrotrichia obscura, the original species of Berthold's (1882) classical observations on the sexuality of this genus, is incorporated to Porphyrostromium. Previously regarded as synonyms, Porphyrostromium ciliare (Carm. ex Harv.) Wynne and P. obscurum (Berth.) nov. comb. proved to be distinct species, differing both in the filamentous and in the peltoid phases of their life cycle. The relationship between P. ciliare and P. boryanum (Montagne) Trevisan, type species of the genus, may only be elucidated by future investigations on the basis of field collected material.

  16. Early development of grateloupia turuturu (Halymeniaceae, Rhodophyta)

    NASA Astrophysics Data System (ADS)

    Wang, Gaoge; Jiang, Chunmei; Wang, Shasha; Wei, Xiaojiao; Zhao, Fengjuan

    2012-03-01

    Grateloupia turuturu is a commercial red alga with potential value in nutraceuticals and pharmaceuticals. To supplement information on its life history and verify whether carpospores can be used for seedling culture, early development of G. turuturu was investigated under culture conditions (27°C, 10-13 μol/(m2·s) in irradiance, photoperiod 10:14 h L:D). Three physiological stages were recognized by continuous microscopic observation: division stage, discoid crust stage, and juvenile seedling stage. At the beginning of the division stage, the carpospores developed germ tubes into which the carpospore protoplasm was evacuated, and then the carpospore protoplasm in the germ tubes began to divide continuously until discoid crusts formed. Finally, upright thalli appeared on the discoid crusts and developed into juvenile seedlings. It took about 60 days for carpospores to develop into juvenile seedlings. The growth parameters, including germination rate for carpospores and discoid crust diameter, were recorded. These results contribute more information on the life cycle, and at the same time are of great significance in the scaling-up of artificial seedling cultures of G. turuturu.

  17. Hypoglossum fujianensis sp. nov. (Delesseriaceae, Rhodophyta) from Fujian Coast, China

    NASA Astrophysics Data System (ADS)

    Zheng, Yi

    1998-12-01

    Hypoglossum fujianensis sp. nov. is an epiphytic alga in the intertidal zone. Plants are light red, 0.9 2 cm high. Margin of branches gives rise to uniseriate hair-like rhizoids, formed outward from the fusion of the second-and third-order cells. Blades are single layered (except the midrib) and uncorticated. Tetrasporangial sori are formed on the middle part of blades. The globular tetrasporangia are developed from lateral pericentral cells.

  18. Transient expression of exogenous gus gene in Porphyra yezoensis (Rhodophyta)

    NASA Astrophysics Data System (ADS)

    Kuang, Mei; Wang, Su-Juan; Li, Yao; Shen, Da-Leng; Zeng, Cheng-Kui

    1998-03-01

    Electroporation, PEC, PEG plus electroporation and Biolistics methods were tested in gene transformation of P. yezoensis. The exogenous gus was from plasmid of pBI121 and pCAMBIA1301, both contain the CaMV35S promoter. The receptors included the protoplasts, tissues and free-living conchocelis filaments of P. yezoensis. Several factors, for example, the voltage, capacitance and bivalent cations, etc., were studied. Results show that these four methods are all efficient for gene transformation in P. yezoensis; and that PEG is the best one, with transformation efficiency of up to 4×10-5. GUS activity was detected 26 days after transformation by using PEG method.

  19. Viscous polysaccharide and starch synthesis in Rhodella reticulata (Porphyridiales, Rhodophyta)

    SciTech Connect

    Kroen, W.K.; Ramus, J. )

    1990-06-01

    Rhodella reticulata Deason, Butler and Rhyne produces copious amounts of a viscous polysaccharide (VP) during growth in batch cultures. The VPs accumulated on the cell surface and in the culture medium once cells ceased growth; starch concurrently accumulated within the cells. Light-saturated {sup 14}C-uptake declined steadily as the cells aged. Net synthesis rates for starch and mucilage were two- and four-fold lower, respectively, in non-growing cells than in growing cells, while the relative partitioning of newly-fixed carbon into these materials was not different. These data suggest that total photosynthetic loading, rather than partitioning into one specific pool, controls cellular synthesis rates. No preferential synthesis of VPs occurred during the stationary phase. The findings have important implications for the commercial production of VPs.

  20. Timing of the evolutionary history of Corallinaceae (Corallinales, Rhodophyta).

    PubMed

    Rösler, Anja; Perfectti, Francisco; Peña, Viviana; Aguirre, Julio; Braga, Juan Carlos

    2017-02-12

    The temporal dimension of the most recent Corallinaceae (order Corallinales) phylogeny was presented here, based on first occurrence time estimates from the fossil record. Calibration of the molecular clock of the genetic marker SSU entailed a separation of Corallinales from Hapalidiales in the Albian (Early Cretaceous ~ 105 mya). Neither the calibration nor the fossil record resolved the succession of appearance of the first three emerging subfamilies: Mastophoroideae, Corallinoideae, and Neogoniolithoideae. The development of the tetra/bisporangial conceptacle roofs by filaments surrounding and interspersed among the sporangial initials was an evolutionary novelty emerging at the Cretaceous-Paleogene boundary (~ 66 mya). This novelty was shared by the subfamilies Hydrolithoideae, Metagoniolithoideae, and Lithophylloideae, which diverged in the early Paleogene. Subclades within the Metagoniolithoideae and Lithophylloideae diversified in the late Oligocene-middle Miocene (~ 28 to 12 mya). The most common reef corallinaceans (Hydrolithon, Porolithon, Harveylithon, "Pneophyllum" conicum, and subclades within Lithophylloideae) appeared in this interval in the Indo-Australian Archipelago. This article is protected by copyright. All rights reserved.

  1. Light acclimation in Porphyridium purpureum (Rhodophyta): Growth, photosynthesis, and phycobilisomes

    SciTech Connect

    Levy, I.; Gantt, E. )

    1988-12-01

    Acclimation to three photon flux densities 10, 35, 180 {mu}E{center dot}m{sup {minus}2}{center dot}s{sup {minus}1} was determined in laboratory cultures of Porphyridium purpureum Bory, Drew and Ross. Cultures grown at low, medium, and high PPFDs had compensation points of <3, 6, and 20 {mu}E{center dot}m{sup {minus}2}{center dot}s{sup {minus}1}, respectively, and saturating irradiances in the initial log phase of 90, 115, 175 {mu}E{center dot}m{sup {minus}2}{center dot}s{sup {minus}1} and up to 240 {mu}E{center dot}m{sup {minus}2}{center dot}s{sup {minus}1} in late log phase. High light cells had the smallest photosynthetic unit size (phycobiliproteins plus chlorophyll), the highest photosynthetic capacity, and the highest growth rates. Photosystem I reaction centers (P700) per cell remained proportional to chlorophyll at ca. 110 chl/P700. However, phycobiliprotein content decreased as did the phycobilisome number (ca. 50%) in high light cells, whereas the phycobilisome size remained the same as in medium and low light cells. We concluded that acclimation of this red alga to varied PPFDs was manifested by the plasticity of the photosystem II antennae with little, if any, affect noted on photosystem I.

  2. PHYLOGEOGRAPHY OF THE GENUS SPONGITES (CORALLINALES, RHODOPHYTA) FROM CHILE(1).

    PubMed

    Vidal, Rodrigo; Meneses, Isabel; Smith, Macarena

    2008-02-01

    Both the records and the descriptions of the crustose species of coralline algae on the southeastern coast of South America are from the early 1900s. Unlike other algae species on the coast of Chile, the biogeography and distribution of crustose corallines have not been studied despite their abundance. Through recent studies, it has been determined that the genus Spongites is the most conspicuous genus along the rocky intertidal of the Chilean coasts. It is also common to the entire coast of the Southern Hemisphere; however, the relationship between species and the possible reasons for their distribution is unknown. We used nuclear and mitochondrial genetic markers and SEM observations of morphological characters to examine Spongites samples from the Southern Hemisphere and to establish the phylogeographic relationships of Chilean Spongites with specimens from other southern coasts. The combination of these analyses revealed the following: (i) a monophyletic clade that represents the Chilean Spongites and (ii) a paraphyletic clade for South African, New Zealand, and Argentine samples. Consequently, we postulate two nonexclusive hypotheses regarding the relationship of Spongites species in the Southern Hemisphere: (i) a complex history of extinction, speciation, and recolonization that might have erased original Gondwanan split patterns, and (ii) an Antarctic Peninsula origin for the Chilean Spongites species.

  3. Chlorophyta and Rhodophyta macroalgae: a source of health promoting phytochemicals.

    PubMed

    Santos, Sonia A O; Vilela, Carla; Freire, Carmen S R; Abreu, Maria H; Rocha, Silvia M; Silvestre, Armando J D

    2015-09-15

    A detailed study of the lipophilic composition of Codium tomentosum, Ulva lactuca, Gracilaria vermiculophylla and Chondrus crispus macroalgae cultivated in the Portuguese coast was carried out by gas chromatography-mass spectrometry before and after alkaline hydrolysis. Their long-chain aliphatic alcohols and monoglycerides compositions are reported for the first time. Additionally, other new compounds were also identified: phytol and neophytadiene in C. tomentosum, U. lactuca and G. vermiculophylla and stigmasterol, α-tocopherol and 24-methylenecholesterol in C. tomentosum. The lipophilic fraction of the studied macroalgae are mainly constituted by fatty acids (110.1-1030.5mgkg(-1) of dry material) and sterols (14.8-1309.1mgkg(-1) of dry material). C. tomentosum showed to be a valuable source of stigmasterol (1229.0mgkg(-1) of dry material) and α-tocopherol (21.8mgkg(-1) of dry material). These results are a relevant contribution for the valorisation of these macroalgae species as sources of valuable phytochemicals.

  4. Galactans of Gracilaria pudumadamensis (Gracilariales, Rhodophyta) of Indian waters.

    PubMed

    Kondaveeti, Stalin; Kumar, Sanjay; Ganesan, Meenakshi S; Siddhanta, Arup K

    2014-09-01

    Galactans from the Indian agarophyte Gracilaria pudumadamensis were extracted and characterized. The isolated native (GP(Native)) and alkali treated (GP(Alkali)) galactans were characterized by IR, 13C NMR, GC-MS and GPC. It was found that GP(Native) and GP(Alkali) were composed mainly of 3,6-anhydro L-galactose, 6-O-methylated D-galactose and galactose in various mole proportions (15.6:69.9:17.5 mole% for GP(Native) and 20.2:69.8:10.0 mole% for GP(Alkali)). The GP(Native) and GP(Alkali) exhibited low gel strengths (< 100 g/cm2) and high melting points (-76 degrees C), which may be due to the presence of high 6-O-Me-galactose contents. The latter, having low sulfate (2.1%), was by far the greatest 6-O-Me-galactose containing polysaccharide in a Gracilaria spp. reported in the literature. This methylated agar contained very low heavy metal ions estimated by inductively coupled plasma spectrophotometry (ICP). The results of this investigation would be useful in bioprospecting of agarophytes, especially those occurring in Indian waters and would be potentially useful in food, personal care and related domains.

  5. [Stress proteins in the cells of Porphyra purpurea (Rhodophyta) thallus].

    PubMed

    Podlipaeva, Iu I; Ful'da, S; Gudkov, A V

    2014-01-01

    Heat shock proteins have been revealed for the first time by the methods of Western blotting using alkaline phosphatase and ECL in the cells of Porphyra purpurea from Kattegat area of the Baltic Sea in normal and experimental stress conditions. It was demonstrated with application of monoclonal anti-Hsp70 antibodies that a slight band about 70 kDa is present constitutively at the film; additionally the polypeptide of about 40 kDa ("Hsp40") has been detected. After heat shock at 28 degrees C during 1 hr significant "expenditure" of Hsp70 was observed, as well as the pronounced induction of "Hsp40"; the induction was expressed especially strongly in 24 hr after the stress application.

  6. Nitrate Assimilation and Crassulacean Acid Metabolism in Leaves of Kalanchoë fedtschenkoi Variety Marginata 1

    PubMed Central

    Chang, Nam Kee; Vines, H. Max; Black, Clanton C.

    1981-01-01

    The enzymes necessary to assimilate ammonia either via glutamine synthetase and glutamate synthase or via the glutamate dehydrogenase pathways are present in both green and white leaf tissues of Kalanchoë fedtschenkoi. Nitrate reductase activity develops to a maximum in a Crassulacean acid metabolism (CAM) plant canopy before either ribulose 1,5-bisphosphate carboxylase, or phosphoenolpyruvate carboxylase, or CAM. Nitrate reductase also is activated each morning and is inactivated late in the day as in other plants. However, there does not appear to be any direct relationship between nitrate reductase activity and the level of acid, its daily pattern or the amplitude of CAM. Though nitrate reductase is activated maximally each day by light, in Kalanchoë leaves for six days the activity followed a precise daily pattern independent of continuous light or dark. Images PMID:16661938

  7. Evaporation from the understorey in the Jarrah ( Eucalyptus marginata Don ex Sm.) forest, southwestern Australia

    NASA Astrophysics Data System (ADS)

    Greenwood, E. A. N.; Klein, L.; Beresford, J. D.; Watson, G. D.; Wright, K. D.

    1985-10-01

    Annual evaporation from groundflora, litter and soil of the jarrah forest was estimated from measurements of daily evaporation by ventilated chambers on several days over two separate 12-month periods. In the first year, when sampling ranged over 0.1 ha of forest, annual evaporation during daylight hours was estimated as 410 mm (0.32 rainfall). In the second year, sampling was more frequent, on a larger scale, and included the night hours. Annual evaporation was estimated at 360 mm (0.36 rainfall). Similarly, in the second year, annual evaporation from two trees of the dominant middle storey species, Banksia grandis, was estimated at 7500 and 18,9001 respectively. The leaf area of these two trees was 9.6 and 22.4 m 2, respectively, so that annual evaporation, when expressed as mm 3 per mm 2 leaf area, was similar for both trees (mean = 820 ± 30 mm). Applying that value to all Banksia trees in a hectare of forest, and using a measured estimate of leaf area index of 0.19, the estimated annual evaporation from the Banksia component was 155 mm (0.16 rainfall). For the upland part of the forest sampled, the combined annual evaporation from the lower and middle storeys accounted for about half (0.51) of the annual rainfall. We conclude that reduced evaporation from the upper storey following clearing or thinning may be strongly counteracted by increased evaporation from the understorey due to increased availability of energy and water.

  8. Direct evaluation of macroalgal removal by herbivorous coral reef fishes

    NASA Astrophysics Data System (ADS)

    Mantyka, C. S.; Bellwood, D. R.

    2007-06-01

    Few studies have examined the relative functional impacts of individual herbivorous fish species on coral reef ecosystem processes in the Indo-Pacific. This study assessed the potential grazing impact of individual species within an inshore herbivorous reef fish assemblage on the central Great Barrier Reef (GBR), by determining which fish species were able to remove particular macroalgal species. Transplanted multiple-choice algal assays and remote stationary underwater digital video cameras were used to quantify the impact of local herbivorous reef fish species on 12 species of macroalgae. Macroalgal removal by the fishes was rapid. Within 3 h of exposure to herbivorous reef fishes there was significant evidence of intense grazing. After 12 h of exposure, 10 of the 12 macroalgal species had decreased to less than 15% of their original mass. Chlorodesmis fastigiata (Chlorophyta) and Galaxaura sp. (Rhodophyta) showed significantly less susceptibility to herbivorous reef fish grazing than all other macroalgae, even after 24 h exposure. Six herbivorous and/or nominally herbivorous reef fish species were identified as the dominant grazers of macroalgae: Siganus doliatus, Siganus canaliculatus, Chlorurus microrhinos, Hipposcarus longiceps, Scarus rivulatus and Pomacanthus sexstriatus. The siganid S. doliatus fed heavily on Hypnea sp., while S. canaliculatus fed intensively on Sargassum sp. Variation in macroalgal susceptibility was not clearly correlated with morphological and/or chemical defenses that have been previously suggested as deterrents against herbivory. Nevertheless, the results stress the potential importance of individual herbivorous reef fish species in removing macroalgae from coral reefs.

  9. Heavy metal concentrations in marine green, brown, and red seaweeds from coastal waters of Yemen, the Gulf of Aden

    NASA Astrophysics Data System (ADS)

    Al-Shwafi, Nabil A.; Rushdi, Ahmed I.

    2008-08-01

    The purpose of this study was to investigate the concentration levels of heavy metals in different species of the main three marine algal divisions from the Gulf of Aden coastal waters, Yemen. The divisions included Chlorophyta—green plants ( Halimeda tuna, Rhizoclonium kochiamum, Caldophora koiei, Enteromorpha compressa, and Caulerpa racemosa species), Phaeophyta—brown seaweeds ( Padina boryana, Turbinaria elatensis, Sargassum binderi, Cystoseira myrica, and Sargassum boveanum species), and Rhodophyta—red seaweeds ( Hypnea cornuta, Champia parvula, Galaxaura marginate, Laurencia paniculata, Gracilaria foliifere, and species). The heavy metals, which included cadmium (Cd), cobalt (Co), copper (Cu), chromium (Cr), Iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), zinc (Zn), and vanadium (V) were measured by Atomic Absorption Spectrophotometer (AAs). The concentrations of heavy metals in all algal species are in the order of Fe >> Cu > Mn > Cr > Zn > Ni > Pb > Cd > V > Co. The results also showed that the uptake of heavy metals by different marine algal divisions was in the order of Chlorophyta > Phaeophyta > Rhodophyta. These heavy metals were several order of magnitude higher than the concentrations of the same metals in seawater. This indicates that marine alga progressively uptake heavy metals from seawater.

  10. Wilsonosiphonia gen. nov. (Rhodomelaceae, Rhodophyta) based on molecular and morpho-anatomical characters.

    PubMed

    Bustamante, Danilo E; Won, Boo Yeon; Miller, Kathy Ann; Cho, Tae Oh

    2017-01-12

    Morphological, anatomical, and molecular sequence data were used to assess the establishment and phylogenetic position of the genus Wilsonosiphonia gen. nov. Phylogenies based on rbcL and concatenated rbcL and cox1 loci support recognition of Wilsonosiphonia gen. nov., sister to Herposiphonia. Diagnostic features for Wilsonosiphonia are rhizoids located at distal ends of pericentral cells and taproot-shaped multicellular tips of rhizoids. Wilsonosiphonia includes three species with diagnostic rbcL and cox1 sequences, Wilsonosiphonia fujiae sp. nov. (the generitype), W. howei comb. nov., and W. indica sp. nov. These three species resemble each other in external morphology, but W. fujiae is distinguished by having two tetrasporangia per segment rather than one, W. indica by having abundant and persistent trichoblasts, and W. howei by having few and deciduous trichoblasts.

  11. Phylogeography of the invasive seaweed Asparagopsis (Bonnemaisoniales, Rhodophyta) reveals cryptic diversity.

    PubMed

    Andreakis, Nikos; Procaccini, Gabriele; Maggs, Christine; Kooistra, Wiebe H C F

    2007-06-01

    The rhodophyte seaweed Asparagopsis armata Harvey is distributed in the northern and southern temperate zones, and its congener Asparagopsis taxiformis (Delile) Trevisan abounds throughout the tropics and subtropics. Here, we determine intraspecific phylogeographic patterns to compare potential causes of the disjunctions in the distributions of both species. We obtained specimens throughout their ranges and inferred phylogenies from the hypervariable domains D1-D3 of the nuclear rDNA LSU, the plastid spacer between the large and small subunits of RuBisCo and the mitochondrial cox 2-3 intergenic spacer. The cox spacer acquired base changes the fastest and the RuBisCo spacer the slowest. Median-joining networks inferred from the sequences revealed the absence of phylogeographic structure in the introduced range of A. armata, corroborating the species' reported recent introduction. A. taxiformis consisted of three nuclear, three plastid and four mitochondrial genetically distinct, lineages (1-4). Mitochondrial lineage 3 is found in the western Atlantic, the Canary Islands and the eastern Mediterranean. Mitochondrial lineages 1, 2, and 4 occur in the Indo-Pacific, but one of them (lineage 2) is also found in the central Mediterranean and southern Portugal. Phylogeographic results suggest separation of Atlantic and Indo-Pacific lineages resulted from the emergence of the Isthmus of Panama, as well as from dispersal events postdating the closure event, such as the invasion of the Mediterranean Sea by mitochondrial lineages 2 and 3. Molecular clock estimates using the Panama closure event as a calibration for the split of lineages 3 and 4 suggest that A. taxiformis diverged into two main cryptic species (1 + 2 and 3 + 4) about 3.2-5.5 million years ago (Ma), and that the separation of the mitochondrial lineages 1 and 2 occurred 1-2.3 Ma.

  12. New Insights on the Terpenome of the Red Seaweed Laurencia dendroidea (Florideophyceae, Rhodophyta)

    PubMed Central

    de Oliveira, Louisi Souza; Tschoeke, Diogo Antonio; de Oliveira, Aline Santos; Hill, Lilian Jorge; Paradas, Wladimir Costa; Salgado, Leonardo Tavares; Thompson, Cristiane Carneiro; Pereira, Renato Crespo; Thompson, Fabiano L.

    2015-01-01

    The red seaweeds belonging to the genus Laurencia are well known as halogenated secondary metabolites producers, mainly terpenoids and acetogennins. Several of these chemicals exhibit important ecological roles and biotechnological applications. However, knowledge regarding the genes involved in the biosynthesis of these compounds is still very limited. We detected 20 different genes involved in the biosynthesis of terpenoid precursors, and 21 different genes coding for terpene synthases that are responsible for the chemical modifications of the terpenoid precursors, resulting in a high diversity of carbon chemical skeletons. In addition, we demonstrate through molecular and cytochemical approaches the occurrence of the mevalonate pathway involved in the biosynthesis of terpenes in L. dendroidea. This is the first report on terpene synthase genes in seaweeds, enabling further studies on possible heterologous biosynthesis of terpenes from L. dendroidea exhibiting ecological or biotechnological interest. PMID:25675000

  13. ORIGIN OF APOMICTIC RED ALGAE: OUTCROSSING STUDIES OF DIFFERENT STRAINS IN CALOGLOSSA MONOSTICHA (CERAMIALES, RHODOPHYTA)(1).

    PubMed

    Kamiya, Mitsunobu; West, John A

    2008-08-01

    Various red algae lack sexual reproduction and propagate by spore recycling, but it is still unknown how apomixis originates. In previous crossing experiments, we obtained an unusual hybrid of Caloglossa monosticha M. Kamiya through the outcrossing between a male from Australia and a female from Indonesia. This hybrid was morphologically identical to a normal tetrasporophyte, but its tetraspores grew into tetrasporophytes and repeated tetraspore recycling. During 5 years of culture, no sexual reproductive structures have formed on the tetrasporelings from this hybrid or its progenies. Further hybridization experiments revealed that all the five female strains from Indonesia successfully crossed with the male strain from the East Alligator River, Australia, and most of the F1 sporophytes demonstrated tetraspore recycling, though the germination rates of these tetraspores were quite low. The ploidy level of the hybrid tetrasporophyte was similar to the normal tetrasporophyte, rather than the parental gametophyte, based on the comparison of relative DNA contents of their nuclei. Single strand conformation polymorphism (SSCP) and sequence analyses of the internal transcribed spacer 1 (ITS1) region indicated that the alleles from both parents were present in all the hybrid tetrasporophytes examined. These results suggest that this hybrid does not carry out meiosis during sporogenesis, and heterozygous diploid sporophytes arose from tetraspores. Therefore, we believe that obligate apomixis was generated through outcrossing between genetically different entities of C. monosticha.

  14. Application of multigene phylogenetics and site-stripping to resolve intraordinal relationships in the Rhodymeniales (Rhodophyta).

    PubMed

    Filloramo, Gina V; Saunders, Gary W

    2016-06-01

    Previous molecular assessments of the red algal order Rhodymeniales have confirmed its monophyly and distinguished the six currently recognized families (viz. Champiaceae, Faucheaceae, Fryeellaceae, Hymenocladiaceae, Lomentariaceae, and Rhodymeniaceae); however, relationships among most of these families have remained unresolved possibly as a result of substitution saturation at deeper phylogenetic nodes. The objective of the current study was to improve rhodymenialean systematics by increasing taxonomic representation and using a more robust multigene dataset of mitochondrial (COB, COI/COI-5P), nuclear (LSU, EF2) and plastid markers (psbA, rbcL). Additionally, we aimed to prevent phylogenetic inference problems associated with substitution saturation (particularly at the interfamilial nodes) by removing fast-evolving sites and analyzing a series of progressively more conservative alignments. The Rhodymeniales was resolved as two major lineages: (i) the Fryeellaceae as sister to the Faucheaceae and Lomentariaceae; and (ii) the Rhodymeniaceae allied to the Champiaceae and Hymenocladiaceae. Support at the interfamilial nodes was highest when 20% of variable sites were removed. Inclusion of Binghamiopsis, Chamaebotrys, and Minium, which were absent in previous phylogenetic investigations, established their phylogenetic affinities while assessment of two genera consistently polyphyletic in phylogenetic analyses, Erythrymenia and Lomentaria, resulted in the proposition of the novel genera Perbella and Fushitsunagia. The taxonomic position of Drouetia was reinvestigated with re-examination of holotype material of D. coalescens to clarify tetrasporangial development in this genus. In addition, we added three novel Australian species to Drouetia as a result of ongoing DNA barcoding assessments-D. aggregata sp. nov., D. scutellata sp. nov., and D. viridescens sp. nov.

  15. Molecular analysis of physiological responses to changes in nitrogen in a marine macroalga, Porphyra yezoensis (Rhodophyta).

    PubMed

    Kakinuma, M; Coury, D A; Nakamoto, C; Sakaguchi, K; Amano, H

    2008-12-01

    The rhodophyte seaweed Porphyra yezoensis, known more commonly world-wide as "nori", is an important commercial crop in Japan. Cultivation of nori in Japan is often affected by outbreaks of "iroochi", a discoloration of the thalli due to a decrease in inorganic nutrients in the culture area that in turn decreases the amount of photosynthetic pigments in the thalli. Treating thalli with inorganic nitrogen can reverse iroochi. In this paper, we report on the characterization of three P. yezoensis genes, a nitrate transporter (PyNRT2) and two urea transporters (PyUT1 and PyUT2), which may be involved in reversing iroochi. The predicted length of the PyNRT2 protein was 479 amino acids (AA), while PyUT1 and PyUT2 were 740 and 680 AA, respectively. PyNRT2 was more similar to NRT2 from a chromophyte than to NRTs from Chlamydomonas and higher plants. The two P. yezoensis UTs had 56% AA identity to each other, and showed the closest relationship to higher plant and yeast DUR3 proteins which formed a subfamily of the sodium-solute symporter protein family. Hydrophobicity plots of the AA sequences showed that the PyNRT2, PyUT1, and PyUT2 included 12, 15, and 16 transmembrane domains, respectively. Southern blot analysis indicated that the P. yezoensis genome has a single NRT2-encoding gene and at least four UT-encoding genes. Expression analysis of PyNRT2 and PyUT genes showed that the messenger RNA level of the PyNRT2 gene reached a maximum after 48 h in the nitrate starvation condition and was then restored to the constitutive level, while expression of the PyUT genes was induced in proportion to treatment times in the nitrate starvation condition. These results suggest that the PyNRT2 and PyUT are responsible for the high-affinity nitrate/urea transport systems that operate under low external nitrate concentrations.

  16. Effects of temperature and irradiance on early development of Chondrus ocellatus Holm (Gigartinaceae, Rhodophyta)

    NASA Astrophysics Data System (ADS)

    Li, Xiao; Zhao, Peng; Wang, Gaoge; Li, Dapeng; Wang, Jicheng; Duan, Delin

    2010-05-01

    Chondrus is a type of commercially produced red seaweed that widely used for food and carrageen extraction. Although the natural life history of the alga had been well understood, the factors influencing development of the tetraspore and carpospore remain poorly understood. In the perspective of seedling resources, the regulation of early development is crucial for the seedling nursing; therefore, it is necessary to understand the physiological influences during its early development. In this study, we studied the effects of temperature and irradiance on the early development of Chondrus ocellatus Holm under laboratory conditions. The released tetraspores and carpospores were cultivated at different temperatures (10-28°C) and irradiances (10, 60 μmol photons m-2s-1) with a photoperiod of 12L:12D. The results indicate that both tetraspores and carpospores are tolerant to temperatures of 10-25°C, and have the highest relative growth rate at 20°C. Irradiance variances influenced the growth of the discoid crusts, and the influence was more significant with increasing temperature; 60 μmol photons m-2s-1 was more suitable than 10 μmol photons m-2s-1. The optimum temperature and irradiance for the development of seedlings was 20°C and 60 μmol photons m-2s-1, respectively.

  17. DEMOGRAPHIC CONSEQUENCES OF COALESCENCE IN SPORELING POPULATIONS OF MAZZAELLA LAMINARIOIDES (GIGARTINALES, RHODOPHYTA)(1).

    PubMed

    Santelices, B; Alvarado, J L

    2008-06-01

    Coalescing macroalgae are ecologically important members of intertidal and shallow subtidal communities. However, we still lack quantitative information on the demographic consequences of coalescence. Using demographic models developed for modular invertebrates, we studied the demography of settlement and early recruitment in the coalescing macroalga Mazzaella laminarioides (Bory) Fredericq. Permanently marked microscopic fields on laboratory-incubated and field-incubated plates were monitored regularly (at 15, 30, 45, and 60 d) using image analysis techniques to evaluate the relative importance of settler abundance, mortality, coalescence (fusion), and fission on the changes in size and numbers of recruits. On the plates, spores settled individually or in groups. Over time, spores in close proximity may coalesce, resulting in a mixture of unisporic and multisporic crusts. When new spores arrive, they may or may not coalesce with previously settled crusts. Coalescence and mortality reduce the number of sporelings, but coalescence increases the size of the sporelings, thereby reducing further probability of sporeling mortality. Crust fissions are negligible in frequency, while the frequency of coalescence increases from ∼25% after only 3 d, to ∼75% after 60 d. Thus, as a result of variable settlement, mortality, and coalescence, any area colonized by M. laminarioides would contain a mixture of crusts of different sizes, ages, and genetic constitution. The interactions between the above three processes create a more complex survivorship curve than the ones known for unitary organisms.

  18. Nuclear DNA content variation in life history phases of the Bonnemasoniaceae (Rhodophyta).

    PubMed

    Salvador Soler, Noemi; Gómez Garreta, Amelia; Ribera Siguan, Ma Antonia; Kapraun, Donald F

    2014-01-01

    Nuclear DNA content in gametophytes and sporophytes or the prostrate phases of the following species of Bonnemaisoniaceae (Asparagopsis armata, Asparagopsis taxiformis, Bonnemaisonia asparagoides, Bonnemaisonia clavata and Bonnemaisonia hamifera) were estimated by image analysis and static microspectrophotometry using the DNA-localizing fluorochrome DAPI (4', 6-diamidino-2-phenylindole, dilactate) and the chicken erythrocytes standard. These estimates expand on the Kew database of DNA nuclear content. DNA content values for 1C nuclei in the gametophytes (spermatia and vegetative cells) range from 0.5 pg to 0.8 pg, and for 2C nuclei in the sporophytes or the prostrate phases range from 1.15-1.7 pg. Although only the 2C and 4C values were observed in the sporophyte or the prostrate phase, in the vegetative cells of the gametophyte the values oscillated from 1C to 4C, showing the possible start of endopolyploidy. The results confirm the alternation of nuclear phases in these Bonnemaisoniaceae species, in those that have tetrasporogenesis, as well as those that have somatic meiosis. The availability of a consensus phylogenetic tree for Bonnemaisoniaceae has opened the way to determine evolutionary trends in DNA contents. Both the estimated genome sizes and the published chromosome numbers for Bonnemaisoniaceae suggest a narrow range of values consistent with the conservation of an ancestral genome.

  19. Induction and cultivation of cloned filaments of Polysiphonia urceolata (Rhodomelaceae, Rhodophyta)

    NASA Astrophysics Data System (ADS)

    Wang, Jinxia; Shao, Kuishuang; Cheng, Bin; Lu, Qinqin; Zhou, Baicheng

    2011-11-01

    A filamentous clone of Polysiphonia urceolata was regenerated from segments cut from the fronds of gametophytes. Unlike wild thalli with short virgate branchlets, the clone was filamentous with few branches. Many transparent trichoblasts arose from pericentral cells during the induction culture, but these were seldom observed during normal growth. The trichoblasts were uniseriate, often colorless, and formed lobed rhizoids rapidly when they came into contact with solid substrates. In addition to morphological characteristics, the photosynthetic properties and growth conditions of the clone differed from those of the mother plant. Cross-gradient light and temperature culture experiments revealed that the most favorable conditions for culture of the filamentous clone were 22°C and 95-120 μE/(m2·s) light intensity. The photosynthetic light saturation value for filaments was approx. 100 μE/(m2·s), which is far lower than that of wild thalli. These results could be used to develop techniques for mass cultures of P. urceolata in photobioreactors for production of seed stock or bioactive products.

  20. Eukaryotic Life Inhabits Rhodolith-forming Coralline Algae (Hapalidiales, Rhodophyta), Remarkable Marine Benthic Microhabitats

    PubMed Central

    Krayesky-Self, Sherry; Schmidt, William E.; Phung, Delena; Henry, Caroline; Sauvage, Thomas; Camacho, Olga; Felgenhauer, Bruce E.; Fredericq, Suzanne

    2017-01-01

    Rhodoliths are benthic calcium carbonate nodules accreted by crustose coralline red algae which recently have been identified as useful indicators of biomineral changes resulting from global climate change and ocean acidification. This study highlights the discovery that the interior of rhodoliths are marine biodiversity hotspots that function as seedbanks and temporary reservoirs of previously unknown stages in the life history of ecologically important dinoflagellate and haptophyte microalgae. Whereas the studied rhodoliths originated from offshore deep bank pinnacles in the northwestern Gulf of Mexico, the present study opens the door to assess the universality of endolithic stages among bloom-forming microalgae spanning different phyla, some of public health concerns (Prorocentrum) in marine ecosystems worldwide. PMID:28368049

  1. New Insights on the terpenome of the red seaweed Laurencia dendroidea (Florideophyceae, Rhodophyta).

    PubMed

    de Oliveira, Louisi Souza; Tschoeke, Diogo Antonio; de Oliveira, Aline Santos; Hill, Lilian Jorge; Paradas, Wladimir Costa; Salgado, Leonardo Tavares; Thompson, Cristiane Carneiro; Pereira, Renato Crespo; Thompson, Fabiano L

    2015-02-10

    The red seaweeds belonging to the genus Laurencia are well known as halogenated secondary metabolites producers, mainly terpenoids and acetogennins. Several of these chemicals exhibit important ecological roles and biotechnological applications. However, knowledge regarding the genes involved in the biosynthesis of these compounds is still very limited. We detected 20 different genes involved in the biosynthesis of terpenoid precursors, and 21 different genes coding for terpene synthases that are responsible for the chemical modifications of the terpenoid precursors, resulting in a high diversity of carbon chemical skeletons. In addition, we demonstrate through molecular and cytochemical approaches the occurrence of the mevalonate pathway involved in the biosynthesis of terpenes in L. dendroidea. This is the first report on terpene synthase genes in seaweeds, enabling further studies on possible heterologous biosynthesis of terpenes from L. dendroidea exhibiting ecological or biotechnological interest.

  2. Biomass and carbon storage of Gracilariopsis lemaneiformis (Rhodophyta) in Zhanshan Bay, Qingdao, China

    NASA Astrophysics Data System (ADS)

    Zhou, Wei; Sui, Zhenghong; Wang, Jinguo; Hu, Yiyi; Kang, Kyoungho; Oh, Junyeong; Kim, Sangchul; Huang, Jianhui; Wang, Pengyun

    2014-09-01

    Marine macroalgae can absorb carbon and play an important role in carbon sequestration. As an important economic macroalga, Gracilariopsis lemaneiformis has the potential to significantly affect carbon absorption and storage in wave-sheltered intertidal reef systems. However, detailed knowledge on seasonal biomass changes and carbon storage of G. lemaneiformis is lacking, especially in many small and scattered ecosystems. Considering the influence of human activities on wild distribution of G. lemaneiformis, the understanding of seasonal dynamics of an economically important species in nature is necessary. In this study, we first investigated seasonal variations in biomass, coverage area, and carbon storage during low tide from August 2011 to July 2012 in Zhanshan Bay, Qingdao, China. Furthermore, we estimated the carbon storage potential of wild G. lemaneiformis using light use efficiency (LUE). The results show that the standing biomass and coverage area changed significantly with season. However, seasonal variations in carbon content and water content were not obvious, with an average content of 35.1% and 83.64%, respectively. Moreover, carbon storage in individual months varied between 0.67 and 47.03 g C/m2, and the value of carbon storage was the highest in August and June and the lowest in February. In Zhanshan Bay, LUE of G. lemaneiformis was only 0.23%. If it is increased to the theoretical maximum (5%-6%), the carbon storage will have an increase of at least 21 times compared with the current, which suggested that carbon storage of wild G. lemaneiformis had a high enhancement potential. The study will help to assess a potential role of G. lemaneiformis in reducing atmospheric CO2.

  3. Development of photosynthetic activity in Porphyridium purpureum (Rhodophyta) following nitrogen starvation

    SciTech Connect

    Levy, I.; Gantt, E. )

    1990-03-01

    The effects of nitrogen limitation on laboratory cultures of Porphyridium purpureum Bory, Drew and Ross were studied under continuous white light illumination (35 {mu}E {times} m{sup {minus}2} {times} s{sup {minus}1}). Growth ceased, respiration exceeded photosynthesis, chlorophyll content was reduced by 80%, and phycoerythrin content was reduced by 99% over a period of 14 days under nitrogen limitation. Recovery upon addition of nitrogen resulted in increased phycobiliprotein content, appearance of phycobilisomes attached to the thylakoids, increased oxygen evolution, and increased fluorescence emission from photosystem 1 (720 nm) and photosystem 2 (685 nm) upon excitation by green light. Growth resumes after 72 h and was concomitant with an increase of chlorophyll, phycoerythrin and phycobilisomes per thylakoid area. The results suggest that photosystem 1 was less affected by nitrogen starvation than photosystem 2 and that the recovery was largely dependent on the restoration of phycobilisomes and other photosystem components.

  4. Phylogenetic relationships of corallinaceae (Corallinales, Rhodophyta): taxonomic implications for reef-building corallines.

    PubMed

    Rösler, Anja; Perfectti, Francisco; Peña, Viviana; Braga, Juan Carlos

    2016-06-01

    A new, more complete, five-marker (SSU, LSU, psbA, COI, 23S) molecular phylogeny of the family Corallinaceae, order Corallinales, shows a paraphyletic grouping of seven well-supported monophyletic clades. The taxonomic implications included the amendment of two subfamilies, Neogoniolithoideae and Metagoniolithoideae, and the rejection of Porolithoideae as an independent subfamily. Metagoniolithoideae contained Harveylithon gen. nov., with H. rupestre comb. nov. as the generitype, and H. canariense stat. nov., H. munitum comb. nov., and H. samoënse comb. nov. Spongites and Pneophyllum belonged to separate clades. The subfamily Neogoniolithoideae included the generitype of Spongites, S. fruticulosus, for which an epitype was designated. Pneophyllum requires reassesment. The generitype of Hydrolithon, H. reinboldii, was a younger heterotypic synonym of H. boergesenii. The evolutionary novelty of the subfamilies Hydrolithoideae, Metagoniolithoideae, and Lithophylloideae was the development of tetra/bisporangial conceptacle roofs by filaments surrounding and interspersed among the sporangial initials.

  5. Antiviral activities of sulfated polysaccharides isolated from Sphaerococcus coronopifolius (Rhodophytha, Gigartinales) and Boergeseniella thuyoides (Rhodophyta, Ceramiales).

    PubMed

    Bouhlal, Rhimou; Haslin, Camille; Chermann, Jean-Claude; Colliec-Jouault, Sylvia; Sinquin, Corinne; Simon, Gaelle; Cerantola, Stephane; Riadi, Hassane; Bourgougnon, Nathalie

    2011-01-01

    Water-soluble sulfated polysaccharides isolated from two red algae Sphaerococcus coronopifolius (Gigartinales, Sphaerococcaceae) and Boergeseniella thuyoides (Ceramiales, Rhodomelaceae) collected on the coast of Morocco inhibited in vitro replication of the Human Immunodeficiency Virus (HIV) at 12.5 μg/mL. In addition, polysaccharides were capable of inhibiting the in vitro replication of Herpes simplex virus type 1 (HSV-1) on Vero cells values of EC₅₀ of 4.1 and 17.2 μg/mL, respectively. The adsorption step of HSV-1 to the host cell seems to be the specific target for polysaccharide action. While for HIV-1, these results suggest a direct inhibitory effect on HIV-1 replication by controlling the appearance of the new generations of virus and potential virucidal effect. The polysaccharides from S. coronopifolius (PSC) and B. thuyoides (PBT) were composed of galactose, 3,6-anhydrogalactose, uronics acids, sulfate in ratios of 33.1, 11.0, 7.7 and 24.0% (w/w) and 25.4, 16.0, 3.2, 7.6% (w/w), respectively.

  6. Sphaerococcus coronopifolius (Rhodophyta, Gigartinales): a Mediterranean red alga with potential and applications in restoration.

    PubMed

    Fratini, Filippo; Rivière, Catherine; Santamaria, Ulderico

    2016-04-25

    Experimental studies conducted on some species of Mediterranean red algae allowed to identify Sphaerococcus coronopifolius Stackhouse as a valid alternative to the Pacific alga Gloiopeltis furcata (Postels & Ruprecht) J. Agardh, for the extraction of a material usable as natural consolidant and adhesive in the field of restoration. Promising results have been observed by comparing the extracts obtained from these two algae after the same extraction procedure. Chemical analysis (FTIR) revealed that S. coronopifolius has qualities similar to G. furcata. Even more promising results for S. coronopifolius compared to G. furcata were observed after the analysis of pH and conductivity, and the adhesion tests carried out on both extracts.

  7. PHYLOGEOGRAPHY OF BATRACHOSPERMUM MACROSPORUM (BATRACHOSPERMALES, RHODOPHYTA) FROM NORTH AND SOUTH AMERICA(1).

    PubMed

    Vis, Morgan L; Cameron Hodge, J; Necchi, Orlando

    2008-08-01

    Phylogeographic trends in Batrachospermum macrosporum Mont. were investigated using the mitochondrial intergenic spacer between the cytochrome oxidase subunit 2 and 3 genes (cox2-3). A total of 11 stream segments were sampled with seven in the coastal plain of North America and four in tropical areas of South America. Fifteen thalli were sampled from seven streams, 14 thalli from two streams, and eight thalli from two streams. There were 16 haplotypes detected using 149 individuals. Of the eight haplotypes from locations in North America, all were 334 base pairs (bp) in length, and of those from South America, five were 344 bp, and three were 348 bp. Two individual networks were produced: one for the haplotypes from North America and another for those from South America, and these could not be joined due to the large number of base pair differences. This split between haplotypes from North and South America was confirmed with sequence data of the rbcL gene. There was very little genetic variation among the haplotypes from the North American locations, leading us to hypothesize that these are fairly recent colonization events along the coastal plain. In contrast, there was high variation among haplotypes from South America, and it would appear that the Amazon serves as a center of diversity. We detected considerable variation in haplotypes among streams, but frequently, a single haplotype in an individual stream segment, which is consistent with data from previous studies of other batrachospermalean taxa, may suggest a single colonization event per stream.

  8. Metal concentration and structural changes in Corallina elongata (Corallinales, Rhodophyta) from hydrothermal vents.

    PubMed

    Couto, Ruben P; Neto, Ana I; Rodrigues, Armindo S

    2010-04-01

    Shallow-water hydrothermal activity is widely present at Azores archipelago. Organisms in such environments present great potential as sentinels of the effects derived from chronically exposure to increased temperature, metal concentrations and reduced pH. This study aimed to evaluate metal concentration in Corallina elongata collected at locations exposed and not exposed to shallow-water hydrothermal activity and evaluate changes in its calcareous structure. Elemental concentration was determined and morphometric analysis was performed by scanning electron microscopy. Thicker cell walls and a bleached appearance were observed on C. elongata specimens from the hydrothermally active location, as well as increased concentrations of elements associated to volcanic activity. This study reports on metal accumulation and morphometric changes in the calcareous structure of C. elongata from a hydrothermally active location, adding new data for further research on such habitats and communities, providing an insight on how coralline algae might be affected by ocean acidification.

  9. Mechanisms of metal tolerance in marine macroalgae, with emphasis on copper tolerance in Chlorophyta and Rhodophyta.

    PubMed

    Moenne, Alejandra; González, Alberto; Sáez, Claudio A

    2016-07-01

    Green and red macroalgae are closely related organisms, and with terrestrial plants, and constitute the base of marine food webs in coastal ecosystems. Green and red seaweeds, as all living organisms, require essential metals, such as copper, iron, zinc, which can act as co-factors for several proteins and enzymes; however, these metals in excess can induce stress and impair cell viability. Most important negative effects of metal excess are related to the induction of an oxidative stress condition, characterized by the over-accumulation of Reactive Oxygen Species (ROS). In this respect, copper, abundant in wastewaters disposed to coastal environments from domestic and industrial activities, has been one of the most studied metals. Different investigations have provided evidence that green and red macroalgae display several defenses against copper excess to prevent, or at least reduce, stress and damage, among which are cellular exclusion mechanisms, synthesis of metal-chelating compounds, and the activation of the antioxidant system. Most important defense mechanisms identified in green and red seaweed involve: metal-binding to cell wall and epibionts; syntheses of metallothioneins and phytochelatins that accumulate in the cytoplasm; and the increase in the activity of antioxidant enzymes such as superoxide dismutase, ascorbate peroxidase, glutathione peroxidase and catalase, and greater production of antioxidant metabolites as glutathione and ascorbate in organelles and the cytoplasm. In this review, we go through historical records, latest advances, and pending tasks aiming to expand our current knowledge on defense mechanisms to copper excess in green and red macroalgae, with emphasis on biochemical and molecular aspects.

  10. Tolerance to oxidative stress induced by desiccation in Porphyra columbina (Bangiales, Rhodophyta)

    PubMed Central

    Contreras-Porcia, Loretto; Thomas, Daniela; Flores, Verónica; Correa, Juan A.

    2011-01-01

    Unravelling the mechanisms underlying desiccation tolerance is crucial in order to understand the position of algal species in the intertidal zone. The alga Porphyra columbina lives in the uppermost part of the rocky intertidal zones around the world and was selected as a model for this study. Naturally desiccated plants were collected during low tide and studied for morphological changes, oxidative burst induction, biomolecule oxidation, antioxidant responses, and photosynthetic status. Naturally hydrated plants collected during high tides were used for comparative purposes. In addition, changes induced by desiccation were assessed in vitro and the capacity to recover from desiccation was determined by rehydrating the fronds in seawater. The global results show that desiccation induces morphological and cellular alterations accompanied by a loss of ∼96% of the water content. Overproduction of reactive oxygen species (ROS) was induced by desiccation and two peaks of H2O2 were detected at 1 and 3 h of desiccation. However, during in vitro rehydration post-desiccation, the ROS quickly returned to the basal levels. At the biomolecular level, only a low production of oxidized proteins was recorded during desiccation, whereas the activity of diverse antioxidant enzymes increased. However, this activity diminished to near basal levels during rehydration. The photosynthetic efficiency (Fv/Fm) during desiccation declined by 94–96% of the values recorded in hydrated plants. This reduction was generated by the low levels of trapped energy flux per cross-section (TRo/CS), electron transport flux per CS (ETo/CS), and density of reaction centres (RC/SCo) as well as the chlorophyll content. The inverse pattern was observed for the levels of phycocyanin and phycoerythrin content. Fv/Fm and the photosynthetic indicators were restored to normal levels after only 5 min of rehydration. The results indicate that desiccation in P. columbina causes overproduction of ROS that is efficiently attenuated. The morphological and photosynthetic changes could be operating as tolerance mechanisms due to the fact that these responses principally prevent biomolecular alteration and cellular collapse. Thus, the activation of different physiological mechanisms helps to explain the high tolerance to desiccation of P. columbina and, at least in part, the position of this species at the highest level in the intertidal zone. PMID:21196477

  11. Pyropia plicata sp. nov. (Bangiales, Rhodophyta): naming a common intertidal alga from New Zealand

    PubMed Central

    Nelson, Wendy A.

    2013-01-01

    Abstract A commonly found red alga of the upper intertidal zone of New Zealand rocky coasts is described for the first time as Pyropia plicata sp. nov. This species has been incorrectly known as Porphyra columbina Mont. (now Pyropia columbina (Mont.) W.A.Nelson) for many years. Pyropia plicata is widespread and common, and it is readily distinguished from other species of bladed Bangiales in New Zealand by its distinctive morphology, with pleated blades attached by a central rhizoidal holdfast. PMID:23794933

  12. Cytochemical characterization and ultrastructural organization in calluses of the agarophyte Gracilariopsis tenuifrons (Gracilariales, Rhodophyta).

    PubMed

    Bouzon, Zenilda Laurita; Schmidt, Eder Carlos; Almeida, Ana Carolina de; Yokoya, Nair S; Oliveira, Mariana Cabral de; Chow, Fungyi

    2011-01-01

    The culture and physiology of red macroalgae calluses are well documented. To date, however, no report has either performed a cytochemical analysis or characterized the ultrastructural organization of calluses at different stages of development and under the effect of plant growth regulators. Therefore, to undertake such analyses, this work studied the red seaweed Gracilariopsis tenuifrons (Bird et Oliveira) Fredericq et Hommersand. Morphology studies suggested three types of calluses: a) terminal callus having an irregular amorphous shape and filamentous projections originating from the cortical region of the thallus; b) apical callus growing on apical branches and having an elongated semispherical shape; and c) intercalary callus developing along the intermediary region of the thallus and having the appearance of small declivities with irregular edges. The abundance of intercalary calluses over terminal and apical calluses is most likely a result of a major cortical surface that would support the cellular growth required to generate calluses. Callus development was initially observed as a matrix of cellular disorganization with filamentous projections; then, the cellular mass seemed to become more compact with spherical uncolored aspect. The presence of starch grains in the inner part of the explant could be explained by absorption from the culture medium and by proper biosynthesis during callus development. Cell wall reaction to staining suggested cellulose and agar composition with acidic polysaccharides. Results suggest that none of the three morphological types of calluses showed any significant differences on the basis of either cytochemistry or ultrastructural organization.

  13. Compsopogon cf. coeruleus, a benthic red alga (Rhodophyta) new to the Laurentian Great Lakes

    USGS Publications Warehouse

    Manny, Bruce A.; Edsall, Thomas A.; Wujek, Daniel E.

    1991-01-01

    We found Compsopogon cf. coeruleus for the first time in the Laurentian Great Lakes, growing on limestone rocks at a depth of 21 m on Six Fathom Bank in central Lake Huron. It is the first freshwater red alga to be found in the Great Lakes and the only red alga ever found on an offshore reef in the Great Lakes. However, because this alga usually inhabits water 10–28 °C and has not survived freezing winter temperatures elsewhere, it may not be a permanent member of the flora.

  14. Complete nuclear ribosomal DNA sequence amplification and molecular analyses of Bangia (Bangiales, Rhodophyta) from China

    NASA Astrophysics Data System (ADS)

    Xu, Jiajie; Jiang, Bo; Chai, Sanming; He, Yuan; Zhu, Jianyi; Shen, Zonggen; Shen, Songdong

    2016-09-01

    Filamentous Bangia, which are distributed extensively throughout the world, have simple and similar morphological characteristics. Scientists can classify these organisms using molecular markers in combination with morphology. We successfully sequenced the complete nuclear ribosomal DNA, approximately 13 kb in length, from a marine Bangia population. We further analyzed the small subunit ribosomal DNA gene (nrSSU) and the internal transcribed spacer (ITS) sequence regions along with nine other marine, and two freshwater Bangia samples from China. Pairwise distances of the nrSSU and 5.8S ribosomal DNA gene sequences show the marine samples grouping together with low divergences (00.003; 0-0.006, respectively) from each other, but high divergences (0.123-0.126; 0.198, respectively) from freshwater samples. An exception is the marine sample collected from Weihai, which shows high divergence from both other marine samples (0.063-0.065; 0.129, respectively) and the freshwater samples (0.097; 0.120, respectively). A maximum likelihood phylogenetic tree based on a combined SSU-ITS dataset with maximum likelihood method shows the samples divided into three clades, with the two marine sample clades containing Bangia spp. from North America, Europe, Asia, and Australia; and one freshwater clade, containing Bangia atropurpurea from North America and China.

  15. Species diversity of the genus Osmundea (Ceramiales, Rhodophyta) in the Macaronesian region.

    PubMed

    Machín-Sánchez, María; Rousseau, Florence; Le Gall, Line; Cassano, Valéria; Neto, Ana I; Sentíes, Abel; T Fujii, Mutue; Gil-Rodríguez, María Candelaria

    2016-08-01

    Species diversity within the genus Osmundea in the Macaronesian region was explored by conducting a comprehensive sampling in the Azores, the Canary, and the Madeira archipelagos. Toward identification, all specimens were first observed alive to verify the absence of corps en cerise, a diagnostic character for the genus and morphometric data were measured (thallus length and width, first-order branches length and width, branchlets length and width, cortical cell length and width in surface view, cortical cell length and width in transverse section). Specimens were sequenced for COI-5P (39 specimens) and three species delimitation methods (Generalized Mixed Yule Coalescent, Automatic Barcode Gap Discovery method, and Poisson Tree Processes) were used to assess the threshold between infra- and interspecific relationships. Subsequently, one or several sequences of plastid-encoded large subunit of RuBisCO (21 specimens) per delimited species were generated to assess the phylogenetic relationships among Macaronesian Osmundea. Moreover, for each delineated species, vegetative and reproductive anatomy was thoroughly documented and, when possible, specimens were either assigned to existing taxa or described as novel species. This integrative approach has provided data for (i) the presence of O. oederi, O. pinnatifida, and O. truncata in Macaronesia; (ii) the proposal of two novel species, O. prudhommevanreinei sp. nov. and O. silvae sp. nov.; and (iii) evidence of an additional species referred as "Osmundea sp.1," which is a sister taxon of O. hybrida.

  16. Transcriptomic analysis of the red seaweed Laurencia dendroidea (Florideophyceae, Rhodophyta) and its microbiome

    PubMed Central

    2012-01-01

    Background Seaweeds of the Laurencia genus have a broad geographic distribution and are largely recognized as important sources of secondary metabolites, mainly halogenated compounds exhibiting diverse potential pharmacological activities and relevant ecological role as anti-epibiosis. Host-microbe interaction is a driving force for co-evolution in the marine environment, but molecular studies of seaweed-associated microbial communities are still rare. Despite the large amount of research describing the chemical compositions of Laurencia species, the genetic knowledge regarding this genus is currently restricted to taxonomic markers and general genome features. In this work we analyze the transcriptomic profile of L. dendroidea J. Agardh, unveil the genes involved on the biosynthesis of terpenoid compounds in this seaweed and explore the interactions between this host and its associated microbiome. Results A total of 6 transcriptomes were obtained from specimens of L. dendroidea sampled in three different coastal locations of the Rio de Janeiro state. Functional annotations revealed predominantly basic cellular metabolic pathways. Bacteria was the dominant active group in the microbiome of L. dendroidea, standing out nitrogen fixing Cyanobacteria and aerobic heterotrophic Proteobacteria. The analysis of the relative contribution of each domain highlighted bacterial features related to glycolysis, lipid and polysaccharide breakdown, and also recognition of seaweed surface and establishment of biofilm. Eukaryotic transcripts, on the other hand, were associated with photosynthesis, synthesis of carbohydrate reserves, and defense mechanisms, including the biosynthesis of terpenoids through the mevalonate-independent pathway. Conclusions This work describes the first transcriptomic profile of the red seaweed L. dendroidea, increasing the knowledge about ESTs from the Florideophyceae algal class. Our data suggest an important role for L. dendroidea in the primary production of the holobiont and the role of Bacteria as consumers of organic matter and possibly also as nitrogen source. Furthermore, this seaweed expressed sequences related to terpene biosynthesis, including the complete mevalonate-independent pathway, which offers new possibilities for biotechnological applications using secondary metabolites from L. dendroidea. PMID:22985125

  17. Physiological responses of macroalga Gracilaria lemaneiformis (Rhodophyta) to UV-B radiation exposure

    NASA Astrophysics Data System (ADS)

    Zhu, Lin; Xiao, Hui; Wang, Ying; Jian, Xiaoyang; Zhang, Zhipeng; Zhang, Huanxin; Tang, Xuexi

    2015-03-01

    This paper aims to evaluate the effects of ultraviolet-B radiation (UVBR) on Gracilaria lemaneiformis, a commercial red macroalga and an important source of agar. To study the in-vitro effect of UVBR on G. lemaneiformis, this plant was cultivated and exposed to photosynthetically active radiation (PAR) at 40 μmol photons/(m2 ·s) and enhanced UVBR (0, 0.36, 0.72, 1.08, 1.44, and 1.80 kJ/(m2 ·d)) for 13 days. The samples were processed for histochemical analysis, and the growth rate, photosynthetic pigment contents, photosynthetic performance, reactive oxygen species levels, membrane permeability, malonyl dialdehyde contents and antioxidant capacity of G. lemaneiformis were investigated. After 13 days of exposure to PAR+UVBR, G. lemaneiformis showed photodamage and photoinhibition of photosynthetic pigments (chlorophyll a and phycoerythrin), leading to a decreased photosynthetic efficiency. Further, there was a corresponding decrease in the relative growth rates and depigmentation and partial necrosis of the apical segments were noted after exposure to PAR+UVBR. Additionally, UVBR induced excess production of superoxide radicals and hydrogen peroxide, eliciting a marked cellular membrane damage and antioxidative response.

  18. UVR defense mechanisms in eurytopic and invasive Gracilaria vermiculophylla (Gracilariales, Rhodophyta).

    PubMed

    Roleda, Michael Y; Nyberg, Cecilia D; Wulff, Angela

    2012-10-01

    The invasive success of Gracilaria vermiculophylla has been attributed to its wide tolerance range to different abiotic factors, but its response to ultraviolet radiation (UVR) is yet to be investigated. In the laboratory, carpospores and vegetative thalli of an Atlantic population were exposed to different radiation treatments consisting of high PAR (photosynthetically active radiation) only (P), PAR+UV-A (PA) and PAR+UV-A+UV-B (PAB). Photosynthesis of carpospores was photoinhibited under different radiation treatments but photosystem II (PSII) function was restored after 12 h under dim white light. Growth of vegetative thalli was significantly higher under radiation supplemented with UVR. Decrease in chlorophyll a (Chl a) under daily continuous 16-h exposure to 300 µmol photons m(-2) s(-1) of PAR suggests preventive accumulation of excited chlorophyll molecules within the antennae to minimize the generation of dangerous reactive oxygen species. Moreover, an increase in total carotenoids and xanthophyll cycle pigments (i.e. violaxanthin, antheraxanthin and zeaxanthin) further suggests effective photoprotection under UVR. The presence of the ketocarotenoid β-cryptoxanthin also indicates protection against UVR and oxidative stress. The initial concentration of total mycosporine-like amino acids (MAAs) in freshly-released spores increased approximately four times after 8-h laboratory radiation treatments. On the other hand, initial specific MAAs in vegetative thalli changed in composition after 7-day exposure to laboratory radiation conditions without affecting the total concentration. The above responses suggest that G. vermiculophylla have multiple UVR defense mechanisms to cope with the dynamic variation in light quantity and quality encountered in its habitat. Beside being eurytopic, the UVR photoprotective mechanisms likely contribute to the current invasive success of the species in shallow lagoons and estuaries exposed to high solar radiation.

  19. AFLP and SCAR markers associated with the sex in Gracilaria lemaneiformis (Rhodophyta).

    PubMed

    Huan, Li; He, Linwen; Zhang, Baoyu; Niu, Jianfeng; Lin, Apeng; Wang, Guangce

    2013-08-01

    Gracilaria lemaneiformis (Bory de Saint-Vincent) Greville, an important marine alga, has great economic and nutritional value. However, during the nonreproductive period, it is difficult to distinguish the sporophyte, male gametophyte, and female gametophyte from each other by appearance. Amplified fragment length polymorphism (AFLP) is a multilocus marker technique, which was used in this study to identify markers associated with G. lemaneiformis sex type. By applying 80 primer combinations in the screening process, three fragments were found that were specific to male or female forms of the alga. A 173 bp band and an 89 bp band were found in the sporophyte and the male gametophyte by using primer E-AGG/M-CGT. E-ACC/M-CGG was used to amplify a 118 bp specific fragment in the sporophyte and the female gametophyte. Sequence characterized amplified region (SCAR) primers were designed and showed the expected bands at the corresponding stages. This suggested that the SCAR markers that had been developed were successful. The joint use of the three primer pairs allowed us to characterize sex and the G. lemaneiformis developmental phase in the nondescript stages. Rapid gender testing is expected to improve cross-breeding experiments and other genetic research in this economically important seaweed.

  20. Thermal Acclimation of Respiration and Photosynthesis in the Marine Macroalga Gracilaria lemaneiformis (Gracilariales, Rhodophyta).

    PubMed

    Zou, Dinghui; Gao, Kunshan

    2013-02-01

    The responses of respiration and photosynthesis to temperature fluctuations in marine macroalgae have the potential to significantly affect coastal carbon fluxes and sequestration. In this study, the marine red macroalga Gracilaria lemaneiformis was cultured at three different temperatures (12, 19, and 26°C) and at high- and low-nitrogen (N) availability, to investigate the acclimation potential of respiration and photosynthesis to temperature change. Measurements of respiratory and photosynthetic rates were made at five temperatures (7°C-33°C). An instantaneous change in temperature resulted in a change in the rates of respiration and photosynthesis, and the temperature sensitivities (i.e., the Q10 value) for both the metabolic processes were lower in 26°C-grown algae than 12°C- or 19°C-grown algae. Both respiration and photosynthesis acclimated to long-term changes in temperature, irrespective of the N availability under which the algae were grown; respiration displayed strong acclimation, whereas photosynthesis only exhibited a partial acclimation response to changing growth temperatures. The ratio of respiration to gross photosynthesis was higher in 12°C-grown algae, but displayed little difference between the algae grown at 19°C and 26°C. We propose that it is unlikely that respiration in G. lemaneiformis would increase significantly with global warming, although photosynthesis would increase at moderately elevated temperatures.

  1. Global Transcriptome Analysis of Gracilaria changii (Rhodophyta) in Response to Agarolytic Enzyme and Bacterium.

    PubMed

    Lim, Ee-Leen; Siow, Rouh-San; Abdul Rahim, Raha; Ho, Chai-Ling

    2016-04-01

    Many bacterial epiphytes of agar-producing seaweeds secrete agarase that degrade algal cell wall matrix into oligoagars which elicit defense-related responses in the hosts. The molecular defense responses of red seaweeds are largely unknown. In this study, we surveyed the defense-related transcripts of an agarophyte, Gracilaria changii, treated with β-agarase through next generation sequencing (NGS). We also compared the defense responses of seaweed elicited by agarase with those elicited by an agarolytic bacterium isolated from seaweed, by profiling the expression of defense-related genes using quantitative reverse transcription real-time PCR (qRT-PCR). NGS detected a total of 391 differentially expressed genes (DEGs) with a higher abundance (>2-fold change with a p value <0.001) in the agarase-treated transcriptome compared to that of the non-treated G. changii. Among these DEGs were genes related to signaling, bromoperoxidation, heme peroxidation, production of aromatic amino acids, chorismate, and jasmonic acid. On the other hand, the genes encoding a superoxide-generating NADPH oxidase and related to photosynthesis were downregulated. The expression of these DEGs was further corroborated by qRT-PCR results which showed more than 90 % accuracy. A comprehensive analysis of their gene expression profiles between 1 and 24 h post treatments (hpt) revealed that most of the genes analyzed were consistently upregulated or downregulated by both agarase and agarolytic bacterial treatments, indicating that the defense responses induced by both treatments are highly similar except for genes encoding vanadium bromoperoxidase and animal heme peroxidase. Our study has provided the first glimpse of the molecular defense responses of G. changii to agarase and agarolytic bacterial treatments.

  2. Investigation of the Gracilaria gracilis (Gracilariales, Rhodophyta) proteome response to nitrogen limitation.

    PubMed

    Naidoo, Rene K; Rafudeen, Muhammad S; Coyne, Vernon E

    2016-06-01

    Inorganic nitrogen has been identified as the major growth-limiting nutritional factor affecting Gracilaria gracilis populations in South Africa. Although the physiological mechanisms implemented by G. gracilis for adaption to low nitrogen environments have been investigated, little is known about the molecular mechanisms of these adaptions. This study provides the first investigation of G. gracilis proteome changes in response to nitrogen limitation and subsequent recovery. A differential proteomics approach employing two-dimensional gel electrophoresis and liquid chromatography-tandem mass spectrometry was used to investigate G. gracilis proteome changes in response to nitrogen limitation and recovery. The putative identity of 22 proteins that changed significantly (P < 0.05) in abundance in response to nitrogen limitation and recovery was determined. The identified proteins function in a range of biological processes including glycolysis, photosynthesis, ATP synthesis, galactose metabolism, protein-refolding and biosynthesis, nitrogen metabolism and cytoskeleton remodeling. The identity of fructose 1,6 biphosphate (FBP) aldolase was confirmed by western blot analysis and the decreased abundance of FBP aldolase observed with two-dimensional gel electrophoresis was validated by enzyme assays and western blots. The identification of key proteins and pathways involved in the G. gracilis nitrogen stress response provide a better understanding of G. gracilis proteome responses to varying degrees of nitrogen limitation and is the first step in the identification of biomarkers for monitoring the nitrogen status of cultivated G. gracilis populations.

  3. Methyl Jasmonate-Induced Lipidomic and Biochemical Alterations in the Intertidal Macroalga Gracilaria dura (Gracilariaceae, Rhodophyta)

    PubMed Central

    Kumari, Puja; Reddy, C.R.K.; Jha, Bhavanath

    2015-01-01

    The role of exogenously added methyl jasmonate (MeJA), a lipid-derived signaling compound, in inducing oxidative stress in the marine red macroalga Gracilaria dura was investigated. MeJA at a concentration of 1–100 µM was a strong stimulant of reactive oxygen species (H2O2, HO· and O2·−) (P < 0.05) causing considerable oxidative stress in G. dura. This further led to lipid peroxidation and degradation of the pigments Chl a and phycocyanin, with a concomitant increase in phycoerythrin. The MeJA-induced oxidative burst also led to the induction of a fatty acid oxidation cascade, resulting in the synthesis of hydroxy-oxylipins and the up-regulation of the 13-lipoxygenase pathway. Electrospray ionization-mass spectrometry-based shotgun lipidomic analysis revealed that monogalactosyldiacylglycerol (a chloroplastic glycerolipid) and phosphatidylcholine (extrachloroplastidic phopholipid) were the most affected lipid classes. The degradation of 18:3-fatty acid-containing monogalactosyldiacylglycerol inferred that it provided fatty acyl chains for the biosynthesis of 13-hydroperoxylinolenic acid, which was further directed towards either the jasmonate pathway or other alternative pathways of the fatty acid oxidation cascade, analogous to higher plants. Also, G. dura modulated the lipid acyl chains in such a way that no significant change was observed in the fatty acid profile of the treated thalli as compared with those of the control, except for C16:0, C16:1 (n-9), C20:3 (n-6) and C20:4 (n-6) (P < 0.05). Furthermore, MeJA caused the accumulation of phenolic compounds and the up-regulation of enzymes involved in secondary metabolism such as polyphenol oxidase, shikimate dehydrogenase and phenylalanine ammonia-lyase, indicating a shift towards secondary metabolism as a defense strategy to combat the induced oxidative stress. PMID:26276825

  4. Changes in ultrastructure and cytochemistry of the agarophyte Gracilaria domingensis (Rhodophyta, Gracilariales) treated with cadmium.

    PubMed

    dos Santos, Rodrigo W; Schmidt, Éder C; Bouzon, Zenilda L

    2013-02-01

    The agarophyte macroalgae Gracilaria domingensis (Kützing) Sonder ex Dickie is widely distributed along the Brazilian coast. While this species produces agarana, it is more important in the human diet. Therefore, the present study aimed to evaluate the biological effects of cadmium on its morphology and cellular organization. To accomplish this, the effects of cadmium in apical segments of G. domingensis were examined in vitro. Over a period of 16 days, the segments were cultivated and exposed to photosynthetically active radiation (PAR) at 80 μmol photons m(-2) s(-1), with cadmium treatments in doses of 100, 200 and 300 μM. The samples were processed for light, transmission and scanning electron microscopy. Histochemical analyses included Toluidine Blue for acidic polysaccharides, Coomassie Brilliant Blue for total protein, and Periodic Acidic Schiff for neutral polysaccharides. In all cadmium treatments, cytochemical analysis showed 1) metachromatic granulation in vacuole and lenticular thickness of the cell wall, 2) a higher concentration of cytoplasmic organelles, and 3) an increase in the number of floridean starch grains. Cadmium also caused changes in the ultrastructure of cortical and subcortical cells, including increased cell wall thickness and vacuole volume, as well as the destruction of chloroplast internal organization and increased number of plastoglobuli. In addition, treated plants showed a gradual increase in surface roughness, apparently the result of cadmium absorption. Taken together, these findings strongly suggested that cadmium negatively affects the agarophyte G. domingensis, posing a threat to the vitality of this plant species as a supplement in the human diet.

  5. Methyl Jasmonate-Induced Lipidomic and Biochemical Alterations in the Intertidal Macroalga Gracilaria dura (Gracilariaceae, Rhodophyta).

    PubMed

    Kumari, Puja; Reddy, C R K; Jha, Bhavanath

    2015-10-01

    The role of exogenously added methyl jasmonate (MeJA), a lipid-derived signaling compound, in inducing oxidative stress in the marine red macroalga Gracilaria dura was investigated. MeJA at a concentration of 1-100 µM was a strong stimulant of reactive oxygen species (H(2)O(2), HO· and O(2) (·-)) (P < 0.05) causing considerable oxidative stress in G. dura. This further led to lipid peroxidation and degradation of the pigments Chl a and phycocyanin, with a concomitant increase in phycoerythrin. The MeJA-induced oxidative burst also led to the induction of a fatty acid oxidation cascade, resulting in the synthesis of hydroxy-oxylipins and the up-regulation of the 13-lipoxygenase pathway. Electrospray ionization-mass spectrometry-based shotgun lipidomic analysis revealed that monogalactosyldiacylglycerol (a chloroplastic glycerolipid) and phosphatidylcholine (extrachloroplastidic phopholipid) were the most affected lipid classes. The degradation of 18:3-fatty acid-containing monogalactosyldiacylglycerol inferred that it provided fatty acyl chains for the biosynthesis of 13-hydroperoxylinolenic acid, which was further directed towards either the jasmonate pathway or other alternative pathways of the fatty acid oxidation cascade, analogous to higher plants. Also, G. dura modulated the lipid acyl chains in such a way that no significant change was observed in the fatty acid profile of the treated thalli as compared with those of the control, except for C16:0, C16:1 (n-9), C20:3 (n-6) and C20:4 (n-6) (P < 0.05). Furthermore, MeJA caused the accumulation of phenolic compounds and the up-regulation of enzymes involved in secondary metabolism such as polyphenol oxidase, shikimate dehydrogenase and phenylalanine ammonia-lyase, indicating a shift towards secondary metabolism as a defense strategy to combat the induced oxidative stress.

  6. Delimitating cryptic species in the Gracilaria domingensis complex (Gracilariaceae, Rhodophyta) using molecular and morphological data.

    PubMed

    Lyra, Goia de M; Gurgel, C Frederico D; Costa, Emmanuelle da S; de Jesus, Priscila B; Oliveira, Mariana C; Oliveira, Eurico C; Davis, Charles C; Nunes, José Marcos de Castro

    2016-12-01

    Species in the genus Gracilaria that display conspicuously flattened vegetative morphologies are a taxonomically challenging group of marine benthic red algae. This is a result of their species richness, morphological similarity, and broad phenotypic plasticity. Within this group, the Gracilaria domingensis complex is one of the most common, conspicuous, and morphologically variable species along the tropical western Atlantic Ocean. Previous research has identified that members of this complex belong to two distantly related clades. However, despite this increased phylogentic resolution, species delimitations within each of these clades remain unclear. Our study assessed the species diversity within this difficult complex using morphological and molecular data from three genetic markers (cox1, UPA, and rbcL). We additionally applied six single-marker species delimitation methods (SDM: ABGD, GMYCs, GMYCm, SPN, bPTP, and PTP) to rbcL, which were largely in agreement regarding species delimitation. These results, combined with our analysis of morphology, indicate that the G. domingensis complex includes seven distinct species, each of which are not all most closely related: G. cervicornis; a ressurected G. ferox; G. apiculata subsp. apiculata; a new species, Gracilaria baiana sp. nov.; G. intermedia subsp. intermedia; G. venezuelensis; and G. domingensis sensu stricto, which includes the later heterotypic synonym, G. yoneshigueana. Our study demonstrates the value of multipronged strategies, including the use of both molecular and morphological approaches, to decipher cryptic species of red algae.

  7. Pyropia plicata sp. nov. (Bangiales, Rhodophyta): naming a common intertidal alga from New Zealand.

    PubMed

    Nelson, Wendy A

    2013-01-01

    A commonly found red alga of the upper intertidal zone of New Zealand rocky coasts is described for the first time as Pyropia plicata sp. nov. This species has been incorrectly known as Porphyra columbina Mont. (now Pyropia columbina (Mont.) W.A.Nelson) for many years. Pyropia plicata is widespread and common, and it is readily distinguished from other species of bladed Bangiales in New Zealand by its distinctive morphology, with pleated blades attached by a central rhizoidal holdfast.

  8. Identification of proteins involved in desiccation tolerance in the red seaweed Pyropia orbicularis (Rhodophyta, Bangiales).

    PubMed

    López-Cristoffanini, Camilo; Zapata, Javier; Gaillard, Fanny; Potin, Philippe; Correa, Juan A; Contreras-Porcia, Loretto

    2015-12-01

    Extreme reduction in cellular water content leads to desiccation, which, if persistent, affects the physiology of organisms, mainly through oxidative stress. Some organisms are highly tolerant to desiccation, including resurrection plants and certain intertidal seaweeds. One such species is Pyropia orbicularis, a rhodophycean that colonizes upper intertidal zones along the Chilean coast. Despite long, daily periods of air exposure due to tides, this alga is highly tolerant to desiccation. The present study examined the proteome of P. orbicularis by 2DE and LC-MS/MS analyses to determine the proteins associated with desiccation tolerance (DT). The results showed that, under natural conditions, there were significant changes in the protein profile during low tide as compared to naturally hydrated plants at high tide. These changes were mainly in newly appeared proteins spots such as chaperones, monodehydroascorbate reductase, and manganese superoxide dismutase, among others. Previously undescribed proteins under desiccation conditions included phycobiliproteins, glyoxalase I, and phosphomannomutase. These changes evidenced that several physiological responses involved in DT are activated during low tide, including decreased photosynthetic activity, increased antioxidant capacity, and the preservation of cell physiology by regulating water content, cell wall structure, and cell volume. Similar responses have been observed in resurrection plants and bryophytes exposed to desiccation. Therefore, the coordinated activation of different desiccation tolerance pathways in P. orbicularis could explain the successful biological performance of this seaweed in the upper intertidal rocky zones.

  9. Coralline algae (Rhodophyta) in a changing world: integrating ecological, physiological, and geochemical responses to global change.

    PubMed

    McCoy, Sophie J; Kamenos, Nicholas A

    2015-02-01

    Coralline algae are globally distributed benthic primary producers that secrete calcium carbonate skeletons. In the context of ocean acidification, they have received much recent attention due to the potential vulnerability of their high-Mg calcite skeletons and their many important ecological roles. Herein, we summarize what is known about coralline algal ecology and physiology, providing context to understand their responses to global climate change. We review the impacts of these changes, including ocean acidification, rising temperatures, and pollution, on coralline algal growth and calcification. We also assess the ongoing use of coralline algae as marine climate proxies via calibration of skeletal morphology and geochemistry to environmental conditions. Finally, we indicate critical gaps in our understanding of coralline algal calcification and physiology and highlight key areas for future research. These include analytical areas that recently have become more accessible, such as resolving phylogenetic relationships at all taxonomic ranks, elucidating the genes regulating algal photosynthesis and calcification, and calibrating skeletal geochemical metrics, as well as research directions that are broadly applicable to global change ecology, such as the importance of community-scale and long-term experiments in stress response.

  10. Toxic effect of metal cation binary mixtures to the seaweed Gracilaria domingensis (Gracilariales, Rhodophyta).

    PubMed

    Mendes, Luiz Fernando; Stevani, Cassius Vinicius; Zambotti-Villela, Leonardo; Yokoya, Nair Sumie; Colepicolo, Pio

    2014-01-01

    The macroalga Gracilaria domingensis is an important resource for the food, pharmaceutical, cosmetic, and biotechnology industries. G. domingensis is at a part of the food web foundation, providing nutrients and microelements to upper levels. As seaweed storage metals in the vacuoles, they are considered the main vectors to magnify these toxic elements. This work describes the evaluation of the toxicity of binary mixtures of available metal cations based on the growth rates of G. domingensis over a 48-h exposure. The interactive effects of each binary mixture were determined using a toxic unit (TU) concept that was the sum of the relative contribution of each toxicant and calculated using the ratio between the toxicant concentration and its endpoint. Mixtures of Cd(II)/Cu(II) and Zn(II)/Ca(II) demonstrated to be additive; Cu(II)/Zn(II), Cu(II)/Mg(II), Cu(II)/Ca(II), Zn(II)/Mg(II), and Ca(II)/Mg(II) mixtures were synergistic, and all interactions studied with Cd(II) were antagonistic. Hypotheses that explain the toxicity of binary mixtures at the molecular level are also suggested. These results represent the first effort to characterize the combined effect of available metal cations, based on the TU concept on seaweed in a total controlled medium. The results presented here are invaluable to the understanding of seaweed metal cation toxicity in the marine environment, the mechanism of toxicity action and how the tolerance of the organism.

  11. The mechanism of adhesion and germination in the carpospores of Porphyra spiralis var. amplifolia (Rhodophyta, Bangiales).

    PubMed

    Ouriques, Luciane Cristina; Schmidt, Eder Carlos; Bouzon, Zenilda Laurita

    2012-02-01

    Spore release is the primary means of dispersion employed by red algae, and it provides insight into the elements linking the stages of their life history. In most red algae, spores are released within a sheath-like envelope of mucilage, which is responsible for their primary attachment. However, few studies have characterized the polysaccharides involved in the adhesion of seaweed spores. Therefore, in this paper, the process of spore germination and adhesion in Porphyra spiralis var. amplifolia is described, as representative of the germination pattern of the Naccaria type. Using FITC-labeled lectins, we discovered high concentrations of α-D-mannose, α-D-glucose and β-D-galactose in the mucilage. The germ tube reacted with RCA-FITC, indicating the presence β-D-galactose, and the rhizoidal cells showed the presence of α-D-mannose, α-D-glucose and β-D-galactose, indicating their importance to substrate adhesion. Using light and transmission electron microscopy, we also conducted an analysis of spore ultrastructure. We found that the differentiation of a vacuole in the spore is one of the most important processes marking the initial stage of germination. Thus, as the degree of vacuolation increases, whole cell contents move towards the germ tube, which undergoes several successive divisions forming the sporophytic phase. Therefore, we can conclude that germination in Porphyra spiralis var. amplifolia is characterized by (1) the fixation of carpospores in the substrate by sugars present in the mucilage and (2) the polarization of cell contents by the processes of vacuolization and germ tube formation.

  12. Tolerance to oxidative stress induced by desiccation in Porphyra columbina (Bangiales, Rhodophyta).

    PubMed

    Contreras-Porcia, Loretto; Thomas, Daniela; Flores, Verónica; Correa, Juan A

    2011-03-01

    Unravelling the mechanisms underlying desiccation tolerance is crucial in order to understand the position of algal species in the intertidal zone. The alga Porphyra columbina lives in the uppermost part of the rocky intertidal zones around the world and was selected as a model for this study. Naturally desiccated plants were collected during low tide and studied for morphological changes, oxidative burst induction, biomolecule oxidation, antioxidant responses, and photosynthetic status. Naturally hydrated plants collected during high tides were used for comparative purposes. In addition, changes induced by desiccation were assessed in vitro and the capacity to recover from desiccation was determined by rehydrating the fronds in seawater. The global results show that desiccation induces morphological and cellular alterations accompanied by a loss of ∼96% of the water content. Overproduction of reactive oxygen species (ROS) was induced by desiccation and two peaks of H(2)O(2) were detected at 1 and 3 h of desiccation. However, during in vitro rehydration post-desiccation, the ROS quickly returned to the basal levels. At the biomolecular level, only a low production of oxidized proteins was recorded during desiccation, whereas the activity of diverse antioxidant enzymes increased. However, this activity diminished to near basal levels during rehydration. The photosynthetic efficiency (F(v)/F(m)) during desiccation declined by 94-96% of the values recorded in hydrated plants. This reduction was generated by the low levels of trapped energy flux per cross-section (TRo/CS), electron transport flux per CS (ETo/CS), and density of reaction centres (RC/SCo) as well as the chlorophyll content. The inverse pattern was observed for the levels of phycocyanin and phycoerythrin content. F(v)/F(m) and the photosynthetic indicators were restored to normal levels after only 5 min of rehydration. The results indicate that desiccation in P. columbina causes overproduction of ROS that is efficiently attenuated. The morphological and photosynthetic changes could be operating as tolerance mechanisms due to the fact that these responses principally prevent biomolecular alteration and cellular collapse. Thus, the activation of different physiological mechanisms helps to explain the high tolerance to desiccation of P. columbina and, at least in part, the position of this species at the highest level in the intertidal zone.

  13. Structural features and gene-expression profiles of actin homologs in Porphyra yezoensis (Rhodophyta).

    PubMed

    Kitade, Yukihiro; Nakamura, Michiko; Uji, Toshiki; Fukuda, Satoru; Endo, Hirotoshi; Saga, Naotsune

    2008-10-15

    The marine red alga Porphyra yezoensis contains an actin gene family consisting of at least four isoforms (PyACT1, 2, 3 and 4). The amino acid identity between isoforms exceeds 83%, and each contains a putative nuclear export signal (NES). We scanned the sequences for amino acids in regions homologous to the intermonomeric interface of actin filaments. Few residues expected to engage in cross-linking were conserved between the four isoforms. The results of the sequence analyses suggest that PyACT2 probably functions in the nucleus as a monomer (G-actin) or in other unconventional forms. In addition, the distribution and position of the introns were different from those in florideophycean actin genes. The expression level of PyACT3 in matured gametophytes was significantly higher than in those in a vegetative state, although the mRNA was detected at similar levels in both apical and basal parts of thalli. The expression levels of PyACT2 and 4, on the other hand, did not change significantly between the matured and vegetative gametophytes. The PyACT3 may serve as a molecular marker for monitoring thallus maturation in this species.

  14. Possible sister groups and phylogenetic relationships among selected North Pacific and North Atlantic Rhodophyta

    NASA Astrophysics Data System (ADS)

    Lindstrom, Sandra C.

    1987-09-01

    Although the cool temperate (boreal) waters of the N. Pacific and N. Atlantic share many similar if not identical species, there have been few studies to test the identity of these species pairs. Whereas such tests are important from a taxonomic perspective, they tell us little if anything about biogeographic relationships. A more useful approach is one employing phylogenetic systematics (cladistics). The interpretation of phylogenetic diagrams (cladograms) in terms of biogeographic area relationships is explained. It is argued that cladistic analyses of taxa occurring in the cool temperate waters of the northern oceans can provide biogeographic tracks, which in turn can suggest the origins and migrations of species and possibly even floras. A number of cool temperate taxa that appear particularly amenable to this approach are discussed, including genera in the Palmariaceae, Corallinaceae, Dumontiaceae, Solieriaceae, Petrocelidaceae, Ceramiaceae and Rhodomelaceae.

  15. Population Studies and Carrageenan Properties in Eight Gigartinales (Rhodophyta) from Western Coast of Portugal

    PubMed Central

    Pereira, Leonel

    2013-01-01

    Eight carrageenophytes, representing seven genera and three families of Gigartinales (Florideophyceae), were studied for 15 months. The reproductive status, dry weight, and carrageenan content have been followed by a monthly random sampling. The highest carrageenan yields were found in Chondracanthus acicularis (61.1%), Gigartina pistillata (59.7%), and Chondracanthus teedei var. lusitanicus (58.0%). Species of Cystocloniaceae family produces predominantly iota-carrageenans; Gigartinaceae family produces hybrid kappa-iota carrageenans (gametophytic plants) and lambda-family carrageenans (sporophytic plants); Phyllophoraceae family produces kappa-iota-hybrid carrageenans. Quadrate destructive sampling method was used to determine the biomass and line transect. Quadrate nondestructive sampling method, applied along a perpendicular transect to the shoreline, was used to calculate the carrageenophytes cover in two periods: autumn/winter and spring/summer. The highest cover and biomass were found in Chondrus crispus (3.75%–570 g/m2), Chondracanthus acicularis (3.45%–99 g/m2), Chondracanthus teedei var. lusitanicus (2.45%–207.5 g/m2), and Mastocarpus stellatus (2.02%–520 g/m2). PMID:24288514

  16. Identification and characterization of a DnaJ gene from red alga Pyropia yezoensis (Bangiales, Rhodophyta)

    NASA Astrophysics Data System (ADS)

    Liu, Jiao; Li, Xianchao; Tang, Xuexi; Zhou, Bin

    2016-03-01

    Members of the DnaJ family are proteins that play a pivotal role in various cellular processes, such as protein folding, protein transport and cellular responses to stress. In the present study, we identified and characterized the full-length DnaJ cDNA sequence from expressed sequence tags of Pyropia yezoensis ( PyDnaJ) via rapid identification of cDNA ends. This cDNA encoded a protein of 429 amino acids, which shared high sequence similarity with other identified DnaJ proteins, such as a heat shock protein 40/DnaJ from Pyropia haitanensis. The relative mRNA expression level of PyDnaJ was investigated using real-time PCR to determine its specific expression during the algal life cycle and during desiccation. The relative mRNA expression level in sporophytes was higher than that in gametophytes and significantly increased during the whole desiccation process. These results indicate that PyDnaJ is an authentic member of the DnaJ family in plants and red algae and might play a pivotal role in mitigating damage to P. yezoensis during desiccation.

  17. Checklist and Bibliography of Benthic Marine Macroalgae Recorded from Northern Australia. I. Rhodophyta,

    DTIC Science & Technology

    1984-01-01

    Puerto Rico." Bot. Jb., 9, 457-470. 76 I Hering, D. (1841). "Diagnoses algarum novarum a cl. Dre. Ferdinand Krauss in Africa australi lectarum." Ann...ASCOT VALE (AUSTRALIA) UNCLASSIFIED J A LEWIS JAN 84 MRL-R-912 F/6 6/3 NLKIIEIIIEEIIF IIII IIU’~" m2 IIIJIL125 1111𔃾L 111 MICROCOPY RESOLUTION TESI

  18. Antiviral Activities of Sulfated Polysaccharides Isolated from Sphaerococcus coronopifolius (Rhodophytha, Gigartinales) and Boergeseniella thuyoides (Rhodophyta, Ceramiales)

    PubMed Central

    Bouhlal, Rhimou; Haslin, Camille; Chermann, Jean-Claude; Colliec-Jouault, Sylvia; Sinquin, Corinne; Simon, Gaelle; Cerantola, Stephane; Riadi, Hassane; Bourgougnon, Nathalie

    2011-01-01

    Water-soluble sulfated polysaccharides isolated from two red algae Sphaerococcus coronopifolius (Gigartinales, Sphaerococcaceae) and Boergeseniella thuyoides (Ceramiales, Rhodomelaceae) collected on the coast of Morocco inhibited in vitro replication of the Human Immunodeficiency Virus (HIV) at 12.5 μg/mL. In addition, polysaccharides were capable of inhibiting the in vitro replication of Herpes simplex virus type 1 (HSV-1) on Vero cells values of EC50 of 4.1 and 17.2 μg/mL, respectively. The adsorption step of HSV-1 to the host cell seems to be the specific target for polysaccharide action. While for HIV-1, these results suggest a direct inhibitory effect on HIV-1 replication by controlling the appearance of the new generations of virus and potential virucidal effect. The polysaccharides from S. coronopifolius (PSC) and B. thuyoides (PBT) were composed of galactose, 3,6-anhydrogalactose, uronics acids, sulfate in ratios of 33.1, 11.0, 7.7 and 24.0% (w/w) and 25.4, 16.0, 3.2, 7.6% (w/w), respectively. PMID:21822410

  19. Effects of weed cover composition on insect pest and natural enemy abundance in a field of Dracaena marginata (Asparagales: Asparagaceae) in Costa Rica.

    PubMed

    Sadof, Clifford S; Linkimer, Mildred; Hidalgo, Eduardo; Casanoves, Fernando; Gibson, Kevin; Benjamin, Tamara J

    2014-04-01

    Weeds and their influence on pest and natural enemy populations were studied on a commercial ornamental farm during 2009 in the Atlantic Zone of Costa Rica. A baseline survey of the entire production plot was conducted in February, along a 5 by 5 m grid to characterize and map initial weed communities of plants, cicadellids, katydids, and armored scales. In total, 50 plant species from 21 families were found. Seven weed treatments were established to determine how weed manipulations would affect communities of our targeted pests and natural enemies. These treatments were selected based on reported effects of specific weed cover on herbivorous insects and natural enemies, or by their use by growers as a cover crop. Treatments ranged from weed-free to being completely covered with endemic species of weeds. Although some weed treatments changed pest abundances, responses differed among arthropod pests, with the strongest effects observed for Caldwelliola and Empoasca leafhoppers. Removal of all weeds increased the abundance of Empoasca, whereas leaving mostly cyperacaeous weeds increased the abundance of Caldwelliola. Weed manipulations had no effect on the abundance of katydid and scale populations. No weed treatment reduced the abundance of all three of the target pests. Differential responses of the two leafhopper species to the same weed treatments support hypotheses, suggesting that noncrop plants can alter the abundance of pests through their effects on arthropod host finding and acceptance, as well as their impacts on natural enemies.

  20. Assessment of four molecular markers as potential DNA barcodes for red algae Kappaphycus Doty and Eucheuma J. Agardh (Solieriaceae, Rhodophyta).

    PubMed

    Tan, Ji; Lim, Phaik-Eem; Phang, Siew-Moi; Hong, Dang Diem; Sunarpi, H; Hurtado, Anicia Q

    2012-01-01

    DNA barcoding has been a major advancement in the field of taxonomy, seeing much effort put into the barcoding of wide taxa of organisms, macro and microalgae included. The mitochondrial-encoded cox1 and plastid-encoded rbcL has been proposed as potential DNA barcodes for rhodophytes, but are yet to be tested on the commercially important carrageenophytes Kappaphycus and Eucheuma. This study gauges the effectiveness of four markers, namely the mitochondrial cox1, cox2, cox2-3 spacer and the plastid rbcL in DNA barcoding on selected Kappaphycus and Eucheuma from Southeast Asia. Marker assessments were performed using established distance and tree-based identification criteria from earlier studies. Barcoding patterns on a larger scale were simulated by empirically testing on the commonly used cox2-3 spacer. The phylogeny of these rhodophytes was also briefly described. In this study, the cox2 marker which satisfies the prerequisites of DNA barcodes was found to exhibit moderately high interspecific divergences with no intraspecific variations, thus a promising marker for the DNA barcoding of Kappaphycus and Eucheuma. However, the already extensively used cox2-3 spacer was deemed to be in overall more appropriate as a DNA barcode for these two genera. On a wider scale, cox1 and rbcL were still better DNA barcodes across the rhodophyte taxa when practicality and cost-efficiency were taken into account. The phylogeny of Kappaphycus and Eucheuma were generally similar to those earlier reported. Still, the application of DNA barcoding has demonstrated our relatively poor taxonomic comprehension of these seaweeds, thus suggesting more in-depth efforts in taxonomic restructuring as well as establishment.

  1. Assessment of Four Molecular Markers as Potential DNA Barcodes for Red Algae Kappaphycus Doty and Eucheuma J. Agardh (Solieriaceae, Rhodophyta)

    PubMed Central

    Tan, Ji; Lim, Phaik-Eem; Phang, Siew-Moi; Hong, Dang Diem; Sunarpi, H.; Hurtado, Anicia Q.

    2012-01-01

    DNA barcoding has been a major advancement in the field of taxonomy, seeing much effort put into the barcoding of wide taxa of organisms, macro and microalgae included. The mitochondrial-encoded cox1 and plastid-encoded rbcL has been proposed as potential DNA barcodes for rhodophytes, but are yet to be tested on the commercially important carrageenophytes Kappaphycus and Eucheuma. This study gauges the effectiveness of four markers, namely the mitochondrial cox1, cox2, cox2-3 spacer and the plastid rbcL in DNA barcoding on selected Kappaphycus and Eucheuma from Southeast Asia. Marker assessments were performed using established distance and tree-based identification criteria from earlier studies. Barcoding patterns on a larger scale were simulated by empirically testing on the commonly used cox2-3 spacer. The phylogeny of these rhodophytes was also briefly described. In this study, the cox2 marker which satisfies the prerequisites of DNA barcodes was found to exhibit moderately high interspecific divergences with no intraspecific variations, thus a promising marker for the DNA barcoding of Kappaphycus and Eucheuma. However, the already extensively used cox2-3 spacer was deemed to be in overall more appropriate as a DNA barcode for these two genera. On a wider scale, cox1 and rbcL were still better DNA barcodes across the rhodophyte taxa when practicality and cost-efficiency were taken into account. The phylogeny of Kappaphycus and Eucheuma were generally similar to those earlier reported. Still, the application of DNA barcoding has demonstrated our relatively poor taxonomic comprehension of these seaweeds, thus suggesting more in-depth efforts in taxonomic restructuring as well as establishment. PMID:23285223

  2. Chemical profile and biological potential of non-polar fractions from Centroceras clavulatum (C. Agardh) Montagne (Ceramiales, Rhodophyta).

    PubMed

    Rocha, Otávio P; De Felício, Rafael; Rodrigues, Ana Helena B; Ambrósio, Daniela L; Cicarelli, Regina Maria B; De Albuquerque, Sérgio; Young, Maria Claudia M; Yokoya, Nair S; Debonsi, Hosana M

    2011-08-19

    The present study reports the Gas Chromatography-Mass Spectrometry (GC-MS) evaluation of the hexanes and dichloromethane fractions from extracts of the red alga Centroceras clavulatum (C. Agardh) Montagne. Twenty three compounds were identified, totaling ca. 42% of both fractions (0.18 g mass extract). The main constituents of the fractions were hexadecanoic acid (17.6%) and pentadecanoic acid (15.9%). Several secondary metabolites with interesting biological activity, such as (-)-loliolide, neophytadiene, phytol were identified. In addition, several classes of secondary metabolites, including phenolic compounds (e.g., phenylacetic acid), terpene derivatives, fatty acids, halogenated compound (e.g., 2-chlorocyclohexenol), lignoids, steroids, esters, amides (e.g., hexadecanamide), ketones, carboxylic acids, aldehydes and alcohols were observed. The occurrence of several of these structural classes is described for the first time in this species. The same fractions analyzed by GC-MS, and a separate set of polar fractions, were evaluated against two life cycle stages (epimastigote and trypomastigote forms) of the protozoan Trypanosoma cruzi and against phytopatogenic fungi Cladosporium cladosporiodes and C. sphaerospermum. The dichloromethane fraction was active against both T. cruzi forms (epimastigote IC(50) = 19.1 μg.mL-1 and trypomastigote IC(50) = 76.2 μg.mL-1). The hexanes and ethyl acetate fractions also displayed activity against both fungi species (200 μg) by TLC-bioautography.

  3. Dietary Supplementation with the Microalga Galdieria sulphuraria (Rhodophyta) Reduces Prolonged Exercise-Induced Oxidative Stress in Rat Tissues

    PubMed Central

    Carfagna, Simona; Napolitano, Gaetana; Barone, Daniela; Pinto, Gabriele; Venditti, Paola

    2015-01-01

    We studied the effects of ten-day 1% Galdieria sulphuraria dietary supplementation on oxidative damage and metabolic changes elicited by acute exercise (6-hour swimming) determining oxygen consumption, lipid hydroperoxides, protein bound carbonyls in rat tissue (liver, heart, and muscle) homogenates and mitochondria, tissue glutathione peroxidase and glutathione reductase activities, glutathione content, and rates of H2O2 mitochondrial release. Exercise increased oxidative damage in tissues and mitochondria and decreased tissue content of reduced glutathione. Moreover, it increased State 4 and decreased State 3 respiration in tissues and mitochondria. G. sulphuraria supplementation reduced the above exercise-induced variations. Conversely, alga supplementation was not able to modify the exercise-induced increase in mitochondrial release rate of hydrogen peroxide and in liver and heart antioxidant enzyme activities. The alga capacity to reduce lipid oxidative damage without reducing mitochondrial H2O2 release can be due to its high content of C-phycocyanin and glutathione, which are able to scavenge peroxyl radicals and contribute to phospholipid hydroperoxide metabolism, respectively. In conclusion, G. sulphuraria ability to reduce exercise-linked oxidative damage and mitochondrial dysfunction makes it potentially useful even in other conditions leading to oxidative stress, including hyperthyroidism, chronic inflammation, and ischemia/reperfusion. PMID:25874021

  4. Expression of the phycoerythrin gene of Gracilaria lemaneiformis (Rhodophyta) in E. coli and evaluation of the bioactivity of recombinant PE

    NASA Astrophysics Data System (ADS)

    Wen, Ruobing; Sui, Zhenghong; Zhang, Xuecheng; Zhang, Shuang; Qin, Song

    2007-10-01

    Phycoerythrin (PE) is one of the most important proteins involved in light capturing during photosynthesis in red algae. Its potential biological activities had gained wide concerns. In the present study, tumor cytotoxic and hydroxyl radical assay were preformed to detect the bioactivity of recombinant PE. Recombinant plasmids pGEX-PE and pBGL were transformed into E. coli BL21 to make two recombinant strains BEX (pGEX-PE) and BGL (pBGL). PE expressing in BEX (pGEX-PE) was validated by SDS-PAGE and Western blotting analysis. SDS-PAGE analysis indicated that the PE-GST fusion protein was mostly inclusion bodies. Specific expression of PE was confirmed by Western blotting analysis. The recombinant E. coli BEX (pGEX-PE) cells were collected and sonicated. The supernatants were reserved for the tumor cytotoxic experiments. The result of tumor cytotoxic assay indicated that the supernatants containing PE had the activity of inhibiting the growth of Hela cells and with the increase of protein concentration, the inhibiting rate increased from 37.31% to 63.26%, which showed significant difference from the control. Hydroxyl radical scavenging effect was tested with supernatants of BEX (pGEX-PE) and BGL (pBGL) cell lysates treated with sonication and heating. For the sonication samples, the scavenging rates of the supernatants of BEX (pGEX-PE) and BGL (pBGL) cell lysates were significantly higher than the negative control BL21(pGEX-4T) ( P<0.02), and the scavenging rates increased slowly following the increase of the protein content. For the heating samples, except for the 0.2 mg mL-1 BGL (pBGL) products, the scavenging effects of the supernatants of BEX (pGEX-PE) and BGL (pBGL) cell lysates were stronger than that of negative control BL21(pGEX-4T). However, the effect intensity was not positively correlated with the increase of the protein concentration. Though a partially decreased hydroxyl radical scavenging activity was led by heating, the biological activity was still retained and conspicuous. This research showed that phycoerythrin protein expressing in E. coli has the potential medical and sanitarian value.

  5. Effects of UV-B irradiation on isoforms of antioxidant enzymes and their activities in red alga Grateloupia filicina (Rhodophyta)

    NASA Astrophysics Data System (ADS)

    Zhao, Jiqiang; Li, Lixia

    2014-11-01

    Macroalgae in a littoral zone are inevitably exposed to UV-B irradiance. We analyzed the effects of UV-B on isoenzyme patterns and activities of superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), and ascorbate peroxidase (APX) of red algae Grateloupia filicina (Lamour.) C. Agardh. The activities of SOD, CAT, and APX changed in response to UV-B in a time- and dose-dependent manner. POX activity increased significantly under all three UV-B treatments. The enzymatic assay showed three distinct bands of SODI (Mn-SOD), SODII (Fe-SOD), and SODIII (CuZn-SOD) under a low (Luv) and medium (Muv) dose of UV-B irradiation, while SODI and SODIII activities decreased significantly when exposed to a high dose of UV-B irradiation (Huv). The activity of POX isoenzymes increased significantly after exposure to UV-B, which is consistent with the total activity. In addition, a clear decrease in activity of CATIV was detected in response to all the three doses of UV treatments. Some bands of APX isoenzyme were also clearly influenced by UV-B irradiation. Correspondingly, the daily growth rate declined under all the three exposure doses, and was especially significant under Muv and Huv treatments. These data suggest that, although the protection mechanisms of antioxidant defense system are partly inducible by UV-B to prevent the damage, G. filicina has incomplete tolerance to higher UV-B irradiation stress.

  6. Aragonite infill in overgrown conceptacles of coralline Lithothamnion spp. (Hapalidiaceae, Hapalidiales, Rhodophyta): new insights in biomineralization and phylomineralogy.

    PubMed

    Krayesky-Self, Sherry; Richards, Joseph L; Rahmatian, Mansour; Fredericq, Suzanne

    2016-04-01

    New empirical and quantitative data in the study of calcium carbonate biomineralization and an expanded coralline psbA framework for phylomineralogy are provided for crustose coralline red algae. Scanning electron microscopy (SEM) and energy dispersive spectrometry (SEM-EDS) pinpointed the exact location of calcium carbonate crystals within overgrown reproductive conceptacles in rhodolith-forming Lithothamnion species from the Gulf of Mexico and Pacific Panama. SEM-EDS and X-ray diffraction (XRD) analysis confirmed the elemental composition of these calcium carbonate crystals to be aragonite. After spore release, reproductive conceptacles apparently became overgrown by new vegetative growth, a strategy that may aid in sealing the empty conceptacle chamber, hence influencing the chemistry of the microenvironment and in turn promoting aragonite crystal growth. The possible relevance of various types of calcium carbonate polymorphs present in the complex internal structure and skeleton of crustose corallines is discussed. This is the first study to link SEM, SEM-EDS, XRD, Microtomography and X-ray microscopy data of aragonite infill in coralline algae with phylomineralogy. The study contributes to the growing body of literature characterizing and speculating about how the relative abundances of carbonate biominerals in corallines may vary in response to changes in atmospheric pCO2 , ocean acidification, and global warming.

  7. Removal of eutrophication factors and heavy metal from a closed cultivation system using the macroalgae, Gracilaria sp. (Rhodophyta)

    NASA Astrophysics Data System (ADS)

    Kang, Kyoung Ho; Sui, Zhenghong

    2010-11-01

    In this study, the ability of macroalgae Gracilaria sp. of removing eutrophication factors and toxic heavy metals Al, Cr, and Zn in a closed cultivation system is reported. The results show that the concentration of the three heavy metals decreased significantly during the experimental period in an algal biomass dependent manner. The biofiltration capacity of the alga for Al, Cr, and Zn is 10.1%-72.6%, 52.5%-83.4% and 36.5%-91.7%, respectively. Using more materials resulted in stronger heavy metal removal. Additionally, the concentration of chl- a, TN, TP and DIN of water samples from aquariums involving large, medium, and small algal biomass cultivation increased first and then decreased during the experiment. COD value of all three groups decreased with time and displayed algal biomass dependency: more algae resulting in a greater COD value than those of less biomass. Furthermore, changes in COD reflect an obvious organic particles deprivation process of algae. This is the first report on heavy metal removal effect by Gracilaria species. The results suggest that macroalgae can be used as a biofilter for the treatment of nutrient-enriched or heavy-metal polluted water, to which an appropriate time range should be carefully determined.

  8. Temperature response of photosynthetic light- and carbon-use characteristics in the red seaweed Gracilariopsis lemaneiformis (Gracilariales, Rhodophyta).

    PubMed

    Zou, Dinghui; Gao, Kunshan

    2014-04-01

    The red seaweed Gracilariopsis is an important crop extensively cultivated in China for high-quality raw agar. In the cultivation site at Nanao Island, Shantou, China, G. lemaneiformis experiences high variability in environmental conditions like seawater temperature. In this study, G. lemaneiformis was cultured at 12, 19, or 26°C for 3 weeks, to examine its photosynthetic acclimation to changing temperature. Growth rates were highest in G. lemaneiformis thalli grown at 19°C, and were reduced with either decreased or increased temperature. The irradiance-saturated rate of photosynthesis (Pmax ) decreased with decreasing temperature, but increased significantly with prolonged cultivation at lower temperatures, indicating the potential for photosynthesis acclimation to lower temperature. Moreover, Pmax increased with increasing temperature (~30 μmol O2  · g(-1) FW · h(-1) at 12°C to 70 μmol O2  · g(-1) FW · h(-1) at 26°C). The irradiance compensation point for photosynthesis (Ic ) decreased significantly with increasing temperature (28 μmol photons · m(-2)  · s(-1) at high temperature vs. 38 μmol photons · m(-2)  · s(-1) at low temperature). Both the photosynthetic light- and carbon-use efficiencies increased with increasing growth or temperatures (from 12°C to 26°C). The results suggested that the thermal acclimation of photosynthetic performance of G. lemaneiformis would have important ecophysiological implications in sea cultivation for improving photosynthesis at low temperature and maintaining high standing biomass during summer. Ongoing climate change (increasing atmospheric CO2 and global warming) may enhance biomass production in G. lemaneiformis mariculture through the improved photosynthetic performances in response to increasing temperature.

  9. Photosynthetic parameters of sexually different parts of Porphyra katadai var. hemiphylla (Bangiales, Rhodophyta) during dehydration and re-hydration.

    PubMed

    Lin, A-Peng; Wang, Guang-Ce; Yang, Fang; Pan, Guang-Hua

    2009-03-01

    Physiological data from extreme habitat organisms during stresses are vital information for comprehending their survival. The intertidal seaweeds are exposed to a combination of environmental stresses, the most influential one being regular dehydration and re-hydration. Porphyra katadai var. hemiphylla is a unique intertidal macroalga species with two longitudinally separated, color distinct, sexually different parts. In this study, the photosynthetic performance of both PSI and PSII of the two sexually different parts of P. katadai thalli during dehydration and re-hydration was investigated. Under low-grade dehydration the variation of photosystems of male and female parts of P. katadai were similar. However, after the absolute water content reached 42%, the PSI of the female parts was nearly shut down while that of the male parts still coordinated well and worked properly with PSII. Furthermore, after re-hydration with a better conditioned PSI, the dehydrated male parts were able to restore photosynthesis within 1 h, while the female parts did not. It is concluded that in P. katadai the susceptibility of photosynthesis to dehydration depends on the accommodative ability of PSI. The relatively lower content of phycobiliprotein in male parts may be the cause for a stronger PSI after severe dehydration.

  10. Unusual algal turfs associated with the rhodophyta Phyllophora crispa: Benthic assemblages along a depth gradient in the Central Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Bonifazi, Andrea; Ventura, Daniele; Gravina, Maria Flavia; Lasinio, Giovanna Jona; Belluscio, Andrea; Ardizzone, Gian Domenico

    2017-02-01

    Macroalgal assemblages dominated by the turf-forming alga Phyllophora crispa are described in detail for the first time in the Central Mediterranean Sea. This particular form of algal growth, which comprises an upper mixed layer of multiple algal species with a basal stratum formed by entangled thalli of P. crispa, was observed for the first time in 2012 along the promontory of Punta del Lazzaretto (Giglio Island, Italy). In this study, this assemblage was analysed to document the diversity of macroalgae and invertebrate associated communities and assess their distribution along a depth gradient. The algae forming turfs grow directly on the rock at low depth up to 10-15 m depth, while they grow above P. crispa from 15 m to 35 m depth, resulting in luxuriant beds covering up to 100% of the substrate. Multivariate analysis revealed clear differences regarding algae and invertebrate species richness and abundance between shallow and deep strata because of the dominance of Phyllophora crispa at depths greater than 20 m. The long laminal thalli of P. crispa favoured sessile fauna colonization, while the vagile species were principally linked to the architectural complexity of the turf layer created by the P. crispa, which increased the microhabitat diversity and favoured sediment deposition within the turf layer. The complex structures of these turf assemblages and their widespread distribution along the whole coast of the island suggest a well-established condition of the communities linked to the high natural sedimentation rate observed in the area.

  11. Delimiting the species Neosiphonia yendoi (Rhodomelaceae, Rhodophyta) based on COI and rbcL genetic variation in Korea and Japan

    NASA Astrophysics Data System (ADS)

    Kim, Byeongseok; Yang, Mi Yeon; Kim, Myung Sook

    2016-09-01

    Although the marine red algal genus Neosiphonia is well characterized, many species of Neosiphonia are poorly understood. To correctly define the species delimitation of Neosiphonia yendoi using genetic variation, owing to the confusion over identification with " N. sphaerocarpa" from Korea, we investigated intensively the haplotype network of the mitochondrial COI and the plastid rbcL genes of specimens collected from Korea and Japan. The molecular analyses indicated that specimens collected in different sites of Korea and Japan belong to the same species, Neosiphonia yendoi and " Neosiphonia sphaerocarpa" from Korea, which is distinguished from N. sphaerocarpa from Florida and is allied with N. yendoi collected from the type locality, Muroran of Japan. A total of 29 COI and 13 rbcL haplotypes were found and the COI haplotype network shows evidence of a clear break between specimens from Jeju Island and all other locations of Korea, suggesting the possibility of cryptic diversity within N. yendoi.

  12. Population genetic analyses are consistent with the introduction of Ceramium secundatum (Ceramiaceae, Rhodophyta) to Narragansett Bay, Rhode Island, USA.

    PubMed

    Bruce, Meghann R; Saunders, Gary W

    2015-11-01

    During ongoing DNA barcode (COI-5P) surveys of the macroalgal flora along the northwest Atlantic coast, we discovered a population of Ceramium secundatum in Narragansett Bay, Rhode Island, USA. This species is regarded as common and widespread in the northeast Atlantic, ranging from Norway to Morocco, but until now has not been reported from the western Atlantic. Several lines of evidence suggest that C. secundatum may be introduced to Narragansett Bay: (1) despite extensive collecting, specimens have only been obtained from a limited geographic range in the northwest Atlantic; (2) three other nonindigenous seaweed species are reportedly introduced in this region, which is thought to be a consequence of shipping; and (3) this species is introduced to South Africa and New Zealand. To investigate this suspected introduction, we applied population genetic analyses (using the cox2-3 spacer) to compare the Narragansett Bay C. secundatum population to native populations in the Republic of Ireland and the United Kingdom. Collectively, analyses of biogeographical and molecular data indicate that C. secundatum is likely introduced to Narragansett Bay. The implications of this discovery are discussed.

  13. Four new species of Pyropia (Bangiales, Rhodophyta) from the west coast of North America: the Pyropia lanceolata species complex updated

    PubMed Central

    Lindstrom, Sandra C.; Hughey, Jeffery R.; Rosas, Luis E. Aguilar

    2015-01-01

    Abstract Recent molecular studies indicate that the Pyropia lanceolata species complex on the west coast of North America is more speciose than previously thought. Based on extensive rbcL gene sequencing of representative specimens we recognize seven species in the complex, three of which are newly described: Pyropia montereyensis sp. nov., Pyropia columbiensis sp. nov., and Pyropia protolanceolata sp. nov. The new species are all lanceolate, at least when young, and occur in the upper mid to high intertidal zone primarily in winter and early spring. Pyropia montereyensis and Pyropia columbiensis are sister taxa that are distributed south and north of Cape Mendocino, respectively, and both occur slightly lower on the shore than Pyropia lanceolata or Pyropia pseudolanceolata. Pyropia protolanceolata is known thus far only from Morro Rock and the Monterey Peninsula, California; it occurs basally to the other species in the complex in the molecular phylogeny. A fourth newly described species, Pyropia bajacaliforniensis sp. nov., is more closely related to Pyropia nereocystis than to species in this complex proper. It is a thin species with undulate margins known only from Moss Landing, Monterey Bay, California, and northern Baja California; it also occurs in the high intertidal in spring. Porphyra mumfordii, a high intertidal winter species that has frequently been confused with species in the Pyropia lanceolata complex, has now been confirmed to occur from Calvert Island, British Columbia, to Pescadero State Park, California. PMID:26312033

  14. The system of sulfated galactans from the red seaweed Gymnogongrus torulosus (Phyllophoraceae, Rhodophyta): Location and structural analysis.

    PubMed

    Estevez, José M; Ciancia, Marina; Cerezo, Alberto S

    2008-09-05

    Sulfated polysaccharides were localized in the cuticle, cortex and medulla of the gametophyte thallus, being more concentrated in the intercellular matrix than in the cell walls. During the water extraction sequence, a small percentage of galactan sulfates (5.1% of dry seaweed) with average low Mr (6-11.4kDa) were extracted at room temperature without disturbing the cellular arrangement, while sulfated galactans of average medium Mr (18-45kDa) were obtained by further hot-water extractions (52.4% of dry seaweed), with diorganization of the tissue. The residue (40.0% of dry seaweed) still contained carrageenan-type (major) and agaran-type (minor) galactans. Part of these galactans was extracted with 8.4% LiCl solution in DMSO, from which "pure" κ/ι-carrageenans were isolated. Carrageenans and agarans were extracted in a ratio 1:0.5, showing the highest amount of agaran-structures for a carrageenophyte. The galactans comprise alternating 4-sulfated (major) and non-sulfated (minor) 3-linked β-d-galactopyranose units, and 4-linked α-galactopyranose units with the following substitutions: (i) non-sulfated and 2-sulfated 3,6-anhydro-α-d-galactopyranose residues in the carrageenan-structures, which belong to the κ-family (κ/ι-carrageenans); (ii) 3-sulfated α-l-galactopyranose units and 2-sulfated 3,6-anhydro-α-l-galactopyranose residues in the agaran-structures. Alkaline treatment and alkaline dialysis of the main extracts gave "pure" κ/ι-carrageenans, showing that carrageenan molecules are extracted together with low Mr agarans or agaran-dl-hybrids.

  15. Chemical structure of the complex pyruvylated and sulfated agaran from the red seaweed Palisada flagellifera (Ceramiales, Rhodophyta).

    PubMed

    Ferreira, Luciana G; Noseda, Miguel D; Gonçalves, Alan G; Ducatti, Diogo R B; Fujii, Mutue T; Duarte, Maria E R

    2012-01-10

    A homogeneous agaran fraction from Palisada flagellifera (Laurencia complex, Rhodomelaceae, Ceramiales) was obtained by aqueous room-temperature extraction, followed by ion-exchange chromatography. This galactan presents a highly complex structure with at least 18 different types of derivatives. The A units were found mostly pyruvylated, 2-sulfated (∼34%), and 6-methylated (∼34%), with the latter partially 2- and 2,4-sulfated. Minor amounts of β-D-galactopyranosyl units 2-, 6- and 2,6-sulfated, 6-glycosylated, and non-substituted are also present. The B-units are L-sugars composed predominantly of their cyclized derivatives, 3,6-anhydrogalactose and 3,6-anhydro-2-O-methylgalactose (∼56%). The former are linked to β-D-galactosyl (6-methyl) (6-glycosylated) units, as well as to 4,6-O-(1-carboxyethylidene)-β-D-galactose 2-sulfate in the proportion of 3:1.8, respectively. A significant amount (∼18%) of the α-L-galactopyranosyl units are linked to pyruvylated β-D-galactose 2-sulfate residues. An important part of the B-units (20%) is represented by α-L-galactose 6-sulfate substituted on C-3 by xylosyl, galactosyl and/or 2,3-di-O-methylgalactose units or sulfate groups that preclude their cyclization to 3,6-anhydrogalactosyl derivative. The precursor units are present in relatively low percentages. Kinetic studies suggest that in P. flagellifera agaran the cyclizable units are linked to 6-O-methyl-β-D-galactosyl and/or β-D-galactosyl units (6-glycosylated). The structural complexity of this polysaccharide is increased by the presence of 2- and 3,6-sulfated α-L-galactoses, with the latter additionally 2-O-methylated. Therefore, the major subfraction obtained from the cold extract contains structurally complex sulfated, methylated, and pyruvylated agaran.

  16. Four new species of Pyropia (Bangiales, Rhodophyta) from the west coast of North America: the Pyropialanceolata species complex updated.

    PubMed

    Lindstrom, Sandra C; Hughey, Jeffery R; Rosas, Luis E Aguilar

    2015-01-01

    Recent molecular studies indicate that the Pyropialanceolata species complex on the west coast of North America is more speciose than previously thought. Based on extensive rbcL gene sequencing of representative specimens we recognize seven species in the complex, three of which are newly described: Pyropiamontereyensis sp. nov., Pyropiacolumbiensis sp. nov., and Pyropiaprotolanceolata sp. nov. The new species are all lanceolate, at least when young, and occur in the upper mid to high intertidal zone primarily in winter and early spring. Pyropiamontereyensis and Pyropiacolumbiensis are sister taxa that are distributed south and north of Cape Mendocino, respectively, and both occur slightly lower on the shore than Pyropialanceolata or Pyropiapseudolanceolata. Pyropiaprotolanceolata is known thus far only from Morro Rock and the Monterey Peninsula, California; it occurs basally to the other species in the complex in the molecular phylogeny. A fourth newly described species, Pyropiabajacaliforniensis sp. nov., is more closely related to Pyropianereocystis than to species in this complex proper. It is a thin species with undulate margins known only from Moss Landing, Monterey Bay, California, and northern Baja California; it also occurs in the high intertidal in spring. Porphyramumfordii, a high intertidal winter species that has frequently been confused with species in the Pyropialanceolata complex, has now been confirmed to occur from Calvert Island, British Columbia, to Pescadero State Park, California.

  17. MESOPHYLLUM SPHAERICUM SP. NOV. (CORALLINALES, RHODOPHYTA): A NEW MAËRL-FORMING SPECIES FROM THE NORTHEAST ATLANTIC(1).

    PubMed

    Peña, Viviana; Adey, Walter H; Riosmena-Rodríguez, Rafael; Jung, Moon-Yung; Afonso-Carrillo, Julio; Choi, Han-Gu; Bárbara, Ignacio

    2011-08-01

    Mesophyllum sphaericum sp. nov. is described based on spherical maërl individuals (up to 10 cm) collected in a shallow subtidal maërl bed in Galicia (NW Spain). The thalli of these specimens are radially organized, composed of arching tiers of compact medullary filaments. Epithallial cells have flattened to rounded outermost walls, and they occur in a single layer. Subepithallial initials are as long as, or longer than the daughter cells that subtend them. Cell fusions are abundant. Multiporate asexual conceptacles are protruding, mound-like with a flattened pore plate, lacking a peripheral raised rim. Filaments lining the pore canal and the conceptacle roof are composed of five to six cells with straight elongate and narrow cells at their base. Carposporangial conceptacles are uniporate, protruding, and conical. Spermatangial conceptacles were not observed. Molecular results placed M. sphaericum near to M. erubescens, but M. sphaericum is anatomically close to M. canariense. The examination of the holotype and herbarium specimens of M. canariense indicated that both species have pore canal filaments with elongate basal cells, but they differ in number of cells (five to six in M. sphaericum vs. four in M. canariense). Based on the character of pore canal filaments, M. canariense shows similarities with M. erubescens (three to five celled). The outermost walls of epithallial cells of M. canariense are flared compared to the round to flattened ones of M. erubescens, the latter being widely accepted for the genus Mesophyllum. The addition of M. sphaericum as new maërl-forming species suggests that European maërl beds are more biodiverse than previously understood.

  18. Patterns of genetic diversity of the cryptogenic red alga Polysiphonia morrowii (Ceramiales, Rhodophyta) suggest multiple origins of the Atlantic populations.

    PubMed

    Geoffroy, Alexandre; Destombe, Christophe; Kim, Byeongseok; Mauger, Stéphane; Raffo, María Paula; Kim, Myung Sook; Le Gall, Line

    2016-08-01

    The red alga Polysiphonia morrowii, native to the North Pacific (Northeast Asia), has recently been reported worldwide. To determine the origin of the French and Argentine populations of this introduced species, we compared samples from these two areas with samples collected in Korea and at Hakodate, Japan, the type locality of the species. Combined analyses of chloroplastic (rbcL) and mitochondrial (cox1) DNA revealed that the French and Argentine populations are closely related and differ substantially from the Korean and Japanese populations. The genetic structure of P. morrowii populations from South Atlantic and North Atlantic, which showed high haplotype diversity compared with populations from the North Pacific, suggested the occurrence of multiple introduction events from areas outside of the so-called native regions. Although similar, the French and Argentine populations are not genetically identical. Thus, the genetic structure of these two introduced areas may have been modified by cryptic and recurrent introduction events directly from Asia or from other introduced areas that act as introduction relays. In addition, the large number of private cytoplasmic types identified in the two introduced regions strongly suggests that local populations of P. morrowii existed before the recent detection of these invasions. Our results suggest that the most likely scenario is that the source population(s) of the French and Argentine populations was not located only in the North Pacific and/or that P. morrowii is a cryptogenic species.

  19. Ocean acidification alleviates low-temperature effects on growth and photosynthesis of the red alga Neosiphonia harveyi (Rhodophyta).

    PubMed

    Olischläger, Mark; Wiencke, Christian

    2013-12-01

    This study aimed to examine interactive effects between ocean acidification and temperature on the photosynthetic and growth performance of Neosiphonia harveyi. N. harveyi was cultivated at 10 and 17.5 °C at present (~380 µatm), expected future (~800 µatm), and high (~1500 µatm) pCO2. Chlorophyll a fluorescence, net photosynthesis, and growth were measured. The state of the carbon-concentrating mechanism (CCM) was examined by pH-drift experiments (with algae cultivated at 10 °C only) using ethoxyzolamide, an inhibitor of external and internal carbonic anhydrases (exCA and intCA, respectively). Furthermore, the inhibitory effect of acetazolamide (an inhibitor of exCA) and Tris (an inhibitor of the acidification of the diffusive boundary layer) on net photosynthesis was measured at both temperatures. Temperature affected photosynthesis (in terms of photosynthetic efficiency, light saturation point, and net photosynthesis) and growth at present pCO2, but these effects decreased with increasing pCO2. The relevance of the CCM decreased at 10 °C. A pCO2 effect on the CCM could only be shown if intCA and exCA were inhibited. The experiments demonstrate for the first time interactions between ocean acidification and temperature on the performance of a non-calcifying macroalga and show that the effects of low temperature on photosynthesis can be alleviated by increasing pCO2. The findings indicate that the carbon acquisition mediated by exCA and acidification of the diffusive boundary layer decrease at low temperatures but are not affected by the cultivation level of pCO2, whereas the activity of intCA is affected by pCO2. Ecologically, the findings suggest that ocean acidification might affect the biogeographical distribution of N. harveyi.

  20. Genome Survey Sequencing and Genetic Background Characterization of Gracilariopsis lemaneiformis (Rhodophyta) Based on Next-Generation Sequencing

    PubMed Central

    Sui, Zhenghong; Fu, Feng; Wang, Jinguo; Chang, Lianpeng; Guo, Weihua; Li, Binbin

    2013-01-01

    Gracilariopsis lemaneiformis has a high economic value and is one of the most important aquaculture species in China. Despite it is economic importance, it has remained largely unstudied at the genomic level. In this study, we conducted a genome survey of Gp. lemaneiformis using next-generation sequencing (NGS) technologies. In total, 18.70 Gb of high-quality sequence data with an estimated genome size of 97 Mb were obtained by HiSeq 2000 sequencing for Gp. lemaneiformis. These reads were assembled into 160,390 contigs with a N50 length of 3.64 kb, which were further assembled into 125,685 scaffolds with a total length of 81.17 Mb. Genome analysis predicted 3490 genes and a GC% content of 48%. The identified genes have an average transcript length of 1,429 bp, an average coding sequence size of 1,369 bp, 1.36 exons per gene, exon length of 1,008 bp, and intron length of 191 bp. From the initial assembled scaffold, transposable elements constituted 54.64% (44.35 Mb) of the genome, and 7737 simple sequence repeats (SSRs) were identified. Among these SSRs, the trinucleotide repeat type was the most abundant (up to 73.20% of total SSRs), followed by the di- (17.41%), tetra- (5.49%), hexa- (2.90%), and penta- (1.00%) nucleotide repeat type. These characteristics suggest that Gp. lemaneiformis is a model organism for genetic study. This is the first report of genome-wide characterization within this taxon. PMID:23875008

  1. Anti-inflammatory, gastroprotective and anti-ulcerogenic effects of red algae Gracilaria changii (Gracilariales, Rhodophyta) extract

    PubMed Central

    2013-01-01

    Background Gracilaria changii (Xia et Abbott) Abbott, Zhang et Xia, a red algae commonly found in the coastal areas of Malaysia is traditionally used for foods and for the treatment of various ailments including inflammation and gastric ailments. The aim of the study was to investigate anti-inflammatory, gastroprotective and anti-ulcerogenic activities of a mass spectrometry standardized methanolic extract of Gracilaria changii. Methods Methanolic extract of Gracilaria changii (MeOHGCM6 extract) was prepared and standardized using mass spectrometry (MS). Anti-inflammatory activities of MeOHGCM6 extract were examined by treating U937 cells during its differentiation with 10 μg/ml MeOHGCM6 extract. Tumour necrosis factors-α (TNF-α) response level and TNF-α and interleukin-6 (IL-6) gene expression were monitored and compared to that treated by 10 nM betamethasone, an anti-inflammatory drug. Gastroprotective and anti-ulcerogenic activities of MeOHGCM6 extract were examined by feeding rats with MeOHGCM6 extract ranging from 2.5 to 500 mg/kg body weight (b.w.) following induction of gastric lesions. Production of mucus and gastric juice, pH of the gastric juice and non-protein sulfhydryls (NP-SH) levels were determined and compared to that fed by 20 mg/kg b.w. omeprazole (OMP), a known anti-ulcer drug. Results MS/MS analysis of the MeOHGCM6 extracts revealed the presence of methyl 10-hydroxyphaeophorbide a and 10-hydroxypheophytin a, known chlorophyll proteins and several unidentified molecules. Treatment with 10 μg/ml MeOHGCM6 extract during differentiation of U937 cells significantly inhibited TNF-α response level and TNF-α and IL-6 gene expression. The inhibitory effect was comparable to that of betamethasone. No cytotoxic effects were recorded for cells treated with the 10 μg/ml MeOHGCM6 extract. Rats fed with MeOHGCM6 extract at 500 mg/kg b.w. showed reduced absolute ethanol-induced gastric lesion sizes by > 99% (p < 0.05). This protective effect was comparable to that conferred by OMP. The pH of the gastric mucus decreased in dose-dependent manner from 5.51 to 3.82 and there was a significant increase in NP-SH concentrations. Conclusions Results from the study, suggest that the mass spectrometry standardized methanolic extract of Gracillaria changii possesses anti-inflammatory, gastroprotective and anti-ulcerogenic properties. Further examination of the active constituent of the extract and its mechanism of action is warranted in the future. PMID:23497105

  2. THE DISTRIBUTION, MORPHOLOGY, AND ECOLOGY OF THREE INTRODUCED ASIATIC SPECIES OF PORPHYRA (BANGIALES, RHODOPHYTA) IN THE NORTHWESTERN ATLANTIC(1).

    PubMed

    Neefus, Christopher D; Mathieson, Arthur C; Bray, Troy L; Yarish, Charles

    2008-12-01

    Distributions of three Asiatic Porphyra species, Porphyra yezoensis Ueda, Porphyra katadae A. Miura, and Porphyra suborbiculata Kjellm., are reported from New England, USA. Species identifications were confirmed by rbcL and nuclear ribosomal DNA internal transcribed spacer-1 (ITS1) sequence comparisons with herbarium specimens, cultures, and GenBank accessions. Two distinct genotypes of P. yezoensis were detected: forma narawaensis A. Miura and f. yezoensis. Forma narawaensis occurs south of Cape Cod, Massachusetts, and has ITS1 sequences identical to cultivars widely grown in Japan. Forma yezoensis occurs in western Long Island Sound and from Cape Cod northward to midcoastal Maine; its ITS1 sequence is identical to a wild specimen from Hokkaido, Japan. P. katadae has been collected from five locations near Cape Cod; its ITS1 sequence is identical to a cultured specimen from Qingdao, China. P. suborbiculata has been collected at several locations south of Cape Cod; its presence in North Carolina and Delaware during the mid-1960s was confirmed from herbarium specimens. Morphological and ecological characteristics for New England populations of the three Asiatic species were compared to original descriptions. New England P. yezoensis f. yezoensis is similar to Ueda's original description of Japanese specimens, but there are morphological differences for P. yezoensis f. narawaensis. In New England, f. narawaensis typically does not attain the length reported in Japan (max. 19 cm versus 100 cm). New England P. katadae is similar to Miura's original description, except for slight differences in thallus thickness and reproductive patterns. By contrast, New England, Japanese, and other populations of P. suborbiculata exhibit pronounced differences in blade coloration, shape and dimensions, reproductive patterns, seasonal occurrence, and general ecology.

  3. The enhancement of cyclic electron flow around photosystem I improves the recovery of severely desiccated Porphyra yezoensis (Bangiales, Rhodophyta).

    PubMed

    Gao, Shan; Wang, Guangce

    2012-07-01

    Porphyra yezoensis, a representative species of intertidal macro-algae, is able to withstand periodic desiccation at low tide but is submerged in seawater at high tide. In this study, changes in photosynthetic electron flow in P. yezoensis during desiccation and re-hydration were investigated. The results suggested that the cyclic electron flow around photosystem I (PSI) increased significantly during desiccation, continued to operate at times of severe desiccation, and showed greater tolerance to desiccation than the electron flow around PSII. In addition, PSI activity in desiccated blades recovered faster than PSII activity during re-hydration. Even though linear electron flow was suppressed by DCMU [3-(3',4'-dichlorophenyl)-1,1-dimethylurea], cyclic electron flow could still be restored. This process was insensitive to antimycin A and could be suppressed by dibromothymoquinone (DBMIB). The prolonged dark treatment of blades reduced the speed in which the cyclic electron flow around PSI recovered, suggesting that stromal reductants, including NAD(P)H, played an important role in the donation of electrons to PSI and were the main cause of the rapid recovery of cyclic electron flow in desiccated blades during re-hydration. These results suggested that cyclic electron flow in P. yezoensis played a significant physiological role during desiccation and re-hydration and may be one of the most important factors allowing P. yezoensis blades to adapt to intertidal environments.

  4. Antioxidant activities and phenolic contents of three red seaweeds (Division: Rhodophyta) harvested from the Gulf of Mannar of Peninsular India.

    PubMed

    Chakraborty, Kajal; Joseph, Deepu; Praveen, Nammunayathuputhenkotta Krishnankartha

    2015-04-01

    The antioxidant activities of methanol extract and its solvent fractions (n-hexane, dichloromethane and ethyl acetate) of three red seaweeds (Hypnea musciformis, H. valentiae, and Jania rubens) collected from the Gulf of Mannar of South eastern coast of India were evaluated, using different in vitro systems, viz., DPPH, ABTS, HO radical scavenging activities, H2O2 scavenging ability, Fe(2+) ion chelating ability and reducing potential. Folin-Ciocalteu method was used to determine the total phenolic content of the extracts/fractions, and the results were expressed as mg of gallic acid equivalent (GAE)/g of the seaweed extracts/fractions. Thiobarbituric acid-reactive substances (TBARS) inhibition assay was employed to assess the ability of the seaweed extracts/fractions to inhibit lipid oxidation. Ethyl acetate (EtOAc) fractions of H. musciformis exhibited significantly higher total phenolic content (205.5 mg GAE/g), DPPH· scavenging activity (IC50 0.6 mg/mL), ABTS(.+) scavenging activity (IC50 0.51 μg/mL), Fe(2+) chelating ability (IC50 0.70 mg/mL), H2O2 scavenging activity (IC50 0.39 mg/mL), reducing ability (Abs700 nm 1.46) and lipid peroxidation inhibitory ability (2.71 MDAEC/kg) (P < 0.05) compared to its n-hexane, DCM fractions, crude MeOH extract and MeOH extracts/fractions of H. valentiae and J. rubens. DCM fraction of J. rubens showed significantly higher hydroxyl radical scavenging activity (IC50 0.55 mg/mL) compared with H. musciformis and H. valentiae (P < 0.05). This study indicated the potential use of red seaweeds, in particular, H. musciformis as candidate species to be used as food supplement for increasing the shelf-life of food industry, and candidates in combating carcinogenesis and inflammatory diseases.

  5. IDENTIFICATION OF CROSS-FERTILIZED CONCHOCELIS USING CLEAVED AMPLIFIED POLYMORPHIC SEQUENCE MARKERS IN CROSS-EXPERIMENTS OF PORPHYRA YEZOENSIS (BANGIALES, RHODOPHYTA)(1).

    PubMed

    Park, Eun-Jeong; Fukuda, Satoru; Endo, Hirotoshi; Kitade, Yukihiro; Saga, Naotsune

    2008-04-01

    As a part of the construction of a Porphyra yezoensis Ueda genetic linkage map, we conducted intraspecific cross-experiments and subsequent screening of cross-fertilized conchocelis by cleaved amplified polymorphic sequence (CAPS) analysis. The cross-experiments were carried out between males of the wildtype (KGJ) and females of the recessive green mutant (TU-2) using two methods, controlled and random crosses. A total of 42 and 186 wildtype-colored conchocelis colonies were obtained from the former and latter experiments, respectively. Among those, 49 DNA samples (14% and 23% obtained from the former and latter crosses, respectively) showed biparental CAPS patterns in the two gene regions (EF-1α open reading frame [ORF] region and V-ATPase). This study represents the first report in which the cross-fertilized conchocelis of P. yezoensis has been directly confirmed by molecular marker. The combination of the simple DNA extraction and CAPS analysis may be applicable in genetic studies of other macroalgae that are monoecious and/or grow slowly in laboratory culture.

  6. Characterization of the putatively introduced red alga Acrochaetium secundatum (Acrochaetiales, Rhodophyta) growing epizoically on the pelage of southern sea otters (Enhydra lutris nereis)

    USGS Publications Warehouse

    Bentall, Gena B.; Rosen, Barry H.; Kunz, Jessica M.; Miller, Melissa A.; Saunders, Gary W.; LaRoche, Nicole L.

    2016-01-01

    Ecological associations between epibionts (organisms that live on the surface of another living organism) and vertebrates have been documented in both marine and terrestrial environments, and may be opportunistic, commensal, or symbiotic (Lewin et al. 1981, Holmes 1985, Allen et al. 1993, Bledsoe et al. 2006, Pfaller et al. 2008, Suutari et al. 2010). Although epibiont proliferation is frequently reported on slow-moving, sparsely haired organisms such as manatees and sloths, reports from densely furred, highly mobile mammals are much less common. There are reports of epizoic algae for several species of pinnipeds (Kenyon and Rice 1959, Scheffer 1962, Baldridge 1977, Allen et al. 1993), which rely to varying degrees on both pelage and blubber for thermoregulation, but the phenomenon has not been widely described. Scheffer (1962) noted that red algae was fairly common on the pelage of northern fur seals (Callorhinus ursinus), pinnipeds for which fur likely makes a comparatively high contribution to thermoregulation (Donohue et al. 2000). For species with pelage that plays a critical role of thermal insulation, it seems implausible that an epibiont would persist on healthy individuals that devote significant energy resources toward grooming and actively maintaining their coat. Biological characteristics of epibiont settlement and attachment, and physiological requirements of epizoic species play key roles in their successful colonization and potential host impacts. To investigate this relationship, we explore a novel discovery of an epizoic alga from southern sea otters, including describing algal development on sea otter hair and molecular identification of the algae.

  7. Grateloupia tenuis Wang et Luan sp. nov. (Halymeniaceae, Rhodophyta): A New Species from South China Sea Based on Morphological Observation and rbcL Gene Sequences Analysis

    PubMed Central

    Wang, Hongwei; Luan, Rixiao

    2013-01-01

    Grateloupia tenuis Wang et Luan sp. nov. is a new species described from Lingshui, Hainan Province, South China Sea. Based on the external form and internal structure, combined with rbcL gene sequence analysis, Grateloupia tenuis is distinct from other Grateloupia species as follows: (1) thalli is slippery and cartilaginous in texture; possess fewer branches, relatively slight main axes, and two or three dichotomous branches; (2) cortex is 5-6 layers; medulla is solid when young, but hollow in old branches; reproductive structures are dispersed in main axes of thalli and lower portions of branchlets; exhibits Grateloupia-type auxiliary cell ampullae; (3) the four studied G. tenuis sequences were positioned in a large Grateloupia clade of Halymeniaceae, which included sister group generitype G. filicina with 68 bp differences; G. tenuis was determined to be a sister taxon to the G. catenata, G. ramosissima, G. orientalis, and G. filiformis subclade. The pairwise distances between G. tenuis and these species were 39 to 50 bp. The sequences of G. tenuis differed by 81–108 bp from the sequences of other samples in Grateloupia; there are 114–133 bp changes between G. tenuis and other genera of Halymeniaceae. In final analysis, we considered Grateloupia tenuis Wang et Luan sp. nov. to be a new species of genus Grateloupia. PMID:24455703

  8. Molecular phylogeny of the genus Chondracanthus (Rhodophyta), focusing on the resurrection of C. okamurae and the description of C. cincinnus sp. nov.

    NASA Astrophysics Data System (ADS)

    Yang, Mi Yeon; Kim, Myung Sook

    2016-09-01

    Determining the taxonomic status of the red algal genus Chondracanthus based on morphological characters is challenging due to the similarity and high degree of plasticity of the thallus. Since the taxonomic history of several Chondracanthus species remains unclear, we analyzed the plastid rbcL and mitochondrial COI genes of the specimens from Korea and Japan, in combination with morphological observations, to examine their phylogenetic relationships. Our results confirmed the distinction of C. okamurae, which is separated from C. intermedius, and identified a novel species, C. cincinnus sp. nov. Three species ( C. okamurae, C. intermedius and C. cincinnus) formed a monophyletic clade with C. tenellus. C. okamurae is distinguished by linear, narrow, cylindrical to compressed, slightly recurved axes, and a high-intertidal to subtidal distribution. It was collected from Korea and Japan, while C. intermedius was identified from Japan only. A new species, Chondracanthus cincinnus sp. nov., is characterized by linear, compressed, strongly recurved axes, and a low-intertidal to subtidal distiribution. Based on the molecular phylogeny using rbcL and COI data, we herein resurrect C. okamurae as a distinct species and identify C. cincinnus as a new species.

  9. Solar radiation (PAR and UVA) and water temperature in relation to biochemical performance of Gelidium corneum (Gelidiales, Rhodophyta) in subtidal bottoms off the Basque coast

    NASA Astrophysics Data System (ADS)

    Quintano, Endika; Ganzedo, Unai; Díez, Isabel; Figueroa, Félix L.; Gorostiaga, José M.

    2013-10-01

    Gelidium corneum (Hudson) J.V. Lamouroux is a very important primary producer in the Cantabrian coastal ecosystem. Some local declines in their populations have been recently detected in the Basque coast. Occurrences of yellowing and an unusual branch breakdown pattern have also been reported for some G. corneum populations. In order to gain further insight into those environmental stressors operating at a local scale, here we investigate if shallow subtidal populations of G. corneum living under potentially different conditions of irradiance (PAR and UVA) and water temperature exhibit differences in some biochemical indicators of stress, namely C:N, antioxidant activity (radical cation of 2,2‧-azino-bis (3-ethylbenzothiazoline-6-sulfonate); ABTS+ assay) and mycosporine-like amino acids (MAAs) (Asterine 330 and Palythine). We hypothesised that G. corneum subjected to higher ambient levels of irradiance and water temperature would show higher C:N ratios, lower antioxidant activity and higher MAA concentrations. Our results partially support this hypothesis. We found that G. corneum exposed to increased levels of irradiance (PAR, UVA) exhibited greater C:N ratios and lower antioxidant activity (higher IC50), whereas no relationship was found regarding MAAs. No differences in biochemical performance in relation to temperature were detected among G. corneum exposed to comparable high light. Similarly, G. corneum growing under lower UVA radiation levels showed no differences in any of the measured biochemical variables with regard to PAR and water temperature. These findings suggest that, among the environmental factors examined, UVA radiation may be an important driver in regulating the along-shore variation in G. corneum biochemical performance. Therefore, the role of irradiance, especially UV radiation, in potential future alterations in Cantabrian G. corneum populations cannot be ruled out as a potential underlying factor.

  10. Evidence for the introduction of the Asian red alga Neosiphonia japonica and its introgression with Neosiphonia harveyi (Ceramiales, Rhodophyta) in the Northwest Atlantic.

    PubMed

    Savoie, Amanda M; Saunders, Gary W

    2015-12-01

    There is currently conflict in the literature on the taxonomic status of the reportedly cosmopolitan species Neosiphonia harveyi, a common red alga along the coast of Atlantic Canada and New England, USA. Neosiphonia harveyi sensu lato was assessed using three molecular markers: COI-5P, ITS and rbcL. All three markers clearly delimited three genetic species groups within N. harveyi sensu lato in this region, which we identified as N. harveyi, N. japonica and Polysiphonia akkeshiensis (here resurrected from synonymy with N. japonica). Although Neosiphonia harveyi is considered by some authors to be introduced to the Atlantic from the western Pacific, it was only confirmed from the North Atlantic suggesting it is native to this area. In contrast, Neosiphonia japonica was collected from only two sites in Rhode Island, USA, as well as from its reported native range in Asia (South Korea), which when combined with data in GenBank indicates that this species was introduced to the Northwest Atlantic. The GenBank data further indicate that N. japonica was also introduced to North Carolina, Spain, Australia and New Zealand. Despite the fact that all three markers clearly delimited N. harveyi and N. japonica as distinct genetic species groups, the ITS sequences for some N. harveyi individuals displayed mixed patterns and additivity indicating introgression of nuclear DNA from N. japonica into N. harveyi in the Northwest Atlantic. Introgression of DNA from an introduced species to a native species (i.e. 'genetic pollution') is one of the possible consequences of species introductions, and we believe this is the first documented evidence for this phenomenon in red algae.

  11. Sequencing type material resolves the identity and distribution of the generitype Lithophyllum incrustans, and related European species L. hibernicum and L. bathyporum (Corallinales, Rhodophyta).

    PubMed

    Hernandez-Kantun, Jazmin J; Rindi, Fabio; Adey, Walter H; Heesch, Svenja; Peña, Viviana; Le Gall, Line; Gabrielson, Paul W

    2015-08-01

    DNA sequences from type material in the nongeniculate coralline genus Lithophyllum were used to unambiguously link some European species names to field-collected specimens, thus providing a great advance over morpho-anatomical identifi-cation. In particular, sequence comparisons of rbcL, COI and psbA genes from field-collected specimens allowed the following conclusion: the generitype species, L. incrustans, occurs mostly as subtidal rhodoliths and crusts on both Atlantic and Mediterranean coasts, and not as the common, NE Atlantic, epilithic, intertidal crust reported in the literature. The heterotypic type material of L. hibernicum was narrowed to one rhodolith belonging in Lithophyllum. As well as occurring as a subtidal rhodolith, L. hibernicum is a common, epilithic and epizoic crust in the intertidal zone from Ireland south to Mediterranean France. A set of four features distinguished L. incrustans from L. hibernicum, including epithallial cell diameter, pore canal shape of sporangial conceptacles and sporangium height and diameter. An rbcL sequence of the lectotype of Lithophyllum bathyporum, which was recently proposed to accommodate Atlantic intertidal collections of L. incrustans, corresponded to a distinct taxon hitherto known only from Brittany as the subtidal, bisporangial, lectotype, but also occurs intertidally in Atlantic Spain. Specimens from Ireland and France morpho-anatomically identified as L. fasciculatum and a specimen from Cornwall likewise identified as L. duckerae were resolved as L. incrustans and L. hibernicum, respectively.

  12. Effects of UV-B radiation on tetraspores of Chondrus ocellatus Holm (Rhodophyta), and effects of red and blue light on repair of UV-B-induced damage

    NASA Astrophysics Data System (ADS)

    Ju, Qing; Xiao, Hui; Wang, You; Tang, Xuexi

    2015-05-01

    We evaluated the effects of red and blue light on the repair of UV-B radiation-induced damage in tetraspores of Chondrus ocellatus Holm. Tetraspores of C. ocellatus were treated with different UV-B radiation levels (0, 36, 72, 108, 144 and 180 J/m2), and thereafter subjected to PAR, darkness, or red or blue light during a 2-h repair stage, each day for 48 days. The diameters and cellular contents of cyclobutane pyrimidine dimmers (CPDs), chlorophyll a (Chl a), phycoerythrin, and UV-B-absorbing mycosporinelike amino acids (MAAs) contents of the tetraspores were determined. Our results show that low doses of UV-B radiation (36 and 72 J/m2) promoted the growth of C. ocellatus; however, increased UV-B radiation gradually reduced the C. ocellatus growth (greater than 72 J/m2). The MAAs (palythine and asterina-330) in C. ocellatus were detected and analyzed by LC/MS. Our results suggest that moderate red light could induce the growth of this alga in aquaculture. In addition, photorepair was inhibited by red light, so there may be some other DNA repair mechanism activated by red light. Blue light promoted the activity of DNA photolyase, greatly improving remediation efficiency. Red and blue lights were found to reduce the capacity of C. ocellatus to form MAAs. Therefore, PAR, red light, and blue light play different roles during the repair processes for damage induced by UV-B radiation.

  13. Evaluation of food grade solvents for lipid extraction and impact of storage temperature on fatty acid composition of edible seaweeds Laminaria digitata (Phaeophyceae) and Palmaria palmata (Rhodophyta).

    PubMed

    Schmid, Matthias; Guihéneuf, Freddy; Stengel, Dagmar B

    2016-10-01

    This study evaluated the impact of different food- and non-food grade extraction solvents on yield and fatty acid composition of the lipid extracts of two seaweed species (Palmaria palmata and Laminaria digitata). The application of chloroform/methanol and three different food grade solvents (ethanol, hexane, ethanol/hexane) revealed significant differences in both, extraction yield and fatty acid composition. The extraction efficiency, in terms of yields of total fatty acids (TFA), was in the order: chloroform/methanol>ethanol>hexane>ethanol/hexane for both species. Highest levels of polyunsaturated fatty acids (PUFA) were achieved by the extraction with ethanol. Additionally the effect of storage temperature on the stability of PUFA in ground and freeze-dried seaweed biomass was investigated. Seaweed samples were stored for a total duration of 22months at three different temperatures (-20°C, 4°C and 20°C). Levels of TFA and PUFA were only stable after storage at -20°C for the two seaweed species.

  14. Taxonomic revision of Gelidium tsengii and Gelidium honghaiwanense sp. nov. (Gelidiales, Rhodophyta) from China based upon molecular and morphological data analyses

    NASA Astrophysics Data System (ADS)

    Wang, Xulei; Xia, Bangmei; Bottalico, Antonella; Wang, Guangce

    2017-01-01

    The taxonomic relationship of Chinese Gelidium tsengii and Gelidium johnstonii was ambiguous. For almost 20 years they have been regarded as distinct taxa and until 2002 G. johnstonii was considered as a misapplied name of G. tsengii. In this study, herbarium specimens that initially attributed to G. tsengii and fresh G. tsengii specimens were used to address the taxonomic issues. In phylogenetic studies, G. tsengii from Dayawan, China, near the type locality of G. tsengii and G. johnstonii from Sonora, Mexico, the type locality of G. johnstonii, formed a monophyletic group with maximum support in rbcL and COI genes analyses, indicating that they were genetically identical. In morphological studies, G. tsengii was similar to G. johnstonii in branching pattern, inner structures and fructiferous organs. Consequently, we considered that semi-circular outline of G. tsengii could no longer be treated as a discrimating feature. G. johnstonii had priority of publication and according to the International Code of Botanical Nomenclature, G. tsengii was proposed as a synonym of G. johnstonii. Gelidium honghaiwanense sp. nov. was described from Guangdong, China on the basis of morphological and molecular data. For vegetative structures, it was characterized by flattened upright frond, regular two-three times branches pinnate or alternate and clavate ultimate branchlets. For reproductive structures, the tetrasporangial sori were in the apical part of branches and the tetrasporangial branchlets were distichously distributed along second order branches. The present study clarified the relationship between G. tsengii and G. johnstonii from Guangdong and added a new Gelidium species to the Chinese algal flora.

  15. Effects of three macroalgae, Ulva linza (Chlorophyta), Corallina pilulifera (Rhodophyta) and Sargassum thunbergii (Phaeophyta) on the growth of the red tide microalga Prorocentrum donghaiense under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Wang, Renjun; Xiao, Hui; Wang, You; Zhou, Wenli; Tang, Xuexi

    2007-10-01

    Allelopathic effects of several concentrations of fresh tissue and dry powder of three macroalgae, Ulva linza, Corallina pilulifera and Sargassum thunbergii, on the red tide microalga Prorocentrum donghaiense were evaluated in microcosms. Preliminary studies on the algicidal effects of one aqueous and four organic solvent extracts from the macroalgae on the microalga were carried out to confirm the existence of allelochemicals in the tissues of the macroalgae. The effects of macroalgal culture medium filtrate on P. donghaiense were investigated using initial or semi-continuous filtrate addition. Furthermore, the potential effects of the microalga on these three macroalgae were also tested. The results of the microcosm assay showed that the growth of P. donghaiense was strongly inhibited by using fresh tissues and dry powder of the three macroalgae. Both aqueous and methanol extracts of the macroalgae had strong growth inhibitory effects on P. donghaiense, while the other three organic solvent extracts (acetone, ether and chloroform) had no apparent effect on its growth; this suggested that the allelochemicals from these three macroalga had relatively high polarities. The three macroalgal culture medium filtrates exhibited apparent growth inhibitory effect on the microalgae under initial or semi-continuous addition, which suggested that the cells of P. donghaiense are sensitive to the allelochemicals. In contrast, P. donghaiense had no apparent effect on the growth of the macroalgae in coexistence experiment.

  16. INDUCTION OF APOMIXIS BY OUTCROSSING BETWEEN GENETICALLY DIVERGENT ENTITIES OF CALOGLOSSA LEPRIEURII (CERAMIALES, RHODOPHYTA) AND EVIDENCE OF HYBRID APOMICTS IN NATURE(1).

    PubMed

    Kamiya, Mitsunobu; West, John A; Hara, Yoshiaki

    2011-08-01

    Our previous study revealed that apomixis, recycling of tetrasporophytes, can be generated through outcrossing between genetically divergent entities of Caloglossa monosticha M. Kamiya, though such apomicts have never been found in nature. In the case of C. leprieurii (Mont.) G. Martens, the most widespread species in this genus, many apomictic strains have been isolated worldwide, but it is unknown whether these apomicts evolved through an outcrossing process similar to that in C. monosticha. In this study, heterogeneity of the apomicts and their sexual relatives as well as their evolutionary relationships was examined using the nuclear-encoded actin gene and plastid-encoded RUBISCO spacer region. Thirteen out of 18 apomictic strains were heterogeneous and contained divergent actin alleles, whereas only two out of 23 sexual strains were heterogeneous. The five homogeneous apomicts were genetically identical, or quite similar, to the sexual strains isolated from adjacent sites. Furthermore, three of the five homogeneous apomicts frequently produced tetraspores that grew into gametophytes, while all the heterogeneous apomicts never generated gametophytes. Apomictic strains from Florida were allotriploid, and each of the three actin sequences was closely related to those of sexual strains from Florida, Peru, and Mexico/Guatemala. In crossing tests, obligate apomixis was generated through the outcrossing between the male from Madagascar and the female from the northwestern Atlantic. These results suggest that outcrossing between genetically divergent sexual entities is one factor that induces apomixis in C. leprieurii.

  17. Biomineralization of calcium carbonate in the cell wall of Lithothamnion crispatum (Hapalidiales, Rhodophyta): correlation between the organic matrix and the mineral phase.

    PubMed

    de Carvalho, Rodrigo Tomazetto; Salgado, Leonardo Tavares; Amado Filho, Gilberto Menezes; Leal, Rachel Nunes; Werckmann, Jacques; Rossi, André Linhares; Campos, Andrea Porto Carreiro; Karez, Cláudia Santiago; Farina, Marcos

    2017-03-04

    Over the past few decades, progress has been made toward understanding the mechanisms of coralline algae mineralization. However, the relationship between the mineral phase and the organic matrix in coralline algae has not yet been thoroughly examined. The aim of this study was to describe the cell wall ultrastructure of Lithothamnion crispatum, a cosmopolitan rhodolith-forming coralline algal species collected near Salvador (Brazil), and examine the relationship between the organic matrix and the nucleation and growth/shape modulation of calcium carbonate crystals. A nanostructured pattern was observed in L. crispatum along the cell walls. At the nanoscale, the crystals from L. crispatum consisted of several single crystallites assembled and associated with organic material. The crystallites in the bulk of the cell wall had a high level of spatial organization. However, the crystals displayed cleavages in the (104) faces after ultrathin sectioning with a microtome. This organism is an important model for biomineralization studies as the crystallographic data do not fit in any of the general biomineralization processes described for other organisms. Biomineralization in L. crispatum is dependent on both the soluble and the insoluble organic matrix, which are involved in the control of mineral formation and organizational patterns through an organic matrix-mediated process. This knowledge concerning the mineral composition and organizational patterns of crystals within the cell walls should be taken into account in future studies of changing ocean conditions as they represent important factors influencing the physico-chemical interactions between rhodoliths and the environment in coralline reefs.

  18. ROLE OF SURFACE WOUNDS AND BROWN ALGAL EPIPHYTES IN THE COLONIZATION OF ASCOPHYLLUM NODOSUM (PHAEOPHYCEAE) FRONDS BY VERTEBRATA LANOSA (RHODOPHYTA)(1).

    PubMed

    Longtin, Caroline M; Scrosati, Ricardo A

    2009-06-01

    Ascophyllum nodosum (L.) Le Jol. forms extensive beds in wave-sheltered, rocky intertidal habitats on the northwestern Atlantic coast. This fucoid seaweed is host to an obligate red algal epiphyte, Vertebrata lanosa (L.) T. A. Chr. [=Polysiphonia lanosa (L.) Tandy], and two facultative brown algal epiphytes, Elachista fucicola (Velley) Aresch. and Pylaiella littoralis (L.) Kjellm. Although V. lanosa can occur throughout most of the length of host fronds, it largely predominates in midfrond segments. The two brown algal epiphytes are restricted to distal segments. Through field experiments conducted in Nova Scotia, Canada, we tested the hypothesis that surface wounds are required for the colonization of distal segments of host fronds by V. lanosa. Distal tissues normally have a smooth surface because of their young age (A. nodosum fronds grow apically). By creating small wounds that mimicked grazing wounds distributed elsewhere on host fronds, we demonstrated that V. lanosa can colonize distal frond segments during the growth and reproductive season (summer and autumn). Approximately half of the artificial wounds were colonized by V. lanosa during this time. The experimental exclusion of both brown algal epiphytes from distal frond segments did not affect colonization by V. lanosa. Thus, we conclude that the absence of surface irregularities on distal segments of host fronds, specifically small wounds, is the main factor explaining the absence of V. lanosa there. We propose that further experimental work clarifying epiphyte distribution in host beds will enhance our ability to understand the functional role of epiphytes in intertidal ecosystems.

  19. Effect of light quality on the accumulation of photosynthetic pigments, proteins and mycosporine-like amino acids in the red alga Porphyra leucosticta (Bangiales, Rhodophyta).

    PubMed

    Korbee, Nathalie; Figueroa, Félix L; Aguilera, José

    2005-08-01

    The effect of different light qualities (white, blue, green, yellow and red light) on photosynthesis, measured as chlorophyll fluorescence, and the accumulation of photosynthetic pigments, proteins and the UV-absorbing mycosporine-like amino acids (MAAs) was studied in the red alga Porphyra leucosticta. Blue light promoted the highest accumulation of nitrogen metabolism derived compounds i.e., MAAs, phycoerythrin and proteins in previously N-starved algae after seven days culture in ammonium enriched medium. Similar results were observed in the culture under white light. In contrast, the lowest photosynthetic capacity i.e., lowest electron transport rate and lowest photosynthetic efficiency as well as the growth rate were found under blue light, while higher values were found in red and white lights. Blue light favored the accumulation of the MAAs porphyra-334, palythine and asterina-330 in P. leucosticta. However, white, green, yellow and red lights favored the accumulation of shinorine. The increase of porphyra-334, palythine and asterina-330 occurred in blue light simultaneous to a decrease in shinorine. The accumulation of MAAs and other nitrogenous compounds in P. leucosticta under blue light could not be attributed to photosynthesis and the action of a non-photosynthetic blue light photoreceptor is suggested. A non-photosynthetic photoreceptor could be also involved in the MAAs interconversion pathways in P. leucosticta.

  20. Effects of sodium bicarbonate concentration on growth, photosynthesis, and carbonic anhydrase activity of macroalgae Gracilariopsis lemaneiformis, Gracilaria vermiculophylla, and Gracilaria chouae (Gracilariales, Rhodophyta).

    PubMed

    Zhou, Wei; Sui, Zhenghong; Wang, Jinguo; Hu, Yiyi; Kang, Kyoung Ho; Hong, Hye Ran; Niaz, Zeeshan; Wei, Huihui; Du, Qingwei; Peng, Chong; Mi, Ping; Que, Zhou

    2016-06-01

    There is potential for bicarbonate to improve crop yields and economic efficiency of marine algae. However, few studies have focused on the effect of bicarbonate on the growth, photosynthesis, and enzyme activity associated with carbon utilization, especially in commercial macroalgae. Here, the addition of bicarbonate (up to 420 mg L(-1)) to macroalgal cultures has been evaluated for Gracilariopsis lemaneiformis, Gracilaria vermiculophylla, and Gracilaria chouae with respect to growth rate, photosynthetic activity, carbonic anhydrase activity, and biochemical composition. The results showed that the effects of NaHCO3 on growth, chlorophyll a, phycoerythrin, photosynthetic oxygen evolution, photochemical parameters of PSI and PSII, carbonic anhydrase activity, and nitrogen content were significant (P < 0.05) and followed the same pattern in the three species. The parameter values were promoted in lower NaHCO3 concentrations (up to 252 or 336 mg L(-1)) and inhibited in higher NaHCO3 concentrations (>336 mg L(-1) for Gp. lemaneiformis and >420 mg L(-1) for the other two species). Moreover, species-specific differences induced by supplementation with bicarbonate were discovered during culture. Optimal concentrations of NaHCO3 used in this study were 252 mg L(-1) for Gp. lemaneiformis and 336 mg L(-1) for G. vermiculophylla and G. chouae. These results suggest that an adequate supplementation of sodium bicarbonate is a viable strategy for promoting growth and photosynthetic activity in some macroalgae as well as for improving biochemical composition. The study will help to accelerate the growth rate of algae and improve the quality of thalli, and will also be useful for enhancing the understanding of carbon utilization in macroalgae.

  1. Effect of Different Light Qualities on Growth, Pigment Content, Chlorophyll Fluorescence, and Antioxidant Enzyme Activity in the Red Alga Pyropia haitanensis (Bangiales, Rhodophyta).

    PubMed

    Wu, Huanyang

    2016-01-01

    Spectral light changes evoke different morphogenetic and photosynthetic responses that can vary among different algae species. The aim of this study is to investigate the photosynthetic characteristics of the red macroalgae grown under different spectrum environments. In this study, Pyropia haitanensis were cultured under blue, red, and green LED and fluorescent tubes light. The growth rate, photopigment composition, chlorophyll fluorescence, and antioxidative enzymes activities in different light spectrums were investigated. The results revealed that growth rate was significantly higher in the thalli grown under blue, green, and fluorescent tubes light. Contents of Chl a and phycobiliprotein in red light were lower among all the growth conditions. Furthermore, a striking increase in SOD and CAT activity was observed in red light treatment along with the NPQ increase. The results revealed that the photosynthetic efficiency and increased growth rate of P. haitanensis benefitted from light spectrums such as blue, green, and fluorescent tubes light by pigment composition and photochemical efficiency manipulation, whereas red light has disadvantageous effects. Accordingly, the results for improving quality and the economic yield of algae species in some extent and the combination of different wavelengths could allow better economic resource exploitation.

  2. Molecular cloning, homology modeling and site-directed mutagenesis of vanadium-dependent bromoperoxidase (GcVBPO1) from Gracilaria changii (Rhodophyta).

    PubMed

    Baharum, H; Chu, W-C; Teo, S-S; Ng, K-Y; Rahim, R Abdul; Ho, C-L

    2013-08-01

    Vanadium-dependent haloperoxidases belong to a class of vanadium enzymes that may have potential industrial and pharmaceutical applications due to their high stability. In this study, the 5'-flanking genomic sequence and complete reading frame encoding vanadium-dependent bromoperoxidase (GcVBPO1) was cloned from the red seaweed, Fracilaria changii, and the recombinant protein was biochemically characterized. The deduced amino acid sequence of GcVBPO1 is 1818 nucleotides in length, sharing 49% identity with the vanadium-dependent bromoperoxidases from Corralina officinalis and Cor. pilulifera, respectively. The amino acid residues associated with the binding site of vanadate cofactor were found to be conserved. The Km value of recombinant GcVBPO1 for Br(-) was 4.69 mM, while its Vmax was 10.61 μkat mg(-1) at pH 7. Substitution of Arg(379) with His(379) in the recombinant protein caused a lower affinity for Br(-), while substitution of Arg(379) with Phe(379) not only increased its affinity for Br(-) but also enabled the mutant enzyme to oxidize Cl(-). The mutant Arg(379)Phe was also found to have a lower affinity for I(-), as compared to the wild-type GcVBPO1 and mutant Arg(379)His. In addition, the Arg(379)Phe mutant has a slightly higher affinity for H2O2 compared to the wild-type GcVBPO1. Multiple cis-acting regulatory elements associated with light response, hormone signaling, and meristem expression were detected at the 5'-flanking genomic sequence of GcVBPO1. The transcript abundance of GcVBPO1 was relatively higher in seaweed samples treated with 50 parts per thousand (ppt) artificial seawater (ASW) compared to those treated in 10 and 30 ppt ASW, in support of its role in the abiotic stress response of seaweed.

  3. GRACILARIA VERMICULOPHYLLA (RHODOPHYTA, GRACILARIALES) IN THE VIRGINIA COASTAL BAYS, USA: COX1 ANALYSIS REVEALS HIGH GENETIC RICHNESS OF AN INTRODUCED MACROALGA.

    PubMed

    Gulbransen, Dana J; McGlathery, Karen J; Marklund, Maria; Norris, James N; Gurgel, Carlos Frederico D

    2012-10-01

    Gracilaria vermiculophylla (Ohmi) Papenfuss is an invasive alga that is native to Southeast Asia and has invaded many estuaries in North America and Europe. It is difficult to differentiate G. vermiculophylla from native forms using morphology and therefore molecular techniques are needed. In this study, we used three molecular markers (rbcL, cox2-cox3 spacer, cox1) to identify G. vermiculophylla at several locations in the western Atlantic. RbcL and cox2-cox3 spacer markers confirmed the presence of G. vermiculophylla on the east coast of the USA from Massachusetts to South Carolina. We used a 507 base pair region of cox1 mtDNA to (i) verify the widespread distribution of G. vermiculophylla in the Virginia (VA) coastal bays and (ii) determine the intraspecific diversity of these algae. Cox1 haplotype richness in the VA coastal bays was much higher than that previously found in other invaded locations, as well as some native locations. This difference is likely attributed to the more intensive sampling design used in this study, which was able to detect richness created by multiple, diverse introductions. On the basis of our results, we recommend that future studies take differences in sampling design into account when comparing haplotype richness and diversity between native and non-native studies in the literature.

  4. Development of chloroplast simple sequence repeats (cpSSRs) for the intraspecific study of Gracilaria tenuistipitata (Gracilariales, Rhodophyta) from different populations

    PubMed Central

    2014-01-01

    Background Gracilaria tenuistipitata is an agarophyte with substantial economic potential because of its high growth rate and tolerance to a wide range of environment factors. This red seaweed is intensively cultured in China for the production of agar and fodder for abalone. Microsatellite markers were developed from the chloroplast genome of G. tenuistipitata var. liui to differentiate G. tenuistipitata obtained from six different localities: four from Peninsular Malaysia, one from Thailand and one from Vietnam. Eighty G. tenuistipitata specimens were analyzed using eight simple sequence repeat (SSR) primer-pairs that we developed for polymerase chain reaction (PCR) amplification. Findings Five mononucleotide primer-pairs and one trinucleotide primer-pair exhibited monomorphic alleles, whereas the other two primer-pairs separated the G. tenuistipitata specimens into two main clades. G. tenuistipitata from Thailand and Vietnam were grouped into one clade, and the populations from Batu Laut, Middle Banks and Kuah (Malaysia) were grouped into another clade. The combined dataset of these two primer-pairs separated G. tenuistipitata obtained from Kelantan, Malaysia from that obtained from other localities. Conclusions Based on the variations in repeated nucleotides of microsatellite markers, our results suggested that the populations of G. tenuistipitata were distributed into two main geographical regions: (i) populations in the west coast of Peninsular Malaysia and (ii) populations facing the South China Sea. The correct identification of G. tenuistipitata strains with traits of high economic potential will be advantageous for the mass cultivation of seaweeds. PMID:24490797

  5. Molluscs associated with the macroalgae of the genus Gracilaria (Rhodophyta): importance of algal fronds as microhabitat in a hypersaline mangrove in Northeastern Brazil.

    PubMed

    Queiroz, R N M; Dias, T L P

    2014-08-01

    The fronds of marine macroalgae play an important role in coastal ecosystems because the algae banks are utilized as a microhabitat by different taxa, including molluscs, one of the most abundant and diverse animals of marine ecosystems. In this study, we characterized the malacofauna associated with the macroalgae Gracilaria domingensis (Kützing) Sonder ex Dickie 1874 and Gracilaria cuneata Areschoug 1854 of a hypersaline mangrove on the northern coast of the state of Rio Grande do Norte, Northeastern Brazil. The first alga dominates in the rainy season and it is substituted by second one in the dry period. A total of 1,490 molluscs were surveyed, representing 56 species in 29 families: 1,081 were associated with G. domingensis and 409 with G. cuneata, the latter showing the greater diversity (H'=1.25). Columbellidae, Neritidae, Pyramidellidae and Cerithiidae were among the most representative families in the number of species and individuals. The micromolluscs were dominant in the algal microhabitat, constituting 74.63% of the malacofauna recorded. The columbellid Parvanachis obesa (C. B. Adams, 1845) was the dominant species followed by the neritid Neritina virginea (Linnaeus, 1758) in both algae. In spite of the annual alternated succession of the algae species, at least 15 mollusc species are common for these algae. Furthermore, juveniles of P. obesa were recorded in both seasons, indicating a continuous reproduction. Possible reasons for difference in abundance, diversity and dominance of molluscs living on these algae are discussed. Both species of substrate-algae represent an important microhabitat for refuge, feeding and the reproduction of small-sized mollusc species during rainy and dry seasons.

  6. Gene cloning, expression and activity analysis of manganese superoxide dismutase from two strains of Gracilaria lemaneiformis (Gracilariaceae, Rhodophyta) under heat stress.

    PubMed

    Lu, Ning; Zang, Xiaonan; Zhang, Xuecheng; Chen, Hao; Feng, Xiaoting; Zhang, Lu

    2012-04-16

    Manganese superoxide dismutase (Mn-SOD) plays a crucial role in antioxidant responses to environmental stress. To determine whether Mn-SOD affects heat resistance of Gracilaria lemaneiformis, we cloned Mn-SOD cDNA sequences of two strains of this red alga, wild type and cultivar 981. Both cDNA sequences contained an ORF of 675 bp encoding 224 amino acid residues. The cDNA sequences and the deduced amino acid sequences of the two strains shared relatively high identity (more than 99%). No intron existed in genomic DNA of Mn-SOD in G. lemaneiformis. Southern blotting indicated that there were multiple copies, possibly four, of Mn-SOD in both strains. Both in the wild type and cultivar 981, SOD mRNA transcription and SOD activity increased under high temperature stress, while cultivar 981 was more heat resistant based on its SOD activity. This research suggests that there may be a direct relationship between SOD activity and the heat resistance of G. lemaneiformis.

  7. A phylogenetic re-appraisal of the family Liagoraceae sensu lato (Nemaliales, Rhodophyta) based on sequence analyses of two plastid genes and postfertilization development.

    PubMed

    Lin, Showe-Mei; Rodríguez-Prieto, Conxi; Huisman, John M; Guiry, Michael D; Payri, Claude; Nelson, Wendy A; Liu, Shao-Lun

    2015-06-01

    The marine red algal family Liagoraceae sensu lato is shown to be polyphyletic based on analyses of a combined rbcL and psaA data set and the pattern of carposporophyte development. Fifteen of eighteen genera analyzed formed a monophyletic lineage that included the genus Liagora. Nemalion did not cluster with Liagoraceae sensu stricto, and Nemaliaceae is reinstated, characterized morphologically by the formation of the primary gonimolobes by longitudinal divisions of the gonimoblast initial. Yamadaella and Liagoropsis, previously placed in the Dermonemataceae, are shown to be independent lineages and are recognized as two new families Yamadaellaceae and Liagoropsidaceae. Yamadaellaceae is characterized by two gonimoblast initials cut off bilaterally from the fertilized carpogonium and diffusely spreading gonimoblast filaments. Liagoropsidaceae is characterized by at least three gonimoblast initials cut off by longitudinal septa from the fertilized carpogonium. In contrast, Liagoraceae sensu stricto is characterized by a single gonimoblast initial cut off transversely or diagonally from the fertilized carpogonium. Reproductive features, such as diffuse gonimoblasts and unfused carpogonial branches following postfertilization, appear to have evolved on more than one occasion in the Nemaliales and are therefore not taxonomically diagnostic at the family level, although they may be useful in recognizing genera.

  8. The Japanese alga Polysiphonia morrowii (Rhodomelaceae, Rhodophyta) on the South Atlantic Ocean: first report of an invasive macroalga inhabiting oyster reefs

    NASA Astrophysics Data System (ADS)

    Croce, M. Emilia; Parodi, Elisa R.

    2014-06-01

    Conspicuous tufts of the filamentous algae Polysiphonia Greville inhabit the reefs of Crassostrea gigas on the Atlantic Patagonian coast. The population was recorded for the first time in 1994 and identified as P. argentinica. This study exhaustively investigated the morphology and reproduction of specimens and the seasonality of the population. The results revealed the identity of the specimens as the invasive Japanese macroalga Polysiphonia morrowii Harvey, on the basis of several striking features: the setaceous and tufted thalli, the corymbose growing apices, the endogenous axillary branches, the urceolate cystocarps and the sharply pointed branches. Sexual reproduction was evidenced; however, fertile male gametophytes were absent in the samples. The population was found almost all year round, but its abundance became higher in autumn and winter. The present study constitutes the first record of this invasive macroalga on the South Atlantic Ocean; the fourth record of an exotic macroalgal species on the Atlantic Patagonian coast; and the first record of an invasive species related to the establishment of C. gigas in Atlantic Patagonia.

  9. Effect of Different Light Qualities on Growth, Pigment Content, Chlorophyll Fluorescence, and Antioxidant Enzyme Activity in the Red Alga Pyropia haitanensis (Bangiales, Rhodophyta)

    PubMed Central

    2016-01-01

    Spectral light changes evoke different morphogenetic and photosynthetic responses that can vary among different algae species. The aim of this study is to investigate the photosynthetic characteristics of the red macroalgae grown under different spectrum environments. In this study, Pyropia haitanensis were cultured under blue, red, and green LED and fluorescent tubes light. The growth rate, photopigment composition, chlorophyll fluorescence, and antioxidative enzymes activities in different light spectrums were investigated. The results revealed that growth rate was significantly higher in the thalli grown under blue, green, and fluorescent tubes light. Contents of Chl a and phycobiliprotein in red light were lower among all the growth conditions. Furthermore, a striking increase in SOD and CAT activity was observed in red light treatment along with the NPQ increase. The results revealed that the photosynthetic efficiency and increased growth rate of P. haitanensis benefitted from light spectrums such as blue, green, and fluorescent tubes light by pigment composition and photochemical efficiency manipulation, whereas red light has disadvantageous effects. Accordingly, the results for improving quality and the economic yield of algae species in some extent and the combination of different wavelengths could allow better economic resource exploitation. PMID:27642603

  10. The effect of cadmium under different salinity conditions on the cellular architecture and metabolism in the red alga Pterocladiella capillacea (Rhodophyta, Gelidiales).

    PubMed

    de L Felix, Marthiellen R; Osorio, Luz K P; Ouriques, Luciane C; Farias-Soares, Francine L; Steiner, Neusa; Kreusch, Marianne; Pereira, Debora T; Simioni, Carmen; Costa, Giulia B; Horta, Paulo A; Chow, Fungyi; Ramlov, Fernanda; Maraschin, Marcelo; Bouzon, Zenilda L; Schmidt, Eder C

    2014-10-01

    The in vitro effect of cadmium (Cd) on apical segments of Pterocladiella capillacea was examined. Over a period of 7 days, the segments were cultivated with the combination of different salinities (25, 35, and 45 practical salinity units) and Cd concentrations, ranging from 0.17 to 0.70 ppm. The effects of Cd on growth rates and content of photosynthetic pigments were analyzed. In addition, metabolic profiling was performed, and samples were processed for microscopy. Serious damage to physiological performance and ultrastructure was observed under different combinations of Cd concentrations and salinity values. Elementary infrared spectroscopy revealed toxic effects registered on growth rate, photosynthetic pigments, chloroplast, and mitochondria organization, as well as changes in lipids and carbohydrates. These alterations in physiology and ultrastructure were, however, coupled to activation of such defense mechanisms as cell wall thickness, reduction of photosynthetic harvesting complex, and flavonoid. In conclusion, P. capillacea is especially sensitive to Cd stress when intermediate concentrations of this pollutant are associated with low salinity values. Such conditions resulted in metabolic compromise, reduction of primary productivity, i.e., photosynthesis, and carbohydrate accumulation in the form of starch granules. Taken together, these findings improve our understanding of the potential impact of this metal in the natural environment.

  11. Allelopathic inhibition of photosynthesis in the red tide-causing marine alga, Scrippsiella trochoidea (Pyrrophyta), by the dried macroalga, Gracilaria lemaneiformis (Rhodophyta)

    NASA Astrophysics Data System (ADS)

    Ye, Changpeng; Liao, Heping; Yang, Yufeng

    2014-07-01

    The red tide-causing microalga, Scrippsiella trochoidea was co-cultured with different quantities of dried macroalga Gracilaria lemaneiformis under laboratory conditions, to characterize the allelopathic inhibition effect of the seaweed on photosynthesis of the microalga. Photosynthetic oxygen evolution was measured, and chlorophyll a (Chl a) fluorescence transient O-J-I-P (O, J, I and P point in primary photochemistry reaction curve in photosystem II) curves associated with its specific parameters were determined. A concentration-dependent inhibition of S. trochoidea was observed when the dried seaweed was added. The rate of light-saturated maximum photosynthetic oxygen evolution (Pmax) was markedly decreased, and the O-J-I-P curve coupled with its specific parameters was reduced. The inhibitory effects of the macroalga on the microalga, according to the JIP-test (the relative fluorescence analysis based on O-J-I-P curve) and the activity of oxygen evolution, include a decrease in the number of active reaction centers, the blocking-up of the electron transport chain, and the damage to the oxygen-evolving complex. This study suggests that dried G. lemaneiformis is effective in inhibiting photosynthesis of S. trochoidea, and could thus be a potential candidate for mitigating S. trochoidea blooms.

  12. Molecular characterization of adenosine 5'-monophosphate deaminase--the key enzyme responsible for the umami taste of nori (Porphyra yezoensis Ueda, Rhodophyta).

    PubMed

    Minami, Seiko; Sato, Minoru; Shiraiwa, Yoshihiro; Iwamoto, Koji

    2011-12-01

    The enzyme adenosine 5'-monophosphate deaminase (AMPD, EC 3.5.4.6) catalyzes the conversion of adenosine 5'-monophosphate to inosine 5'-mononucleotide (IMP). IMP is generally known as the compound responsible for the umami taste of the edible red alga Porphyra yezoensis Ueda that is known in Japan as nori. Therefore, we suspect that AMPD plays a key role in providing a favorable nori taste. In this study, we undertake the molecular characterization of nori-derived AMPD. The nori AMPD protein has a molecular mass of 55 kDa as estimated from both gel filtration and sodium dodecyl sulfate polyacrylamide gel electrophoresis. The calculated molecular mass from the amino acid sequence deduced from cDNA is 57.1 kDa. The isoelectric point is 5.71. The coding region of AMPD consists of 1,566 bp encoding 522 amino acids and possesses a transmembrane domain and two N-glycosylation sites. The sequence identity of nori AMPD in human and yeast AMPDs was found to be less than 50% and 20% in DNA and amino acid sequences, respectively. Proline in the conserved motif of [SA]-[LIVM]-[NGS]-[STA]-D-D-P was found to be converted to glutamate. These results indicate that nori AMPD is a novel type of AMPD.

  13. Effects of natural radiation, photosynthetically active radiation and artificial ultraviolet radiation-B on the chloroplast organization and metabolism of Porphyra acanthophora var. brasiliensis (Rhodophyta, Bangiales).

    PubMed

    Bouzon, Zenilda L; Chow, Fungyi; Zitta, Carmen S; dos Santos, Rodrigo W; Ouriques, Luciane C; Felix, Marthiellen R de L; Osorio, Luz K P; Gouveia, Claudiane; Martins, Roberta de Paula; Latini, Alexandra; Ramlov, Fernanda; Maraschin, Marcelo; Schmidt, Eder C

    2012-12-01

    We undertook a study of Porphyra acanthophora var. brasiliensis to determine its responses under ambient conditions, photosynthetically active radiation (PAR), and PAR+UVBR (ultraviolet radiation-B) treatment, focusing on changes in ultrastructure, and cytochemistry. Accordingly, control ambient samples were collected in the field, and two different treatments were performed in the laboratory. Plants were exposed to PAR at 60 μmol photons m-2 s-1 and PAR + UVBR at 0.35 W m-2 for 3 h per day during 21 days of in vitro cultivation. Confocal laser scanning microscopy analysis of the vegetative cells showed single stellate chloroplast in ambient and PAR samples, but in PAR+UVBR-exposed plants, the chloroplast showed alterations in the number and form of arms. Under PAR+UVBR treatment, the thylakoids of the chloroplasts were disrupted, and an increase in the number of plastoglobuli was observed, in addition to mitochondria, which appeared with irregular, disrupted morphology compared to ambient and PAR samples. After UVBR exposure, the formation of carpospores was also observed. Plants under ambient conditions, as well as those treated with PAR and PAR+UVBR, all showed different concentrations of enzymatic response, including glutathione peroxidase and reductase activity. In summary, the present study demonstrates that P. acanthophora var. brasiliensis shows the activation of distinct mechanisms against natural radiation, PAR and PAR+UVBR.

  14. The physiological links of the increased photosystem II activity in moderately desiccated Porphyra haitanensis (Bangiales, Rhodophyta) to the cyclic electron flow during desiccation and re-hydration.

    PubMed

    Gao, Shan; Niu, Jianfeng; Chen, Weizhou; Wang, Guangce; Xie, Xiujun; Pan, Guanghua; Gu, Wenhui; Zhu, Daling

    2013-09-01

    Photosynthetic electron flow changed considerably during desiccation and re-hydration of the intertidal macroalgae Porphyra haitanensis. Activities of both photosystem (PSI) and photosystem (PSII) increased significantly at moderate desiccation levels. Whereas PSII activity was abolished at an absolute water content (AWC) <24 %, PSI remained active with progressive decreases in AWC to values as low as 16 %. This result suggested that cyclic electron flow around PSI was still active after inactivation of linear electron flow following severe desiccation. Moreover, the PSI activity was restored more rapidly than that of PSII upon re-hydration. Pretreatment of the blades with 3-(3',4'-dichlorophenyl)-1,1-dimethylurea (DCMU) suppressed PSII activity following desiccation to an AWC of ~16 % AWC. Cyclic electron flow around PSI decreased markedly in blades pretreated with DCMU than in blades without pretreatment of DCMU during re-hydration in seawater containing DCMU. All results suggested that the activity of PSII under desiccation conditions plays an important role in the operation of cyclic electron flow during desiccation and its recovery during re-hydration. Therefore, we proposed the PSII activity during desiccation could eventually lead to the accumulation of NADPH, which could serve as electron donor for P700(+) and promote its recovery during re-hydration, thereby favoring the operation of cyclic electron flow.

  15. Morphological and photosynthetic variations in the process of spermatia formation from vegetative cells in Porphyra yezoensis Ueda (Bangiales, Rhodophyta) and their responses to desiccation.

    PubMed

    Yang, Rui-Ling; Zhou, Wei; Shen, Song-Dong; Wang, Guang-Ce; He, Lin-Wen; Pan, Guang-Hua

    2012-05-01

    Porphyra yezoensis has a macroscopic foliage gametophyte phase with only a single cell layer, and is ideally suited for the study of the sexual differentiation process, from the vegetative cell to the spermatia. Firstly, we compared variations in the responses of the vegetative and male sectors to desiccation. Later, cell tracking experiments were carried out during the formation of spermatia from vegetative cells. The two sectors showed similar tolerance to desiccation, and the formation of spermatia from vegetative cells was independent of the degree of desiccation. Both light and scanning electron microscopy (SEM) observations of the differentiation process showed that the formation of spermatia could be divided into six phases: the one-cell, two-cell, four-cell, eight-cell, pre-release and spermatia phases. Photomicrographs of Fluorescent Brightener staining showed that the released spermatia had no cell walls. Photosynthetic data showed that there was a significant rise in Y(II) in the four-cell phase, indicating an increase in photosynthetic efficiency of PSII during this phase. We propose that this photosynthetic rise may be substantial and provide the increased energy needed for the formation and release of spermatia in P. yezoensis.

  16. Taxonomy, molecular phylogeny, and ultrastructural morphology of Olpidiopsis porphyrae sp. nov. (Oomycetes, straminipiles), a unicellular obligate endoparasite of Bangia and Porphyra spp. (Bangiales, Rhodophyta).

    PubMed

    Sekimoto, Satoshi; Yokoo, Kazunari; Kawamura, Yoshio; Honda, Daiske

    2008-03-01

    Olpidiopsis porphyrae sp. nov., a marine oomycete endoparasite that infects the commercially cultivated red alga Porphyra yezoensis, is described and its phylogenetic position based on molecular data and ultrastructural morphology is discussed. O. porphyrae infects the host Porphyra by means of encysted zoospores. Spherical-shaped holocarpic thalli develop within the cytoplasm of its algal host, which produce monoplanetic, subapically biflagellate zoospores. The characteristic features of this isolate are the ellipsoidal, unicellular thallus and simple holocarpic zoosporangial development, which show morphological similarity with the genus Olpidiopsis. Laboratory infection experiments with a wide range of green, brown, and red algae revealed that O. porphyrae infects several stages of the bangialean red algae (the genera Bangia and Porphyra). Molecular phylogenetic analyses inferred from both SSU rRNA and cox2 genes showed O. porphyrae branched before the main saprolegnian and peronosporalean lineages within the monophyletic oomycete clade, indicating its phylogenetic separation from them. A single or double K-body-like organelle, which contains tubular inclusions, is found located to one side of the zoospore nucleus and shows similarities to homologous organelles previously described in O. saprolegniae. The ultrastructural morphology of O. porphyrae with zoospore initials containing K-bodies and tubular mitochondrial cristae is characteristic of oomycetes. Group I intron-like multiple insertions were found in the SSU rRNA gene of O. porphyrae. This is the first report of SSU group I introns in the class Oomycetes.

  17. Effects of thermal stress on the growth of an intertidal population of Ellisolandia elongata (Rhodophyta) from N-W Mediterranean Sea.

    PubMed

    Nannini, Matteo; De Marchi, Lucia; Lombardi, Chiara; Ragazzola, Federica

    2015-12-01

    Coralline algae are calcareous algae able to build biogenic structures, thus playing a key-role as marine biodiversity promoters and calcium carbonate producers. The aim was to estimate the growth of Ellisolandia elongata under thermal stress. E. elongata were cultured for 2, 4 and 6 months under "natural" temperature (Tc) and increased temperature (Ti = Tc + 3 °C). In order to determine a possible culturing effect, growth in the field was also measured. For the first time, Alizarin Red S dye was used in high energy shallow water environments. Thallus linear extension was higher in the cultured specimens (Tc and Ti) compared to the field specimens. The carbonate mass in the field was higher than in Ti and Tc after 2, 4 months but decreased after 6 months. Partly unknown in situ environmental factors could have affected growth and calcification rates in the field while thermal adaptation could explain growth rates in the culturing experiment.

  18. Next-Generation Sequencing of an 88-Year-Old Specimen of the Poorly Known Species Liagora japonica (Nemaliales, Rhodophyta) Supports the Recognition of Otohimella gen. nov.

    PubMed Central

    Suzuki, Masahiro; Segawa, Takahiro; Mori, Hiroshi; Akiyoshi, Ayumi; Ootsuki, Ryo; Kurihara, Akira; Sakayama, Hidetoshi; Kitayama, Taiju; Abe, Tsuyoshi; Kogame, Kazuhiro; Kawai, Hiroshi; Nozaki, Hisayoshi

    2016-01-01

    Liagora japonica is a red algal species distributed in temperate regions of Japan. This species has not been collected from its type locality on the Pacific coast of Japan since 1927 and seems to have become extinct in this area. For molecular characterization of L. japonica, we extracted DNA from the topotype material of L. japonica collected in 1927, analyzed seven genes using Illumina next-generation sequencing, and compared these data with sequences from modern samples of similar red algae collected from the Japan Sea coast of Japan. Both morphological and molecular data from modern samples and historical specimens (including the lectotype and topotype) suggest that the specimens from the Pacific and Japan Sea coasts of Japan should be treated as a single species, and that L. japonica is phylogenetically separated from the genus Liagora. Based on the phylogenetic results and examination of reproductive structures, we propose Otohimella japonica gen. et comb. nov., characterized morphologically by diffuse carposporophytes, undivided carposporangia, and involucral filaments initiated only from the cortical cell on the supporting cell. PMID:27388436

  19. Associations among coral reef macroalgae influence feeding by herbivorous fishes

    NASA Astrophysics Data System (ADS)

    Loffler, Z.; Bellwood, D. R.; Hoey, A. S.

    2015-03-01

    Benthic macroalgae often occur in close association with other macroalgae, yet the implications of such associations on coral reefs are unclear. We selected three pairs of commonly associated macroalgae on inshore reefs of the Great Barrier Reef and exposed them, either independently or paired, to herbivore assemblages. Pairing the palatable alga Acanthophora with the calcified and chemically defended Galaxaura resulted in a 69 % reduction in the consumption of Acanthophora, but had no effect on the consumption of Galaxaura. The reduced consumption of Acanthophora was related to 53-85 % reductions in the feeding rates of two herbivorous fish species, Kyphosus vaigiensis and Siganus doliatus. Neither Acanthophora nor Sargassum were afforded protection when paired with the brown macroalga Turbinaria. Although limited to one of the three species pairings, such associations between algae may allow the ecological persistence of palatable species in the face of intense herbivory, enhancing macroalgal diversity on coral reefs.

  20. Sediments influence accumulation of two macroalgal species through novel but differing interactions with nutrients and herbivory

    NASA Astrophysics Data System (ADS)

    Clausing, Rachel J.; Bittick, Sarah Joy; Fong, Caitlin R.; Fong, Peggy

    2016-12-01

    Despite increasing concern that sediment loads from disturbed watersheds facilitate algal dominance on tropical reefs, little is known of how sediments interact with two primary drivers of algal communities, nutrients and herbivory. We examined the effects of sediment loads on the thalli of two increasingly abundant genera of macroalgae, Galaxaura and Padina, in a bay subject to terrestrial sediment influx in Mo'orea, French Polynesia. Field experiments examining (1) overall effects of ambient sediments and (2) interacting effects of sediments (ambient/removal) and herbivores (caged/uncaged) demonstrated that sediments had strong but opposite effects on both species' biomass accumulation. Sediment removal increased accumulation of Padina boryana Thivy 50% in the initial field experiment but had no effect in the second; rather, in a novel interaction, herbivores overcompensated for increases in tissue nutrient stores that occurred with sediments loads, likely by preferential consumption of nutrient-rich meristematic tissues. Despite negative effects of sediments on biomass, Padina maintained rapid growth across treatments in both experiments. In contrast, positive growth in Galaxaura divaricata Kjellman only occurred with ambient sediment loads. In mesocosm experiments testing interactions of added nutrients and sediments on growth, Galaxaura grew at equivalent rates with sediments (collected from thalli on the reef) as with additions of nitrate and phosphate, suggesting sediments provide a nutrient subsidy. For Padina, however, the only effect was a 50% reduction in growth with sediment. Overall, retention of thallus sediments creates a positive feedback that Galaxaura appears to require to sustain net growth, while Padina merely tolerates sediments. These results indicate that sediments can modify nutrient and herbivore control of algae in ways that differ among species, with the potential for strong and unexpected effects on the abundance and composition of

  1. Docile sitters and active fighters in paper wasps: a tale of two queens

    NASA Astrophysics Data System (ADS)

    Kardile, Sujata; Gadagkar, Raghavendra

    2002-02-01

    Ropalidia marginata and Ropalidia cyathiformis are sympatric, primitively eusocial paper wasps widely distributed in peninsular India. We compare the two species, especially their queens, in an attempt to begin to understand the role of the power of queens over their workers, in social organisation and evolution. Queens of R. marginata have lower levels of activity, rates of interactions and dominance behaviour, compared with queens of R. cyathiformis. For the same variables, R. marginata queens are either indistinguishable from or have lower values than their workers, while R. cyathiformis queens have higher values than their workers. R. marginata queens never occupy the top rank while R. cyathiformis queens are always at the top of the behavioural dominance hierarchies of their colonies. R. marginata queens thus do not appear to use dominance behaviour to suppress reproduction by their workers, while R. cyathiformis queens appear to do so. These different mechanisms used by the two queens to regulate worker reproduction give them different powers over their workers, because R. marginata queens are completely successful in suppressing reproduction by their nestmates while in R. cyathiformis colonies, other individuals also sometimes lay eggs. There is also some evidence that the different powers of the queens result in different mechanisms of regulation of worker foraging in the two species - decentralised, self-regulation in R. marginata and relatively more centralised regulation by the queen in R. cyathiformis. Thus we show here, perhaps for the first time, that the power of the queens over their workers can have important consequences for social organisation and evolution.

  2. Phytophthora multivora sp. nov., a new species recovered from declining Eucalyptus, Banksia, Agonis and other plant species in Western Australia.

    PubMed

    Scott, P M; Burgess, T I; Barber, P A; Shearer, B L; Stukely, M J C; Hardy, G E St J; Jung, T

    2009-06-01

    A new Phytophthora species, isolated from rhizosphere soil of declining or dead trees of Eucalyptus gomphocephala, E. marginata, Agonis flexuosa, and another 13 plant species, and from fine roots of E. marginata and collar lesions of Banksia attenuata in Western Australia, is described as Phytophthora multivora sp. nov. It is homothallic and produces semipapillate sporangia, smooth-walled oogonia containing thick-walled oospores, and paragynous antheridia. Although morphologically similar to P. citricola, phylogenetic analyses of the ITS and cox1 gene regions demonstrate that P. multivora is unique. Phytophthora multivora is pathogenic to bark and cambium of E. gomphocephala and E. marginata and is believed to be involved in the decline syndrome of both eucalypt species within the tuart woodland in south-west Western Australia.

  3. An annotated checklist and key to the Bulgarian cockroaches (Dictyoptera: Blattodea).

    PubMed

    Hristov, Georgi H; Chobanov, Dragan P

    2016-08-23

    An annotated checklist of the Bulgarian species of cockroaches is prepared based on a full published scientific record and own unpublished data. According to the current state of knowledge the Bulgarian cockroach fauna includes 17 species and subspecies. One synonymization is established-Phyllodromica marginata erythronota Br. v. W., syn. n. = Ph. marginata. Two species (Capraiellus tamaninii and Supella longipalpa) are recorded for the first time for this country and other three (Ectobius punctatissimus, Phyllodromica subaptera and Phyllodromica pallida) are eliminated from the list of the Bulgarian fauna. The list is complemented with maps and full locality data and a dichotomic identification key for the studied taxa is presented.

  4. Environmental variability drives rapid and dramatic changes in nutrient limitation of tropical macroalgae with different ecological strategies

    NASA Astrophysics Data System (ADS)

    Clausing, Rachel J.; Fong, Peggy

    2016-06-01

    Nitrogen (N) or phosphorus (P) limits primary productivity in nearly every ecosystem worldwide, yet how limitation changes over time, particularly in connection to variation in environmental drivers, remains understudied. We evaluated temporal and species-specific variability in the relative importance of N and P limitation among tropical macroalgae in two-factor experiments conducted twice after rains and twice after dry conditions to explore potential linkages to environmental drivers. We studied three common macroalgal species with varying ecological strategies: a fast-growing opportunist, Dictyota bartayresiana; and two calcifying species likely to be slower growing, Galaxaura fasciculata and Padina boryana. On the scale of days to weeks, nutrient responses ranged among and within species from no limitation to increases in growth by 20 and 40 % over controls in 3 d with N and P addition, respectively. After light rain or dry conditions, Dictyota grew rapidly (up to ~60 % in 3 d) with little indication of nutrient limitation, while Padina and Galaxaura shifted between N, P, or no limitation. All species grew slowly or lost mass after a large storm, presumably due to unfavorable conditions on the reef prior to the experiment that limited nutrient uptake. Padina and Galaxaura both became nutrient limited 3 d post-storm, while Dictyota did not. These results suggest that differing capabilities for nutrient uptake and storage dictate the influence of nutrient history and thus drive nutrient responses and, in doing so, may allow species with differing ecological strategies to coexist in a fluctuating environment. Moreover, the great variability in species' responses indicates that patterns of nutrient limitation are more complex than previously recognized, and generalizations about N versus P limitation of a given system may not convey the inherent complexity in governing conditions and processes.

  5. Screening for antibacterial and antifungal activities in some marine algae from the Fujian coast of China with three different solvents

    NASA Astrophysics Data System (ADS)

    Zheng, Yi; Chen, Yin-Shan; Lu, Hai-Sheng

    2001-12-01

    Three different solvents viz ethanol, acetone and methanol-toluene (3:1) were used to extract antibiotics from 23 species of marine algae belonging to the Chlorophyta, Phaeophyta and Rhodophyta. Their crude extracts were tested for antibacterial and antifungal activities. Among them, the ethanol extract showed the strongest activity against the bacteria and fungi tested. Four species of the Rhodophyta ( Laurencia okamurai, Dasya scoparia, Grateloupia filicina and plocamium telfairiae) showed a wide spectrum of antibacterial activity. Every solvent extract from the four species was active against all the bacteria tested. The test bacterium Pseudomonas solancearum and the fungus Penicilium citrinum were most sensitive to the extracts of marine algae. In general, the extracts of seaweeds inhibited bacteria more strongly than fungi and species of the Rhodophyta showed the greatest activity against the bacteria and fungi tested.

  6. Assessing Installation Ethnobotanical Resources Using Land Condition Trend Analysis (LCTA) Data: A Fort Riley, Kansas, Case Study

    DTIC Science & Technology

    1998-07-01

    missouriensis G F Gleditsia triacanthos S B Crataegus phaenopyrum G F Glycyrrhiza lepidota S F Croton monanthogynus S F Grindelia squarrosa S B...angustifolia s X Euphorbia marginata s X Fragaria virginiana s X Fraxinus pennsylvanica s X Glycyrrhiza lepidota s X Grindelia squarrosa s X

  7. Biomechanics of selected arborescent and shrubby monocotyledons

    PubMed Central

    Haushahn, Tobias; Fink, Samuel; Speck, Thomas

    2016-01-01

    Main aims of the study are a deepened understanding of the mechanically relevant (ultra-)structures and the mechanical behaviour of various arborescent and shrubby monocotyledons and obtaining the structure–function relationships of different structurally conspicuous parts in Dracaena marginata stems. The stems of five different “woody” monocotyledon species were dissected and the mechanical properties of the most noticeable tissues in the five monocotyledons and, additionally, of individual vascular bundles in D. marginata, were tested under tensile stress. Results for Young’s moduli and density of these tissues were assessed as well as the area, critical strain, Young’s modulus and tensile strength of the vascular bundles in Dracaena marginata. These analyses allowed for generating a model for the mechanical interaction of tissues and vascular bundles of the stem in D. marginata as well as filling major “white spots” in property charts for biological materials. Additionally we shortly discuss the potential significance of such studies for the development of branched and unbranched bio-inspired fibre-reinforced materials and structures with enhanced properties. PMID:28144511

  8. The evolution of complexity in social organization-A model using dominance-subordinate behavior in two social wasp species.

    PubMed

    Nandi, Anjan K; Bhadra, Anindita; Sumana, Annagiri; Deshpande, Sujata A; Gadagkar, Raghavendra

    2013-06-21

    Dominance and subordinate behaviors are important ingredients in the social organizations of group living animals. Behavioral observations on the two eusocial species Ropalidia marginata and Ropalidia cyathiformis suggest varying complexities in their social systems. The queen of R. cyathiformis is an aggressive individual who usually holds the top position in the dominance hierarchy although she does not necessarily show the maximum number of acts of dominance, while the R. marginata queen rarely shows aggression and usually does not hold the top position in the dominance hierarchy of her colony. In R. marginata, more workers are involved in dominance-subordinate interactions as compared to R. cyathiformis. These differences are reflected in the distribution of dominance-subordinate interactions among the hierarchically ranked individuals in both the species. The percentage of dominance interactions decreases gradually with hierarchical ranks in R. marginata while in R. cyathiformis it first increases and then decreases. We use an agent-based model to investigate the underlying mechanism that could give rise to the observed patterns for both the species. The model assumes, besides some non-interacting individuals, the interaction probabilities of the agents depend on their pre-differentiated winning abilities. Our simulations show that if the queen takes up a strategy of being involved in a moderate number of dominance interactions, one could get the pattern similar to R. cyathiformis, while taking up the strategy of very low interactions by the queen could lead to the pattern of R. marginata. We infer that both the species follow a common interaction pattern, while the differences in their social organization are due to the slight changes in queen as well as worker strategies. These changes in strategies are expected to accompany the evolution of more complex societies from simpler ones.

  9. Classification, naming and evolutionary history of glycosyltransferases from sequenced green and red algal genomes.

    PubMed

    Ulvskov, Peter; Paiva, Dionisio Soares; Domozych, David; Harholt, Jesper

    2013-01-01

    The Archaeplastida consists of three lineages, Rhodophyta, Virideplantae and Glaucophyta. The extracellular matrix of most members of the Rhodophyta and Viridiplantae consists of carbohydrate-based or a highly glycosylated protein-based cell wall while the Glaucophyte covering is poorly resolved. In order to elucidate possible evolutionary links between the three advanced lineages in Archaeplastida, a genomic analysis was initiated. Fully sequenced genomes from the Rhodophyta and Virideplantae and the well-defined CAZy database on glycosyltransferases were included in the analysis. The number of glycosyltransferases found in the Rhodophyta and Chlorophyta are generally much lower then in land plants (Embryophyta). Three specific features exhibited by land plants increase the number of glycosyltransferases in their genomes: (1) cell wall biosynthesis, the more complex land plant cell walls require a larger number of glycosyltransferases for biosynthesis, (2) a richer set of protein glycosylation, and (3) glycosylation of secondary metabolites, demonstrated by a large proportion of family GT1 being involved in secondary metabolite biosynthesis. In a comparative analysis of polysaccharide biosynthesis amongst the taxa of this study, clear distinctions or similarities were observed in (1) N-linked protein glycosylation, i.e., Chlorophyta has different mannosylation and glucosylation patterns, (2) GPI anchor biosynthesis, which is apparently missing in the Rhodophyta and truncated in the Chlorophyta, (3) cell wall biosynthesis, where the land plants have unique cell wall related polymers not found in green and red algae, and (4) O-linked glycosylation where comprehensive orthology was observed in glycosylation between the Chlorophyta and land plants but not between the target proteins.

  10. Comparative magnetic measurements of migratory ant and its only termite prey

    NASA Astrophysics Data System (ADS)

    Esquivel, D. M. S.; Wajnberg, E.; Cernicchiaro, G. R.; Alves, O. C.

    2004-07-01

    Termites and ants are social insects living organized in nests in castes. Behavioral studies with the migratory ant Pachycondyla marginata have shown that it conducts well-organized predatory raids toward nests of its only prey, the termite Neocapritermes opacus. The magnetic materials in these two insects were studied using a SQUID magnetometer for two orientations. The Jr/ Js and Jr/ χ0, ratios were calculated from the two insects hysteresis curves. These ratios are in the range of magnetite pseudo-single or multi-domain particle values. The magnetic material are distinguishable by Hc values (30 Oe for ants and 100 Oe for termites) and by the magnetization magnitude, which is about two magnitude orders higher in the termite than in migratory ant. The Pachycondyla marginata SQUID results show an anisotropy in the magnetic material arrangement while for Neocapritermes opacus termite it is revealed by FMR spectra.

  11. Seaweed-coral interactions: variance in seaweed allelopathy, coral susceptibility, and potential effects on coral resilience.

    PubMed

    Bonaldo, Roberta M; Hay, Mark E

    2014-01-01

    Tropical reefs are in global decline with seaweeds commonly replacing corals. Negative associations between macroalgae and corals are well documented, but the mechanisms involved, the dynamics of the interactions, and variance in effects of different macroalgal-coral pairings are poorly investigated. We assessed the frequency, magnitude, and dynamics of macroalgal-coral competition involving allelopathic and non-allelopathic macroalgae on three, spatially grouped pairs of no-take Marine Protected Areas (MPAs) and non-MPAs in Fiji. In non-MPAs, biomass of herbivorous fishes was 70-80% lower, macroalgal cover 4-9 fold higher, macroalgal-coral contacts 5-15 fold more frequent and 23-67 fold more extensive (measured as % of colony margin contacted by macroalgae), and coral cover 51-68% lower than in MPAs. Coral contacts with allelopathic macroalgae occurred less frequently than expected by chance across all sites, while contact with non-allelopathic macroalgae tended to occur more frequently than expected. Transplants of allelopathic macroalgae (Chlorodesmis fastigiata and Galaxaura filamentosa) against coral edges inflicted damage to Acropora aspera and Pocillopora damicornis more rapidly and extensively than to Porites cylindrica and Porites lobata, which appeared more resistant to these macroalgae. Montipora digitata experienced intermediate damage. Extent of damage from macroalgal contact was independent of coral colony size for each of the 10 macroalgal-coral pairings we established. When natural contacts with Galaxaura filamentosa were removed in the field, recovery was rapid for Porites lobata, but Pocillopora damicornis did not recover and damage continued to expand. As macroalgae increase on overfished tropical reefs, allelopathy could produce feedbacks that suppress coral resilience, prevent coral recovery, and promote the stability of algal beds in habitats previously available to corals.

  12. Seaweed-Coral Interactions: Variance in Seaweed Allelopathy, Coral Susceptibility, and Potential Effects on Coral Resilience

    PubMed Central

    Bonaldo, Roberta M.; Hay, Mark E.

    2014-01-01

    Tropical reefs are in global decline with seaweeds commonly replacing corals. Negative associations between macroalgae and corals are well documented, but the mechanisms involved, the dynamics of the interactions, and variance in effects of different macroalgal-coral pairings are poorly investigated. We assessed the frequency, magnitude, and dynamics of macroalgal-coral competition involving allelopathic and non-allelopathic macroalgae on three, spatially grouped pairs of no-take Marine Protected Areas (MPAs) and non-MPAs in Fiji. In non-MPAs, biomass of herbivorous fishes was 70–80% lower, macroalgal cover 4–9 fold higher, macroalgal-coral contacts 5–15 fold more frequent and 23–67 fold more extensive (measured as % of colony margin contacted by macroalgae), and coral cover 51–68% lower than in MPAs. Coral contacts with allelopathic macroalgae occurred less frequently than expected by chance across all sites, while contact with non-allelopathic macroalgae tended to occur more frequently than expected. Transplants of allelopathic macroalgae (Chlorodesmis fastigiata and Galaxaura filamentosa) against coral edges inflicted damage to Acropora aspera and Pocillopora damicornis more rapidly and extensively than to Porites cylindrica and Porites lobata, which appeared more resistant to these macroalgae. Montipora digitata experienced intermediate damage. Extent of damage from macroalgal contact was independent of coral colony size for each of the 10 macroalgal-coral pairings we established. When natural contacts with Galaxaura filamentosa were removed in the field, recovery was rapid for Porites lobata, but Pocillopora damicornis did not recover and damage continued to expand. As macroalgae increase on overfished tropical reefs, allelopathy could produce feedbacks that suppress coral resilience, prevent coral recovery, and promote the stability of algal beds in habitats previously available to corals. PMID:24465707

  13. Phospholipases and galactolipases trigger oxylipin-mediated wound-activated defence in the red alga Gracilaria chilensis against epiphytes.

    PubMed

    Lion, Ulrich; Wiesemeier, Theresa; Weinberger, Florian; Beltrán, Jessica; Flores, Verónica; Faugeron, Sylvain; Correa, Juan; Pohnert, Georg

    2006-03-01

    We investigated the wound response of the commercially important red alga, Gracilaria chilensis, in order to obtain insight into its interaction with epiphytic pests. After wounding, the host releases free fatty acids as well as the hydroxylated eicosanoids, 8R-hydroxy eicosatetraenoic acid (8-HETE) and 7S,8R-dihydroxy eicosatetraenoic acid (7,8-di-HETE). While the release of free arachidonic acid and subsequent formation of 8-HETE is controlled by phospholipase A, 7,8-di-HETE production is independent of this lipase. This dihydroxylated fatty acid might be directly released from galactolipids. Physiologically relevant concentrations of oxylipins reduced spore settlement of Acrochaetium sp. (Rhodophyta, Acrochaetiaceae) and suppressed the development of hapteria in Ceramium rubrum (Rhodophyta, Ceramiaceae) when these model epiphytes were exposed to artificial surfaces that contained 8-HETE or 7,8-di-HETE. Thus, the immediate release of oxylipins can be seen as G. chilensis defence against epiphytes.

  14. Seaweed composition from Bintulu coast of Sarawak, Malaysia.

    PubMed

    Zawawi, Mohd Hafizbillah; Idris, Mohd Hanafi; Kamal, Abu Hena Mustafa; King, Wong Sing

    2014-08-01

    Species composition of seaweed and distribution were investigated in the coastal waters of Bintulu, Sarawak. The seaweed samples were collected during low tide between May 2011 and May 2012 from the six different stations. In total 54 species of seaweeds were identified from study areas of Bintulu coastal waters. Among them, 23 species were from Rhodophyta with 11 families, 15 species were from Phaeophyta with 2 families and 16 species were from Chlorophyta with 10 families: Seventeen species of seaweeds were recorded from the Tanjung Batu, while 23 species from Pantai Telekom, 14 species from Golden Beach, 26 species from Kuala Similajau, 12 species from Kuala Nyalau and 21 species from Batu Mandi. Seaweeds abundance was high in rocky substrate and Rhodophyta (11 families and 23 species) was the common and highest group of seaweeds in this coastal areas. Present study recorded high diversified seaweed species at the rocky shore area compare to reef area.

  15. Gulf Coast Deep Water Port Facilities study. Appendix B. North Central Gulf Hydrobiological Zones.

    DTIC Science & Technology

    1973-04-01

    alga flora of the Mississippi coast. Previous knowledge of the algal flora was limited primarily to the work of Taylor (1954). Eleuterius (1972...Rhodophyta, 7 of Chlorophyta, 5 of Phaeophyta, and 4 of Cyanophyta. In comparing the algal flora of the Chandeleur Islands to previous collections in...Changes in the Mississippi Sound," J. Mississippi A cad. Sci., 12. 1966. pp. 418-419. Mullahy, J.H., "Preliminary Survey of the Algal Flora of the Chandeleur

  16. [Presence of lectins, tannins and protease inhibitors in venezuelan marine algae].

    PubMed

    Perez-Lorenzo, S; Levy-Benshimol, A; Gomez-Acevedo, S

    1998-01-01

    The presence of lectins, tannins and protease inhibitors was studied in 27 algae species collected at four Venezuelan coral rift sites. Among the species studied, only six had hemagglutinating activity, apparently due to their lectin content. Higher hemagglutinating titers were obtained when the extracts were tested on pronase-treated erythrocytes. Hemagglutination was inhibited by simple sugars and by bovine submaxillary gland mucine. GaINAc was the only inhibitor of the hemagglutination caused by Grateulopia filicina extracts. None of the compounds tested inhibited the hemagglutination caused by Halimeda opuntia. The polyvinylpolypirrolidone treatment abolished the hemagglutinating activity of both brown and red algae. However, in Grateulopia filicina and Hypnea cervicornis (Rhodophyta) hemagglutinating activity persisted after the polyvinylpolypirrolidone treatment, presumably due to the presence of true lectins in those algae. Tannin content (presumably phlorotannins) was higher in the Phaeophyta as compared to the Rhodophyta. The brown alga Padina gymnospora had the higher content of these polyphenols. Trypsin inhibitors were detected, in minute ammounts, only in Padina gymnospora (Phaeophyta) and Acantophora spicifera (Rhodophyta). No subtilisin inhibition was observed whatsoever.

  17. Reconstructing the complex evolutionary history of mobile plasmids in red algal genomes

    PubMed Central

    Lee, JunMo; Kim, Kyeong Mi; Yang, Eun Chan; Miller, Kathy Ann; Boo, Sung Min; Bhattacharya, Debashish; Yoon, Hwan Su

    2016-01-01

    The integration of foreign DNA into algal and plant plastid genomes is a rare event, with only a few known examples of horizontal gene transfer (HGT). Plasmids, which are well-studied drivers of HGT in prokaryotes, have been reported previously in red algae (Rhodophyta). However, the distribution of these mobile DNA elements and their sites of integration into the plastid (ptDNA), mitochondrial (mtDNA), and nuclear genomes of Rhodophyta remain unknown. Here we reconstructed the complex evolutionary history of plasmid-derived DNAs in red algae. Comparative analysis of 21 rhodophyte ptDNAs, including new genome data for 5 species, turned up 22 plasmid-derived open reading frames (ORFs) that showed syntenic and copy number variation among species, but were conserved within different individuals in three lineages. Several plasmid-derived homologs were found not only in ptDNA but also in mtDNA and in the nuclear genome of green plants, stramenopiles, and rhizarians. Phylogenetic and plasmid-derived ORF analyses showed that the majority of plasmid DNAs originated within red algae, whereas others were derived from cyanobacteria, other bacteria, and viruses. Our results elucidate the evolution of plasmid DNAs in red algae and suggest that they spread as parasitic genetic elements. This hypothesis is consistent with their sporadic distribution within Rhodophyta. PMID:27030297

  18. Development of defoliating insects and their preferences for host plants under varying temperatures in a subtropical evergreen forest in eastern China

    NASA Astrophysics Data System (ADS)

    Jing, Jun; Xia, Lingdan; Li, Kai

    2016-09-01

    The aim of this work was to understand the development of defoliating insects and their preferences for host plants under varying temperatures in a subtropical evergreen broad-leaved forest in China. We measured the main developmental parameters of three typical defoliating insects (i.e., Ourapteryx ebuleata szechuana, Biston marginata, and Euproctis angulata) and their preferences for five host plants at temperatures from 16°C to 31°C at 3°C intervals in the Tiantong National Forest Research station in eastern China. The results showed the following. 1) An appropriate rise in temperature increases the survival rate with an increase in the number of offspring. The developmental durations for these three insects were shortened, and pupal weight increased with an increase in temperature. 2) A shift in the preference for host plants for these three insects was observedat elevated temperatures. They all preferred to feed on Schima superba and Castanopsis sclerophylla at elevated temperatures, showing an opposite response to the other three plants. The daily leaf consumption of the three insects was positively correlated with their feeding preference, with more leaves being consumed from the plants they preferred. 3) For O. ebuleata szechuana larvae, daily leaf consumption initially increased and then decreased with increasing temperatures. In contrast, Biston marginata and Euproctis angulata larvae consumed more leaves at elevated temperatures. The feeding preferences of O. ebuleata szechuana and Biston marginata were more sensitive to changing temperatures than that of Euproctis angulata laevae. We concluded that increased numbers of offspring and generations, pupal weights, and a shift in preference to two plants for these three defoliating insects might lead to severe damage to these two plants which would enhance the fragmentation and decrease the stability of the forest communities under changing temperatures. Meanwhile, the variations in the responses of

  19. Species of Pseudorhabdosynochus (Monogenea, Diplectanidae) from Groupers (Mycteroperca spp., Epinephelidae) in the Mediterranean and Eastern Atlantic Ocean, with Special Reference to the 'Beverleyburtonae Group' and Description of Two New Species.

    PubMed

    Chaabane, Amira; Neifar, Lassad; Gey, Delphine; Justine, Jean-Lou

    2016-01-01

    Pseudorhabdosynochus Yamaguti, 1958 is a species-rich diplectanid genus, mainly restricted to the gills of groupers (Epinephelidae) and especially abundant in warm seas. Species from the Mediterranean are not fully documented. Two new and two previously known species from the gills of Mycteroperca spp. (M. costae, M. rubra, and M. marginata) in the Mediterranean and Eastern Atlantic Ocean are described here from new material and slides kept in collections. Identifications of newly collected fish were ascertained by barcoding of cytochrome c oxidase subunit I (COI) sequences. Pseudorhabdosynochus beverleyburtonae (Oliver, 1984) Kritsky & Beverley-Burton, 1986 and P. sosia Neifar & Euzet 2007 are redescribed from type-specimens and new specimens collected off Tunisia and Libya from M. marginata and M. costae, respectively. Pseudorhabdosynochus oliveri n. sp., from M. marginata (type-host) off the Mediterranean coast of France (type-locality), is described from specimens found among voucher specimens of P. beverleyburtonae deposited by Guy Oliver in the collection of the Muséum National d'Histoire Naturelle, Paris. Pseudorhabdosynochus oliveri is distinguished by the shape of its sclerotised vagina; it was not found in the other localities investigated. Pseudorhabdosynochus hayet n. sp. is described from M. rubra (type host) off Senegal (type-locality) and Tunisia. Pseudorhabdosynochus hayet is morphologically similar to P. sosia (type-host: M. costae) but was distinguished by differences in measurements of the vagina and male copulatory organ, different host, and divergent COI sequences. The four species (P. beverleyburtonae, P. sosia, P. oliveri, and P. hayet) share common characteristics such as squamodiscs with 2 innermost circular rows of rodlets and a similar general structure of the sclerotised vagina; we propose to group them into a 'beverleyburtonae group' within Pseudorhabdosynochus.

  20. Species of Pseudorhabdosynochus (Monogenea, Diplectanidae) from Groupers (Mycteroperca spp., Epinephelidae) in the Mediterranean and Eastern Atlantic Ocean, with Special Reference to the ‘Beverleyburtonae Group’ and Description of Two New Species

    PubMed Central

    Neifar, Lassad; Gey, Delphine; Justine, Jean-Lou

    2016-01-01

    Pseudorhabdosynochus Yamaguti, 1958 is a species-rich diplectanid genus, mainly restricted to the gills of groupers (Epinephelidae) and especially abundant in warm seas. Species from the Mediterranean are not fully documented. Two new and two previously known species from the gills of Mycteroperca spp. (M. costae, M. rubra, and M. marginata) in the Mediterranean and Eastern Atlantic Ocean are described here from new material and slides kept in collections. Identifications of newly collected fish were ascertained by barcoding of cytochrome c oxidase subunit I (COI) sequences. Pseudorhabdosynochus beverleyburtonae (Oliver, 1984) Kritsky & Beverley-Burton, 1986 and P. sosia Neifar & Euzet 2007 are redescribed from type-specimens and new specimens collected off Tunisia and Libya from M. marginata and M. costae, respectively. Pseudorhabdosynochus oliveri n. sp., from M. marginata (type-host) off the Mediterranean coast of France (type-locality), is described from specimens found among voucher specimens of P. beverleyburtonae deposited by Guy Oliver in the collection of the Muséum National d’Histoire Naturelle, Paris. Pseudorhabdosynochus oliveri is distinguished by the shape of its sclerotised vagina; it was not found in the other localities investigated. Pseudorhabdosynochus hayet n. sp. is described from M. rubra (type host) off Senegal (type-locality) and Tunisia. Pseudorhabdosynochus hayet is morphologically similar to P. sosia (type-host: M. costae) but was distinguished by differences in measurements of the vagina and male copulatory organ, different host, and divergent COI sequences. The four species (P. beverleyburtonae, P. sosia, P. oliveri, and P. hayet) share common characteristics such as squamodiscs with 2 innermost circular rows of rodlets and a similar general structure of the sclerotised vagina; we propose to group them into a ‘beverleyburtonae group’ within Pseudorhabdosynochus. PMID:27532108

  1. Experimental determination of trace element partition coefficients in cultured benthic foraminifera

    NASA Astrophysics Data System (ADS)

    Havach, Suzanne M.; Chandler, G. Thomas; Wilson-Finelli, Amy; Shaw, Timothy J.

    2001-04-01

    We present the first trace metal partition coefficients obtained from reproducing cultures of deep-sea benthic foraminifera. Paleoceanographically important species, including juvenile Bulimina marginata, Cibicidoides pachyderma, and Uvigerina peregrina, were maintained in sediment microcosms at 10°C, 35 psu, and pH 8 for 1-3 years. Juvenile foraminifera were separated, cleaned, and dissolved under clean conditions for determination of trace metal partition coefficients on recently deposited (1-3 months) foraminiferal calcite. In addition to the deep-sea species, we analyzed a shallow water benthic foraminifer, Ammonia beccarii. Overlying water samples were collected from the microcosms concurrent to the period of calcification (3 months prior to separation). Ba/Ca partition coefficients ( DBa) were measured in replicate for benthic foraminifera species Bulimina marginata (0.24 ± 0.07), Uvigerina peregrina (0.24 ± 0.06, Ammonia beccarii (0.20 ± 0.04). The DBa for Bulimina marginata and Uvigerina peregrina were found to closely match the range from the Ontong Java Plateau. Sample size limitations allowed for only one analysis of DBa for Cibicidoides pachyderma. However, our nonreplicated DBa of 0.5 ± 0.1 falls within the accepted range of core top samples (0.37 ± 0.06). We report a DCd for Ammonia of 1.0 ± 0.5, for Cibicidoides of 4 ± 2, for Bulimina of 3 ± 1, and for Uvigerina 2 ± 1 which all fall within the ranges reported for core top calibrations. The large uncertainties in DCd reflect variation in dissolved Cd concentration in the artificial seawater reservoir due to loss and replacement of Cd during the course of the experiment. The variability between species is probably the result of variability in pore water Cd in the sediment culture system and may reflect habitat effects.

  2. [Structure and dynamics of the community associated to cultivated Gracilariopsis tenuifrons (Gracilariacea) in Chacopata, Sucre, Venezuela. I: Faunistic inventory].

    PubMed

    Barrios, J; Lemus, A

    2000-12-01

    The associated fauna of Gracilariopsis tenuifrons (Gracilariaceae, Rhodophyta) cultures was collected between October 1994 and December 1996 in Chacopata (Sucre State, Venezuela) and preserved in 10% formaldehyde. The species list includes 17 Crustacea, 14 Mollusca and six Polychaeta, the remaining taxa added ten species (total 47 species in eight Phyla). Grazing by mesoherbivores affected the algae and the mollusk Aplysia protea damaged new cultures significantly. The abundance of tubes built by the amphipod Euricthonius brasiliensis impairs algal aspect and facilitates colonization by other organisms.

  3. The betaines from Chinese seaweeds

    NASA Astrophysics Data System (ADS)

    Han, Li-Jun; Fan, Xiao; Yan, Xiao-Jun

    2002-03-01

    Cation-exchange chromatography was selected to extract and separate betaines from marine algae. On the basis of the special chemical characteristics of the betaines and their analogues, Dragendorff's reagent (KBiI4) was used to test the existence of betaines and their analogues in marine algae. The total content of betaines from seven species was obtained by using the Reinkeate salt precipitation method. The results showed that the content of betaines in two species of Chlorophyta and two species of Rhodophyta were relatively high, and that the content of betaines in Enteromopha prolifera could even reach to 0.9%. The content in the three species of Phaeophyta was relatively low.

  4. Spatial patterns of seaweed distribution in Malaysia using GIS

    NASA Astrophysics Data System (ADS)

    Lian, Du Hai; Sim, Jillian Ooi Lean; Fauzi, Rosmadi; Moi, Phang Siew

    2008-10-01

    The objective of this article is to represent spatial patterns of seaweed distribution in Malaysia. Seaweeds have been collected since 1984 along coastlines of 4675 km of peninsular Malaysia, Sabah, and Sarawak. However, there is no seaweed database and they cannot be displayed in a geographic view. Therefore, a database with 805 georeferenced observations was setup and GIS is used to analyze seaweed diversity based on this database. The highest number of observations is 94 which occur along east coastline of peninsular Malaysia. The highest number of species richness is 82 which are also along east coastline of peninsular Malaysia. Rhodophyta has the highest species richness while Chlorophyta has the least species richness.

  5. Immunotoxicity activity from various essential oils of Angelica genus from South Korea against Aedes aegypti L.

    PubMed

    Chung, Ill-Min; Kim, Eun-Hye; Lee, Jai-Heon; Lee, Young-Choon; Moon, Hyung-In

    2012-02-01

    The leaves of Angelica anomala Lallemant, Angelica cartilagino-marginata var. distans (Nakai) Kitag, Angelica czernevia (Fisch. et Meyer) Kitagawa, Angelica dahurica Benth. et Hooker, Angelica decursiva (Miq.) Franch. & Sav, Angelica fallax Boissieu, Angelica gigas Nakai, Angelica japonica A. gray were essential oil extracted and immunotoxicity effects were studied. The Angelica anomala, A. cartilagino-marginata var. distans, A. czernevia, A. dahurica, A. decursiva, A. fallax, A. gigas, A. japonica essential oil yield were 4.13, 4.83, 4.45, 3.25, 4.11, 4.73, 4.34 and 4.21%. The A. dahurica essential oil had a significant toxic effect against early fourth-stage larvae of Aedes aegypti L with a lethal concentration 50 (LC₅₀) value of 43.12 ppm and an LC₉₀ value of 65.23 ppm. The above indicates that essential oil contents may play a more important role in the toxicity of essential oil.

  6. [Negative air ions generated by plants upon pulsed electric field stimulation applied to soil].

    PubMed

    Wu, Ren-ye; Deng, Chuan-yuan; Yang, Zhi-jian; Weng, Hai-yong; Zhu, Tie-jun-rong; Zheng, Jin-gui

    2015-02-01

    This paper investigated the capacity of plants (Schlumbergera truncata, Aloe vera var. chinensis, Chlorophytum comosum, Schlumbergera bridgesii, Gymnocalycium mihanovichii var. friedrichii, Aspidistra elatior, Cymbidium kanran, Echinocactus grusonii, Agave americana var. marginata, Asparagus setaceus) to generate negative air ions (NAI) under pulsed electric field stimulation. The results showed that single plant generated low amounts of NAI in natural condition. The capacity of C. comosum and G. mihanovichii var. friedrichii generated most NAI among the above ten species, with a daily average of 43 ion · cm(-3). The least one was A. americana var. marginata with the value of 19 ion · cm(-3). When proper pulsed electric field stimulation was applied to soil, the NAI of ten plant species were greatly improved. The effect of pulsed electric field u3 (average voltage over the pulse period was 2.0 x 10(4) V, pulse frequency was 1 Hz, and pulse duration was 50 ms) was the greatest. The mean NAI concentration of C. kanran was the highest 1454967 ion · cm(-3), which was 48498.9 times as much as that in natural condition. The lowest one was S. truncata with the value of 34567 ion · cm(-3), which was 843.1 times as much as that in natural condition. The capacity of the same plants to generate negative air ion varied extremely under different intensity pulsed electric fields.

  7. Signaling hunger through aggression—the regulation of foraging in a primitively eusocial wasp

    NASA Astrophysics Data System (ADS)

    Lamba, Shakti; Chandrasekhar, K.; Gadagkar, Raghavendra

    2008-07-01

    Primitively eusocial wasps are generally headed by behaviorally dominant queens who use their aggression to suppress worker reproduction. In contrast, queens in the primitively eusocial wasp Ropalidia marginata are strikingly docile and non-aggressive. However, workers exhibit dominance-subordinate interactions among themselves. These interactions do not appear to reflect reproductive competition because there is no correlation between the relative position of an individual in the dominance hierarchy of the colony and the likelihood that she will succeed a lost/removed queen. Based on the observation that foraging continues unaltered in the absence of the queen and the correlation between dominance behavior and foraging, we have previously suggested that dominance-subordinate interactions among workers in R. marginata have been co-opted to serve the function of decentralized, self-organized regulation of foraging. This idea has been supported by an earlier experimental study where it was found that a reduced demand for food led to a significant decrease in dominance behavior. In this study, we perform the converse experiment, demonstrate that dominance behavior increases under conditions of starvation, and thus provide further evidence in support of the hypothesis that intranidal workers signal hunger through aggression.

  8. Lutein epoxide cycle, light harvesting and photoprotection in species of the tropical tree genus Inga.

    PubMed

    Matsubara, Shizue; Krause, G Heinrich; Seltmann, Martin; Virgo, Aurelio; Kursar, Thomas A; Jahns, Peter; Winter, Klaus

    2008-04-01

    Dynamics and possible function of the lutein epoxide (Lx) cycle, that is, the reversible conversion of Lx to lutein (L) in the light-harvesting antennae, were investigated in leaves of tropical tree species. Photosynthetic pigments were quantified in nine Inga species and species from three other genera. In Inga, Lx levels were high in shade leaves (mostly above 20 mmol mol(-1) chlorophyll) and low in sun leaves. In Virola surinamensis, both sun and shade leaves exhibited very high Lx contents (about 60 mmol mol(-1) chlorophyll). In Inga marginata grown under high irradiance, Lx slowly accumulated within several days upon transfer to deep shade. When shade leaves of I. marginata were briefly exposed to the sunlight, both violaxanthin and Lx were quickly de-epoxidized. Subsequently, overnight recovery occurred only for violaxanthin, not for Lx. In such leaves, containing reduced levels of Lx and increased levels of L, chlorophyll fluorescence induction showed significantly slower reduction of the photosystem II electron acceptor, Q(A), and faster formation as well as a higher level of non-photochemical quenching. The results indicate that slow Lx accumulation in Inga leaves may improve light harvesting under limiting light, while quick de-epoxidation of Lx to L in response to excess light may enhance photoprotection.

  9. Magnetic resonance imaging reveals functional anatomy and biomechanics of a living dragon tree

    PubMed Central

    Hesse, Linnea; Masselter, Tom; Leupold, Jochen; Spengler, Nils; Speck, Thomas; Korvink, Jan Gerrit

    2016-01-01

    Magnetic resonance imaging (MRI) was used to gain in vivo insight into load-induced displacements of inner plant tissues making a non-invasive and non-destructive stress and strain analysis possible. The central aim of this study was the identification of a possible load-adapted orientation of the vascular bundles and their fibre caps as the mechanically relevant tissue in branch-stem-attachments of Dracaena marginata. The complex three-dimensional deformations that occur during mechanical loading can be analysed on the basis of quasi-three-dimensional data representations of the outer surface, the inner tissue arrangement (meristem and vascular system), and the course of single vascular bundles within the branch-stem-attachment region. In addition, deformations of vascular bundles could be quantified manually and by using digital image correlation software. This combination of qualitative and quantitative stress and strain analysis leads to an improved understanding of the functional morphology and biomechanics of D. marginata, a plant that is used as a model organism for optimizing branched technical fibre-reinforced lightweight trusses in order to increase their load bearing capacity. PMID:27604526

  10. Magnetic resonance imaging reveals functional anatomy and biomechanics of a living dragon tree.

    PubMed

    Hesse, Linnea; Masselter, Tom; Leupold, Jochen; Spengler, Nils; Speck, Thomas; Korvink, Jan Gerrit

    2016-09-08

    Magnetic resonance imaging (MRI) was used to gain in vivo insight into load-induced displacements of inner plant tissues making a non-invasive and non-destructive stress and strain analysis possible. The central aim of this study was the identification of a possible load-adapted orientation of the vascular bundles and their fibre caps as the mechanically relevant tissue in branch-stem-attachments of Dracaena marginata. The complex three-dimensional deformations that occur during mechanical loading can be analysed on the basis of quasi-three-dimensional data representations of the outer surface, the inner tissue arrangement (meristem and vascular system), and the course of single vascular bundles within the branch-stem-attachment region. In addition, deformations of vascular bundles could be quantified manually and by using digital image correlation software. This combination of qualitative and quantitative stress and strain analysis leads to an improved understanding of the functional morphology and biomechanics of D. marginata, a plant that is used as a model organism for optimizing branched technical fibre-reinforced lightweight trusses in order to increase their load bearing capacity.

  11. Competition induces allelopathy but suppresses growth and anti-herbivore defence in a chemically rich seaweed.

    PubMed

    Rasher, Douglas B; Hay, Mark E

    2014-02-22

    Many seaweeds and terrestrial plants induce chemical defences in response to herbivory, but whether they induce chemical defences against competitors (allelopathy) remains poorly understood. We evaluated whether two tropical seaweeds induce allelopathy in response to competition with a reef-building coral. We also assessed the effects of competition on seaweed growth and seaweed chemical defence against herbivores. Following 8 days of competition with the coral Porites cylindrica, the chemically rich seaweed Galaxaura filamentosa induced increased allelochemicals and became nearly twice as damaging to the coral. However, it also experienced significantly reduced growth and increased palatability to herbivores (because of reduced chemical defences). Under the same conditions, the seaweed Sargassum polycystum did not induce allelopathy and did not experience a change in growth or palatability. This is the first demonstration of induced allelopathy in a seaweed, or of competitors reducing seaweed chemical defences against herbivores. Our results suggest that the chemical ecology of coral-seaweed-herbivore interactions can be complex and nuanced, highlighting the need to incorporate greater ecological complexity into the study of chemical defence.

  12. d-Amino Acid Position Influences the Anticancer Activity of Galaxamide Analogs: An Apoptotic Mechanism Study

    PubMed Central

    Bai, Defa; Yu, Siming; Zhong, Shenghui; Zhao, Bingxin; Qiu, Shaoling; Chen, Jianwei; Lunagariya, Jignesh; Liao, Xiaojian; Xu, Shihai

    2017-01-01

    Galaxamide, an extract from Galaxaura filamentosa, is a cyclic pentapeptide containing five l-leucines. Due to the particular cyclic structure and the excellent anticancer activity, synthesis of Galaxamide and its analogs and their subsequent bio-applications have attracted great attention. In the present work, we synthesized six Galaxamide analogs by replacing one of the l-leucines with phenylalanine and varying the d-amino acid position. The anticancer effect of the synthesized Galaxamide analogs was tested against four in vitro human cancer cell lines, human hepatocellular cells (HepG2), human breast cancer cell (MCF-7), human breast adenocarcinoma cells (MDA-MB-435) and a human cervical carcinoma cell line (Hela). Results showed that Galaxamide analogs with different d-amino acid positions displayed distinct anticancer potential. The Galaxamide analog containing d-amino acid at position 5 (Analog-6) presented the strongest anticancer activity. The mechanism study revealed that Analog-6 could cause the early apoptosis of HepG2 cells by inhibiting their growth in the sub-G1 stage of the cell cycle and induce the chromatin condensation and fragmentation, which can be seen as 68% of HepG2 cells inhibited in the sub-G1 stage. Moreover, a mitochondria-mediated pathway was found to be involved in the apoptotic process of Analog-6 on HepG2 cells. PMID:28287429

  13. Cryptic effects of habitat declines: coral-associated fishes avoid coral-seaweed interactions due to visual and chemical cues

    PubMed Central

    Brooker, Rohan M.; Brandl, Simon J.; Dixson, Danielle L.

    2016-01-01

    Seaweed-dominated coral reefs are becoming increasingly common as environmental conditions shift away from those required by corals and toward those ideal for rampant seaweed growth. How coral-associated organisms respond to seaweed will not only impact their fate following environmental change but potentially also the trajectories of the coral communities on which they rely. However, behavioral responses by coral-associated organisms to seaweeds are poorly understood. This study examined interactions between a guild of obligate and opportunistic coral-feeding butterflyfishes (Chaetodontidae) and scleractinian corals to determine whether fishes continue to interact with corals in contact with seaweed or if they are avoided. Under natural conditions, all species interacted almost exclusively with seaweed-free corals. In a controlled patch reef experiment, fishes avoided corals in physical contact with seaweed, irrespective of dietary preferences. When visual seaweed cues were removed, butterflyfish continued to avoid corals that had been in contact with the allelopathic Galaxaura filamentosa, suggesting that chemical cues produced by coral-seaweed interactions are repellent. These findings suggest that, due to deleterious visual and chemical cues produced by coral-seaweed interactions, coral-associated organisms may struggle to locate resources as seaweed-free corals decline in abundance. PMID:26725835

  14. Induction of apoptosis by three marine algae through generation of reactive oxygen species in human leukemic cell lines.

    PubMed

    Huang, Huey-Lan; Wu, Shwu-Li; Liao, Hui-Fen; Jiang, Chii-Ming; Huang, Ray-Ling; Chen, Yu-Yawn; Yang, Yuh-Cheng; Chen, Yu-Jen

    2005-03-09

    In this study, we examined the antitumor effect of marine algae extracts on human hepatoma and leukemia cells. Ethyl acetate extracts from Colpomenia sinuosa (Cs-EA), Halimeda discoidae (Hd-EA), and Galaxaura oblongata (Go-EA) directly inhibited the growth of human hepatoma HuH-7 cells and leukemia U937 and HL-60 cells in a time- and dose-dependent manner. Specifically, these algae extracts induced apoptosis of U937 and HL-60 cells as evaluated by detection of hypodiploid cells using flow cytometry and observation of condensed and fragmented nuclei in algae extract-treated cells. Intracellular reactive oxygen species (ROS), especially hydrogen peroxide and superoxide anion, were increased about 2-3-fold in U937 cells treated with Cs-EA for 3-5 h. Interestingly, antioxidant N-acetylcysteine effectively blocked Cs-EA-, Hd-EA-, and Go-EA-induced apoptosis, suggesting that ROS is a key mediator in the apoptotic signaling pathway. In conclusion, our results show that algae extracts induce apoptosis in human leukemia cells through generation of ROS.

  15. Macroalgal terpenes function as allelopathic agents against reef corals.

    PubMed

    Rasher, Douglas B; Stout, E Paige; Engel, Sebastian; Kubanek, Julia; Hay, Mark E

    2011-10-25

    During recent decades, many tropical reefs have transitioned from coral to macroalgal dominance. These community shifts increase the frequency of algal-coral interactions and may suppress coral recovery following both anthropogenic and natural disturbance. However, the extent to which macroalgae damage corals directly, the mechanisms involved, and the species specificity of algal-coral interactions remain uncertain. Here, we conducted field experiments demonstrating that numerous macroalgae directly damage corals by transfer of hydrophobic allelochemicals present on algal surfaces. These hydrophobic compounds caused bleaching, decreased photosynthesis, and occasionally death of corals in 79% of the 24 interactions assayed (three corals and eight algae). Coral damage generally was limited to sites of algal contact, but algae were unaffected by contact with corals. Artificial mimics for shading and abrasion produced no impact on corals, and effects of hydrophobic surface extracts from macroalgae paralleled effects of whole algae; both findings suggest that local effects are generated by allelochemical rather than physical mechanisms. Rankings of macroalgae from most to least allelopathic were similar across the three coral genera tested. However, corals varied markedly in susceptibility to allelopathic algae, with globally declining corals such as Acropora more strongly affected. Bioassay-guided fractionation of extracts from two allelopathic algae led to identification of two loliolide derivatives from the red alga Galaxaura filamentosa and two acetylated diterpenes from the green alga Chlorodesmis fastigiata as potent allelochemicals. Our results highlight a newly demonstrated but potentially widespread competitive mechanism to help explain the lack of coral recovery on many present-day reefs.

  16. d-Amino Acid Position Influences the Anticancer Activity of Galaxamide Analogs: An Apoptotic Mechanism Study.

    PubMed

    Bai, Defa; Yu, Siming; Zhong, Shenghui; Zhao, Bingxin; Qiu, Shaoling; Chen, Jianwei; Lunagariya, Jignesh; Liao, Xiaojian; Xu, Shihai

    2017-03-10

    Galaxamide, an extract from Galaxaura filamentosa, is a cyclic pentapeptide containing five l-leucines. Due to the particular cyclic structure and the excellent anticancer activity, synthesis of Galaxamide and its analogs and their subsequent bio-applications have attracted great attention. In the present work, we synthesized six Galaxamide analogs by replacing one of the l-leucines with phenylalanine and varying the d-amino acid position. The anticancer effect of the synthesized Galaxamide analogs was tested against four in vitro human cancer cell lines, human hepatocellular cells (HepG₂), human breast cancer cell (MCF-7), human breast adenocarcinoma cells (MDA-MB-435) and a human cervical carcinoma cell line (Hela). Results showed that Galaxamide analogs with different d-amino acid positions displayed distinct anticancer potential. The Galaxamide analog containing d-amino acid at position 5 (Analog-6) presented the strongest anticancer activity. The mechanism study revealed that Analog-6 could cause the early apoptosis of HepG₂ cells by inhibiting their growth in the sub-G1 stage of the cell cycle and induce the chromatin condensation and fragmentation, which can be seen as 68% of HepG₂ cells inhibited in the sub-G1 stage. Moreover, a mitochondria-mediated pathway was found to be involved in the apoptotic process of Analog-6 on HepG₂ cells.

  17. Cryptic effects of habitat declines: coral-associated fishes avoid coral-seaweed interactions due to visual and chemical cues.

    PubMed

    Brooker, Rohan M; Brandl, Simon J; Dixson, Danielle L

    2016-01-04

    Seaweed-dominated coral reefs are becoming increasingly common as environmental conditions shift away from those required by corals and toward those ideal for rampant seaweed growth. How coral-associated organisms respond to seaweed will not only impact their fate following environmental change but potentially also the trajectories of the coral communities on which they rely. However, behavioral responses by coral-associated organisms to seaweeds are poorly understood. This study examined interactions between a guild of obligate and opportunistic coral-feeding butterflyfishes (Chaetodontidae) and scleractinian corals to determine whether fishes continue to interact with corals in contact with seaweed or if they are avoided. Under natural conditions, all species interacted almost exclusively with seaweed-free corals. In a controlled patch reef experiment, fishes avoided corals in physical contact with seaweed, irrespective of dietary preferences. When visual seaweed cues were removed, butterflyfish continued to avoid corals that had been in contact with the allelopathic Galaxaura filamentosa, suggesting that chemical cues produced by coral-seaweed interactions are repellent. These findings suggest that, due to deleterious visual and chemical cues produced by coral-seaweed interactions, coral-associated organisms may struggle to locate resources as seaweed-free corals decline in abundance.

  18. Paper Synthesis, Cytotoxicity and Apoptosis Induction in Human Tumor Cells by Galaxamide and Its Analogues

    PubMed Central

    Xiao, Xi; Liao, Xiaojian; Qiu, Shaoling; Liu, Zihao; Du, Bin; Xu, Shihai

    2014-01-01

    Our previous study reported that galaxamide, which is a cyclo-pentapeptide containing five leucines that was extracted from Galaxaura filamentosa, displayed remarkable anticancer cytotoxicity. This novel cyclo-peptide provided a new skeleton for the structural modifications used in finding new drugs with better anticancer properties. In this study, five analogues were synthesized based on changing the number of d/l amino acids by adding a new amino acid, phenylalanine. Galaxamide and five of its analogues were evaluated through MTT assays to examine their cytotoxic activities. We found that modified analogue 5, which is referred to as A5, displayed broad spectrum cytotoxic activity toward every cell line tested; in addition, the IC50 of A5 was lower than that of galaxamide and the other analogues. Furthermore, we used flow cytometry and western blot assays to investigate whether galaxamide and A5 could induce cancer cell apoptosis. The flow cytometric studies showed that HepG2 cells treated with different concentrations of galaxamide or A5 over 72 h displayed significant and dose-dependent increases in the percentages of early-stage apoptotic cells. Western blotting revealed that both compounds induce caspase-dependent apoptosis in HepG2 cells through a mitochondria-mediated pathway. The results demonstrate that galaxamide and its analogues have potential applications as clinical anticancer drugs. PMID:25231922

  19. Bathymetric variation of epiphytic assemblages on Posidonia oceanica (L.) Delile leaves in relation to anthropogenic disturbance in the southeastern Mediterranean.

    PubMed

    Ben Brahim, Mounir; Mabrouk, Lotfi; Hamza, Asma; Mahfoudi, Mabrouka; Bouain, Abderrahmane; Aleya, Lotfi

    2014-12-01

    A survey of the epiphytic leaves of Posidonia oceanica was conducted along a depth transect at both the control station Attaya in the Kerkennah Islands and the disturbed Mahres station on the Sfax coast (Tunisia). Samples were collected by scuba divers at depths of 5, 10, 15, and 20 m in July 2008. We evaluated whether the pattern of spatial variability of the macroepiphyte assemblages of leaves of Posidonia oceanica differed in relation to anthropogenic interference. The results indicate that the decrease in shoot density and leaf length according to depth was low at Mahres. The biomass of epiphytic leaves and the percentage cover of epiphytic assemblages decreased with depth for both stations and heavily at Mahres, this decline being related to anthropogenic disturbance. This study shows that the highest values of epifauna and epiflora were detected at the disturbed station Mahres. Macroalgae assemblages decreased with depth at both stations and were dominated by Rhodophyta, whereas the percentage cover of the epifauna leaf that decreases according to depth was dominated by Hydrozoa and Bryozoa. Changes in epiphyte assemblages, epiphytic biomass, percentage cover, and species richness in proportion to Heterokontophyta, Rhodophyta, Cyanobacteria, Hydrozoa, Porifera, and Tunicata between the two stations constitute promising tools for detecting environmental disturbance.

  20. Macroalgal communities of intertidal rock pools in the northwest coast of Portugal

    NASA Astrophysics Data System (ADS)

    Araújo, Rita; Sousa-Pinto, I.; Bárbara, I.; Quintino, V.

    2006-09-01

    Macroalgal communities in littoral rock pools of the Northwest coast of Portugal were studied along 60 km of coastline. Thirty-eight pools were sampled twice between March and August 2003. Rhodophyta were the dominant algue group, whether the pools were located lower or upper on the shore, except in pools located between 2 and 3 meters where Rhodophyta share the dominance with Chlorophyta. Species richness increased from pools located at higher levels on the beach to the ones located lower on the shore. The macroalgal communities' species composition was the major source of variability between rock pools. Each pool presented a unique combination of species, forming particular communities. A reduced number of species with high percent cover are the main factor creating the differences between the pools. Also, clear differences could be found between the species compositions of macroalgal communities located in the pools and in the surrounding emergent substrata. The environmental variables considered in this study (tidal height, maximum pool depth, maximum pool width and maximum pool length), were poorly related to the communities' species composition. The results suggest that each pool is unique regarding its macroalgal community structure and that the environmental factors considered in this study were not of major importance in determining the variability between pools.

  1. Red Algal Phylogenomics Provides a Robust Framework for Inferring Evolution of Key Metabolic Pathways

    PubMed Central

    Qiu, Huan; Yoon, Hwan Su; Bhattacharya, Debashish

    2016-01-01

    Red algae comprise an anciently diverged, species-rich phylum with morphologies that span unicells to large seaweeds. Here, leveraging a rich red algal genome and transcriptome dataset, we used 298 single-copy orthologous nuclear genes from 15 red algal species to erect a robust multi-gene phylogeny of Rhodophyta. This tree places red seaweeds (Bangiophyceae and Florideophyceae) at the base of the mesophilic red algae with the remaining non-seaweed mesophilic lineages forming a well-supported sister group. The early divergence of seaweeds contrasts with the evolution of multicellular land plants and brown algae that are nested among multiple, unicellular or filamentous sister lineages. Using this novel perspective on red algal evolution, we studied the evolution of the pathways for isoprenoid biosynthesis. This analysis revealed losses of the mevalonate pathway on at least three separate occasions in lineages that contain Cyanidioschyzon, Porphyridium, and Chondrus. Our results establish a framework for in-depth studies of the origin and evolution of genes and metabolic pathways in Rhodophyta. PMID:28018750

  2. New records of benthic marine algae and Cyanobacteria for Costa Rica, and a comparison with other Central American countries

    NASA Astrophysics Data System (ADS)

    Bernecker, Andrea; Wehrtmann, Ingo S.

    2009-09-01

    We present the results of an intensive sampling program carried out from 2000 to 2007 along both coasts of Costa Rica, Central America. The presence of 44 species of benthic marine algae is reported for the first time for Costa Rica. Most of the new records are Rhodophyta (27 spp.), followed by Chlorophyta (15 spp.), and Heterokontophyta, Phaeophycea (2 spp.). Overall, the currently known marine flora of Costa Rica is comprised of 446 benthic marine algae and 24 Cyanobacteria. This species number is an under estimation, and will increase when species of benthic marine algae from taxonomic groups where only limited information is available (e.g., microfilamentous benthic marine algae, Cyanobacteria) are included. The Caribbean coast harbors considerably more benthic marine algae (318 spp.) than the Pacific coast (190 spp.); such a trend has been observed in all neighboring countries. Compared to other Central American countries, Costa Rica has the highest number of reported benthic marine algae; however, Panama may have a similarly high diversity after unpublished results from a Rhodophyta survey (Wysor, unpublished) are included. Sixty-two species have been found along both the Pacific and Caribbean coasts of Costa Rica; we discuss this result in relation to the emergence of the Central American Isthmus.

  3. Marine macrophytes as effective lead biosorbents.

    PubMed

    Pennesi, Chiara; Totti, Cecilia; Romagnoli, Tiziana; Bianco, Barbara; De Michelis, Ida; Beolchini, Francesca

    2012-01-01

    Several species of seagrass and marine macrophytes were investigated for their biosorption performance in the removal of lead from aqueous solution. The effect of pH on the equilibrium of the seagrass Cymodocea nodosa as a biosorbent also was studied. It was found that increasing pH increased lead biosorption, with a maximum uptake of approximately 140 mg/g in the range pH 3.3 to 5. Equilibrium data at different pH levels were successfully fitted to competitive equilibrium models. In addition, the seaweeds belonging to different phyla (i.e., Chlorophyta, Heterokontophyta, and Rhodophyta) were studied for the effect of their structure on equilibrium at a constant pH 5. The brown algae (Heterokontophyta) showed the highest potential for lead sorption, with a maximum uptake of 220 mg/g for C. compressa and 140 mg/g for S. lomentaria. The green algae (Chlorophyta) showed lead uptake in the range 40 to 90 mg/g, and the red algae (Rhodophyta) was least effective, with uptake in the range 10 to 40 mg/g.

  4. Nuclear DNA Content Estimates in Multicellular Green, Red and Brown Algae: Phylogenetic Considerations

    PubMed Central

    KAPRAUN, DONALD F.

    2005-01-01

    • Background and Aims Multicellular eukaryotic algae are phylogenetically disparate. Nuclear DNA content estimates have been published for fewer than 1 % of the described species of Chlorophyta, Phaeophyta and Rhodophyta. The present investigation aims to summarize the state of our knowledge and to add substantially to our database of C-values for theses algae. • Methods The DNA-localizing fluorochrome DAPI (4′, 6-diamidino-2-phenylindole) and RBC (chicken erythrocyte) standard were used to estimate 2C values with static microspectrophotometry. • Key Results 2C DNA contents for 85 species of Chlorophyta range from 0·2–6·1 pg, excluding the highly polyploidy Charales and Desmidiales with DNA contents of up to 39·2 and 20·7 pg, respectively. 2C DNA contents for 111 species of Rhodophyta range from 0·1–2·8 pg, and for 44 species of Phaeophyta range from 0·2–1·8 pg. • Conclusions New availability of consensus higher-level molecular phylogenies provides a framework for viewing C-value data in a phylogenetic context. Both DNA content ranges and mean values are greater in taxa considered to be basal. It is proposed that the basal, ancestral genome in each algal group was quite small. Both mechanistic and ecological processes are discussed that could have produced the observed C-value ranges. PMID:15596456

  5. Studies on marine algae for haemagglutinic activity.

    PubMed

    Alam, M T; Usmanghani, K

    1994-07-01

    Lectins (agglutinins) are important in medical and immunological applications. Phytohaemagglutinins have been found useful in blood banking. Keeping in view of these facts, the marine algae found at Karachi coastal region have been screened for agglutinic activity by using human erythrocytes of A, B, AB and 0 group. Altogether 53 algal samples were collected and subjected to extraction, fractionation serial dilution and titre determinations. The total marine algae screened for haemagglutinic activity were 44 out of these 14, 13 and 17 belonged to Chlorophyta, Phaeophyta, and Rhodophyta respectively. Among these three groups the Rhodophyta showed the highest number of lytic activity. The green marine alga Valoniopsis pachynema showed a titre value between 2(2) and 2(3), which is statistically significant. In case of brown marine algae Colpomenia sinuosa was found to be active (titre 2(3)), while Dictyota dichotoma, D. indica and Iyengaria stellata, furnished week titre value as 2(2). The red marine algae screened were 17, out of these 4 spp. showed significant activity (titre 2(3)), and these are Gelidium usmanghani, Gracilaria foliifera Hypnea pannosa and Hynea valentiae. While Scinaia fascicularis, Scinaia indica and Champia parvula were found to be weak in their onset on human erythrocytes. The results obtained were quite in agreement with those reported in the literature.

  6. [Distribution characteristics of benthic algae in intertidal zone of Ma' an Archipelago of Zhejiang Province].

    PubMed

    Zhang, Shou-Yu; Liang, Jun; Wang, Zhen-Hua; Wang, Kai

    2008-10-01

    Based on the survey of benthic algae in the intertidal zone of Ma' an Archipelago from March to July 2007, the algal species composition, distribution, and temperature feature were studied. The dominant algal species in the study area were preliminarily analyzed by using similarity indices (S(c)) and index of relative importance (IRI(c)). A total of 31 species sampled in sublittoral area were identified, among which, 7 species of 5 genera belonged to Chlorophyta, 8 species of 5 genera belonged to Phaeophyta, and 16 species of 14 genera belonged to Rhodophyta. Topical and selective distribution species influenced by wave and tide were identified in the intertidal zone. Ulva pertusa and Sargassum thunbergii were found in all survey area. Rhodophyta was the dominant species, with the occurring frequency being up to 61.1%, and Chlorophyta showed quite uniformed horizontal distribution. In addition, 81% of sampled species were from low-tide zone, and some were extended from mid-tide zone to low-tide zone. The composition comparability between mid-tide and low-tide species was 0.47, and the convergence effect in mid-tide and low-tide zone was higher than that in high-tide and mid-tide zone. The sublittoral area of Ma' an Archipelago showed obvious vertical zoning character, with temperate species being absolute abundant, and the warm-water species dominant. The marine floral texture of Ma' an Archipelago belongs to warm temperate-subtropical transitional marine flora.

  7. Codon Adaptation of Plastid Genes

    PubMed Central

    Suzuki, Haruo; Morton, Brian R.

    2016-01-01

    Codon adaptation is codon usage bias that results from selective pressure to increase the translation efficiency of a gene. Codon adaptation has been studied across a wide range of genomes and some early analyses of plastids have shown evidence for codon adaptation in a limited set of highly expressed plastid genes. Here we study codon usage bias across all fully sequenced plastid genomes which includes representatives of the Rhodophyta, Alveolata, Cryptophyta, Euglenozoa, Glaucocystophyceae, Rhizaria, Stramenopiles and numerous lineages within the Viridiplantae, including Chlorophyta and Embryophyta. We show evidence that codon adaptation occurs in all genomes except for two, Theileria parva and Heicosporidium sp., both of which have highly reduced gene contents and no photosynthesis genes. We also show evidence that selection for codon adaptation increases the representation of the same set of codons, which we refer to as the adaptive codons, across this wide range of taxa, which is probably due to common features descended from the initial endosymbiont. We use various measures to estimate the relative strength of selection in the different lineages and show that it appears to be fairly strong in certain Stramenopiles and Chlorophyta lineages but relatively weak in many members of the Rhodophyta, Euglenozoa and Embryophyta. Given these results we propose that codon adaptation in plastids is widespread and displays the same general features as adaptation in eubacterial genomes. PMID:27196606

  8. Generic redescription, two new species, and a key to the species of the cicada genus Ariasa Distant, 1905 with the description of a new genus (Hemiptera: Cicadidae: Cicadinae: Fidicinini).

    PubMed

    Sanborn, Allen F

    2016-07-13

    The cicada genus Ariasa Distant, 1905 is redescribed.  Ariasa albimaculosa n. sp. is described from Colombia and A. bartletti n. sp. is described from Peru.  The current 14 species of Ariasa are listed along with their synonymies, known distribution of each species, and a key to the species is provided.  The first records of Ariasa bilaqueata (Uhler, 1903) for Peru and French Guiana are provided. Cracenpsaltria brasiliorum (Kirkaldy, 1909) rev. stat., n. comb. is determined to be the correct name for the taxon Cicada marginata Olivier, 1790 and the new genus Cracenpsaltria n. gen. is erected for the taxon.  The distribution of C. brasiliorum rev. stat., n. comb. is expanded to include Bolivia and Peru.

  9. The function of resilin in beetle wings.

    PubMed Central

    Haas, F; Gorb, S; Blickhan, R

    2000-01-01

    This account shows the distribution of elastic elements in hind wings in the scarabaeid Pachnoda marginata and coccinellid Coccinella septempunctata (both Coleoptera). Occurrence of resilin, a rubber-like protein, in some mobile joints together with data on wing unfolding and flight kinematics suggest that resilin in the beetle wing has multiple functions. First, the distribution pattern of resilin in the wing correlates with the particular folding pattern of the wing. Second, our data show that resilin occurs at the places where extra elasticity is needed, for example in wing folds, to prevent material damage during repeated folding and unfolding. Third, resilin provides the wing with elasticity in order to be deformable by aerodynamic forces. This may result in elastic energy storage in the wing. PMID:10983820

  10. New Coleoptera records from New Brunswick, Canada: Megalopodidae and Chrysomelidae

    PubMed Central

    Webster, Reginald P.; LeSage, Laurent; DeMerchant, Ian

    2012-01-01

    Abstract Zeugophora varians Crotch and the family Megalopodidae are newly recorded for New Brunswick, Canada. Twenty-eight species of Chrysomelidae are newly recorded for New Brunswick, including Acalymma gouldi Barber, Altica knabii Blatchley, Altica rosae Woods, Altica woodsi Isely, Bassareus mammifer (Newman), Chrysolina marginata (Linnaeus), Chrysomela laurentia Brown, Crepidodera violacea Melsheimer, Cryptocephalus venustus Fabricius, Neohaemonia melsheimeri (Lacordaire), Neohaemonia nigricornis (Kirby), Pachybrachis bivittatus (Say), Pachybrachis m-nigrum (Melsheimer), Phyllobrotica limbata (Fabricius), Psylliodes affinis (Paykull), Odontota dorsalis (Thunberg), Ophraella communa (LeSage), Ophraella cribrata (LeConte), Ophraella notata (Fabricius), Systena hudsonias (Forster), Tricholochmaea ribicola (Brown), and Tricholochmaea rufosanguinea (Say), which are also newly recorded for the Maritime provinces. Collection data, habitat data, and distribution maps are presented for all these species. PMID:22539900

  11. Magnetic material arrangement in oriented termites: a magnetic resonance study

    NASA Astrophysics Data System (ADS)

    Alves, O. C.; Wajnberg, E.; de Oliveira, J. F.; Esquivel, D. M. S.

    2004-06-01

    Temperature dependence of the magnetic resonance is used to study the magnetic material in oriented Neocapritermes opacus (N.o.) termite, the only prey of the migratory ant Pachycondyla marginata (P.m.). A broad line in the g=2 region, associated to isolated nanoparticles shows that at least 97% of the magnetic material is in the termite's body (abdomen + thorax). From the temperature dependence of the resonant field and from the spectral linewidths, we estimate the existence of magnetic nanoparticles 18.5 ± 0.3 nm in diameter and an effective magnetic anisotropy constant, Keff between 2.1 and 3.2 × 10 4 erg/cm 3. A sudden change in the double integrated spectra at about 100 K for N.o. with the long body axis oriented perpendicular to the magnetic field can be attributed to the Verwey transition, and suggests an organized film-like particle system.

  12. Contribution of gall microscopic structure to taxonomy of gallicolous aphids on Pistacia.

    PubMed

    Álvarez, R; Martinez, J-J I; Muñoz-Viveros, A L; Molist, P; Abad-González, J; Nieto Nafría, J M

    2016-09-01

    Aphids inducing galls on Pistacia plants belong to the tribe Fordini. According to the Heie & Wegierek classification, the genera are grouped into three subtribes. Previous microscopic studies showed that this taxonomy is not consistent with the histological characteristics of the galls. In this paper, galls induced by Aplonerura lentisci, Asiphonella cynodonti, Forda riccobonii, Slavun wertheimae and Smynthurodes betae were analyzed for the first time, as well as nine other galls previously described. Based on histological features three groups of galls can be establish: the first group comprises closed galls, induced by Baizongia pistaciae, Geoica utricularia, Rectinasus buxtoni and Slavun wertheimae; the second group includes two species of Geopemphigus (G. blackmani and G. torsus), and the third one is divided into two subgroups, the first comprises Aplonerura lentisci, Asiphonella cynodonti and Geopemphigus morral, and the second that includes Forda formicaria, F. marginata, F. riccobonii, Paracletus cimiciformis and Smynthurodes betae. An identification key of species based on microscopic features of galls is presented.

  13. [Diatoms from Unare and Píritu Lagoons, Anzoátegui state, Venezuela. Subclass Bacillariophycidae D. G. Mann ].

    PubMed

    Subero-Pino, Sonia S; Diaz-Ramos, José R; Sanchez-Suarez, Isaac G; Ferraz-Reyes, Elvira

    2002-01-01

    The diatom flora of Unare and Píritu Lagoons, Venezuela, comprises freshwater, estuarine and marine organisms. In this paper, 15 species of diatoms belonging to the subclass Bacillariophyceae D.G. Mann are described. Water samples from Unare and Píritu lagoons (Venezuela) were collected from November 1988 to July 1989. Samples were fixed with neutral formaldehyde (10%) and were examined under phase contrast microscopy. Species under study were Dictyoneis marginata (Lewis) Cleve, Cymbella affinis (Kützing) Cleve, Cymbella sp., Achnanthes brevipes var. intermedia (Kützing) Cleve, Lyrella irroratoides (Hustedt) Mann, Navicula carinifera (Grunow) Peragallo, Navicula liber (W. Smith) Peragallo, Navicula vacillans (Schmidt) Peragallo, Navicula sp, Amphora crassa var. campechiana Grunow, Amphora decussata Grunow, Caloneis powelli (Lewis) Cholnoky, Tryblionella acuta (Cleve) Mann in Round et al., Tryblionella apiculata Gregory, Surirella febigerii Lewis.

  14. A new species of the genus Parasa Moore (Lepidoptera: Limacodidae) from Yemen.

    PubMed

    Solovyev, Alexey V; Saldaitis, Aidas

    2010-01-01

    A new species Parasa dusii Solovyev and Saldaitis from northern Yemen is described (holotype in Museum Witt, Munich; Germany). The species has tendency to lose the green pigment typical for other congeners. It is provisionally placed into the genus Parasa Moore, 1859 where it is closely related to P. divisa West, 1940, P. catori Bethune-Baker, 1911, P. marginata West, 1940, P. thamia Rungs, 1951, P. dentina Hering, 1932, P. ananii Karsch, 1896, and P. semiochracea Hering, 1933. The relationship of the new species to these African species suggests its secondary penetration into the Arabian Peninsula from an origin in tropical Africa. The problems of monophyly of the genus Parasa and several associated genera are briefly discussed. All important characters of the new species, and some related species, are illustrated.

  15. A New Species of the Genus Parasa Moore (Lepidoptera: Limacodidae) from Yemen

    PubMed Central

    Solovyev, Alexey V.; Saldaitis, Aidas

    2010-01-01

    A new species Parasa dusii Solovyev and Saldaitis from northern Yemen is described (holotype in Museum Witt, Munich; Germany). The species has tendency to lose the green pigment typical for other congeners. It is provisionally placed into the genus Parasa Moore, 1859 where it is closely related to P. divisa West, 1940, P. catori Bethune-Baker, 1911, P. marginata West, 1940, P. thamia Rungs, 1951, P. dentina Hering, 1932, P. ananii Karsch, 1896, and P. semiochracea Hering, 1933. The relationship of the new species to these African species suggests its secondary penetration into the Arabian Peninsula from an origin in tropical Africa. The problems of monophyly of the genus Parasa and several associated genera are briefly discussed. All important characters of the new species, and some related species, are illustrated. PMID:21265613

  16. Pleistocene survival of an archaic dwarf baleen whale (Mysticeti: Cetotheriidae)

    NASA Astrophysics Data System (ADS)

    Boessenecker, Robert W.

    2013-04-01

    Pliocene baleen whale assemblages are characterized by a mix of early records of extant mysticetes, extinct genera within modern families, and late surviving members of the extinct family Cetotheriidae. Although Pleistocene baleen whales are poorly known, thus far they include only fossils of extant genera, indicating Late Pliocene extinctions of numerous mysticetes alongside other marine mammals. Here a new fossil of the Late Neogene cetotheriid mysticete Herpetocetus is reported from the Lower to Middle Pleistocene Falor Formation of Northern California. This find demonstrates that at least one archaic mysticete survived well into the Quaternary Period, indicating a recent loss of a unique niche and a more complex pattern of Plio-Pleistocene faunal overturn for marine mammals than has been previously acknowledged. This discovery also lends indirect support to the hypothesis that the pygmy right whale ( Caperea marginata) is an extant cetotheriid, as it documents another cetotheriid nearly surviving to modern times.

  17. Seven New Recorded Species in Five Genera of the Strophariaceae in Korea

    PubMed Central

    Cho, Hae Jin; Lee, Hyun; Park, Jae Young; Park, Myung Soo; Kim, Nam Kyu; Eimes, John A.; Kim, Changmu; Han, Sang-Kuk

    2016-01-01

    Most known species in the Strophariaceae are decomposers and grow on various kind of organic matter. Approximately 18 genera and 1,316 species in the Strophariaceae have been reported worldwide. Through an ongoing survey of indigenous fungi in Korea, 29 specimens belonging to the Strophariaceae were collected from 2012 to 2016. These specimens were identified based on morphological characteristics and molecular analysis of internal transcribed spacer sequences. Fifteen taxa were confirmed, with eight species matching those previously recorded. Seven species in five genera were shown to be new records in Korea: Galerina marginata, Gymnopilus crociphyllus, Gymnopilus picreus, Hebeloma birrus, Hebeloma cavipes, Pholiota multicingulata, and Psilocybe thaizapoteca. In this study, we provide detailed morphological descriptions of these species and investigate their evolutionary relationships by constructing phylogenetic trees. PMID:27790064

  18. Spider sedation induced by defensive chemicals of milliped prey*

    PubMed Central

    Carrel, James E.; Eisner, Thomas

    1984-01-01

    Wolf spiders (Lycosa spp.) show delayed induced sedation (total immobilization) of prolonged duration (in the order of days) after attacks upon millipeds (Glomeris marginata). The sedation is specifically attributable to glomerin and homoglomerin, two previously characterized quinazolinones present in the defensive secretion of Glomeris. Median sedative doses for the quinazolinones are in the range of 1-7 μg per spider, a fraction of the total (60-90 μg) present in the secretion of medium to full-grown millipeds. A sedative effect upon an invertebrate predator has not previously been demonstrated for an animal defense. Quinazolinones include the synthetic drug methaqualone (Quaalude), a potent human sedative. Images PMID:16593414

  19. Benthic foraminifera show some resilience to ocean acidification in the northern Gulf of California, Mexico.

    PubMed

    Pettit, L R; Hart, M B; Medina-Sánchez, A N; Smart, C W; Rodolfo-Metalpa, R; Hall-Spencer, J M; Prol-Ledesma, R M

    2013-08-30

    Extensive CO2 vents have been discovered in the Wagner Basin, northern Gulf of California, where they create large areas with lowered seawater pH. Such areas are suitable for investigations of long-term biological effects of ocean acidification and effects of CO2 leakage from subsea carbon capture storage. Here, we show responses of benthic foraminifera to seawater pH gradients at 74-207m water depth. Living (rose Bengal stained) benthic foraminifera included Nonionella basispinata, Epistominella bradyana and Bulimina marginata. Studies on foraminifera at CO2 vents in the Mediterranean and off Papua New Guinea have shown dramatic long-term effects of acidified seawater. We found living calcareous benthic foraminifera in low pH conditions in the northern Gulf of California, although there was an impoverished species assemblage and evidence of post-mortem test dissolution.

  20. The correspondence between water temperature and coiling direction in Bulimina

    NASA Astrophysics Data System (ADS)

    Collins, Laurel S.

    1990-06-01

    The influence of temperature on the direction of coiling in the benthic foraminifera Bulimina marginata d'Orbigny and B. aculeata d'Orbigny is investigated by direct comparison of specimens and temperature data measured at or near the sites of collection. Nine samples from the Gulf of Mexico and 16 samples from the Gulf of Maine south to New Jersey are used. These areas include cold temperate and subtropical regions, the continental shelf, slope, and a semirestricted gulf. Complicating factors of life cycle stage and possible ontogenetic change are eliminated. Dextrality is strongly associated with warm temperatures, but cold temperatures do not produce predominantly sinistrally coiled individuals. This is the first demonstration of an unambiguous correlation between temperature and coiling direction in benthic foraminifera.

  1. Enchytraeidae (Oligochaeta, Annelida) from a field site in Portugal, with the description of five new species and a redescription of Enchylea heteroducta Nielsen & Christensen, 1963.

    PubMed

    Schmelz, Rodiger M; Collado, Rut

    2013-01-01

    Five new species of terrestrial Enchytraeidae (Oligochaeta, Clitellata) are described from an experimental field area in Portugal. Achaeta coimbrensis sp. nov. belongs to a group of species without pyriform glands and with lateral spermathecal ectal pores. Fridericia sousai sp. nov., F. roembkei sp. nov., F. marginata sp. nov., and F. ciliotheca sp. nov. have a maximum of four chaetae per bundle and two spermathecal diverticula, a character combination shared by c. 30 other species of this genus. The new Fridericia species are distinguished from these congeners by combinations of characters, but the ventral pattern of the clitellum alone is sufficient to separate the new species from each other. Enchylea heteroducta Nielsen & Christensen, 1963 is redescribed, this being the first record after the original description and the first record from a natural habitat. Further 16 species of enchytraeids are recorded, and there are now 32 species of enchytraeids known from Portugal.

  2. Social insect colony as a biological regulatory system: modelling information flow in dominance networks.

    PubMed

    Nandi, Anjan K; Sumana, Annagiri; Bhattacharya, Kunal

    2014-12-06

    Social insects provide an excellent platform to investigate flow of information in regulatory systems since their successful social organization is essentially achieved by effective information transfer through complex connectivity patterns among the colony members. Network representation of such behavioural interactions offers a powerful tool for structural as well as dynamical analysis of the underlying regulatory systems. In this paper, we focus on the dominance interaction networks in the tropical social wasp Ropalidia marginata-a species where behavioural observations indicate that such interactions are principally responsible for the transfer of information between individuals about their colony needs, resulting in a regulation of their own activities. Our research reveals that the dominance networks of R. marginata are structurally similar to a class of naturally evolved information processing networks, a fact confirmed also by the predominance of a specific substructure-the 'feed-forward loop'-a key functional component in many other information transfer networks. The dynamical analysis through Boolean modelling confirms that the networks are sufficiently stable under small fluctuations and yet capable of more efficient information transfer compared to their randomized counterparts. Our results suggest the involvement of a common structural design principle in different biological regulatory systems and a possible similarity with respect to the effect of selection on the organization levels of such systems. The findings are also consistent with the hypothesis that dominance behaviour has been shaped by natural selection to co-opt the information transfer process in such social insect species, in addition to its primal function of mediation of reproductive competition in the colony.

  3. Revision of the genus Morphosphaera Baly (Coleoptera: Chrysomelidae: Galerucinae).

    PubMed

    Lee, Chi-Feng; Bezdĕk, Jan

    2016-10-28

    The genus Morphosphaera Baly, 1861 is revised. Eleven species are considered as valid, including, M. takizawai sp. nov. (Mt. Basor, 90 km N of Gua Musang, Malaysia, W. Kelantan), described from Malaysia and Indonesia. Color photos of habitus and drawings of diagnostic characters from eleven species are presented. The following synonymies are proposed: M. sodalis Chen, 1935 and M. brunnea Maulik, 1936 are junior synonyms of M. albipennis Allard, 1889; M. margaritacea Laboissière, 1930, M. viridipennis Laboissière, 1930, and M. prava Maulik, 1936 are junior synonyms of M. coomani Laboissière, 1930; M. gracilicornis Chen, 1963 is a junior synonym of M. maculicollis Baly, 1861; M. cavaleriei Laboissière, 1930, M. cincticollis Laboissière, 1930, M. marginata Laboissière, 1930, M. purpurea Laboissière, 1930, M. gingkoae Gressitt & Kimoto, 1963, and M. metallescens Gressitt & Kimoto, 1963 are junior synonyms of M. sumatrana Jacoby, 1886. The type material of M. impunctata Allard, 1890 from the Philippines was not found and its taxonomic status remains uncertain. Morphosphaera peregrina Weise, 1913 is transferred to the genus Borneola Mohamedsaid, 1998 nov. comb. A neotype is designated for Chrysomela japonica Hornstedt, 1788. Lectotypes are designated for the following species: Adorium chrysomeloides Bates, 1866, A. japonicum Baly, 1874, Morphosphaera albipennis Allard, 1889, M. bimaculata Chûjô, 1938, M. caerulea Jacoby, 1896, M. cavaleriei Laboissière, 1930, M. collaris Laboissière, 1930, M. formosa Laboissière, 1930, M. marginata Laboissière, 1930, M. montivaga Maulik, 1936, M. prava Maulik, 1936, M. purpurea Laboissière, 1930, M. sumatrana Jacoby, 1886, M. viridipennis Laboissière, 1930, and Galerucida simplex Weise, 1922.

  4. Gene expression patterns of the coral Acropora millepora in response to contact with macroalgae

    NASA Astrophysics Data System (ADS)

    Shearer, T. L.; Rasher, D. B.; Snell, T. W.; Hay, M. E.

    2012-12-01

    Contact with macroalgae often causes coral mortality, but the roles of abrasion versus shading versus allelopathy in these interactions are rarely clear, and effects on gene expression are unknown. Identification of gene expression changes within corals in response to contact with macroalgae can provide insight into the mode of action of allelochemicals, as well as reveal transcriptional strategies of the coral that mitigate damage from this competitive interaction, enabling the coral to survive. Gene expression responses of the coral Acropora millepora after long-term (20 days) direct contact with macroalgae ( Chlorodesmis fastigiata, Dictyota bartayresiana, Galaxaura filamentosa, and Turbinaria conoides) and short-term (1 and 24 h) exposure to C. fastigiata thalli and their hydrophobic extract were assessed. After 20 days of exposure, T. conoides thalli elicited no significant change in visual bleaching or zooxanthellae PSII quantum yield within A. millepora nubbins, but stimulated the greatest alteration in gene expression of all treatments. Chlorodesmis fastigiata, D. bartayresiana, and G. filamentosa caused significant visual bleaching of coral nubbins and reduced the PSII quantum yield of associated zooxanthellae after 20 days, but elicited fewer changes in gene expression relative to T. conoides at day 20. To evaluate initial molecular processes leading to reduction of zooxanthella PSII quantum yield, visual bleaching, and coral death, short-term exposures to C. fastigiata thalli and hydrophobic extracts were conducted; these interactions revealed protein degradation and significant changes in catalytic and metabolic activity within 24 h of contact. These molecular responses are consistent with the hypothesis that allelopathic interactions lead to alteration of signal transduction and an imbalance between reactive oxidant species production and antioxidant capabilities within the coral holobiont. This oxidative imbalance results in rapid protein degradation

  5. Gene Expression of Corals in Response to Macroalgal Competitors

    PubMed Central

    Shearer, Tonya L.; Snell, Terry W.; Hay, Mark E.

    2014-01-01

    As corals decline and macroalgae proliferate on coral reefs, coral-macroalgal competition becomes more frequent and ecologically important. Whether corals are damaged by these interactions depends on susceptibility of the coral and traits of macroalgal competitors. Investigating changes in gene expression of corals and their intracellular symbiotic algae, Symbiodinium, in response to contact with different macroalgae provides insight into the biological processes and cellular pathways affected by competition with macroalgae. We evaluated the gene expression profiles of coral and Symbiodinium genes from two confamilial corals, Acropora millepora and Montipora digitata, after 6 h and 48 h of contact with four common macroalgae that differ in their allelopathic potency to corals. Contacts with macroalgae affected different biological pathways in the more susceptible (A. millepora) versus the more resistant (M. digitata) coral. Genes of coral hosts and of their associated Symbiodinium also responded in species-specific and time-specific ways to each macroalga. Changes in number and expression intensity of affected genes were greater after 6 h compared to 48 h of contact and were greater following contact with Chlorodesmis fastigiata and Amphiroa crassa than following contact with Galaxaura filamentosa or Turbinaria conoides. We documented a divergence in transcriptional responses between two confamilial corals and their associated Symbiodinium, as well as a diversity of dynamic responses within each coral species with respect to the species of macroalgal competitor and the duration of exposure to that competitor. These responses included early initiation of immune processes by Montipora, which is more resistant to damage after long-term macroalgal contact. Activation of the immune response by corals that better resist algal competition is consistent with the hypothesis that some macroalgal effects on corals may be mediated by microbial pathogens. PMID:25500576

  6. Gene expression patterns of the coral Acropora millepora in response to contact with macroalgae.

    PubMed

    Shearer, Tl; Rasher, Db; Snell, Tw; Hay, Me

    2012-12-01

    Contact with macroalgae often causes coral mortality, but the roles of abrasion versus shading versus allelopathy in these interactions are rarely clear and effects on gene expression are unknown. Identification of gene expression changes within corals in response to contact with macroalgae can provide insight into the mode of action of allelochemicals, as well as reveal transcriptional strategies of the coral that mitigate damage from this competitive interaction, enabling the coral to survive. Gene expression responses of the coral Acropora millepora after long-term (20 d) direct contact with macroalgae (Chlorodesmis fastigiata, Dictyota bartayresiana, Galaxaura filamentosa and Turbinaria conoides) and short-term (1 h and 24 h) exposure to C. fastigiata thalli and their hydrophobic extract were assessed. After 20 d of exposure, T. conoides thalli elicited no significant change in visual bleaching or zooxanthellae PSII quantum yield within A. millepora nubbins, but stimulated the greatest alteration in gene expression of all treatments. Chlorodesmis fastigiata, D. bartayresiana and G. filamentosa caused significant visual bleaching of coral nubbins and reduced the PSII quantum yield of associated zooxanthellae after 20 d, but elicited fewer changes in gene expression relative to T. conoides at day 20. To evaluate initial molecular processes leading to reduction of zooxanthella PSII quantum yield, visual bleaching, and coral death, short-term exposures to C. fastigiata thalli and hydrophobic extracts were conducted; these interactions revealed protein degradation and significant changes in catalytic and metabolic activity within 24 h of contact. These molecular responses are consistent with the hypothesis that allelopathic interactions lead to alteration of signal transduction and an imbalance between reactive oxidant species production and antioxidant capabilities within the coral holobiont. This oxidative imbalance results in rapid protein degradation and

  7. Among-habitat algal selectivity by browsing herbivores on an inshore coral reef

    NASA Astrophysics Data System (ADS)

    Loffler, Zoe; Bellwood, David R.; Hoey, Andrew S.

    2015-06-01

    Understanding how the impact of different herbivores varies spatially on coral reefs is important in qualifying the resistance of coral reefs to disturbance events and identifying the processes that structure algal communities. We used assays of six common macroalgae ( Acanthophora spicifera, Caulerpa taxifolia, Galaxaura rugosa, Laurencia sp. Sargassum sp., and Turbinaria ornata) and remote underwater video cameras to quantify herbivory in two habitats (reef crest and slope) across multiple sites on Orpheus Island, Great Barrier Reef. Rates of herbivory varied among macroalgal taxa, habitats, and sites. Reductions in algal biomass were greatest for Sargassum sp. (36 % 4 h-1), intermediate for A. spicifera, Laurencia sp., C. taxifolia, and T. ornata (17-33 % 4 h-1) and lowest for G. rugosa (6 % 4 h-1). Overall, rates of herbivory were generally greater on the reef crest (30 % 4 h-1) than the reef slope (21 % 4 h-1). This difference in rates of herbivory coincided with a marked shift in the dominant herbivores between habitats. Kyphosus vaigiensis, despite only feeding on three species of macroalgae ( Sargassum sp., T. ornata, and A. spicifera), was responsible for 34 % of all bites recorded on the reef crest yet did not take a single bite from algae on the reef slope. In contrast, Siganus doliatus took bites on every species of algae in both habitats, accounting for 40 % of bites on the reef crest and 74 % of all bites recorded on the reef slope. This difference in the number of macroalgal species targeted by herbivores and the habitat/s in which they feed adds another dimension of complexity to our understanding of coral reef herbivore dynamics.

  8. The leaves of green plants as well as a cyanobacterium, a red alga, and fungi contain insulin-like antigens.

    PubMed

    Silva, L B; Santos, S S S; Azevedo, C R; Cruz, M A L; Venâncio, T M; Cavalcante, C P; Uchôa, A F; Astolfi Filho, S; Oliveira, A E A; Fernandes, K V S; Xavier-Filho, J

    2002-03-01

    We report the detection of insulin-like antigens in a large range of species utilizing a modified ELISA plate assay and Western blotting. We tested the leaves or aerial parts of species of Rhodophyta (red alga), Bryophyta (mosses), Psilophyta (whisk ferns), Lycopodophyta (club mosses), Sphenopsida (horsetails), gymnosperms, and angiosperms, including monocots and dicots. We also studied species of fungi and a cyanobacterium, Spirulina maxima. The wide distribution of insulin-like antigens, which in some cases present the same electrophoretic mobility as bovine insulin, together with results recently published by us on the amino acid sequence of an insulin isolated from the seed coat of jack bean (Canavalia ensiformis) and from the developing fruits of cowpea (Vigna unguiculata), suggests that pathways depending on this hormone have been conserved through evolution.

  9. Seaweed survival after consumption by the greenbeak parrotfish, Scarus trispinosus

    NASA Astrophysics Data System (ADS)

    Tâmega, F. T. S.; Figueiredo, M. A. O.; Ferreira, C. E. L.; Bonaldo, R. M.

    2016-03-01

    We assessed the survival of seaweed (macroalgae and cyanobacteria) after consumption by the greenbeak parrotfish, Scarus trispinosus, in northeastern Brazil. Samples of S. trispinosus feces were collected, inoculated on filter paper, and kept in the laboratory and field for 60 and 30 d, respectively. Comparisons of samples inoculated with feces to those without (controls) revealed a marked increase in the abundance and diversity of seaweed in samples inoculated with feces in both laboratory and field experiments. These results were consistent between summer and winter, although the seaweed species differed. A total of one cyanobacterium and 16 macroalgal taxa (nine rhodophytes, five heterokontophytes, and two chlorophytes) were recorded in the inoculated samples. Rhodophyta also presented the highest abundance across treatments, possibly because of their higher resistance to parrotfish digestion, greater ingestion, or both. The survival of cyanobacteria and macroalgae after consumption by S. trispinosus suggests that parrotfishes may contribute to seaweed dispersion on tropical reefs.

  10. Preliminary observations on the benthic marine algae of the Gorringe seabank (northeast Atlantic Ocean)

    NASA Astrophysics Data System (ADS)

    Tittley, Ian; da Silva Vaz Álvaro, Nuno Miguel; de Melo Azevedo Neto, Ana Isabel

    2014-06-01

    Examination of marine samples collected in 2006 from the Gettysburg and Ormonde seamounts on the Gorringe seabank southwest of Portugal has revealed 29 benthic Chlorophyta, Phaeophyceae (Ochrophyta), and Rhodophyta that were identified provisionally to genus and to species. Combining lists for the present and a previous expedition brings the total of algae thus far recorded to 48. The brown alga Zonaria tournefourtii and the red alga Cryptopleura ramosa were the most abundant species in the present collections. The kelp Laminaria ochroleuca was present only in the Gettysburg samples while Saccorhiza polyschides was observed only on the Ormonde seamount. Comparisons with the benthic marine algae recorded on seamounts in the mid-Atlantic Azores archipelago show features in common, notably kelp forests of L. ochroleuca at depths below 30 m and Z. tournefortii dominance in shallower waters.

  11. Polysaccharides of the red algae.

    PubMed

    Usov, Anatolii I

    2011-01-01

    Red algae (Rhodophyta) are known as the source of unique sulfated galactans, such as agar, agarose, and carrageenans. The wide practical uses of these polysaccharides are based on their ability to form strong gels in aqueous solutions. Gelling polysaccharides usually have molecules built up of repeating disaccharide units with a regular distribution of sulfate groups, but most of the red algal species contain more complex galactans devoid of gelling ability because of various deviations from the regular structure. Moreover, several red algae may contain sulfated mannans or neutral xylans instead of sulfated galactans as the main structural polysaccharides. This chapter is devoted to a description of the structural diversity of polysaccharides found in the red algae, with special emphasis on the methods of structural analysis of sulfated galactans. In addition to the structural information, some data on the possible use of red algal polysaccharides as biologically active polymers or as taxonomic markers are briefly discussed.

  12. Phycobilins and Phycobiliproteins Used in Food Industry and Medicine.

    PubMed

    Solymosi, Katalin; Mysliwa-Kurdziel, Beata

    2016-09-12

    Open tetrapyrroles termed phycobilins represent the major photosynthetic accessory pigments of several cyanobacteria and some eukaryotic algae such as the Glaucophyta, Cryptophyta and Rhodophyta. These pigments are covalently bound to so-called phycobiliproteins which are in general organized into phycobilisomes on the thylakoid membranes. In this work we first briefly describe the physico-chemical properties, biosynthesis, occurrence, in vivo localization and roles of the phycobilin pigments and the phycobiliproteins. Then the potential applications and uses of these pigments, pigment-protein complexes and related products by the food industry (e.g., as LinaBlue® or the so-called spirulina extract used as coloring food), by the health industry or as fluorescent dyes are critically reviewed. In addition to the stability, bioavailability and safety issues of purified phycobilins and phycobiliproteins, literature data about their antioxidant, anticancer, anti-inflammatory, immunomodulatory, hepatoprotective, nephroprotective and neuroprotective effects, and their potential use in photodynamic therapy (PDT) are also discussed.

  13. Invertebrate communities associated with Bangia atropurpurea and Cladophora glomerata in western Lake Erie

    USGS Publications Warehouse

    Chilton, E.W.; Lowe, R.L.; Schurr, K.M.

    1986-01-01

    The appearance of the marine alga Bangia atropurpurea (Rhodophyta) in Lake Erie has been followed by its rapid dispersal throughout the eulittoral zone of the lake. Bangia was extensively sampled to determine its suitability as a habitat for littoral organisms. Present data indicate that the only organisms capable of maintaining populations on Bangia filaments are larval Chironomidae. Cladophora supports a larger and more diverse community. It is concluded that the mucilaginous cell wall of Bangia provides a less stable substrate for attached or clinging organisms than does the cellulose cell wall of Cladophora. The presence of Bangia in the littoral zone of Lake Erie results in a reduction of the quantity and diversity of algal epiphytes and may negatively impact the littoral food web.

  14. Occurrence of (210)Po in marine macroalgae inhabiting a coastal nuclear zone, southeast coast of India.

    PubMed

    Praveen Pole, R P; Feroz Khan, M; Godwin Wesley, S

    2017-04-01

    The activity concentration of (210)Po in 26 species of marine macroalgae found along coast near to a nuclear installation in southeast coast of India was studied. Phaeophytes were found to accumulate the maximum (210)Po concentration and chlorophytes the minimum. The average (210)Po activity concentration values in the three groups were 6.2 ± 2.5 Bq kg(-1) (Chlorophyta), 14.4 ± 5.2 Bq kg(-1) (Phaeophyta) and 11.3 ± 3.9 Bq kg(-1) (Rhodophyta). A statistically significant variation in accumulation was found between groups (p < 0.05). The un-weighted dose rate to these algae due to (210)Po was calculated to be well below the benchmark dose limit of 10 μGy h(-1).

  15. De novo transcriptome analysis of the red seaweed Gracilaria chilensis and identification of linkers associated with phycobilisomes.

    PubMed

    Vorphal, María Alejandra; Gallardo-Escárate, Cristian; Valenzuela-Muñoz, Valentina; Dagnino-Leone, Jorge; Vásquez, José Aleikar; Martínez-Oyanedel, José; Bunster, Marta

    2017-02-01

    This work reports the results of the Illumina RNA-Seq of a wild population of female haploid plants of Gracilaria chilensis (Bird et al., 1986) (Rhodophyta, Gigartinalis). Most transcripts were de novo assembled in 12,331 contigs with an average length of 1756bp, showing that 96.64% of the sequences were annotated with known proteins. In particular, the identification of linker proteins of phycobilisomes (PBS) is reported. Linker proteins have primary been identified in cyanobacteria but the information available about them in eukaryotic red alga is not complete, and this is the first report in G. chilensis. This resource will also provide the basis for the study of metabolic pathways related to polysaccharide production.

  16. The fouling of fish farm cage nets as bioindicator of aquaculture pollution in the Adriatic Sea (Croatia).

    PubMed

    Sliskovic, Merica; Jelic-Mrcelic, Gorana; Antolic, Boris; Anicic, Ivica

    2011-02-01

    A fouling assemblage (including density, species richness and diversity, and biomass) growing on netting of fish farm cages was investigated in Stracinska Bay--Location 1 and Peles Bay--Location 2 (Croatia) in order to test the efficiency of fouling as a bioindicator of organic pollution. A total number of 40 algal taxa in Location 1 and total number of 22 algal taxa in Location 2 were identified, with a dominance of opportunistic species (ESG II). We found domination of algal species over animal species and absolute dominance of Rhodophyta which are typical fouler in the Adriatic Sea. Low diversity and species richness with increase in value of the R/P index (occasionally higher than 6) were recorded in Location 2, indicating a certain impact of nutrient enrichment from fish culture facilities on a fouling community structure.

  17. Coral and macroalgal exudates vary in neutral sugar composition and differentially enrich reef bacterioplankton lineages

    PubMed Central

    Nelson, Craig E; Goldberg, Stuart J; Wegley Kelly, Linda; Haas, Andreas F; Smith, Jennifer E; Rohwer, Forest; Carlson, Craig A

    2013-01-01

    Increasing algal cover on tropical reefs worldwide may be maintained through feedbacks whereby algae outcompete coral by altering microbial activity. We hypothesized that algae and coral release compositionally distinct exudates that differentially alter bacterioplankton growth and community structure. We collected exudates from the dominant hermatypic coral holobiont Porites spp. and three dominant macroalgae (one each Ochrophyta, Rhodophyta and Chlorophyta) from reefs of Mo'orea, French Polynesia. We characterized exudates by measuring dissolved organic carbon (DOC) and fractional dissolved combined neutral sugars (DCNSs) and subsequently tracked bacterioplankton responses to each exudate over 48 h, assessing cellular growth, DOC/DCNS utilization and changes in taxonomic composition (via 16S rRNA amplicon pyrosequencing). Fleshy macroalgal exudates were enriched in the DCNS components fucose (Ochrophyta) and galactose (Rhodophyta); coral and calcareous algal exudates were enriched in total DCNS but in the same component proportions as ambient seawater. Rates of bacterioplankton growth and DOC utilization were significantly higher in algal exudate treatments than in coral exudate and control incubations with each community selectively removing different DCNS components. Coral exudates engendered the smallest shift in overall bacterioplankton community structure, maintained high diversity and enriched taxa from Alphaproteobacteria lineages containing cultured representatives with relatively few virulence factors (VFs) (Hyphomonadaceae and Erythrobacteraceae). In contrast, macroalgal exudates selected for less diverse communities heavily enriched in copiotrophic Gammaproteobacteria lineages containing cultured pathogens with increased VFs (Vibrionaceae and Pseudoalteromonadaceae). Our results demonstrate that algal exudates are enriched in DCNS components, foster rapid growth of bacterioplankton and select for bacterial populations with more potential VFs than

  18. Functional Traits for Carbon Access in Macrophytes

    PubMed Central

    Pfister, Catherine A.; Wootton, J. Timothy

    2016-01-01

    Understanding functional trait distributions among organisms can inform impacts on and responses to environmental change. In marine systems, only 1% of dissolved inorganic carbon in seawater exists as CO2. Thus the majority of marine macrophytes not only passively access CO2 for photosynthesis, but also actively transport CO2 and the more common bicarbonate (HCO3-, 92% of seawater dissolved inorganic carbon) into their cells. Because species with these carbon concentrating mechanisms (CCMs) are non-randomly distributed in ecosystems, we ask whether there is a phylogenetic pattern to the distribution of CCMs among algal species. To determine macrophyte traits that influence carbon uptake, we assessed 40 common macrophyte species from the rocky intertidal community of the Northeast Pacific Ocean to a) query whether macrophytes have a CCM and b) determine the evolutionary history of CCMs, using ancestral state reconstructions and stochastic character mapping based on previously published data. Thirty-two species not only depleted CO2, but also concentrated and depleted HCO3-, indicative of a CCM. While analysis of CCMs as a continuous trait in 30 families within Phylum Rhodophyta showed a significant phylogenetic signal under a Brownian motion model, analysis of CCMs as a discrete trait (presence or absence) indicated that red algal families are more divergent than expected in their CCM presence or absence; CCMs are a labile trait within the Rhodophyta. In contrast, CCMs were present in each of 18 Ochrophyta families surveyed, indicating that CCMs are highly conserved in the brown algae. The trait of CCM presence or absence was largely conserved within Families. Fifteen of 23 species tested also changed the seawater buffering capacity, or Total Alkalinity (TA), shifting DIC composition towards increasing concentrations of HCO3- and CO2 for photosynthesis. Manipulating the external TA of the local environment may influence carbon availability in boundary layers and

  19. Coral and macroalgal exudates vary in neutral sugar composition and differentially enrich reef bacterioplankton lineages.

    PubMed

    Nelson, Craig E; Goldberg, Stuart J; Wegley Kelly, Linda; Haas, Andreas F; Smith, Jennifer E; Rohwer, Forest; Carlson, Craig A

    2013-05-01

    Increasing algal cover on tropical reefs worldwide may be maintained through feedbacks whereby algae outcompete coral by altering microbial activity. We hypothesized that algae and coral release compositionally distinct exudates that differentially alter bacterioplankton growth and community structure. We collected exudates from the dominant hermatypic coral holobiont Porites spp. and three dominant macroalgae (one each Ochrophyta, Rhodophyta and Chlorophyta) from reefs of Mo'orea, French Polynesia. We characterized exudates by measuring dissolved organic carbon (DOC) and fractional dissolved combined neutral sugars (DCNSs) and subsequently tracked bacterioplankton responses to each exudate over 48 h, assessing cellular growth, DOC/DCNS utilization and changes in taxonomic composition (via 16S rRNA amplicon pyrosequencing). Fleshy macroalgal exudates were enriched in the DCNS components fucose (Ochrophyta) and galactose (Rhodophyta); coral and calcareous algal exudates were enriched in total DCNS but in the same component proportions as ambient seawater. Rates of bacterioplankton growth and DOC utilization were significantly higher in algal exudate treatments than in coral exudate and control incubations with each community selectively removing different DCNS components. Coral exudates engendered the smallest shift in overall bacterioplankton community structure, maintained high diversity and enriched taxa from Alphaproteobacteria lineages containing cultured representatives with relatively few virulence factors (VFs) (Hyphomonadaceae and Erythrobacteraceae). In contrast, macroalgal exudates selected for less diverse communities heavily enriched in copiotrophic Gammaproteobacteria lineages containing cultured pathogens with increased VFs (Vibrionaceae and Pseudoalteromonadaceae). Our results demonstrate that algal exudates are enriched in DCNS components, foster rapid growth of bacterioplankton and select for bacterial populations with more potential VFs than

  20. Cloning, molecular characterization, and phylogeny of two evolutionary distinct glutamine synthetase isoforms in the green microalga Haematococcus pluvialis (Chlorophyceae).

    PubMed

    Reinecke, Diana L; Zarka, Aliza; Leu, Stefan; Boussiba, Sammy

    2016-12-01

    Haematococcus pluvialis (Chlorophyta) is a widely used microalga of great economic potential, yet its molecular genetics and evolution are largely unknown. We present new detailed molecular and phylogenetic analysis of two glutamine synthetase (GS) enzymes and genes (gln) under the Astaxanthin-inducing conditions of light- and nitrogen-stress. Structure analysis identified key residues and confirmed two decameric GS2 holoenzymes, a cytoplasmic enzyme, termed GS2c , and a plastidic form, termed GS2p , due to chloroplast-transit peptides at its N-terminus. Gene expression analysis showed dissociation of mRNA, protein, and enzyme activity levels for both GS2 under different growth conditions, indicating the strong post-transcriptional regulation. Data-mining identified novel and specified published gln genes from Prasinophyceae, Chlorophyta, Trebouxiophyceae, Charophyceae, Bryophyta, Lycopodiophyta, Spermatophyta, and Rhodophyta. Phylogenetic analysis found homologues to the cytosolic GS2c of H. pluvialis in all other photo- and non-photosynthetic Eukaryota. The chloroplastic GS2p was restricted to Chlorophyta, Bryophyta, some Proteobacteria and Fungii; no homologues were identified in Spermatophyta or other Eukaryota. This indicates two independent prokaryotic donors for these two gln genes in H. pluvialis. Combined phylogenetic analysis of GS, chl-b synthase, elongation factor, and light harvesting complex homologues project a newly refined model of Viridiplantae evolution. Herein, a GS1 evolved into the cytosolic GS2c and was passed on to all Eukaryota. Later, the chloroplastic GS2p entered the Archaeplastida lineage via a horizontal gene transfer at the divergence of Chlorophyta and Rhodophyta lineages. GS2p persisted in Chlorophyta and Bryophyta, but was lost during Spermatophyta evolution. These data suggest the revision of GS classification and nomenclature, and extend our understanding of the photosynthetic Eukaryota evolution.

  1. Biodiversity patterns of macrophyte and macroinvertebrate communities in two lagoons of Western Greece.

    NASA Astrophysics Data System (ADS)

    Fyttis, G.; Reizopoulou, S.; Papastergiadou, E.

    2012-04-01

    Aquatic macrophytes and benthic macroinvertebrates were studied seasonally (Spring, Autumn, Summer) between the years 2009 - 2011 in two coastal lagoons (Kotychi and Prokopos) located in Peloponnese, Greece, in order to investigate spatial and temporal biodiversity trends related to hydrological processes (degree of confinement, nitrates, phosphates, chl-a, total suspended materials, light irradiance, pH, salinity, temperature and dissolved oxygen). Kotychi lagoon presents a better communication with the sea, while Prokopos has a high degree of confinement. Both ecosystems seasonally receive freshwater input from streams. The submerged aquatic macrophytes constituted a major component of the ecosystems studied. In total, 22 taxa of aquatic macrophytes (angiosperms and macroalgae), 16 taxa for Kotychi (2 Rhodophyta, 8 Chlorophyta, 5 Magnoliophyta, 1 Streptophyta) and 14 taxa for Prokopos (1 Rhodophyta, 5 Chlorophyta, 5 Magnoliophyta, 3 Streptophyta) were found. Ruppia cirrhosa, and Potamogeton pectinatus were dominant in both lagoons. Kotychi lagoon was also dominated by Zostera noltii and Prokopos by Zannichellia pallustris ssp. pedicellata, while the biomass of aquatic species peaked during the summer periods, in both lagoons. The total number of macroinvertebrates found in the lagoons was 28 taxa for Kotychi and 19 for Prokopos. Chironomidae were dominant in both lagoons, while Kotychi was also dominated by Lekanesphaera monodi and Monocorophium insidiosum, and Prokopos by Ostracoda and Lekanesphaera monodi. Benthic diversity ranged from 1.33 to 2.57 in Kotychi and from 0.67 to 2.48 in Prokopos. Species richness, diversity, and abundance of benthic macroinvertebrates were strongly related to aquatic vegetation and to the degree of communication with the marine environment. Moreover, species richness and abundance of both macrophytes and macroinvertebrates were mainly dependent on depth, temperature, pH and concentration of total suspended materials (TSM). Results

  2. Ecophysiology of photosynthesis in macroalgae.

    PubMed

    Raven, John A; Hurd, Catriona L

    2012-09-01

    Macroalgae occur in the marine benthos from the upper intertidal to depths of more than 200 m, contributing up to 1 Pg C per year to global primary productivity. Freshwater macroalgae are mainly green (Chlorophyta) with some red (Rhodophyta) and a small contribution of brown (Phaeophyceae) algae, while in the ocean all three higher taxa are important. Attempts to relate the depth distribution of three higher taxa of marine macroalgae to their photosynthetic light use through their pigmentation in relation to variations in spectral quality of photosynthetically active radiation (PAR) with depth (complementary chromatic adaptation) and optical thickness (package effect) have been relatively unsuccessful. The presence (Chlorophyta, Phaeophyceae) or absence (Rhodophyta) of a xanthophyll cycle is also not well correlated with depth distribution of marine algae. The relative absence of freshwater brown algae does not seem to be related to their photosynthetic light use. Photosynthetic inorganic carbon acquisition in some red and a few green macroalgae involves entry of CO(2) by diffusion. Other red and green macroalgae, and brown macroalgae, have CO(2) concentrating mechanisms; these frequently involve acid and alkaline zones on the surface of the alga with CO(2) (produced from HCO(3) (-)) entering in the acid zones, while some macroalgae have CCMs based on active influx of HCO(3) (-). These various mechanisms of carbon acquisition have different responses to the thickness of the diffusion boundary layer, which is determined by macroalgal morphology and water velocity. Energetic predictions that macroalgae growing at or near the lower limit of PAR for growth should rely on diffusive CO(2) entry without acid and alkaline zones, and on NH(4) (+) rather than NO(3) (-) as nitrogen source, are only partially borne out by observation. The impact of global environmental change on marine macroalgae mainly relates to ocean acidification and warming with shoaling of the

  3. Please mind the gap - Visual census and cryptic biodiversity assessment at central Red Sea coral reefs.

    PubMed

    Pearman, John K; Anlauf, Holger; Irigoien, Xabier; Carvalho, Susana

    2016-07-01

    Coral reefs harbor the most diverse assemblages in the ocean, however, a large proportion of the diversity is cryptic and, therefore, undetected by standard visual census techniques. Cryptic and exposed communities differ considerably in species composition and ecological function. This study compares three different coral reef assessment protocols: i) visual benthic reef surveys: ii) visual census of Autonomous Reef Monitoring Structures (ARMS) plates; and iii) metabarcoding techniques of the ARMS (including sessile, 106-500 μm and 500-2000 μm size fractions), that target the cryptic and exposed communities of three reefs in the central Red Sea. Visual census showed a dominance of Cnidaria (Anthozoa) and Rhodophyta on the reef substrate, while Porifera, Bryozoa and Rhodophyta were the most abundant groups on the ARMS plates. Metabarcoding, targeting the 18S rRNA gene, significantly increased estimates of the species diversity (p < 0.001); revealing that Annelida were generally the dominant phyla (in terms of reads) of all fractions and reefs. Furthermore, metabarcoding detected microbial eukaryotic groups such as Syndiniophyceae, Mamiellophyceae and Bacillariophyceae as relevant components of the sessile fraction. ANOSIM analysis showed that the three reef sites showed no differences based on the visual census data. Metabarcoding showed a higher sensitivity for identifying differences between reef communities at smaller geographic scales than standard visual census techniques as significant differences in the assemblages were observed amongst the reefs. Comparison of the techniques showed no similar patterns for the visual techniques while the metabarcoding of the ARMS showed similar patterns amongst fractions. Establishing ARMS as a standard tool in reef monitoring will not only advance our understanding of local processes and ecological community response to environmental changes, as different faunal components will provide complementary information but

  4. Non-indolyl cruciferous phytoalexins: Nasturlexins and tridentatols, a striking convergent evolution of defenses in terrestrial plants and marine animals?

    PubMed

    Pedras, M Soledade C; To, Q Huy

    2015-05-01

    Highly specialized chemical defense pathways are a particularly noteworthy metabolic characteristic of sessile organisms, whether terrestrial or marine, providing protection against pests and diseases. For this reason, knowledge of the metabolites involved in these processes is crucial to producing ecologically fit crops. Toward this end, the elicited chemical defenses of the crucifer watercress (Nasturtium officinale R. Br.), i.e. phytoalexins, were investigated and are reported. Almost three decades after publication of cruciferous phytoalexins derived from (S)-Trp, phytoalexins derived from other aromatic amino acids were isolated; their chemical structures were determined by analyses of their spectroscopic data and confirmed by synthesis. Nasturlexin A, nasturlexin B, and tridentatol C are hitherto unknown phenyl containing cruciferous phytoalexins produced by watercress under abiotic stress; tridentatol C is also produced by a marine animal (Tridentata marginata), where it functions in chemical defense against predators. The biosynthesis of these metabolites in both a terrestrial plant and a marine animal suggests a convergent evolution of unique metabolic pathways recruited for defense.

  5. Soil Microbial Community Successional Patterns during Forest Ecosystem Restoration ▿†

    PubMed Central

    Banning, Natasha C.; Gleeson, Deirdre B.; Grigg, Andrew H.; Grant, Carl D.; Andersen, Gary L.; Brodie, Eoin L.; Murphy, D. V.

    2011-01-01

    Soil microbial community characterization is increasingly being used to determine the responses of soils to stress and disturbances and to assess ecosystem sustainability. However, there is little experimental evidence to indicate that predictable patterns in microbial community structure or composition occur during secondary succession or ecosystem restoration. This study utilized a chronosequence of developing jarrah (Eucalyptus marginata) forest ecosystems, rehabilitated after bauxite mining (up to 18 years old), to examine changes in soil bacterial and fungal community structures (by automated ribosomal intergenic spacer analysis [ARISA]) and changes in specific soil bacterial phyla by 16S rRNA gene microarray analysis. This study demonstrated that mining in these ecosystems significantly altered soil bacterial and fungal community structures. The hypothesis that the soil microbial community structures would become more similar to those of the surrounding nonmined forest with rehabilitation age was broadly supported by shifts in the bacterial but not the fungal community. Microarray analysis enabled the identification of clear successional trends in the bacterial community at the phylum level and supported the finding of an increase in similarity to nonmined forest soil with rehabilitation age. Changes in soil microbial community structure were significantly related to the size of the microbial biomass as well as numerous edaphic variables (including pH and C, N, and P nutrient concentrations). These findings suggest that soil bacterial community dynamics follow a pattern in developing ecosystems that may be predictable and can be conceptualized as providing an integrated assessment of numerous edaphic variables. PMID:21724890

  6. Cytophotometric and biochemical analyses of DNA in pentaploid and diploid Agave species.

    PubMed

    Cavallini, A; Natali, L; Cionini, G; Castorena-Sanchez, I

    1996-04-01

    Nuclear DNA content, chromatin structure, and DNA composition were investigated in four Agave species: two diploid, Agave tequilana Weber and Agave angustifolia Haworth var. marginata Hort., and two pentaploid, Agave fourcroydes Lemaire and Agave sisalana Perrine. It was determined that the genome size of pentaploid species is nearly 2.5 times that of diploid ones. Cytophotometric analyses of chromatin structure were performed following Feulgen or DAPI staining to determine optical density profiles of interphase nuclei. Pentaploid species showed higher frequencies of condensed chromatin (heterochromatin) than diploid species. On the other hand, a lower frequency of A-T rich (DAPI stained) heterochromatin was found in pentaploid species than in diploid ones, indicating that heterochromatin in pentaploid species is made up of sequences with base compositions different from those of diploid species. Since thermal denaturation profiles of extracted DNA showed minor variations in the base composition of the genomes of the four species, it is supposed that, in pentaploid species, the large heterochromatin content is not due to an overrepresentation of G-C repetitive sequences but rather to the condensation of nonrepetitive sequences, such as, for example, redundant gene copies switched off in the polyploid complement. It is suggested that speciation in the genus Agave occurs through point mutations and minor DNA rearrangements, as is also indicated by the relative stability of the karyotype of this genus. Key words : Agave, DNA cytophotometry, DNA melting profiles, chromatin structure, genome size.

  7. Juvenile morphology: a clue to the origins of the most mysterious of mysticetes?

    PubMed

    Marx, Felix G; Buono, Mónica R; Fordyce, R Ewan; Boessenecker, R W

    2013-03-01

    The origin of the pygmy right whale (Caperea marginata) has long been one of the most vexing conundrums of marine mammal evolution. The extremely disparate skeletal structure of Caperea and a patchy fossil record have left morphology and molecules at odds: whereas most morphological analyses ally Caperea with right whales (Balaenidae), most molecular studies instead suggest a close relationship with rorquals (Balaenopteridae) and grey whales (Eschrichtiidae). The morphological evidence supporting a Caperea-balaenid clade consists of several shared features of the skull and mandible, as traditionally observed in adult individuals. Here, we show that at least two of these features, the ascending process of the maxilla and the coronoid process, arise from substantially different precursors early during ontogeny and therefore likely do not represent genuine synapomorphies. Both of these juvenile morphologies have adult counterparts in the fossil record, thus indicating that the ontogenetic variation in the living species may be a genuine reflection of differing ancestral states. This new evidence contradicts previous morphological hypotheses on the origins of Caperea and may help to reconcile morphological and molecular evidence.

  8. Ovarian development in a primitively eusocial wasp: social interactions affect behaviorally dominant and subordinate wasps in opposite directions relative to solitary females.

    PubMed

    Shukla, Shantanu; Pareek, Vidhi; Gadagkar, Raghavendra

    2014-07-01

    In many primitively eusocial wasp species new nests are founded either by a single female or by a small group of females. In the single foundress nests, the lone female develops her ovaries, lays eggs as well as tends her brood. In multiple foundress nests social interactions, especially dominance-subordinate interactions, result in only one 'dominant' female developing her ovaries and laying eggs. Ovaries of the remaining 'subordinate' cofoundresses remain suppressed and these individuals function as workers and tend the dominant's brood. Using the tropical, primitively eusocial polistine wasp Ropalidia marginata and by comparing wasps held in isolation and those kept as pairs in the laboratory, we demonstrate that social interactions affect ovarian development of dominant and subordinate wasps among the pairs in opposite directions, suppressing the ovaries of the subordinate member of the pair below that of solitary wasps and boosting the ovaries of dominant member of the pair above that of solitary females. In addition to being of physiological interest, such mirror image effects of aggression on the ovaries of the aggressors and their victims, suggest yet another mechanism by which subordinates can enhance their indirect fitness and facilitate the evolution of worker behavior by kin selection.

  9. Looking for long-term changes in hydroid assemblages (Cnidaria, Hydrozoa) in Alboran Sea (South-Western Mediterranean): a proposal of a monitoring point for the global warming

    NASA Astrophysics Data System (ADS)

    González-Duarte, Manuel María; Megina, Cesar; Piraino, Stefano

    2014-12-01

    In the last 20-30 years, the temperature of the Mediterranean Sea has increased and global warming is allowing the establishment of tropical-affinity species into more temperate zones. Sessile communities are particularly useful as a baseline for ecological monitoring; however, a lack of historical data series exists for sessile marine organisms without commercial interest. Hydroids are ubiquitous components of the benthic sessile fauna on rocky shores and have been used as bio-indicators of environmental conditions. In this study on the benthic hydroid assemblages of the Chafarinas Islands (Alboran Sea, South-Western Mediterranean), we characterized the hydroid assemblages, identified the bathymetric gradients, and compared them with a previous study carried out in 1991. Hydroid assemblages showed a significant difference both between year and among depths. Furthermore, eight species not present in 1991 were found, including two possible new species and the tropical and subtropical species Sertularia marginata. Due to its strategic position at the entrance of the Mediterranean and the existence of previous data on hydroid assemblages, the Chafarinas Islands are proposed as a possible monitoring point for entrance of Atlantic tropical species into the Mediterranean Sea.

  10. Profiling of Amatoxins and Phallotoxins in the Genus Lepiota by Liquid Chromatography Combined with UV Absorbance and Mass Spectrometry

    PubMed Central

    Sgambelluri, R. Michael; Epis, Sara; Sassera, Davide; Luo, Hong; Angelos, Evan R.; Walton, Jonathan D.

    2014-01-01

    Species in the mushroom genus Lepiota can cause fatal mushroom poisonings due to their content of amatoxins such as α-amanitin. Previous studies of the toxin composition of poisonous Lepiota species relied on analytical methods of low sensitivity or resolution. Using liquid chromatography coupled to UV absorbance and mass spectrometry, we analyzed the spectrum of peptide toxins present in six Italian species of Lepiota, including multiple samples of three of them collected in different locations. Field taxonomic identifications were confirmed by sequencing of the internal transcribed spacer (ITS) regions. For comparison, we also analyzed specimens of Amanita phalloides from Italy and California, a specimen of A. virosa from Italy, and a laboratory-grown sample of Galerina marginata. α-Amanitin, β-amanitin, amanin, and amaninamide were detected in all samples of L. brunneoincarnata, and α-amanitin and γ-amanitin were detected in all samples of L. josserandii. Phallotoxins were not detected in either species. No amatoxins or phallotoxins were detected in L. clypeolaria, L. cristata, L. echinacea, or L. magnispora. The Italian and California isolates of A. phalloides had similar profiles of amatoxins and phallotoxins, although the California isolate contained more β-amanitin relative to α-amanitin. Amaninamide was detected only in A. virosa. PMID:25098279

  11. Insects associated with Jatropha curcas Linn. (Euphorbiaceae) in west Niger.

    PubMed

    Habou, Zakari Abdoul; Adam, Toudou; Haubruge, Eric; Mergeai, Guy; Verheggen, François J

    2014-01-01

    Jatropha curcas has been introduced into Niger since 2004 by International Crops Research Institute for the Semi-Arid Tropics (ICRISAT). This plant is cultivated for its oil, which can be used as a Biofuel. Through direct and indirect insect collection methods, an inventory of the insect associated with J. curcas has been conducted in Western Niger during two rainy seasons (from June to October) in 2010 and 2011. We have identified insects belonging to the following families: Acrididae (Oedaleus senegalensis Krauss, Oedaleus nigeriensis Uvarov, Heteracris leani Uvarov, Catantops stramineus Walker, Parga cyanoptera Uvarov, and Acanthacris ruficornis citrina Audinet-Serville), Pyrgomorphidae (Poekilocerus bufonius hieroglyphicus Klug), Cetoniidae (Pachnoda interrupta Olivier, Pachnoda marginata aurantia Herbst, Pachnoda sinuata Heinrich and McClain, and Rhabdotis sobrina Gory and Percheron), Meloidae (Decapotoma lunata Pallas), Pentatomidae (Agonoscelis versicoloratus Dallas, Nezara viridula Linn, and Antestia sp. Kirkaldy), Coreidae (Leptoglossus membranaceus Fabricius and Cletus trigonus Thunberg), and Scutelleridae (Calidea panaethiopica Kirkaldy). Origin and potential impact on J. curcas of all these insect species are presented and discussed. The lower insect's diversity indexes are observed in 2010 and 2011 for Niamey, Saga, and Gaya because of semi-arid character of the Sahelian area.

  12. Ingested and biomineralized magnetic material in the prey Neocapritermes opacus termite: FMR characterization

    NASA Astrophysics Data System (ADS)

    de Oliveira, J. F.; Alves, O. C.; Esquivel, D. M. S.; Wajnberg, E.

    2008-03-01

    The temperature dependence of Ferromagnetic Resonance spectra, from 5 K to 280 K, was used to study the magnetic material present in Neocapritermes opacus termite, the only prey of the Pachycondyla marginata ant. The analysis of the resonant field and peak-to-peak linewidth allowed estimating the particle diameters and the effective anisotropy energy density, KEFF, as a sum of the bulk and surface contributions. It allowed to magnetically distinguish the particles of termites as collected in field from those of termites after 3 days under a cellulose diet, introduced to eliminate ingested/digested material. The data also, suggest the presence of oriented magnetite nanoparticles with diameters of 11.6 ± 0.3 nm in termites as collected in field and (14.0 ± 0.4 nm) in that under a cellulose diet. Differences between their KEFF and its components are also observed. Two transitions are revealed in the resonant field temperature dependence, one at about 50 K that was associated to surface effects and the other at about 100 K attributed to the Verwey transition.

  13. Profiling of amatoxins and phallotoxins in the genus Lepiota by liquid chromatography combined with UV absorbance and mass spectrometry.

    PubMed

    Sgambelluri, R Michael; Epis, Sara; Sassera, Davide; Luo, Hong; Angelos, Evan R; Walton, Jonathan D

    2014-08-05

    Species in the mushroom genus Lepiota can cause fatal mushroom poisonings due to their content of amatoxins such as α-amanitin. Previous studies of the toxin composition of poisonous Lepiota species relied on analytical methods of low sensitivity or resolution. Using liquid chromatography coupled to UV absorbance and mass spectrometry, we analyzed the spectrum of peptide toxins present in six Italian species of Lepiota, including multiple samples of three of them collected in different locations. Field taxonomic identifications were confirmed by sequencing of the internal transcribed spacer (ITS) regions. For comparison, we also analyzed specimens of Amanita phalloides from Italy and California, a specimen of A. virosa from Italy, and a laboratory-grown sample of Galerina marginata. α-Amanitin, β-amanitin, amanin, and amaninamide were detected in all samples of L. brunneoincarnata, and α-amanitin and γ-amanitin were detected in all samples of L. josserandii. Phallotoxins were not detected in either species. No amatoxins or phallotoxins were detected in L. clypeolaria, L. cristata, L. echinacea, or L. magnispora. The Italian and California isolates of A. phalloides had similar profiles of amatoxins and phallotoxins, although the California isolate contained more β-amanitin relative to α-amanitin. Amaninamide was detected only in A. virosa.

  14. The Antibacterial Activity of Honey Derived from Australian Flora

    PubMed Central

    Irish, Julie; Blair, Shona; Carter, Dee A.

    2011-01-01

    Chronic wound infections and antibiotic resistance are driving interest in antimicrobial treatments that have generally been considered complementary, including antimicrobially active honey. Australia has unique native flora and produces honey with a wide range of different physicochemical properties. In this study we surveyed 477 honey samples, derived from native and exotic plants from various regions of Australia, for their antibacterial activity using an established screening protocol. A level of activity considered potentially therapeutically useful was found in 274 (57%) of the honey samples, with exceptional activity seen in samples derived from marri (Corymbia calophylla), jarrah (Eucalyptus marginata) and jellybush (Leptospermum polygalifolium). In most cases the antibacterial activity was attributable to hydrogen peroxide produced by the bee-derived enzyme glucose oxidase. Non-hydrogen peroxide activity was detected in 80 (16.8%) samples, and was most consistently seen in honey produced from Leptospermum spp. Testing over time found the hydrogen peroxide-dependent activity in honey decreased, in some cases by 100%, and this activity was more stable at 4°C than at 25°C. In contrast, the non-hydrogen peroxide activity of Leptospermum honey samples increased, and this was greatest in samples stored at 25°C. The stability of non-peroxide activity from other honeys was more variable, suggesting this activity may have a different cause. We conclude that many Australian honeys have clinical potential, and that further studies into the composition and stability of their active constituents are warranted. PMID:21464891

  15. The antibacterial activity of honey derived from Australian flora.

    PubMed

    Irish, Julie; Blair, Shona; Carter, Dee A

    2011-03-28

    Chronic wound infections and antibiotic resistance are driving interest in antimicrobial treatments that have generally been considered complementary, including antimicrobially active honey. Australia has unique native flora and produces honey with a wide range of different physicochemical properties. In this study we surveyed 477 honey samples, derived from native and exotic plants from various regions of Australia, for their antibacterial activity using an established screening protocol. A level of activity considered potentially therapeutically useful was found in 274 (57%) of the honey samples, with exceptional activity seen in samples derived from marri (Corymbia calophylla), jarrah (Eucalyptus marginata) and jellybush (Leptospermum polygalifolium). In most cases the antibacterial activity was attributable to hydrogen peroxide produced by the bee-derived enzyme glucose oxidase. Non-hydrogen peroxide activity was detected in 80 (16.8%) samples, and was most consistently seen in honey produced from Leptospermum spp. Testing over time found the hydrogen peroxide-dependent activity in honey decreased, in some cases by 100%, and this activity was more stable at 4 °C than at 25 °C. In contrast, the non-hydrogen peroxide activity of Leptospermum honey samples increased, and this was greatest in samples stored at 25 °C. The stability of non-peroxide activity from other honeys was more variable, suggesting this activity may have a different cause. We conclude that many Australian honeys have clinical potential, and that further studies into the composition and stability of their active constituents are warranted.

  16. The T-box genes H15 and optomotor-blind in the spiders Cupiennius salei, Tegenaria atrica and Achaearanea tepidariorum and the dorsoventral axis of arthropod appendages.

    PubMed

    Janssen, Ralf; Feitosa, Natalia M; Damen, Wim G M; Prpic, Nikola-Michael

    2008-01-01

    Dorsoventral axis formation in the legs of the fly Drosophila melanogaster requires the T-box genes optomotor-blind (omb) and H15. Evolutionary conservation of the patterning functions of these genes is unclear, because data on H15 expression in the spider Cupiennius salei did not support a general role of H15 in ventral fate specification. However, H15 has a paralogous gene, midline (mid) in Drosophila and H15 duplicates are also present in Cupiennius and the millipede Glomeris marginata. H15 therefore seems to have been subject to gene duplication opening the possibility that the previous account on Cupiennius has overlooked one or several paralogs. We have studied omb- and H15-related genes in two additional spider species, Tegenaria atrica and Achearanea tepidariorum and show that in both species one of the H15 genes belongs to a third group of spider H15 genes that has an expression pattern very similar to the H15 pattern in Drosophila. The expression patterns of all omb-related genes are also very similar to the omb expression pattern in Drosophila. These data suggest that the dorsoventral patterning functions of omb and H15 are conserved in the arthropods and that the previous conclusions were based on an incomplete data set in Cupiennius. Our results emphasize the importance of a broad taxon sampling in comparative studies.

  17. Shallow water heterobranch sea slugs (Gastropoda: Heterobranchia) from the Región de Atacama, northern Chile

    PubMed Central

    Valdés, Ángel

    2016-01-01

    The coast of northern Chile has been sparsely studied in regards to its invertebrate fauna, with just a few works reviewing the distribution of local mollusks. This work presents a survey of the shallow water heterobranch sea slugs currently occurring around the port of Caldera (27 °S), in the Región de Atacama, northern Chile. Eight species of sea slugs were found in this study: Aplysiopsis cf. brattstroemi (Marcus, 1959), Baptodoris peruviana (d’Orbigny, 1837), Diaulula variolata (d’Orbigny, 1837), Doris fontainii d’Orbigny, 1837, Onchidella marginata (Couthouy in Gould, 1852), Phidiana lottini (Lesson, 1831), Tyrinna delicata (Abraham, 1877) and the new species Berthella schroedli sp. nov., described herein. All of the species found in the area are endemic to South America, having distributions in the southeastern Pacific and South Atlantic Oceans, from Ancash, Perú to Peninsula Valdés, Argentina, and two of them represent species which are endemic to the Chilean coasts (Aplysiopsis cf. brattstroemi and Berthella schroedli). The finding of a previously undescribed species emphasizes the need of further surveys, particularly in subtidal and deeper waters, in order to improve the knowledge on this neglected fauna in Atacama. PMID:27168975

  18. Behavioral responses of freshwater mussels to experimental dewatering

    USGS Publications Warehouse

    Galbraith, Heather S.; Blakeslee, Carrie J.; Lellis, William A.

    2015-01-01

    Understanding the effects of flow alteration on freshwater ecosystems is critical for predicting species responses and restoring appropriate flow regimes. We experimentally evaluated the effects of 3 dewatering rates on behavior of 6 freshwater mussel species in the context of water-removal rates observed in 21 Atlantic Coast rivers. Horizontal movement differed significantly among species and dewatering rates, but a significant species × dewatering interaction suggested that these factors influence movement in complex ways. Species differences in movement were evident only in controls and under slow dewatering rates, but these differences disappeared at moderate and fast dewatering rates. Burrowing behavior did not differ with respect to species identity or dewatering rate. The proportion of individuals that became stranded did not differ among species, but most individuals became stranded under low and moderate dewatering, and all individuals became stranded under fast dewatering. Mortality after stranding differed strongly among species along a gradient from 25% inPyganodon cataracta to 92% in Alasmidonta marginata. Together, these results suggest that species behavior may differ under gradual dewatering, but all species in our study are poorly adapted for rapid dewatering. Most of the 21 rivers we assessed experienced dewatering events comparable to our moderate rate, and several experienced events comparable to our fast rate. Dewatering events that exceed the movement or survival capability of most mussel species can be expected to result in assemblage-wide impacts. Consequently, the rate of water level change may be important in refining target flow conditions for restoration.

  19. Elemental composition of biomineralized amorphous mineral granules isolated from ants: correlation with ingested mineral particles from the soil.

    PubMed

    Carneiro, Fabricia G; Keim, Carolina N; Acosta-Avalos, Daniel; Farina, Marcos

    2013-01-01

    Amorphous mineral granules are formed by concentric mineral layers containing polyphosphate, pyrophosphate and/or orthophosphate and several metallic cations such as Mg(2+), Ca(2+), K(+), Mn(2+), Fe(3+), Cu(2+), and Zn(2+). In this work, we analyzed amorphous mineral granules isolated from the ant species Camponotus abdominalis, Camponotus sp., Acromyrmex subterraneus and Pachycondyla marginata by energy-dispersive X-ray analysis. The elemental composition of the granules was compared to that of mineral particles, probably soil particles, to access the influence of the environment and of specific characteristics of each ant species in the elemental composition of the amorphous mineral granules. Both the granules and mineral particles presented Mg, Ca, Fe, and Zn in the four species. Additionally, Al tended to be present in both (or none) of the two types of material in a given ant species, suggesting that the aluminum found in the amorphous mineral granules could be derived from ingested soil particles. On the other hand, Sr was found in the amorphous mineral granules of some of the studied ant species, but not in the mineral particles. The fact that 3/4 of the elements found in the granules were found also in the mineral particles suggests that the mineral composition of the soil plays a fundamental role in the accumulation of some elements in the amorphous mineral granules of ants. These results suggest a major role of soil particles as a source of micronutrients for the four ant species.

  20. Effective use of high CO2 efflux at the soil surface in a tropical understory plant

    PubMed Central

    Ishida, Atsushi; Nakano, Takashi; Adachi, Minaco; Yoshimura, Kenichi; Osada, Noriyuki; Ladpala, Phanumard; Diloksumpun, Sapit; Puangchit, Ladawan; Yoshimura, Jin

    2015-01-01

    Many terrestrial plants are C3 plants that evolved in the Mesozoic Era when atmospheric CO2 concentrations ([CO2]) were high. Given current conditions, C3 plants can no longer benefit from high ambient [CO2]. Kaempferia marginata Carey is a unique understory ginger plant in the tropical dry forests of Thailand. The plant has two large flat leaves that spread on the soil surface. We found a large difference in [CO2] between the partly closed space between the soil surface and the leaves (638 µmol mol−1) and the atmosphere at 20 cm above ground level (412 µmol mol−1). This finding indicates that the plants capture CO2 efflux from the soil. Almost all of the stomata are located on the abaxial leaf surface. When ambient air [CO2] was experimentally increased from 400 to 600 μmol mol−1, net photosynthetic rates increased by 45 to 48% under near light-saturated conditions. No significant increase was observed under low light conditions. These data demonstrate that the unique leaf structure enhances carbon gain by trapping soil CO2 efflux at stomatal sites under relatively high light conditions, suggesting that ambient air [CO2] can serve as an important selective agent for terrestrial C3 plants. PMID:25758763

  1. Gene expression suggests conserved mechanisms patterning the heads of insects and myriapods.

    PubMed

    Janssen, Ralf; Budd, Graham E; Damen, Wim G M

    2011-09-01

    Segmentation, i.e. the subdivision of the body into serially homologous units, is one of the hallmarks of the arthropods. Arthropod segmentation is best understood in the fly Drosophila melanogaster. But different from the situation in most arthropods in this species all segments are formed from the early blastoderm (so called long-germ developmental mode). In most other arthropods only the anterior segments are formed in a similar way (so called short-germ developmental mode). Posterior segments are added one at a time or in pairs of two from a posterior segment addition zone. The segmentation mechanisms are not universally conserved among arthropods and only little is known about the genetic patterning of the anterior segments. Here we present the expression patterns of the insect head patterning gene orthologs hunchback (hb), orthodenticle (otd), buttonhead-like (btdl), collier (col), cap-n-collar (cnc) and crocodile (croc), and the trunk gap gene Krüppel (Kr) in the myriapod Glomeris marginata. Conserved expression of these genes in insects and a myriapod suggests that the anterior segmentation system may be conserved in at least these two classes of arthropods. This finding implies that the anterior patterning mechanism already existed in the last common ancestor of insects and myriapods.

  2. A Link No Longer Missing: New Evidence for the Cetotheriid Affinities of Caperea

    PubMed Central

    Marx, Felix G.; Fordyce, R. Ewan

    2016-01-01

    The origins of the enigmatic pygmy right whale Caperea marginata, the only living member of its subfamily (Neobalaeninae), are an outstanding mystery of cetacean evolution. Its strikingly disparate morphology sets Caperea apart from all other whales, and has turned it into a wildcard taxon that holds the key to understanding modern baleen whale diversity. Morphological cladistics generally ally this species with right whales, whereas molecular analyses consistently cluster it with rorquals and grey whales (Balaenopteroidea). A recent study potentially resolved this conflict by proposing that Caperea belongs with the otherwise extinct Cetotheriidae, but has been strongly criticised on morphological grounds. Evidence from the neobalaenine fossil record could potentially give direct insights into morphological transitions, but is currently limited to just a single species: the Late Miocene Miocaperea pulchra, from Peru. We show that Miocaperea has a highly unusual morphology of the auditory region, resulting from a–presumably feeding-related–strengthening of the articulation of the hyoid apparatus with the skull. This distinctive arrangement is otherwise only found in the extinct Cetotheriidae, which makes Miocaperea a “missing link” that demonstrates the origin of pygmy right whales from cetotheriids, and confirms the latter’s resurrection from the dead. PMID:27711216

  3. [Presence, abundance and reproductive strategies of ferns in disturbed areas of Sierra Nevada, México].

    PubMed

    Rodríguez Romero, Ma Lucía; Zavala Hurtado, José Alejandro; Pacheco, Leticia

    2011-03-01

    Diverse reproductive strategies shown by ferns and lycophytes allow them to colonize a variety of habitats, particularly after the incidence of natural or anthropogenic disturbances. This study assessed the presence, abundance and reproductive strategies of ferns growing in soils of temperate forests with different levels of disturbance at the Sierra Nevada mountain range in the State of Mexico. Vegetation, soil and environmental variables were recorded in 200 m2 permanent plots located in four forest stands. One-Way ANOVA and Canonical Correspondence Analysis resulted in the recognition of three landscape types defined by the degree of environmental alteration: low, moderate and severe. Also, from five soil samples collected in each stand, germination of ferns and lycophytes was induced. A positive relationship was found between the alteration degree and Cheilanthes abundance. Under a low landscape alteration regime, species richness is restricted to Cheilanthes bonariensis, C. marginata and Pellaea ternifolia subsp. ternifolia. The soil is a reservoir of spores of Cheilanthes and Pellaea ternifolia subsp. ternifolia because their spores can remain viable for different time intervals. Apogamy is the usual reproductive strategy of Cheilanthes species in disturbed ecosystems, although these species also show sexual reproduction in natural ecosystems with adequate water availability. Apogamy may be related to a shorter generation time in comparison with a low disturbed ecosystem. On the other hand, Pellaea ternifolia subsp. ternifolia only has sexual reproduction. Apogamy might be related to a faster generation in comparison with a low disturbed ecosystem.

  4. Juvenile morphology: A clue to the origins of the most mysterious of mysticetes?

    NASA Astrophysics Data System (ADS)

    Marx, Felix G.; Buono, Mónica R.; Fordyce, R. Ewan; Boessenecker, R. W.

    2013-03-01

    The origin of the pygmy right whale ( Caperea marginata) has long been one of the most vexing conundrums of marine mammal evolution. The extremely disparate skeletal structure of Caperea and a patchy fossil record have left morphology and molecules at odds: whereas most morphological analyses ally Caperea with right whales (Balaenidae), most molecular studies instead suggest a close relationship with rorquals (Balaenopteridae) and grey whales (Eschrichtiidae). The morphological evidence supporting a Caperea-balaenid clade consists of several shared features of the skull and mandible, as traditionally observed in adult individuals. Here, we show that at least two of these features, the ascending process of the maxilla and the coronoid process, arise from substantially different precursors early during ontogeny and therefore likely do not represent genuine synapomorphies. Both of these juvenile morphologies have adult counterparts in the fossil record, thus indicating that the ontogenetic variation in the living species may be a genuine reflection of differing ancestral states. This new evidence contradicts previous morphological hypotheses on the origins of Caperea and may help to reconcile morphological and molecular evidence.

  5. A novel plant-fungus symbiosis benefits the host without forming mycorrhizal structures.

    PubMed

    Kariman, Khalil; Barker, Susan J; Jost, Ricarda; Finnegan, Patrick M; Tibbett, Mark

    2014-03-01

    • Most terrestrial plants form mutually beneficial symbioses with specific soil-borne fungi known as mycorrhiza. In a typical mycorrhizal association, fungal hyphae colonize plant roots, explore the soil beyond the rhizosphere and provide host plants with nutrients that might be chemically or physically inaccessible to root systems. • Here, we combined nutritional, radioisotopic ((33)P) and genetic approaches to describe a plant growth promoting symbiosis between the basidiomycete fungus Austroboletus occidentalis and jarrah (Eucalyptus marginata), which has quite different characteristics. • We show that the fungal partner does not colonize plant roots; hyphae are localized to the rhizosphere soil and vicinity and consequently do not transfer nutrients located beyond the rhizosphere. Transcript profiling of two high-affinity phosphate (Pi) transporter genes (EmPHT1;1 and EmPHT1;2) and hyphal-mediated (33)Pi uptake suggest that the Pi uptake shifts from an epidermal to a hyphal pathway in ectomycorrhizal plants (Scleroderma sp.), similar to arbuscular mycorrhizal symbioses, whereas A. occidentalis benefits its host indirectly. The enhanced rhizosphere carboxylates are linked to growth and nutritional benefits in the novel symbiosis. • This work is a starting point for detailed mechanistic studies on other basidiomycete-woody plant relationships, where a continuum between heterotrophic rhizosphere fungi and plant beneficial symbioses is likely to exist.

  6. Spatial distribution and seasonal changes of mayflies (Insecta, Ephemeroptera) in a Western Balkan peat bog.

    PubMed

    Vilenica, Marina; Brigić, Andreja; Kerovec, Mladen; Gottstein, Sanja; Ternjej, Ivančica

    2016-01-01

    Peat bogs are unique wetland ecosystems of high conservation value all over the world, yet data on the macroinvertebrates (including mayfly assemblages) in these habitats are still scarce. Over the course of one growing season, mayfly assemblages were sampled each month, along with other macroinvertebrates, in the largest and oldest Croatian peat bog and an adjacent stream. In total, ten mayfly species were recorded: two species in low abundance in the peat bog, and nine species in significantly higher abundance in the stream. Low species richness and abundance in the peat bog were most likely related to the harsh environmental conditions and mayfly habitat preferences. In comparison, due to the more favourable habitat conditions, higher species richness and abundance were observed in the nearby stream. Three of the recorded species, Caenis luctuosa from the peat bog, and Eurylophella karelica and Leptophlebia marginata from the stream are new records for the Croatian mayfly fauna. Typical Central European life cycle patterns were confirmed for several species (e.g. Baetis vernus, Nigrobaetis niger, Electrogena ujhelyii), while for several others (e.g. Habrophlebia fusca, Paraleptophlebia submarginata) some discrepancies were observed. Therefore, these results provide new and valuable information on the ecology of mayflies in peat bog habitats.

  7. Intraspecific and interspecific polyploidy of Brazilian species of the genus Inga (Leguminosae: Mimosoideae).

    PubMed

    Figueiredo, M F; Bruno, R L A; Barros e Silva, A E; Nascimento, S; Oliveira, I G; Felix, L P

    2014-04-29

    We investigated the karyotypes of 13 species of six sections of the genus Inga (Leguminosae-Mimosoideae) from Brazil. We used conventional Giemsa staining to identify numerical chromosomal variations and looked for karyotypic evolutionary patterns. The karyotypes generally had small chromosomes, varying from metacentric to submetacentric, with a basic number x=13. Nine of the species showed 2n=2x=26 (I. thibaudiana, I. cayennensis, I. ingoides, I. edulis, I. vera, I. subnuda, I. striata, I. bollandii, and Inga sp), while 2n=4x=52 was seen in a population of Inga cylindrical and of I. capitata, and in five populations of I. laurina. Additionally, 2n=8x=104 was observed in a population of I. cayennensis. Eight of these counts were new, while the counts of 2n=52 for I. laurina and 2n=26 for I. marginata, I. vera, I. subnuda, and I. edulis confirmed previous studies. We did not find cytological stability among the sections studied, with occurrence of significant intra- and inter-specific numerical variations. We conclude that polyploidy has played a significant role in karyotypic evolution in this group and that it occurred independently in several sections of the genus.

  8. Induced remanent magnetization of social insects

    NASA Astrophysics Data System (ADS)

    Wajnberg, E.; Cernicchiaro, G.; Acosta-Avalos, D.; El-Jaick, L. J.; Esquivel, D. M. S.

    2001-05-01

    The induced remanent magnetization (IRM) of honeybees Apis mellifera and ants as Pachycondyla marginata, a migratory species, and Solenopsis sp., a fire ant, was obtained using a SQUID magnetometer from 10 to 300 K. An anomalous sharp change of the remanent magnetization is observed at 67±0.2 K for migratory ants. The IRM at room temperature indicates the presence of at least 10 times lower concentration of magnetic material in the whole fire ant as compared to the migratory ant abdomen (0.22±0.33×10 -6 emu/ant, and 2.8±1.2×10 -6 emu/abdomen, respectively). Our results in honeybee abdomen (4.6±0.9×10 -6 emu/abdomen) agree with other reported values. IRM at room temperature in ants and honeybees indicates the presence of single domain (SD) or aggregates of magnetite nanoparticles. The loss of remanence from 77 to 300 K can be related to the stable-superparamagnetic (SPM) transition of small particles (less than ca. 30 nm). From these values and considering their estimated volumes an upper limit 10 10 SPM and 10 9 SD or aggregate particles are obtained in these insects.

  9. Spatial distribution and seasonal changes of mayflies (Insecta, Ephemeroptera) in a Western Balkan peat bog

    PubMed Central

    Vilenica, Marina; Brigić, Andreja; Kerovec, Mladen; Gottstein, Sanja; Ternjej, Ivančica

    2016-01-01

    Abstract Peat bogs are unique wetland ecosystems of high conservation value all over the world, yet data on the macroinvertebrates (including mayfly assemblages) in these habitats are still scarce. Over the course of one growing season, mayfly assemblages were sampled each month, along with other macroinvertebrates, in the largest and oldest Croatian peat bog and an adjacent stream. In total, ten mayfly species were recorded: two species in low abundance in the peat bog, and nine species in significantly higher abundance in the stream. Low species richness and abundance in the peat bog were most likely related to the harsh environmental conditions and mayfly habitat preferences. In comparison, due to the more favourable habitat conditions, higher species richness and abundance were observed in the nearby stream. Three of the recorded species, Caenis luctuosa from the peat bog, and Eurylophella karelica and Leptophlebia marginata from the stream are new records for the Croatian mayfly fauna. Typical Central European life cycle patterns were confirmed for several species (e.g. Baetis vernus, Nigrobaetis niger, Electrogena ujhelyii), while for several others (e.g. Habrophlebia fusca, Paraleptophlebia submarginata) some discrepancies were observed. Therefore, these results provide new and valuable information on the ecology of mayflies in peat bog habitats. PMID:28138280

  10. Three New Species and Nine New Records in the Genus Arthonia from South Korea

    PubMed Central

    Lee, Beeyoung Gun

    2016-01-01

    Arthonia coreana, Arthonia superpallens, and Arthonia zelkovae are new species from South Korea. All new species are in the Euarthonia tribe, based on the key characteristics of colorless hypothecium and multi-cellular spores. A. coreana has a dull brownish hypophloedal thallus without bleaching and rounded or curved big apothecia in comparison with those of Arthonia punctiformis. A. coreana consistently exhibits 4-septate ascospores, which is a distinctive characteristic that distinguishes it from other Arthonia species. A. superpallens has a white-greenish thallus, pale yellowish apothecia, and a trentepohlioid alga. However, A. superpallens has no distinct prothallus, adnate, and convex apothecia, no pycnidia, and is UV-, in contrast with related species in the Arthonia antillarum group. A. zelkovae has a white, epiphloedal thallus, brownish-black epruinose apothecia covered with a whitish bark layer, and smaller ascospores in comparison with those of A. punctiformis. A. zelkovae consists of a chlorococcoid alga, which differs from related Arthonia species such as A. punctiformis, Arthonia pinastri, and Arthonia glaucella. Although A. zelkovae is similar to Arthonia dispersa in its white-colored thallus, blackish apothecia, and the presence of a chlorococcoid photobiont, A. zelkovae differs from the latter in having larger-sized 3-septate ascospores. Arthonia cinnabarina f. marginata, A. glaucella, Arthonia ilicinella, Arthonia lapidicola, Arthonia leioplacella, Arthonia pertabescens, A. pinastri, Arthonia spadicea, and Arthonia stellaris are newly described in Korea. The diagnostic characteristics of these species are discussed and presented. An artificial key is provided to facilitate identification of Arthonia species from Northeast Asia. PMID:28154479

  11. A Link No Longer Missing: New Evidence for the Cetotheriid Affinities of Caperea.

    PubMed

    Marx, Felix G; Fordyce, R Ewan

    2016-01-01

    The origins of the enigmatic pygmy right whale Caperea marginata, the only living member of its subfamily (Neobalaeninae), are an outstanding mystery of cetacean evolution. Its strikingly disparate morphology sets Caperea apart from all other whales, and has turned it into a wildcard taxon that holds the key to understanding modern baleen whale diversity. Morphological cladistics generally ally this species with right whales, whereas molecular analyses consistently cluster it with rorquals and grey whales (Balaenopteroidea). A recent study potentially resolved this conflict by proposing that Caperea belongs with the otherwise extinct Cetotheriidae, but has been strongly criticised on morphological grounds. Evidence from the neobalaenine fossil record could potentially give direct insights into morphological transitions, but is currently limited to just a single species: the Late Miocene Miocaperea pulchra, from Peru. We show that Miocaperea has a highly unusual morphology of the auditory region, resulting from a-presumably feeding-related-strengthening of the articulation of the hyoid apparatus with the skull. This distinctive arrangement is otherwise only found in the extinct Cetotheriidae, which makes Miocaperea a "missing link" that demonstrates the origin of pygmy right whales from cetotheriids, and confirms the latter's resurrection from the dead.

  12. Anatomy of nasal complex in the southern right whale, Eubalaena australis (Cetacea, Mysticeti)

    PubMed Central

    Buono, Mónica R; Fernández, Marta S; Fordyce, R Ewan; Reidenberg, Joy S

    2015-01-01

    The nasal region of the skull has undergone dramatic changes during the course of cetacean evolution. In particular, mysticetes (baleen whales) conserve the nasal mammalian pattern associated with the secondary function of olfaction, and lack the sound-producing specializations present in odontocetes (toothed whales, dolphins and porpoises). To improve our understanding of the morphology of the nasal region of mysticetes, we investigate the nasal anatomy, osteology and myology of the southern right whale, Eubalaena australis, and make comparisons with other mysticetes. In E. australis external deflection surfaces around the blowholes appear to divert water off the head, and differ in appearance from those observed in balaenopterids, eschrichtiids and cetotherids. In E. australis the blowholes are placed above hypertrophied nasal soft tissues formed by fat and nasal muscles, a pattern also observed in balaenopterids (rorqual mysticetes) and a cetotherid (pygmy right whale, Caperea marginata). Blowhole movements are due to the action of five nasofacial muscles: dilator naris superficialis, dilator naris profundus, depressor alae nasi, constrictor naris, and retractor alae nasi. The dilator naris profundus found in E. australis has not been previously reported in balaenopterids. The other nasofacial muscles have a similar arrangement in balaenopterids, with minor differences. A novel structure, not reported previously in any mysticete, is the presence of a vascular tissue (rete mirabile) covering the lower nasal passage. This vascular tissue could play a role in warming inspired air, or may engorge to accommodate loss of respiratory space volume due to gas compression from increased pressure during diving. PMID:25440939

  13. Rescuing biogeographic legacy data: The "Thor" Expedition, a historical oceanographic expedition to the Mediterranean Sea

    PubMed Central

    Mavraki, Dimitra; Fanini, Lucia; Tsompanou, Marilena; Gerovasileiou, Vasilis; Nikolopoulou, Stamatina; Chatzinikolaou, Eva; Plaitis, Wanda

    2016-01-01

    Abstract Background This article describes the digitization of a series of historical datasets based οn the reports of the 1908–1910 Danish Oceanographical Expeditions to the Mediterranean and adjacent seas. All station and sampling metadata as well as biodiversity data regarding calcareous rhodophytes, pelagic polychaetes, and fish (families Engraulidae and Clupeidae) obtained during these expeditions were digitized within the activities of the LifeWatchGreece Research Ιnfrastructure project and presented in the present paper. The aim was to safeguard public data availability by using an open access infrastructure, and to prevent potential loss of valuable historical data on the Mediterranean marine biodiversity. New information The datasets digitized here cover 2,043 samples taken at 567 stations during a time period from 1904 to 1930 in the Mediterranean and adjacent seas. The samples resulted in 1,588 occurrence records of pelagic polychaetes, fish (Clupeiformes) and calcareous algae (Rhodophyta). In addition, basic environmental data (e.g. sea surface temperature, salinity) as well as meterological conditions are included for most sampling events. In addition to the description of the digitized datasets, a detailed description of the problems encountered during the digitization of this historical dataset and a discussion on the value of such data are provided. PMID:28174510

  14. Seaweeds in cold seas: evolution and carbon acquisition.

    PubMed

    Raven, John A; Johnston, Andrew M; Kübler, Janet E; Korb, Rebecca; McInroy, Shona G; Handley, Linda L; Scrimgeour, Charlie M; Walker, Diana I; Beardall, John; Clayton, Margaret N; Vanderklift, Mathew; Fredriksen, Stein; Dunton, Kenneth H

    2002-10-01

    Much evidence suggests that life originated in hydrothermal habitats, and for much of the time since the origin of cyanobacteria (at least 2.5 Ga ago) and of eukaryotic algae (at least 2.1 Ga ago) the average sea surface and land surface temperatures were higher than they are today. However, there have been at least four significant glacial episodes prior to the Pleistocene glaciations. Two of these (approx. 2.1 and 0.7 Ga ago) may have involved a 'Snowball Earth' with a very great impact on the algae (sensu lato) of the time (cyanobacteria, Chlorophyta and Rhodophyta) and especially those that were adapted to warm habitats. By contrast, it is possible that heterokont, dinophyte and haptophyte phototrophs only evolved after the Carboniferous-Permian ice age (approx. 250 Ma ago) and so did not encounter low (

  15. New records of marine algae in Vietnam

    NASA Astrophysics Data System (ADS)

    Le Hau, Nhu; Ly, Bui Minh; Van Huynh, Tran; Trung, Vo Thanh

    2015-06-01

    In May, 2013, a scientific expedition was organized by the Vietnam Academy of Science and Technology (VAST) and the Far Eastern Branch of the Russian Academy of Sciences (FEBRAS) through the frame of the VAST-FEBRAS International Collaboration Program. The expedition went along the coast of Vietnam from Quang Ninh to Kien Giang. The objective was to collect natural resources to investigate the biological and biochemical diversity of the territorial waters of Vietnam. Among the collected algae, six taxa are new records for the Vietnam algal flora. They are the red algae Titanophora pikeana (Dickie) Feldmann from Cu Lao Xanh Island, Laurencia natalensis Kylin from Tho Chu Island, Coelothrix irregularis (Harvey) Børgesen from Con Dao Island, the green algae Caulerpa oligophylla Montagne, Caulerpa andamanensis (W.R. Taylor) Draisma, Prudhomme et Sauvage from Phu Quy Island, and Caulerpa falcifolia Harvey & Bailey from Ly Son Island. The seaweed flora of Vietnam now counts 833 marine algal taxa, including 415 Rhodophyta, 147 Phaeophyceae, 183 Chlorophyta, and 88 Cyanobacteria.

  16. Microcystins and cyanophyte extracts inhibit or promote the photosynthesis of fluvial algae. Ecological and management implications.

    PubMed

    García-Espín, Laura; Cantoral, Enrique A; Asencio, Antonia D; Aboal, Marina

    2017-04-05

    The ecological influence of cyanotoxins on aquatic biota remains unclear despite the numerous published references on toxicological and sanitary problems related with cyanophyte proliferation. The effects of microcystins and cyanophyte extracts on the photosynthesis of the algae that belong to two taxonomic groups, Rhodophyta and Bacillariophyta, were studied in an attempt to elucidate their role in the intraspecific competence and physiognomy of fluvial communities. The data showed that both cyanobacteria extracts and pure microcystin-LR affected the photosynthetic activity of all the tested organisms, diatoms (Fistulifera pelliculosa, Gomphonema parvulum, Nitzschia frustulum and Stephanodiscus minutulus) and red algae (Chroothece richteriana) at environmentally relevant concentrations. Effects varied with strains and time, and promoted or inhibited photosynthesis. The microcystins and the other compounds present in cyanobacteria extracts may explain the competence effects observed in nature, especially in calcareous environments where they predominate, and after disturbing events like heavy rains or floods, which may destroy cyanophyte mats and release toxic or inhibitory compounds in a seasonal scale pattern.

  17. Recent mobility of plastid encoded group II introns and twintrons in five strains of the unicellular red alga Porphyridium.

    PubMed

    Perrineau, Marie-Mathilde; Price, Dana C; Mohr, Georg; Bhattacharya, Debashish

    2015-01-01

    Group II introns are closely linked to eukaryote evolution because nuclear spliceosomal introns and the small RNAs associated with the spliceosome are thought to trace their ancient origins to these mobile elements. Therefore, elucidating how group II introns move, and how they lose mobility can potentially shed light on fundamental aspects of eukaryote biology. To this end, we studied five strains of the unicellular red alga Porphyridium purpureum that surprisingly contain 42 group II introns in their plastid genomes. We focused on a subset of these introns that encode mobility-conferring intron-encoded proteins (IEPs) and found them to be distributed among the strains in a lineage-specific manner. The reverse transcriptase and maturase domains were present in all lineages but the DNA endonuclease domain was deleted in vertically inherited introns, demonstrating a key step in the loss of mobility. P. purpureum plastid intron RNAs had a classic group IIB secondary structure despite variability in the DIII and DVI domains. We report for the first time the presence of twintrons (introns-within-introns, derived from the same mobile element) in Rhodophyta. The P. purpureum IEPs and their mobile introns provide a valuable model for the study of mobile retroelements in eukaryotes and offer promise for biotechnological applications.

  18. Biomass and Habitat Characteristics of Epiphytic Macroalgae in the Sibuti Mangroves, Sarawak, Malaysia.

    PubMed

    Isa, Hasmidah Md; Kamal, Abu Hena Mustafa; Idris, Mohd Hanafi; Rosli, Zamri; Ismail, Johan

    2017-01-01

    Mangroves support diverse macroalgal assemblages as epibionts on their roots and tree trunks. These algae provide nutrients to the primary consumers in the aquatic food web and have been reported to be substantial contributors to marine ecosystems. The species diversity, biomass, and habitat characteristics of mangrove macroalgae were investigated at three stations in the Sibuti mangrove estuary, Sarawak, Malaysia, from November 2012 to October 2013. Three groups of macroalgae were recorded and were found to be growing on mangrove prop roots, namely Rhodophyta (Caloglossa ogasawaraensis, Caloglossa adhaerens, Caloglossa stipitata, Bostrychia anomala, and Hypnea sp.), Chlorophyta (Chaetomorpha minima and Chaetomorpha sp.), and Phaeophyta (Dictyota sp.). The biomass of macroalgae was not influenced (p>0.05) by the season in this mangrove forest habitat. The macroalgal species Hypnea sp. contributed the highest biomass at both Station 1 (210.56 mg/cm(2)) and Station 2 (141.72 mg/cm(2)), while the highest biomass was contributed by B. anomala (185.89 mg/cm(2)) at Station 3. This study shows that the species distribution and assemblages of mangrove macroalgae were influenced by environmental parameters such as water nutrients, dissolved solids, and salinity in the estuarine mangrove habitats of Sibuti, Sarawak.

  19. Macroalgae in a spring stream in Shanxi Province: composition and relation to physical and chemical variables

    NASA Astrophysics Data System (ADS)

    Hu, Bianfang; Xie, Shulian

    2007-07-01

    Fourteen stream segments were investigated throughout the Xin’an Spring in Shanxi Province, China in 2004. The variation ranges in stream size, current velocity, discharge, dissolved oxygen, and specific conductance were large. Twenty-two macroalgae species were found in the stream. Major divisions in terms of species numbers were Chlorophyta (59.1%), Cyanophyta (22.8%), Xanthophyta (9.1%), Rhodophyta (4.5%) and Charophyta (4.5%). The most widespread species, Cladophora rivularis (50.0%), also Oedogonium sp. (42.9%) and Spirogyra sp. (42.9%) were well represented throughout the stream, whereas another 10 species were found in only one sampling site. Total percentage cover varied from <1% to 90%. Red algae Batrachospermum acuatum and the charophytes Chara vulgaris have the highest percentage cover. Among the parameters analyzed, the stream width, specific conductance and dissolved oxygen were the ones that more closely related to the species number and percentage cover of macroalgal communities. The species number of each site was negatively correlated with dissolved oxygen content. The total percentage cover of the macroalgae was negatively correlated with the stream width and the specific conductance.

  20. Climate change and the microbiology of the Antarctic Peninsula region.

    PubMed

    Pearce, David A

    2008-01-01

    Antarctic terrestrial ecosystems are cold, dry, low nutrient environments, with large temperature fluctuations and paradoxically low levels of water availability. These extreme environments are dominated by microorganisms (viruses, archaea, eubacteria, fungi and microsporidia, alveolata, stmramenopila, rhodophyta, green algae and protists), which can either tolerate or are adapted to exploit unfavourable growth conditions. However, climate change is altering the growth environment in Antarctica, and so selection pressures on these microorganisms are changing which, in turn, might affect microbial activity in key processes such as biogeochemical cycling. Although the direct effect of a change in, for example, temperature, is known for very few Antarctic microorganisms, molecular techniques (to monitor population structure) and genomic techniques (to identify specific gene function) are starting to give us an insight into what the potential effects of climate change might be at the cellular level. The key to how microorganisms respond to such change depends upon the rate and magnitude of the change along with the physiological capability of microorganisms to adapt or tolerate those changes. Here we will examine a number of case studies in which the effects of factors such as temperature, nutrient availability, grazing, salinity, seasonal cycle and carbon dioxide concentration have each been demonstrated to affect bacterial community structure in polar and alpine ecosystems. The results suggest that the spatial distribution of genetic variation and, hence, comparative rates of evolution, colonization and extinction are particularly important when considering the response of microbial communities to climate change.

  1. DGDG and Glycolipids in Plants and Algae.

    PubMed

    Kalisch, Barbara; Dörmann, Peter; Hölzl, Georg

    2016-01-01

    Photosynthetic organelles in plants and algae are characterized by the high abundance of glycolipids, including the galactolipids mono- and digalactosyldiacylglycerol (MGDG, DGDG) and the sulfolipid sulfoquinovosyldiacylglycerol (SQDG). Glycolipids are crucial to maintain an optimal efficiency of photosynthesis. During phosphate limitation, the amounts of DGDG and SQDG increase in the plastids of plants, and DGDG is exported to extraplastidial membranes to replace phospholipids. Algae often use betaine lipids as surrogate for phospholipids. Glucuronosyldiacylglycerol (GlcADG) is a further glycolipid that accumulates under phosphate deprived conditions. In contrast to plants, a number of eukaryotic algae contain very long chain polyunsaturated fatty acids of 20 or more carbon atoms in their glycolipids. The pathways and genes for galactolipid and sulfolipid synthesis are largely conserved between plants, Chlorophyta, Rhodophyta and algae with complex plastids derived from secondary or tertiary endosymbiosis. However, the relative contribution of the endoplasmic reticulum- and plastid-derived lipid pathways for glycolipid synthesis varies between plants and algae. The genes for glycolipid synthesis encode precursor proteins imported into the photosynthetic organelles. While most eukaryotic algae contain the plant-like galactolipid (MGD1, DGD1) and sulfolipid (SQD1, SQD2) synthases, the red alga Cyanidioschyzon harbors a cyanobacterium-type DGDG synthase (DgdA), and the amoeba Paulinella, derived from a more recent endosymbiosis event, contains cyanobacterium-type enzymes for MGDG and DGDG synthesis (MgdA, MgdE, DgdA).

  2. Hydrodynamic transport of drifting macroalgae through a tidal cut

    NASA Astrophysics Data System (ADS)

    Biber, Patrick D.

    2007-09-01

    Drifting macroalgae are unattached seaweeds that are commonly found in many South Florida and Gulf of Mexico shallow-water seagrass habitats. They are primarily comprised of species of red algae (Rhodophyta) and some brown algae (Phaeophyta). Because of the unattached nature of these species, drift algae have the ability to be moved around the landscape primarily by tidal, as well as wind-driven and alongshore currents. Numerous invertebrates and some fish species are typically found associated with drift algal clumps and aggregations. Transport of drift algae is an important dispersal mechanism for both the plants and their associated fauna. Dispersal distances have been studied in numerous locations over a range of spatial scales. However, little is known about quantities of algal material that are involved. In this study I report on composition and biomass of drifting algae that are transported through a tidal inlet in Biscayne Bay, Florida. Sargassum (a brown alga) and about 12 genera of red algae were found in three seasonal collections (Aug., Dec., May). Total biomass collected varied among seasons, with larger average amounts of drift algae collected in May than the other two months sampled. From this data, I calculate the approximate quantities of drift algae that are potentially moving in, or out of, Biscayne Bay, about a half to one ton of biomass per day.

  3. dEMBF: A Comprehensive Database of Enzymes of Microalgal Biofuel Feedstock

    PubMed Central

    Misra, Namrata; Panda, Prasanna Kumar; Parida, Bikram Kumar; Mishra, Barada Kanta

    2016-01-01

    Microalgae have attracted wide attention as one of the most versatile renewable feedstocks for production of biofuel. To develop genetically engineered high lipid yielding algal strains, a thorough understanding of the lipid biosynthetic pathway and the underpinning enzymes is essential. In this work, we have systematically mined the genomes of fifteen diverse algal species belonging to Chlorophyta, Heterokontophyta, Rhodophyta, and Haptophyta, to identify and annotate the putative enzymes of lipid metabolic pathway. Consequently, we have also developed a database, dEMBF (Database of Enzymes of Microalgal Biofuel Feedstock), which catalogues the complete list of identified enzymes along with their computed annotation details including length, hydrophobicity, amino acid composition, subcellular location, gene ontology, KEGG pathway, orthologous group, Pfam domain, intron-exon organization, transmembrane topology, and secondary/tertiary structural data. Furthermore, to facilitate functional and evolutionary study of these enzymes, a collection of built-in applications for BLAST search, motif identification, sequence and phylogenetic analysis have been seamlessly integrated into the database. dEMBF is the first database that brings together all enzymes responsible for lipid synthesis from available algal genomes, and provides an integrative platform for enzyme inquiry and analysis. This database will be extremely useful for algal biofuel research. It can be accessed at http://bbprof.immt.res.in/embf. PMID:26727469

  4. Identification of protein N-termini in Cyanophora paradoxa cyanelles: transit peptide composition and sequence determinants for precursor maturation

    PubMed Central

    Köhler, Daniel; Dobritzsch, Dirk; Hoehenwarter, Wolfgang; Helm, Stefan; Steiner, Jürgen M.; Baginsky, Sacha

    2015-01-01

    Glaucophyta, rhodophyta, and chloroplastida represent the three main evolutionary lineages that diverged from a common ancestor after primary endosymbiosis. Comparative analyses between members of these three lineages are a rich source of information on ancestral plastid features. We analyzed the composition and the cleavage site of cyanelle transit peptides from the glaucophyte Cyanophora paradoxa by terminal amine labeling of substrates (TAILS), and compared their characteristics to those of representatives of the chloroplastida. Our data show that transit peptide architecture is similar between members of these two lineages. This entails a comparable modular structure, an overrepresentation of serine or alanine and similarities in the amino acid composition around the processing peptidase cleavage site. The most distinctive difference is the overrepresentation of phenylalanine in the N-terminal 1–10 amino acids of cyanelle transit peptides. A quantitative proteome analysis with periplasm-free cyanelles identified 42 out of 262 proteins without the N-terminal phenylalanine, suggesting that the requirement for phenylalanine in the N-terminal region is not absolute. Proteins in this set are on average of low abundance, suggesting that either alternative import pathways are operating specifically for low abundance proteins or that the gene model annotation is incorrect for proteins with fewer EST sequences. We discuss these two possibilities and provide examples for both interpretations. PMID:26257763

  5. Biofilms on tuff stones at historical sites: identification and removal by nonthermal effects of radiofrequencies.

    PubMed

    Cennamo, P; Caputo, P; Giorgio, A; Moretti, A; Pasquino, N

    2013-10-01

    A methodology aiming at identifying and removing biofilms from cultural heritage was applied to stones from tuff walls in historical sites. Identification of phototrophic encrusting microorganisms was carried out by optical and electron microscopy, as well as by molecular techniques (DNA analyses and denaturing gradient gel electrophoresis (DGGE)). In all sites, the examination of microbial components of biofilms resulted in the identification of 17 species belonging to Cyanobacteria, Rhodophyta, Bacillariophyta and Chlorophyta, with Cyanobacteria being the dominant components in all biofilms. In order to remove the biofilms, an innovative technique based on the use of nonthermal effects of radiofrequencies was adopted. The source of the electromagnetic fields was a signal generator connected to a horn antenna through an amplifier to provide the power boost required to generate the target field amplitude. Seven days after exposure to radiofrequency electromagnetic field, about 50 % reduction of biofilm was observed; after 14 days, biofilm extension was reduced by about 90 %. DGGE analyses performed after 14 days confirmed these visual inspections. Also, DGGE analyses carried out before and 14 days after treatments showed that 12 out of 17 identified species disappeared. A complete visual disappearance of biofilms was observed a month after the beginning of treatments. DGGE repeated at this time confirmed the total disappearance of biofilm-forming species. Treated stones, when transferred back to their original sites, did not show any microorganism re-growing after 6 months. No alteration in the color and structural consistency of tuff substrata was observed after radiofrequency treatments.

  6. Genetic Affinities between Trans-Oceanic Populations of Non-Buoyant Macroalgae in the High Latitudes of the Southern Hemisphere

    PubMed Central

    Fraser, Ceridwen I.; Zuccarello, Giuseppe C.; Spencer, Hamish G.; Salvatore, Laura C.; Garcia, Gabriella R.; Waters, Jonathan M.

    2013-01-01

    Marine biologists and biogeographers have long been puzzled by apparently non-dispersive coastal taxa that nonetheless have extensive transoceanic distributions. We here carried out a broad-scale phylogeographic study to test whether two widespread Southern Hemisphere species of non-buoyant littoral macroalgae are capable of long-distance dispersal. Samples were collected from along the coasts of southern Chile, New Zealand and several subAntarctic islands, with the focus on high latitude populations in the path of the Antarctic Circumpolar Current or West Wind Drift. We targeted two widespread littoral macroalgal species: the brown alga Adenocystisutricularis (Ectocarpales, Heterokontophyta) and the red alga Bostrychiaintricata (Ceramiales, Rhodophyta). Phylogenetic analyses were performed using partial mitochondrial (COI), chloroplast (rbcL) and ribosomal nuclear (LSU / 28S) DNA sequence data. Numerous deeply-divergent clades were resolved across all markers in each of the target species, but close phylogenetic relationships – even shared haplotypes – were observed among some populations separated by large oceanic distances. Despite not being particularly buoyant, both Adenocystisutricularis and Bostrychiaintricata thus show genetic signatures of recent dispersal across vast oceanic distances, presumably by attachment to floating substrata such as wood or buoyant macroalgae. PMID:23894421

  7. Marine flora of the Iles Eparses (Scattered Islands): A longitudinal transect through the Mozambique Channel

    NASA Astrophysics Data System (ADS)

    Mattio, L.; Zubia, M.; Maneveldt, G. W.; Anderson, R. J.; Bolton, J. J.; de Gaillande, C.; De Clerck, O.; Payri, C. E.

    2016-04-01

    The diversity of marine macrophytes of small islands in the South Western Indian Ocean region has been poorly documented and little or no information is available for the Iles Eparses (or Scattered Islands) in the Mozambique Channel. We present the first species checklist for the three largest islands of the Iles Eparses: Europa, Juan de Nova and Glorioso. Overall, with a total of 321 marine macrophyte species recorded (incl. 56% Rhodophyta, 27% Chlorophyta, 15% Phaeophyceae and 2% Magnoliophyta; Europa: 134 spp., Juan de Nova: 157 spp. and Glorioso: 170 spp.) these islands harbour 23.5% of the total species recorded for the Mozambique Channel region. We report 36 new records for the Mozambique Channel including 29 undescribed new and cryptic species. Our results highlight a decrease in species richness southward in the Channel. Because of their longitudinal arrangement between the northern and the southern ends of the Channel and their central position, Europa, Juan de Nova and Glorioso Islands represent data points of particular biogeographical interest and could be critical 'stepping stones' for connectivity in the highly dynamic Mozambique Channel region.

  8. Seasonal variations in biomass and species composition of seaweeds along the northern coasts of Persian Gulf (Bushehr Province)

    NASA Astrophysics Data System (ADS)

    Dadolahi-Sohrab, A.; Garavand-Karimi, M.; Riahi, H.; Pashazanoosi, H.

    2012-02-01

    This study was carried out to evaluate the seasonal variations of seaweed biomass and species composition at six different sites along the coastal areas in Bushehr Province. Sampling depths varied among sites, from 0.3 to 2.0 m below mean sea level. A total of 37 (i.e., 10 Chlorophyta, 12 Phaeophyta and 15 Rhodophyta) seaweed species were collected. Studies were conducted for quantifying the seaweeds during four seasons from October 2008 until July 2009. During present research, Ulva intestinalis and Cladophora nitellopsis of green, Polycladia myrica, Sirophysalia trinodis and Sargassum angustifolium of brown and Gracilaria canaliculata and Hypnea cervicornis of red seaweeds showed highest biomass in coastal areas of Bushehr Province. The Cheney`s ratio of 2.1 indicated a temperate algal flora to this area. All sites exhibited more than 50% similarity of algal species, indicating a relatively homogenous algal distribution. Total biomass showed the highest value of 3280.7 ± 537.8 g dry wt m - 2 during summer and lowest value of 856.9 ± 92.0 g dry wt m - 2 during winter. During this study, the highest and lowest seaweed biomass were recorded on the site 2 (2473.7 ± 311.0 g dry wt m - 2) and site 5 (856.7 ± 96.8 g dry wt m - 2), respectively.

  9. Screening of agglutinins in marine algae from Fujian coast of China

    NASA Astrophysics Data System (ADS)

    Zheng, Yi; Lu, Hai-Sheng

    2002-09-01

    Thirty-three species of marine algae belonging to Rhodophyta, Phaeophyta and Chlorophyta from the Fujian coast were examined for agglutinins with different animal and human erythrocytes. Protein extracts from 26 species were active against at least one type of the erythrocytes tested. There were 3 species ( Grateloupia imbricata, Ishige foliacea and Entermorpha prolifera) whose extracts could agglutimate all the erythrocytes used. The lowest protein concentration required to produce erythrocyte agglutination varied remarkably, from 3.1 μg/ml to 500 μg/ml. The strongest activity was found in the agglutination of rabbit erythrocytes by Gloiopeltis furcata extract. Inhibition assays performed with nine mono- and bisaccharides indicated that agglutinations of rabbit erythrocytes by extracts of 7 species were inhibited by one or more types of the sugars assayed. The agglutinating activity shown by extracts of most species was not affected when the test solution was heated to 90°C, but was lost at 95°C 100°C. A few extracts lost their activity at 60°C, 65°C and 75°C, respectively.

  10. Biomass and Habitat Characteristics of Epiphytic Macroalgae in the Sibuti Mangroves, Sarawak, Malaysia

    PubMed Central

    Isa, Hasmidah Md; Kamal, Abu Hena Mustafa; Idris, Mohd Hanafi; Rosli, Zamri; Ismail, Johan

    2017-01-01

    Mangroves support diverse macroalgal assemblages as epibionts on their roots and tree trunks. These algae provide nutrients to the primary consumers in the aquatic food web and have been reported to be substantial contributors to marine ecosystems. The species diversity, biomass, and habitat characteristics of mangrove macroalgae were investigated at three stations in the Sibuti mangrove estuary, Sarawak, Malaysia, from November 2012 to October 2013. Three groups of macroalgae were recorded and were found to be growing on mangrove prop roots, namely Rhodophyta (Caloglossa ogasawaraensis, Caloglossa adhaerens, Caloglossa stipitata, Bostrychia anomala, and Hypnea sp.), Chlorophyta (Chaetomorpha minima and Chaetomorpha sp.), and Phaeophyta (Dictyota sp.). The biomass of macroalgae was not influenced (p>0.05) by the season in this mangrove forest habitat. The macroalgal species Hypnea sp. contributed the highest biomass at both Station 1 (210.56 mg/cm2) and Station 2 (141.72 mg/cm2), while the highest biomass was contributed by B. anomala (185.89 mg/cm2) at Station 3. This study shows that the species distribution and assemblages of mangrove macroalgae were influenced by environmental parameters such as water nutrients, dissolved solids, and salinity in the estuarine mangrove habitats of Sibuti, Sarawak. PMID:28228913

  11. Temporal and spatial variations in the distribution of macroalgal communities along the Yantai coast, China

    NASA Astrophysics Data System (ADS)

    Han, Qiuying; Liu, Dongyan

    2014-05-01

    To explore the impact of environmental variables on macroalgal their temporal and spatial distributions were examined along the Yantai coast, China between April 2010 and March 2011. Macroalgae sampling was conducted monthly at four sites along the coast: Jiahe River estuary, Zhifu Island, Fisherman's Wharf, and Yangma Island. The species composition and abundance, and their relationship with environmental variables were assessed. Along the Yantai coast, 35 macroalgae species were identified, including 24 Rhodophyta spp., 7 Chlorophyta, and 4 Phaeophyta spp. Highest species numbers were recorded in the summer at all sampling sites, except in the Jiahe River estuary. Macroalgae biomass was the greatest in the summer. Year-round, the highest species number and dry biomass recorded at Fisherman's Wharf and Yangma Island was attributed to the substrate type. In summer, Ulva pertusa Kjellman was the dominant species identified along the Yantai coast, which indicates a risk of macroalgae blooms. Our results show that seawater temperature and nutrients appear to significantly affect the temporal and spatial patterns of macroalgal abundance along the Yantai coast. The effects of environmental variables on the macroalgae on the Yantai coast need further study.

  12. Isolation, expression and characterization of rbcL gene from Ulva prolifera J. Agardh (Ulvophyceae, Chlorophyta)

    NASA Astrophysics Data System (ADS)

    Shao, Zhanru; Li, Wei; Guo, Hui; Duan, Delin

    2015-12-01

    Ulva prolifera is a typical green alga in subtidal areas and can grow tremendously fast. A highly efficient Rubisco enzyme which is encoded by UpRbcL gene may contribute to the rapid growth. In this study, the full-length UpRbcL open reading frame (ORF) was identified, which encoded a protein of 474 amino acids. Phylogenetic analysis of UpRbcL sequences revealed that Chlorophyta had a closer genetic relationship with higher plants than with Rhodophyta and Phaeophyta. The two distinct residues (aa11 and aa91) were presumed to be unique for Rubisco catalytic activity. The predicted three-dimensional structure showed that one α/β-barrel existed in the C-terminal region, and the sites for Mg2+ coordination and CO2 fixation were also located in this region. Gene expression profile indicated that UpRbcL was expressed at a higher level under light exposure than in darkness. When the culture temperature reached 35°C, the expression level of UpRbcL was 2.5-fold lower than at 15°C, and the carboxylase activity exhibited 13.8-fold decrease. UpRbcL was heterologously expressed in E. coli and was purified by Ni2+ affinity chromatography. The physiological and biochemical characterization of recombinant Rubisco will be explored in the future.

  13. Seasonal variation in biomass and species composition of seaweeds stranded along Port Okha, northwest coast of India

    NASA Astrophysics Data System (ADS)

    Thakur, Mukund C.; Reddy, C. R. K.; Jha, Bhavanath

    2008-06-01

    Port Okha coast, which is known for its luxuriant growth of a diverse assemblage of seaweeds on Saurashtra coast, is found to have abundant quantities of seaweeds being drifted and washed ashore every year. Studies conducted for quantifying the stranded seaweeds from May 2004 to April 2005 showed an average biomass value of 3.10 kg fresh wt/m2/month with maximum being 6.60 kg fresh wt/m2 in April. The stranded weeds constituted a total of 62 species during the entire study period. Of this, Rhodophyta ranked high with 26 species followed by Chlorophyta with 22 species and Phaeophyta with 14 species. The stranded seaweeds that were washed ashore provide valuable floristic information about the intertidal and near shore sub-tidal algae of the respective regions. Although natural senescence of seaweeds is one of the major factors, strong currents primarily forced by tides, also contribute to the uprooting and subsequent drifting of seaweeds on to the beach. This ultimately causes changes in floristic features of the existing algal beds.

  14. Precambrian palaeontology in the light of molecular phylogeny - an example: the radiation of the green algae

    NASA Astrophysics Data System (ADS)

    Teyssèdre, B.

    2007-09-01

    The problem of the antiquity of the radiation of the green algae (phylum Viridiplantae) has been hotly debated and is still controversial today. A method combining Precambrian paleontology and molecular phylogeny is applied to shed light on this topic. As a critical method, molecular phylogeny is essential for avoiding taxonomic mistakes. As a heuristic method, it helps us to discern to what extent the presence of such and such clade is likely at such and such time, and it may even suggest the attribution of some fossil to a clade whose taxonomic position will be distinctly defined even though it has no previously known representative. Some well characterized Precambrian fossils of green algae are Palaeastrum and Proterocladus at Svanbergfjellet (ca. 750 Ma), Tasmanites and Pterospermella at Thule (ca. 1200 Ma), Spiromorpha at Ruyang (ca. 1200 Ma) and Leiosphaeridia crassa at Roper (ca. 1450 Ma). The position of these fossils in the taxonomy and the phylogeny of the Viriplantae is discussed. The conclusions are that the Chlorophyceae and the Ulvophyceae were separated long before 750 Ma, that the Chlorophyta and the Streptophyta were separated long before 1200 Ma and that the last common ancestor of the Viridiplantae and the Rhodophyta was possibly two billion years old.

  15. Main nutritional contents of 30 Dalian coastal microalgae species

    NASA Astrophysics Data System (ADS)

    Su, Xiurong; Liu, Huihui; Chen, Kwan Paul

    2004-12-01

    This paper reports results of study on the contents of proteins, amino acids, polysaccharose and uronic acids in 30 species of macroalgae from Shicao, Heishijiao, Shimiao, and Xiaofujiazhuang in the vicinity of Dalian City, N.E.China. The results showed that the protein contents of the 30 algae from highest (112.55 μ g/ml) to the lowest (0.24 μg/ml) was in the descending order of Dictyopteris ndalata, Gelidium vagum, Gymnogongrus japonican, Ectocarpus confervoides, Tinocladia crassa, Sargassum thunberii. In general, the protein content in red algae was higher than that in brown algae. The content of free amino acids showed no significent differences from 7.44 μg/ml4.96 μg/ml in all these algae, in the descending order of Gymnogongrus japonican, Sargassum confusum, Undoria pinnatifida, Laminaria japonica and Ectocarpus confervoides. The content of polysaccharose varied from 168.2 μ/ml-22.15 μg/ml in the descending order of Symphocladia latiuscula, Scytosiphon lomentarius, Desmarestia viridis., Tinocladia crassa, Gracilaria asiatica and Porphyra yezoensis. The content of uronic acids is from 196.24μg/ml-20.77 μg/ml in the descending order of Ulva lactuca, Symphyoclaldia latiuscula, Scytosiphon lomentarius, Ceramimum kodoi, Gracilaria vemucosa and Porphyra yezoensis. The fatty acids in 30 species of algae belong to Rhodophyta, Chlorophyta and Phaeophyta. Most phaeophytes have many (4 12) types of fatty acids.

  16. Thermochemical conversion pathways of Kappaphycus alvarezii granules through study of kinetic models.

    PubMed

    Das, Prasanta; Mondal, Dibyendu; Maiti, Subarna

    2017-03-10

    Kappaphycus alvarezii seaweed belongs to the class of red alga (Rhodophyta). The granules obtained after recovery of "sap" (liquid plant stimulant) from freshly harvested alga is a promising biomass feedstock for energy application. Herein we report the kinetic behaviour of the granules using thermogravimetric analysis (TGA) at different heating rates in N2 atmosphere and thermogravimetric-mass spectrometry (TG-MS) analysis. Sawdust as lignocellulosic biomass is considered for comparative study. Four different kinetic models (i) multilinear regression technique, (ii) Friedman method, (iii) Flynn-Wall-Ozawa (FWO) method and (iv) Kissinger-Akahira-Sunose (KAS) method are used to evaluate the apparent activation energy (Ea), the pre-exponential factor (Aα) and the overall reaction order (n). Maximum SO2 peak at 300°C and 950°C (from TG-MS), indicates that slow pyrolysis at 500°C, with a packed bed lime scrubber at the outlet during temperature rise, is the best suited thermochemical pathway for energy harnessing.

  17. Genome-wide identification of transcription factors and transcription-factor binding sites in oleaginous microalgae Nannochloropsis

    PubMed Central

    Hu, Jianqiang; Wang, Dongmei; Li, Jing; Jing, Gongchao; Ning, Kang; Xu, Jian

    2014-01-01

    Nannochloropsis spp. are a group of oleaginous microalgae that harbor an expanded array of lipid-synthesis related genes, yet how they are transcriptionally regulated remains unknown. Here a phylogenomic approach was employed to identify and functionally annotate the transcriptional factors (TFs) and TF binding-sites (TFBSs) in N. oceanica IMET1. Among 36 microalgae and higher plants genomes, a two-fold reduction in the number of TF families plus a seven-fold decrease of average family-size in Nannochloropsis, Rhodophyta and Chlorophyta were observed. The degree of similarity in TF-family profiles is indicative of the phylogenetic relationship among the species, suggesting co-evolution of TF-family profiles and species. Furthermore, comparative analysis of six Nannochloropsis genomes revealed 68 “most-conserved” TFBS motifs, with 11 of which predicted to be related to lipid accumulation or photosynthesis. Mapping the IMET1 TFs and TFBS motifs to the reference plant TF-“TFBS motif” relationships in TRANSFAC enabled the prediction of 78 TF-“TFBS motif” interaction pairs, which consisted of 34 TFs (with 11 TFs potentially involved in the TAG biosynthesis pathway), 30 TFBS motifs and 2,368 regulatory connections between TFs and target genes. Our results form the basis of further experiments to validate and engineer the regulatory network of Nannochloropsis spp. for enhanced biofuel production. PMID:24965723

  18. Isolation and characterization of agar-digesting Vibrio species from the rotten thallus of Gracilariopsis heteroclada Zhang et Xia.

    PubMed

    Martinez, Joval N; Padilla, Philip Ian P

    2016-08-01

    Gracilariopsis heteroclada Zhang et Xia (Gracilariaceae, Rhodophyta) is one of the most studied marine seaweeds due to its economic importance. This has been cultivated extensively on commercial scale in the Philippines and other Asian countries. However, sustainable production of G. heteroclada in the Philippines could not be maximized due to the occurrence of rotten thallus disease. Thus, isolation and characterization of agar-digesting bacteria from the rotten thalli of G. heteroclada was conducted. A total of seven representative bacterial isolates were randomly selected based on their ability to digest agar as evidenced by the formation of depressions around the bacterial colonies on nutrient agar plates supplemented with 1.5% NaCl and liquefaction of agar. Gram-staining and biochemical characterization revealed that isolates tested were gram-negative rods and taxonomically identified as Vibrio parahaemolyticus (86-99.5%) and Vibrio alginolyticus (94.2-97.7%), respectively. It is yet to be confirmed whether these agar-digesting vibrios are involved in the induction and development of rotten thallus disease in G. heteroclada in concomitance with other opportunistic bacterial pathogens coupled with adverse environmental conditions.

  19. Distribution of Sargassum natans and some of its epibionts in the Sargasso Sea

    NASA Astrophysics Data System (ADS)

    Niermann, U.

    1986-12-01

    Sargassum was collected during the Sargasso Sea Eel Expedition in Spring 1979. On average, the morphological form type Sargassum natans (I) made up 85 % of the total wet weight of the samples. South of the thermal front, larger amounts of weeds were observed. Here, the bladder size of S. natans (I) was significantly smaller (surface 47±7 mm2) than in the northern part (surface: 64±15 mm2), while phylloids showed no differences. The composition and density of some epibionts were examined. Membranipora tuberculata (Bryozoa), Clytia noliformis (Hydrozoa) and the calcarious algae “ Melobesia sp.” (Rhodophyta) were studied quantitatively according to different features at 17 stations. M. tuberculata was the most abundant epibiont followed by C. noliformis. Compared with these species, " Melobesia sp." occurred in considerably lower quantities. M. tuberculata showed a preference for bladders rather than phylloids; C. noliformis was found more frequently on phylloids than on bladders. " Melobesia sp." did not show any preference. Frequency and abundance of these epibionts were higher north of the thermal front than south of this front. North of the front S. natans (I) was less abundant but bladders were larger.

  20. The effect of nutrient enrichment on the growth, nucleic acid concentrations, and elemental stoichiometry of coral reef macroalgae

    PubMed Central

    Reef, Ruth; Pandolfi, John M; Lovelock, Catherine E

    2012-01-01

    The growth rate hypothesis (GRH) links growth rates with organism elemental stoichiometry. Support for the GRH was found for many animal species, but less so for plants. This is the first study to test the GRH in macroalgae. Tropical coral reef macroalgae from three lineages, Caulerpa serrulata (Chlorophyta), Laurencia intricata (Rhodophyta), and Sargassum polyphyllum (Phaeophyceae) were grown enriched with nitrogen or phosphorous and under control conditions at Heron Island on the Great Barrier Reef, Australia. Growth rate, photosynthesis, nucleic acid composition, and elemental stoichiometry were measured. Nutrient enrichment had positive effects on photosynthetic rates and on investment in RNA. However, growth rate was not correlated with either photosynthetic rates or RNA content; thus, we did not find support for the GRH in tropical macroalgae. Macroalgae, especially L. intricata, accumulated P to very high levels (>0.6% of dry weight). The growth rate response to tissue P concentrations was unimodal. Above 0.21%, P accumulation had negative effects on growth. Nitrogen was not stored, but evidence of futile cycling was observed. The capacity to store large amounts of P is probably an adaptation to the low and patchy nutrient environment of the tropical oceans. PMID:22957199

  1. Overview on Biological Activities and Molecular Characteristics of Sulfated Polysaccharides from Marine Green Algae in Recent Years

    PubMed Central

    Wang, Lingchong; Wang, Xiangyu; Wu, Hao; Liu, Rui

    2014-01-01

    Among the three main divisions of marine macroalgae (Chlorophyta, Phaeophyta and Rhodophyta), marine green algae are valuable sources of structurally diverse bioactive compounds and remain largely unexploited in nutraceutical and pharmaceutical areas. Recently, a great deal of interest has been developed to isolate novel sulfated polysaccharides (SPs) from marine green algae because of their numerous health beneficial effects. Green seaweeds are known to synthesize large quantities of SPs and are well established sources of these particularly interesting molecules such as ulvans from Ulva and Enteromorpha, sulfated rhamnans from Monostroma, sulfated arabinogalactans from Codium, sulfated galacotans from Caulerpa, and some special sulfated mannans from different species. These SPs exhibit many beneficial biological activities such as anticoagulant, antiviral, antioxidative, antitumor, immunomodulating, antihyperlipidemic and antihepatotoxic activities. Therefore, marine algae derived SPs have great potential for further development as healthy food and medical products. The present review focuses on SPs derived from marine green algae and presents an overview of the recent progress of determinations of their structural types and biological activities, especially their potential health benefits. PMID:25257786

  2. dEMBF: A Comprehensive Database of Enzymes of Microalgal Biofuel Feedstock.

    PubMed

    Misra, Namrata; Panda, Prasanna Kumar; Parida, Bikram Kumar; Mishra, Barada Kanta

    2016-01-01

    Microalgae have attracted wide attention as one of the most versatile renewable feedstocks for production of biofuel. To develop genetically engineered high lipid yielding algal strains, a thorough understanding of the lipid biosynthetic pathway and the underpinning enzymes is essential. In this work, we have systematically mined the genomes of fifteen diverse algal species belonging to Chlorophyta, Heterokontophyta, Rhodophyta, and Haptophyta, to identify and annotate the putative enzymes of lipid metabolic pathway. Consequently, we have also developed a database, dEMBF (Database of Enzymes of Microalgal Biofuel Feedstock), which catalogues the complete list of identified enzymes along with their computed annotation details including length, hydrophobicity, amino acid composition, subcellular location, gene ontology, KEGG pathway, orthologous group, Pfam domain, intron-exon organization, transmembrane topology, and secondary/tertiary structural data. Furthermore, to facilitate functional and evolutionary study of these enzymes, a collection of built-in applications for BLAST search, motif identification, sequence and phylogenetic analysis have been seamlessly integrated into the database. dEMBF is the first database that brings together all enzymes responsible for lipid synthesis from available algal genomes, and provides an integrative platform for enzyme inquiry and analysis. This database will be extremely useful for algal biofuel research. It can be accessed at http://bbprof.immt.res.in/embf.

  3. Divergence time estimates and the evolution of major lineages in the florideophyte red algae

    PubMed Central

    Yang, Eun Chan; Boo, Sung Min; Bhattacharya, Debashish; Saunders, Gary W.; Knoll, Andrew H.; Fredericq, Suzanne; Graf, Louis; Yoon, Hwan Su

    2016-01-01

    The Florideophyceae is the most abundant and taxonomically diverse class of red algae (Rhodophyta). However, many aspects of the systematics and divergence times of the group remain unresolved. Using a seven-gene concatenated dataset (nuclear EF2, LSU and SSU rRNAs, mitochondrial cox1, and plastid rbcL, psaA and psbA genes), we generated a robust phylogeny of red algae to provide an evolutionary timeline for florideophyte diversification. Our relaxed molecular clock analysis suggests that the Florideophyceae diverged approximately 943 (817–1,049) million years ago (Ma). The major divergences in this class involved the emergence of Hildenbrandiophycidae [ca. 781 (681–879) Ma], Nemaliophycidae [ca. 661 (597–736) Ma], Corallinophycidae [ca. 579 (543–617) Ma], and the split of Ahnfeltiophycidae and Rhodymeniophycidae [ca. 508 (442–580) Ma]. Within these clades, extant diversity reflects largely Phanerozoic diversification. Divergences within Florideophyceae were accompanied by evolutionary changes in the carposporophyte stage, leading to a successful strategy for maximizing spore production from each fertilization event. Our research provides robust estimates for the divergence times of major lineages within the Florideophyceae. This timeline was used to interpret the emergence of key morphological innovations that characterize these multicellular red algae. PMID:26892537

  4. Characterization and Comparison of the Structural Features, Immune-Modulatory and Anti-Avian Influenza Virus Activities Conferred by Three Algal Sulfated Polysaccharides

    PubMed Central

    Song, Lin; Chen, Xiaolin; Liu, Xiaodong; Zhang, Fubo; Hu, Linfeng; Yue, Yang; Li, Kecheng; Li, Pengcheng

    2015-01-01

    Three marine macroalgae, i.e., Grateloupia filicina, Ulva pertusa and Sargassum qingdaoense, were selected as the deputies of Rhodophyta, Chlorophyta and Ochrophyta for comparative analysis of the molecular structures and biological activities of sulfated polysaccharides (SP). The ratio of water-soluble polysaccharides, the monosaccharide composition and the sulfated contents of three extracted SPs were determined, and their structures were characterized by Fourier transformation infrared spectroscopy. In addition, biological activity analysis showed that all three SPs had immune-modulatory activity both in vitro and in vivo, and SPs from S. qingdaoense had the best effect. Further bioassays showed that three SPs could not only enhance the immunity level stimulated by inactivated avian influenza virus (AIV) in vivo but also significantly inhibited the activity of activated AIV (H9N2 subtype) in vitro. G. filicina SP exhibited the strongest anti-AIV activity. These results revealed the variations in structural features and bioactivities among three SPs and indicated the potential adjuvants for immune-enhancement and anti-AIV. PMID:26729137

  5. Macroalgae of Izmir Gulf: Dictyotaceae exhibit high in vitro anti-cancer activity independent from their antioxidant capabilities.

    PubMed

    Çelenk, Fatma Gül; Özkaya, Ali Burak; Sukatar, Atakan

    2016-12-01

    In this study, 24 marine macroalgae collected from the coastline of Izmir Gulf were examined for their antioxidant activities and their effects on cell proliferation. Crude extracts were obtained from samples with cold methanol extraction. Antioxidant activity was evaluated as 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging activity and total phenolic content (TPC); growth inhibitory effects of the extracts were determined by using WST-8. Amongst the species, Polysiphonia denuata (Rhodophyta) and Cystoseira species (Phaeophyceae) have been noticed by their high DPPH radical scavenging activities and TPCs. As expected, there was a strong correlation between these tests. Dictyota dichotoma (Phaeophyceae) showed the highest anti-cancer activity on MCF-7 cells with an IC50 of 17.2 ng mL(-1). Flow cytometry analyses demonstrated that D. dichotoma methanolic extract strongly induced apoptosis. This extract exhibited moderate viability inhibition on MCF10A cells (IC50: 49.3 ng mL(-1)), suggesting a potential use of the extracts or its compounds for cancer therapy. There was no correlation between anti-cancer potential and antioxidant content of the extracts.

  6. Effects of different light conditions on repair of UV-B-induced damage in carpospores of Chondrus ocellatus Holm

    NASA Astrophysics Data System (ADS)

    Ju, Qing; Xiao, Hui; Wang, You; Tang, Xuexi

    2015-05-01

    We evaluated the effects of ultraviolet-B (UV-B) radiation and different light conditions on the repair of UV-B-induced damage in carpospores of Chondrus ocellatus Holm (Rhodophyta) in laboratory experiments. Carpospores were treated daily with different doses of UV-B radiation for 48 days, when vertical branches had formed in all treatments; after each daily treatment, the carpospores were subjected to photosynthetically active radiation (PAR), darkness, red light, or blue light during a 2-h repair stage. Carpospore diameters were measured every 4 days. We measured the growth and cellular contents of cyclobutane pyrimidine dimers (CPDs), chlorophyll a, phycoerythrin, and UV-B-absorbing mycosporine-like amino acids (MAAs) in carpospores on Day 48. Low doses of UV-B radiation (36 and 72 J/m2) accelerated the growth of C. ocellatus. However, as the amount of UV-B radiation increased, the growth rate decreased and morphological changes occurred. UV-B radiation significant damaged DNA and photosynthetic pigments and induced three kind of MAAs, palythine, asterina-330, and shinorine. PAR conditions were best for repairing UV-B-induced damage. Darkness promoted the activity of the DNA darkrepair mechanism. Red light enhanced phycoerythrin synthesis but inhibited light repair of DNA. Although blue light, increased the activity of DNA photolyase, greatly improving remediation efficiency, the growth and development of C. ocellatus carpospores were slower than in other light treatments.

  7. Sterols from the red algae, Gracilaria salicornia and Hypnea flagelliformis, from Persian Gulf

    PubMed Central

    Nasir, Masoumeh; Saeidnia, Soodabeh; Mashinchian-Moradi, Ali; Gohari, Ahmad R.

    2011-01-01

    Context: Two of the important algae from Persian Gulf are Gracilaria salicornia and Hypnea flageliformis (Rhodophyta). Antibacterial, antifungal, and cytotoxic effects of the mentioned algae have been presented in the previous studies. Aim: In this study, the isolation and structural elucidation of the sterols from these algae are reported. Materials and Methods: The separation and purification of the compounds were carried out with silica gel, sephadex LH20 column chromatography (CC) and HPLC to obtain six pure compounds 1-6. The structural elucidation of the constituents was based on the data obtained from H-NMR,13C-NMR, HMBC, HSQC, DEPT, and EI-MS. Results: The isolated compounds from G. salicornia were identified as 22-dehydrocholesterol (1), cholesterol (2), oleic acid (3), and stigmasterol (4), and the isolated constituents from H. flagelliformis were identified as 22-dehydrocholesterol (1), cholesterol (2), oleic acid (3), cholesterol oleate (5), and (22E)-cholesta-5,22-dien-3β-ol-7-one (6) based on the spectral data compared to those reported in the literature. Conclusion: Red algae are enriched with cholesterol polysaccharides. We first reported the presence of cholesteryl oleate and (22E)-cholesta-5,22-dien-3β-ol-7-one in H. flagelliformis. PMID:21716930

  8. Larvicidal Activity against Aedes aegypti and Molluscicidal Activity against Biomphalaria glabrata of Brazilian Marine Algae.

    PubMed

    Guedes, Elíca Amara Cecília; de Carvalho, Cenira M; Ribeiro Junior, Karlos Antonio Lisboa; Lisboa Ribeiro, Thyago Fernando; de Barros, Lurdiana Dayse; de Lima, Maria Raquel Ferreira; Prado Moura, Flávia de Barros; Goulart Sant'ana, Antônio Euzebio

    2014-01-01

    This study investigated the biological activities of five benthic marine algae collected from Northeastern Region of Brazil. The tested activities included larvicidal activity against Aedes aegypti, molluscicidal activity against Biomphalaria glabrata, and toxicity against Artemia salina. Extracts of Ulva lactuca (Chlorophyta), Padina gymnospora, Sargassum vulgare (Phaeophyta), Hypnea musciformis, and Digenea simplex (Rhodophyta) were prepared using different solvents of increasing polarity, including dichloromethane, methanol, ethanol, and water. Of the extracts screened, the dichloromethane extracts of H. musciformis and P. gymnospora exhibited the highest activities and were subjected to bioassay-guided fractionation in hexane and chloroform. The chloroform fractions of the P. gymnospora and H. musciformis extracts showed molluscicidal activity at values below 40  μ g·mL(-1) (11.1460  μ g·mL(-1) and 25.8689  μ g·mL(-1), resp.), and the chloroform and hexane fractions of P. gymnospora showed larvicidal activity at values below 40  μ g·mL(-1) (29.018  μ g·mL(-1) and 17.230  μ g·mL(-1), resp.). The crude extracts were not toxic to A. salina, whereas the chloroform and hexane fractions of P. gymnospora (788.277  μ g·mL(-1) and 706.990  μ g·mL(-1)) showed moderate toxicity, indicating that the toxic compounds present in these algae are nonpolar.

  9. Carrageenan as a dry strength additive for papermaking

    PubMed Central

    Liu, Zhenhua; Li, Xinping; Xie, Wei

    2017-01-01

    Carrageenans are commercially important sulfated gums found in various species of red seaweeds (Rhodophyta), wherein they serve a structural function similar to that of pectins in land plants. In this study, carrageenan was used independently or in combination with cationic polyacrylamide (CPAM) and/or Al2(SO4)3 to explore its application as a dry strength additive in papermaking. Strength index determination, ash content detection, FTIR characterization and SEM observation were performed on prepared handsheets. The results showed that with 0.6% Al2(SO4)3 and 0.2% carrageenan as additives, the tensile index increased by 13.53% and precipitated calcium carbonate (PCC) retention increased by 57.06%. With 0.6% Al2(SO4)3, 0.2% carrageenan and 0.03% CPAM as additives, PCC retention increased by 121% while the tensile index did not fall compared to handsheets without additives, indicating that carrageenan could enhance the strength of handsheets and be used as an anionic dry strength agent. PMID:28170422

  10. Asparagopsis armata and Sphaerococcus coronopifolius as a natural source of antimicrobial compounds.

    PubMed

    Pinteus, Susete; Alves, Celso; Monteiro, Hugo; Araújo, Ernesto; Horta, André; Pedrosa, Rui

    2015-03-01

    Methanol, n-hexane and dichloromethane extracts of twelve marine macro-algae (Rhodophyta, Chlorophyta and Heterokontophyta divisions) from Peniche coast (Portugal) were evaluated for their antibacterial and antifungal activity. The antibacterial activity was evaluated by disc diffusion method against Bacillus subtilis (gram positive bacteria) and Escherichia coli (gram negative bacteria). Saccharomyces cerevisiae was used as a model for the antifungal activity by evaluating the growth inhibitory activity of the extracts. The high antibacterial activity was obtained by the Asparagopsis armata methanolic extract (10 mm-0.1 mg/disc), followed by the Sphaerococcus coronopifolius n-hexane extract (8 mm-0.1 mg/disc), and the Asparagopsis armata dichloromethane extract (12 mm-0.3 mg/disc) against Bacillus subtilis. There were no positive results against Escherichia coli. Sphaerococcus coronopifolius revealed high antifungal potential for n-hexane (IC50 = 40.2 µg/ml), dichloromethane (IC50 = 78.9 µg/ml) and methanolic (IC50 = 55.18 µg/ml) extracts against Saccharomyces cerevisiae growth. The antifungal potency of the Sphaerococcus coronopifolius extracts was similar with the standard amphotericin B. Asparagopsis armata and Sphaerococcus coronopifolius reveal to be interesting sources of natural compounds with antimicrobial properties.

  11. [Punta Cocles coral reef, Caribbean Coast of Costa Rica].

    PubMed

    Fernández, Cindy; Alvarado, Juan José

    2004-12-01

    This paper describes the Punta Cocles reef (Limón, Costa Rica). Data were obtained by sampling nine transects along the coast and observations done by skin diving between September and November of 2002. This reef consist of 10.5 hectares, where 13 species of corals, 39 of macroalgae, two of seagrasses, two of zoantids, one anemone, one corallimorpharian, and one sponge were identified. Life coral coverage (16%), was higher than in other years (5% for 1985, and 13.2% for 1995), and death coral coverage was very low (0.2%). Macroalgae have the highest coverage (59%), particularly brown algae with a patchy distribution of Sargassum and Padina. Laurencia brongniartii (Rhodophyta) is added to the list of marine flora of Costa Rica. The Punta Cocles reef works as a refuge for organisms, because there are no towns or river mouths nearby, and because of the coast formation. The refuge character is enhanced by the environmental conscience of the people that live close to the reef and help to protect the environment.

  12. Selection of effective macroalgal species and tracing nitrogen sources on the different part of Yantai coast, China indicated by macroalgal δ(15)N values.

    PubMed

    Wang, Yujue; Liu, Dongyan; Richard, Pierre; Di, Baoping

    2016-01-15

    To determine the dominant nitrogen sources and select effective macroalgal species for monitoring eutrophication along the Yantai coast, the total carbon (TOC), total nitrogen (TN) and nitrogen stable isotope ratio (δ(15)N) in macroalgal tissue were analyzed in conjunction with environmental variables in seawater along the Yantai coastline. The ranges of macroalgal tissue δ(15)N values together with dissolved inorganic nitrogen (DIN) composition indicated that except for the atmospheric deposition, there were three dominant types of nitrogen sources along the Yantai coast, with the agricultural fertilizer usage and factorial wastewater input at the S1 (Zhifu Island coast), the sewage discharge at S2 (the Moon Bay coast), the sewage discharge together with aquaculture impacts at S3 (Fisherman Wharf coast) and S4 (the Horse Island coast). Macroalgal growth were not limited by DIN but limited by P at S2, S3 and S4. Macroalgal species suitable or not for DIN source tracing along the Yantai coast were discussed. For sites with low DIN concentration, many species of three phyla could be used for DIN sources tracing with Laurencia okamurai, Gloiopeltis furcata and Ulva pertusa being ideal species. For site with high DIN concentration, however, species of Rhodophyta were not suitable and only Scytosiphon lomentaria and Monostroma nitidium were chosen.

  13. The effect of nutrient enrichment on the growth, nucleic acid concentrations, and elemental stoichiometry of coral reef macroalgae.

    PubMed

    Reef, Ruth; Pandolfi, John M; Lovelock, Catherine E

    2012-08-01

    The growth rate hypothesis (GRH) links growth rates with organism elemental stoichiometry. Support for the GRH was found for many animal species, but less so for plants. This is the first study to test the GRH in macroalgae. Tropical coral reef macroalgae from three lineages, Caulerpa serrulata (Chlorophyta), Laurencia intricata (Rhodophyta), and Sargassum polyphyllum (Phaeophyceae) were grown enriched with nitrogen or phosphorous and under control conditions at Heron Island on the Great Barrier Reef, Australia. Growth rate, photosynthesis, nucleic acid composition, and elemental stoichiometry were measured. Nutrient enrichment had positive effects on photosynthetic rates and on investment in RNA. However, growth rate was not correlated with either photosynthetic rates or RNA content; thus, we did not find support for the GRH in tropical macroalgae. Macroalgae, especially L. intricata, accumulated P to very high levels (>0.6% of dry weight). The growth rate response to tissue P concentrations was unimodal. Above 0.21%, P accumulation had negative effects on growth. Nitrogen was not stored, but evidence of futile cycling was observed. The capacity to store large amounts of P is probably an adaptation to the low and patchy nutrient environment of the tropical oceans.

  14. Impact of seaweed beachings on dynamics of δ(15)N isotopic signatures in marine macroalgae.

    PubMed

    Lemesle, Stéphanie; Mussio, Isabelle; Rusig, Anne-Marie; Menet-Nédélec, Florence; Claquin, Pascal

    2015-08-15

    A fine-scale survey of δ(15)N, δ(13)C, tissue-N in seaweeds was conducted using samples from 17 sampling points at two sites (Grandcamp-Maisy (GM), Courseulles/Mer (COU)) along the French coast of the English Channel in 2012 and 2013. Partial triadic analysis was performed on the parameter data sets and revealed the functioning of three areas: one estuary (EstA) and two rocky areas (GM(∗), COU(∗)). In contrast to oceanic and anthropogenic reference points similar temporal dynamics characterized δ(15)N signatures and N contents at GM(∗) and COU(∗). Nutrient dynamics were similar: the N-concentrations in seawater originated from the River Seine and local coastal rivers while P-concentrations mainly from these local rivers. δ(15)N at GM(∗) were linked to turbidity suggesting inputs of autochthonous organic matter from large-scale summer seaweed beachings made up of a mixture of Rhodophyta, Phaeophyta and Chlorophyta species. This study highlights the coupling between seaweed beachings and nitrogen sources of intertidal macroalgae.

  15. Analysis of Porphyra membrane transporters demonstrates gene transfer among photosynthetic eukaryotes and numerous sodium-coupled transport systems.

    PubMed

    Chan, Cheong Xin; Zäuner, Simone; Wheeler, Glen; Grossman, Arthur R; Prochnik, Simon E; Blouin, Nicolas A; Zhuang, Yunyun; Benning, Christoph; Berg, Gry Mine; Yarish, Charles; Eriksen, Renée L; Klein, Anita S; Lin, Senjie; Levine, Ira; Brawley, Susan H; Bhattacharya, Debashish

    2012-04-01

    Membrane transporters play a central role in many cellular processes that rely on the movement of ions and organic molecules between the environment and the cell, and between cellular compartments. Transporters have been well characterized in plants and green algae, but little is known about transporters or their evolutionary histories in the red algae. Here we examined 482 expressed sequence tag contigs that encode putative membrane transporters in the economically important red seaweed Porphyra (Bangiophyceae, Rhodophyta). These contigs are part of a comprehensive transcriptome dataset from Porphyra umbilicalis and Porphyra purpurea. Using phylogenomics, we identified 30 trees that support the expected monophyly of red and green algae/plants (i.e. the Plantae hypothesis) and 19 expressed sequence tag contigs that show evidence of endosymbiotic/horizontal gene transfer involving stramenopiles. The majority (77%) of analyzed contigs encode transporters with unresolved phylogenies, demonstrating the difficulty in resolving the evolutionary history of genes. We observed molecular features of many sodium-coupled transport systems in marine algae, and the potential for coregulation of Porphyra transporter genes that are associated with fatty acid biosynthesis and intracellular lipid trafficking. Although both the tissue-specific and subcellular locations of the encoded proteins require further investigation, our study provides red algal gene candidates associated with transport functions and novel insights into the biology and evolution of these transporters.

  16. Immunomodulatory properties of the protein fraction from Phorphyra columbina.

    PubMed

    Cian, Raúl E; López-Posadas, Rocío; Drago, Silvina R; de Medina, Fermín Sánchez; Martínez-Augustin, Olga

    2012-08-22

    The phycobiliproteins from Rhodophyta , R-phycoerythrin (R-PE) and C-phycocyanin (C-PC), have been shown to exert immunomodulatory effects. This study evaluated the effects of a Phorphyra columbina protein fraction (PF) and R-PE and C-PC on rat primary splenocytes, macrophages, and T-lymphocytes in vitro. PF featured various protein species, including R-PE and C-PC. PF showed mitogenic effects on rat splenocytes and was nontoxic to cells except at 1 g L(-1) protein. IL-10 secretion was enhanced by PF in rat splenocytes, macrophages, and especially T-lymphocytes, whereas it was markedly diminished by R-PE and C-PC. The production of pro-inflammatory cytokines by macrophages was inhibited. The effect of PF on IL-10 was evoked by JNK/p38 MAPK and NF-κB-dependent pathways in macrophages and T-lymphocytes. It was concluded that PF has immunomodulatory effects on macrophages and lymphocytes that appear to be predominantly anti-inflammatory via up-regulated IL-10 production and cannot be accounted for by R-PE and C-PC.

  17. Comparisons of the fungal and protistan communities among different marine sponge holobionts by pyrosequencing.

    PubMed

    He, Liming; Liu, Fang; Karuppiah, Valliappan; Ren, Yi; Li, Zhiyong

    2014-05-01

    To date, the knowledge of eukaryotic communities associated with sponges remains limited compared with prokaryotic communities. In a manner similar to prokaryotes, it could be hypothesized that sponge holobionts have phylogenetically diverse eukaryotic symbionts, and the eukaryotic community structures in different sponge holobionts were probably different. In order to test this hypothesis, the communities of eukaryota associated with 11 species of South China Sea sponges were compared with the V4 region of 18S ribosomal ribonucleic acid gene using 454 pyrosequencing. Consequently, 135 and 721 unique operational taxonomic units (OTUs) of fungi and protists were obtained at 97 % sequence similarity, respectively. These sequences were assigned to 2 phyla of fungi (Ascomycota and Basidiomycota) and 9 phyla of protists including 5 algal phyla (Chlorophyta, Haptophyta, Streptophyta, Rhodophyta, and Stramenopiles) and 4 protozoal phyla (Alveolata, Cercozoa, Haplosporidia, and Radiolaria) including 47 orders (12 fungi, 35 protists). Entorrhizales of fungi and 18 orders of protists were detected in marine sponges for the first time. Particularly, Tilletiales of fungi and Chlorocystidales of protists were detected for the first time in marine habitats. Though Ascomycota, Alveolata, and Radiolaria were detected in all the 11 sponge species, sponge holobionts have different fungi and protistan communities according to OTU comparison and principal component analysis at the order level. This study provided the first insights into the fungal and protistan communities associated with different marine sponge holobionts using pyrosequencing, thus further extending the knowledge on sponge-associated eukaryotic diversity.

  18. Decadal changes in the distribution of common intertidal seaweeds in Galicia (NW Iberia).

    PubMed

    Piñeiro-Corbeira, Cristina; Barreiro, Rodolfo; Cremades, Javier

    2016-02-01

    Seaweed assemblages in Atlantic Europe are been distorted by global change, but the intricate coastal profile of the area suggests that susceptibility may differ between regions. In particular, NW Iberia is an important omission because no study has systematically assessed long-term changes in a large number of species. Using intertidal surveys for 33 common perennial seaweeds, we show that the average number of species per site declined significantly from 1998-99 to 2014 in NW Iberia. The largest drops in site occupancy were detected in kelps, fucoids, and carrageenan-producing Rhodophyta. Parallel analyses revealed significant upward trends in SST, air temperature, and strong waves; meanwhile, nutrients decreased slightly except in areas affected by local inputs. Similar changes reported for subtidal assemblages in other parts of Atlantic Europe suggest that the drivers may be ubiquitous. Nonetheless, a more proper assessment of both global and local impacts, will require further surveys, and the regular monitoring of intertidal perennial seaweeds appears as a cost-effective alternative to discriminate genuine long-term trends from transitory fluctuations.

  19. Atmospheric Dispersal of Bioactive Streptomyces albidoflavus Strains Among Terrestrial and Marine Environments.

    PubMed

    Sarmiento-Vizcaíno, Aida; Braña, Alfredo F; González, Verónica; Nava, Herminio; Molina, Axayacatl; Llera, Eva; Fiedler, Hans-Peter; Rico, José M; García-Flórez, Lucía; Acuña, José L; García, Luis A; Blanco, Gloria

    2016-02-01

    Members of the Streptomyces albidoflavus clade, identified by 16S rRNA sequencing and phylogenetic analyses, are widespread among predominant terrestrial lichens (Flavoparmelia caperata and Xanthoria parietina) and diverse intertidal and subtidal marine macroalgae, brown red and green (Phylum Heterokontophyta, Rhodophyta, and Chlorophyta) from the Cantabrian Cornice. In addition to these terrestrial and coastal temperate habitats, similar strains were also found to colonize deep-sea ecosystems and were isolated mainly from gorgonian and solitary corals and other invertebrates (Phylum Cnidaria, Annelida, Echinodermata, Arthropoda, and Porifera) living up to 4700-m depth and at a temperature of 2-4 °C in the submarine Avilés Canyon. Similar strains have been also repeatedly isolated from atmospheric precipitations (rain drops, snow, and hailstone) collected in the same area throughout a year observation time. These ubiquitous strains were found to be halotolerant, psychrotolerant, and barotolerant. Bioactive compounds with diverse antibiotic and cytotoxic activities produced by these strains were identified by high-performance liquid chromatography (HPLC) and database comparison. These include antibacterials (paulomycins A and B), antifungals (maltophilins), antifungals displaying also cytotoxic activities (antimycins and 6-epialteramides), and the antitumor compound fredericamycin. A hypothetical dispersion model is here proposed to explain the biogeographical distribution of S. albidoflavus strains in terrestrial, marine, and atmospheric environments.

  20. Macroalgal Introductions by Hull Fouling on Recreational Vessels: Seaweeds and Sailors

    NASA Astrophysics Data System (ADS)

    Mineur, Frédéric; Johnson, Mark P.; Maggs, Christine A.

    2008-10-01

    Macroalgal invasions in coastal areas have been a growing concern during the past decade. The present study aimed to assess the role of hull fouling on recreational yachts as a vector for macroalgal introductions. Questionnaire and hull surveys were carried out in marinas in France and Spain. The questionnaires revealed that the majority of yacht owners are aware of seaweed introductions, usually undertake short range journeys, dry dock their boat at least once a year, and use antifouling paints. The hull survey showed that many in-service yachts were completely free of macroalgae. When present, fouling assemblages consisted mainly of one to two macroalgal species. The most commonly found species was the tolerant green seaweed Ulva flexuosa. Most of the other species found are also cosmopolitan and opportunistic. A few nonnative and potentially invasive Ceramiales (Rhodophyta) were found occasionally on in-service yachts. On the basis of the information gathered during interviews of yacht owners in the surveyed area, these occurrences are likely to be uncommon. However they can pose a significant risk of primary or secondary introductions of alien macroalgal species, especially in the light of the increase in yachting activities. With large numbers of recreational yachts and relatively rare occurrences of nonnative species on hulls, comprehensive screening programs do not seem justified or practical. The risks of transferring nonnative species may, however, be minimized by encouraging the behaviors that prevent fouling on hulls and by taking action against neglected boats before they can act as vectors.

  1. Potential and limits of Raman spectroscopy for carotenoid detection in microorganisms: implications for astrobiology

    PubMed Central

    Jehlička, Jan; Edwards, Howell G. M.; Osterrothová, Kateřina; Novotná, Julie; Nedbalová, Linda; Kopecký, Jiří; Němec, Ivan; Oren, Aharon

    2014-01-01

    In this paper, it is demonstrated how Raman spectroscopy can be used to detect different carotenoids as possible biomarkers in various groups of microorganisms. The question which arose from previous studies concerns the level of unambiguity of discriminating carotenoids using common Raman microspectrometers. A series of laboratory-grown microorganisms of different taxonomic affiliation was investigated, such as halophilic heterotrophic bacteria, cyanobacteria, the anoxygenic phototrophs, the non-halophilic heterotrophs as well as eukaryotes (Ochrophyta, Rhodophyta and Chlorophyta). The data presented show that Raman spectroscopy is a suitable tool to assess the presence of carotenoids of these organisms in cultures. Comparison is made with the high-performance liquid chromatography approach of analysing pigments in extracts. Direct measurements on cultures provide fast and reliable identification of the pigments. Some of the carotenoids studied are proposed as tracers for halophiles, in contrast with others which can be considered as biomarkers of other genera. The limits of application of Raman spectroscopy are discussed for a few cases where the current Raman spectroscopic approach does not allow discriminating structurally very similar carotenoids. The database reported can be used for applications in geobiology and exobiology for the detection of pigment signals in natural settings. PMID:25368348

  2. Plant and animal glycolate oxidases have a common eukaryotic ancestor and convergently duplicated to evolve long-chain 2-hydroxy acid oxidases.

    PubMed

    Esser, Christian; Kuhn, Anke; Groth, Georg; Lercher, Martin J; Maurino, Veronica G

    2014-05-01

    Glycolate oxidase (GOX) is a crucial enzyme of plant photorespiration. The encoding gene is thought to have originated from endosymbiotic gene transfer between the eukaryotic host and the cyanobacterial endosymbiont at the base of plantae. However, animals also possess GOX activities. Plant and animal GOX belong to the gene family of (L)-2-hydroxyacid-oxidases ((L)-2-HAOX). We find that all (L)-2-HAOX proteins in animals and archaeplastida go back to one ancestral eukaryotic sequence; the sole exceptions are green algae of the chlorophyta lineage. Chlorophyta replaced the ancestral eukaryotic (L)-2-HAOX with a bacterial ortholog, a lactate oxidase that may have been obtained through the primary endosymbiosis at the base of plantae; independent losses of this gene may explain its absence in other algal lineages (glaucophyta, rhodophyta, and charophyta). We also show that in addition to GOX, plants possess (L)-2-HAOX proteins with different specificities for medium- and long-chain hydroxyacids (lHAOX), likely involved in fatty acid and protein catabolism. Vertebrates possess lHAOX proteins acting on similar substrates as plant lHAOX; however, the existence of GOX and lHAOX subfamilies in both plants and animals is not due to shared ancestry but is the result of convergent evolution in the two most complex eukaryotic lineages. On the basis of targeting sequences and predicted substrate specificities, we conclude that the biological role of plantae (L)-2-HAOX in photorespiration evolved by co-opting an existing peroxisomal protein.

  3. Last glacial to Holocene productivity and oxygen changes based on benthic foraminiferal assemblages from the western Alboran Sea

    NASA Astrophysics Data System (ADS)

    Pérez-Asensio, José N.; Cacho, Isabel; Frigola, Jaime; Pena, Leopoldo D.; Asioli, Alessandra; Kuhlmann, Jannis; Huhn, Katrin

    2016-04-01

    and the additional taxa of the assemblage (Bolivina spathulata, Bolivina subspinescens, Bulimina marginata, Bolivina variabilis and Uvigerina peregrina) also thrive in mesotrophic environments with fresh organic matter supply and moderate oxygen content. The lower part of the early Holocene (10.5-7.3 ka) is dominated by the Cassidulina obtusa assemblage including Bolivina subspinescens, Bolivina variabilis, Bulimina marginata, Gyroidina altiformis, Nonionella iridea and Quinqueloculina sp. as associated taxa. A highly diverse mesotrophic setting with slightly higher oxygenation can be inferred for this assemblage. This is supported by the higher abundance of epifaunal-shallow infaunal taxa and the presence of G. altiformis and Quinqueloculina sp. Finally, the highly diverse Alabaminella weddellensis assemblage occurs along the upper part of the core (7.3-0 ka) encompassing the upper early Holocene and late Holocene. Additional species of this assemblages are Uvigerina mediterranea, Melonis barleeanus, Cassidulina laevigata, Cassidulina obtusa and Uvigerina peregrina. This assemblage suggests mesotrophic conditions with a more continuous organic matter supply as pointed out by the occurrence of U. mediterranea and the intermediate infaunal M. barleeanus that can feed from more degraded organic matter. The onset of this assemblage around 7.3 ka might be related to the establishment of the semi-permanent productive 'Malaga cell" dated at 7.7 ka.

  4. Social insect colony as a biological regulatory system: modelling information flow in dominance networks

    PubMed Central

    Nandi, Anjan K.; Sumana, Annagiri; Bhattacharya, Kunal

    2014-01-01

    Social insects provide an excellent platform to investigate flow of information in regulatory systems since their successful social organization is essentially achieved by effective information transfer through complex connectivity patterns among the colony members. Network representation of such behavioural interactions offers a powerful tool for structural as well as dynamical analysis of the underlying regulatory systems. In this paper, we focus on the dominance interaction networks in the tropical social wasp Ropalidia marginata—a species where behavioural observations indicate that such interactions are principally responsible for the transfer of information between individuals about their colony needs, resulting in a regulation of their own activities. Our research reveals that the dominance networks of R. marginata are structurally similar to a class of naturally evolved information processing networks, a fact confirmed also by the predominance of a specific substructure—the ‘feed-forward loop’—a key functional component in many other information transfer networks. The dynamical analysis through Boolean modelling confirms that the networks are sufficiently stable under small fluctuations and yet capable of more efficient information transfer compared to their randomized counterparts. Our results suggest the involvement of a common structural design principle in different biological regulatory systems and a possible similarity with respect to the effect of selection on the organization levels of such systems. The findings are also consistent with the hypothesis that dominance behaviour has been shaped by natural selection to co-opt the information transfer process in such social insect species, in addition to its primal function of mediation of reproductive competition in the colony. PMID:25320069

  5. Initial growth of leguminous trees and shrubs in a cut gold mined area in Minas Gerais State, Brazil

    SciTech Connect

    Dias, L.E.; Campello, E.F.C.; Ribeiro, E.S. Jr.; Mello, J.W.V.

    1999-07-01

    In an opencast gold mining in Minas Gerais State, Brazil, leguminous trees and shrubs were used to revegetate an acid cut mined area. the substrate was high in pyrite content (3%) and received 50 cm of covered material in two layers: (1) insulating layer of 20 cm where clay or a mining refuse (MR) was used to prevent the pyrite oxidation, and (2) an upper layer with 30 cm formed by topsoil or topsoil + urban compost (3:1 v/v). After the application of the cover materials, planting holes were manually made spaced by 1 x 1 m. Each hole received limestone (100 g), rock phosphate (150 g), potassium chloride (45 g) and cattle manure (2 L). Fifteen leguminous species were planted an each plot (15 x 8 m), spaced by 1.0 x 1.0 m (one specie per row). Sixteen months after the planting the plants were evaluated and the results showed an effect of substrate on the plants survival, height, and diameter. The use of clay as insulating layer was better than mining refuse and the plants did not respond to the addition of urban compost to the topsoil. Among the evaluated species, Thephrosia sinapau, Erytrina verna, Dipterix alata and Stryphnodenadrum guyanensis showed a mortality rate of 100% after 16 months while Sesbania marginata, Acacaia holosericea, Mimosa pellita, Acacia crassicarpa, Acacia mangium and Acacia angustissima exhibited more adaptation capacity to the acid substrate. Analyses from the substrate showed higher exchangeable acidity (Al{sup 3+}) for the plots receiving MR as insulating layer. This study has applications for the acid mine drainage from coal mines of Brazil.

  6. The phylogeny of Mediterranean tortoises and their close relativesbased on complete mitochondrial genome sequences from museumspecimens

    SciTech Connect

    Parham, James F.; Macey, J. Robert; Papenfuss, Theodore J.; Feldman, Chris R.; Turkozan, Oguz; Polymeni, Rosa; Boore, Jeffrey

    2005-04-29

    As part of an ongoing project to generate a mitochondrial database for terrestrial tortoises based on museum specimens, the complete mitochondrial genome sequences of 10 species and a {approx}14 kb sequence from an eleventh species are reported. The sampling of the present study emphasizes Mediterranean tortoises (genus Testudo and their close relatives). Our new sequences are aligned, along with those of two testudinoid turtles from GenBank, Chrysemys picta and Mauremys reevesii, yielding an alignment of 14,858 positions, of which 3,238 are parsimony informative. We develop a phylogenetic taxonomy for Testudo and related species based on well-supported, diagnosable clades. Several well-supported nodes are recovered, including the monophyly of a restricted Testudo, T. kleinmanni + T. marginata (the Chersus clade), and the placement of the enigmatic African pancake tortoise (Malacochersustornieri) within the predominantly Palearctic greater Testudo group (Testudona tax. nov.). Despite the large amount of sequence reported, there is low statistical support for some nodes within Testudona and Sowe do not propose names for those groups. A preliminary and conservative estimation of divergence times implies a late Miocene diversification for the testudonan clade (6-12 million years ago), matching their first appearance in the fossil record. The multi-continental distribution of testudonan turtles can be explained by the establishment of permanent connections between Europe, Africa, and Asia at this time. The arrival of testudonan turtles to Africa occurred after one or more initial tortoise invasions gave rise to the diverse (>25 species) 'Geochelone complex.'Two unusual genomic features are reported for the mtDNA of one tortoise, M. tornieri: (1) nad4 has a shift of reading frame that we suggest is resolved by translational frameshifting of the mRNA on the ribosome during protein synthesis and (2) there are two copies of the control region and trnF, with the latter

  7. Using mushroom farm and anaerobic digestion wastewaters as supplemental fertilizer sources for growing container nursery stock in a closed system.

    PubMed

    Chong, C; Purvis, P; Lumis, G; Holbein, B E; Voroney, R P; Zhou, H; Liu, H-W; Alam, M Z

    2008-04-01

    Wastewaters from farm and composting operations are often rich in select nutrients that potentially can be reutilized in crop production. Liners of silverleaf dogwood (Cornus alba L. 'Argenteo-marginata'), common ninebark [Physocarpus opulifolius (L.) Maxim.], and Anthony Waterer spirea (Spiraeaxbumalda Burvénich 'Anthony Waterer') were grown in 6L containers filled with a bark-based commercial mix. Plants were fertigated daily via a computer-controlled multi-fertilizer injector with three recirculated fertilizer treatments: (1) a stock (control) solution with complete macro- and micro-nutrients, electrical conductivity (EC) 2.2 dS m(-1); (2) wastewater from a mushroom farm; and (3) process wastewater from anaerobic digestion of municipal solid waste. The wastewaters used in both treatments 2 and 3 were diluted with tap water, and the computer was programmed to amend, dispense and recirculate nutrients based on the same target EC as in treatment 1. For comparison, there was a traditional controlled-release fertilizer treatment [Nutryon 17-5-12 (17N-2P-10K) plus micro-nutrients topdressed at a rate of 39 g/plant, nutrients not recirculated]. All three species responded similarly to the three recirculated fertilizer treatments. Growth with the recirculated treatments was similar and significantly higher than that obtained with controlled-release fertilizer. Throughout the study, the EC measured in wastewater-derived nutrient solutions, and also in the container substrate, were similar or close to those of the control treatment, although there were small to large differences among individual major nutrients. There was no sign of nutrient deficiency or toxicity symptoms to the plants. Small to moderate excesses in concentrations of SO(4), Na, and/or Cl were physiologically tolerable to the species.

  8. Photosynthesis, photoprotection, and growth of shade-tolerant tropical tree seedlings under full sunlight.

    PubMed

    Krause, G Heinrich; Winter, Klaus; Matsubara, Shizue; Krause, Barbara; Jahns, Peter; Virgo, Aurelio; Aranda, Jorge; García, Milton

    2012-09-01

    High solar radiation in the tropics is known to cause transient reduction in photosystem II (PSII) efficiency and CO(2) assimilation in sun-exposed leaves, but little is known how these responses affect the actual growth performance of tropical plants. The present study addresses this question. Seedlings of five woody neotropical forest species were cultivated under full sunlight and shaded conditions. In full sunlight, strong photoinhibition of PSII at midday was documented for the late-successional tree species Ormosia macrocalyx and Tetragastris panamensis and the understory/forest gap species, Piper reticulatum. In leaves of O. macrocalyx, PSII inhibition was accompanied by substantial midday depression of net CO(2) assimilation. Leaves of all species had increased pools of violaxanthin-cycle pigments. Other features of photoacclimation, such as increased Chl a/b ratio and contents of lutein, β-carotene and tocopherol varied. High light caused strong increase of tocopherol in leaves of T. panamensis and another late-successional species, Virola surinamensis. O. macrocalyx had low contents of tocopherol and UV-absorbing substances. Under full sunlight, biomass accumulation was not reduced in seedlings of T. panamensis, P. reticulatum, and V. surinamensis, but O. macrocalyx exhibited substantial growth inhibition. In the highly shade-tolerant understory species Psychotria marginata, full sunlight caused strongly reduced growth of most individuals. However, some plants showed relatively high growth rates under full sun approaching those of seedlings at 40 % ambient irradiance. It is concluded that shade-tolerant tropical tree seedlings can achieve efficient photoacclimation and high growth rates in full sunlight.

  9. Diplectanids from Mycteroperca spp. (Epinephelidae) in the Mediterranean Sea: Redescriptions of six species from material collected off Tunisia and Libya, proposal for the 'Pseudorhabdosynochus riouxi group', and a taxonomic key.

    PubMed

    Chaabane, Amira; Neifar, Lassad; Justine, Jean-Lou

    2017-01-01

    Diplectanid monogeneans are gill parasites that can infect fish in huge numbers and thus become harmful, especially in maricultured fish. It is therefore useful to have taxonomic tools, such as keys, to identify species. The following diplectanid species from groupers of the Mediterranean Sea were studied: five species of Pseudorhabdosynochus Yamaguti, 1958, including P. riouxi (Oliver, 1986) Kritsky & Beverley-Burton, 1986 from the dusky grouper Mycteroperca marginata, P. enitsuji Neifar & Euzet, 2007, P. bouaini Neifar & Euzet, 2007, P. dolicocolpos Neifar & Euzet, 2007 and P. sinediscus Neifar & Euzet, 2007 from the goldblotch grouper M. costae, and Echinoplectanum echinophallus (Euzet & Oliver, 1965) Justine & Euzet, 2006 from the dusky grouper. New material was obtained from fish collected from off Tunisia and Libya and compared to the type-material and voucher specimens in museum collections. Identifications of fish were confirmed by barcoding of cytochrome c oxidase subunit I (COI) sequences. The sclerotized vagina was considered the most important structure for systematics. The three species P. riouxi, P. bouaini, and P. enitsuji share a common general structure of the sclerotized vagina with a conspicuous spherical secondary chamber. We thus propose the 'Pseudorhabdosynochus riouxi group' to accommodate them. Pseudorhabdosynochus dolicocolpos has an elongate vaginal structure that is completely different from all its congeneric species reported from the Mediterranean Sea, and Pseudorhabdosynochus sinediscus has a sclerotized vagina in which the secondary chamber is not visible, and a haptor without squamodiscs. A taxonomic key to diplectanid species on Mycteroperca spp. in the Mediterranean Sea is proposed; it includes ten species of Pseudorhabdosynochus and one species of Echinoplectanum.

  10. Benthic foraminiferal response to sedimentary disturbance in the Capbreton canyon (Bay of Biscay, NE Atlantic)

    NASA Astrophysics Data System (ADS)

    Duros, P.; Silva Jacinto, R.; Dennielou, B.; Schmidt, S.; Martinez Lamas, R.; Gautier, E.; Roubi, A.; Gayet, N.

    2017-02-01

    Living (Rose Bengal stained) and dead benthic foraminifera were investigated at 6 deep-sea sites sampled in the Capbreton canyon area (Bay of Biscay, France). Three sites were located along the canyon axis at 301 m, 983 m and 1478 m and 3 stations were positioned on adjacent terraces at 251 m, 894 m and 1454 m. Sedimentary features indicate that frequent sedimentary disturbances of different magnitudes occur along the Capbreton canyon axis and adjacent terraces. Such environmental conditions cause the presence of very particular benthic environments. Along the 6 studied sites, different foraminiferal responses to various sedimentary patterns are observed revealing the complexity of this canyon environment. Some sites (Gitan 3 (canyon axis), Gitan 5 (canyon axis) and Gitan 6 (terrace)) are characterized by moderate to low standing stocks and low diversity and are mainly dominated by pioneer taxa such as Fursenkoina brady, Reophax dentaliniformis and Technitella melo suggesting a recent response to turbidite deposits recorded at these sites. Others sites (Gitan 1 and Gitan 2) show extremely high standing stocks and are mainly dominated by the opportunistic Bolivina subaenariensis and Bulimina marginata. Such faunal characteristics belonging to a more advanced stage of ecosystem colonization indicates strongly food-enriched sediment but extremely unstable conditions. Moderate standing stocks and diverse assemblage composed of species such as Uvigerina mediterranea and U. peregrina has only been observed at the terrace site Gitan 4. More stable sedimentary conditions recorded at this terrace seem to be suitable to the development of a dense and diverse foraminiferal community. Numerous neritic allochtonous species were observed in the dead foraminiferal fauna. These allochthonous species mainly originate from shelf areas (<60 m).

  11. An Exploration on Greenhouse Gas and Ammonia Production by Insect Species Suitable for Animal or Human Consumption

    PubMed Central

    Oonincx, Dennis G. A. B.; van Itterbeeck, Joost; Heetkamp, Marcel J. W.; van den Brand, Henry; van Loon, Joop J. A.; van Huis, Arnold

    2010-01-01

    Background Greenhouse gas (GHG) production, as a cause of climate change, is considered as one of the biggest problems society is currently facing. The livestock sector is one of the large contributors of anthropogenic GHG emissions. Also, large amounts of ammonia (NH3), leading to soil nitrification and acidification, are produced by livestock. Therefore other sources of animal protein, like edible insects, are currently being considered. Methodology/Principal Findings An experiment was conducted to quantify production of carbon dioxide (CO2) and average daily gain (ADG) as a measure of feed conversion efficiency, and to quantify the production of the greenhouse gases methane (CH4) and nitrous oxide (N2O) as well as NH3 by five insect species of which the first three are considered edible: Tenebrio molitor, Acheta domesticus, Locusta migratoria, Pachnoda marginata, and Blaptica dubia. Large differences were found among the species regarding their production of CO2 and GHGs. The insects in this study had a higher relative growth rate and emitted comparable or lower amounts of GHG than described in literature for pigs and much lower amounts of GHG than cattle. The same was true for CO2 production per kg of metabolic weight and per kg of mass gain. Furthermore, also the production of NH3 by insects was lower than for conventional livestock. Conclusions/Significance This study therefore indicates that insects could serve as a more environmentally friendly alternative for the production of animal protein with respect to GHG and NH3 emissions. The results of this study can be used as basic information to compare the production of insects with conventional livestock by means of a life cycle analysis. PMID:21206900

  12. Macrofauna assemblage composition and soil moisture interact to affect soil ecosystem functions

    NASA Astrophysics Data System (ADS)

    Collison, E. J.; Riutta, T.; Slade, E. M.

    2013-02-01

    Changing climatic conditions and habitat fragmentation are predicted to alter the soil moisture conditions of temperate forests. It is not well understood how the soil macrofauna community will respond to changes in soil moisture, and how changes to species diversity and community composition may affect ecosystem functions, such as litter decomposition and soil fluxes. Moreover, few studies have considered the interactions between the abiotic and biotic factors that regulate soil processes. Here we attempt to disentangle the interactive effects of two of the main factors that regulate soil processes at small scales - moisture and macrofauna assemblage composition. The response of assemblages of three common temperate soil invertebrates (Glomeris marginata Villers, Porcellio scaber Latreille and Philoscia muscorum Scopoli) to two contrasting soil moisture levels was examined in a series of laboratory mesocosm experiments. The contribution of the invertebrates to the leaf litter mass loss of two common temperate tree species of contrasting litter quality (easily decomposing Fraxinus excelsior L. and recalcitrant Quercus robur L.) and to soil CO2 fluxes were measured. Both moisture conditions and litter type influenced the functioning of the invertebrate assemblages, which was greater in high moisture conditions compared with low moisture conditions and on good quality vs. recalcitrant litter. In high moisture conditions, all macrofauna assemblages functioned at equal rates, whereas in low moisture conditions there were pronounced differences in litter mass loss among the assemblages. This indicates that species identity and assemblage composition are more important when moisture is limited. We suggest that complementarity between macrofauna species may mitigate the reduced functioning of some species, highlighting the importance of maintaining macrofauna species richness.

  13. Fungal Planet description sheets: 320-370.

    PubMed

    Crous, P W; Wingfield, M J; Guarro, J; Hernández-Restrepo, M; Sutton, D A; Acharya, K; Barber, P A; Boekhout, T; Dimitrov, R A; Dueñas, M; Dutta, A K; Gené, J; Gouliamova, D E; Groenewald, M; Lombard, L; Morozova, O V; Sarkar, J; Smith, M Th; Stchigel, A M; Wiederhold, N P; Alexandrova, A V; Antelmi, I; Armengol, J; Barnes, I; Cano-Lira, J F; Castañeda Ruiz, R F; Contu, M; Courtecuisse, Pr R; da Silveira, A L; Decock, C A; de Goes, A; Edathodu, J; Ercole, E; Firmino, A C; Fourie, A; Fournier, J; Furtado, E L; Geering, A D W; Gershenzon, J; Giraldo, A; Gramaje, D; Hammerbacher, A; He, X-L; Haryadi, D; Khemmuk, W; Kovalenko, A E; Krawczynski, R; Laich, F; Lechat, C; Lopes, U P; Madrid, H; Malysheva, E F; Marín-Felix, Y; Martín, M P; Mostert, L; Nigro, F; Pereira, O L; Picillo, B; Pinho, D B; Popov, E S; Rodas Peláez, C A; Rooney-Latham, S; Sandoval-Denis, M; Shivas, R G; Silva, V; Stoilova-Disheva, M M; Telleria, M T; Ullah, C; Unsicker, S B; van der Merwe, N A; Vizzini, A; Wagner, H-G; Wong, P T W; Wood, A R; Groenewald, J Z

    2015-06-01

    Novel species of fungi described in the present study include the following from Malaysia: Castanediella eucalypti from Eucalyptus pellita, Codinaea acacia from Acacia mangium, Emarcea eucalyptigena from Eucalyptus brassiana, Myrtapenidiella eucalyptorum from Eucalyptus pellita, Pilidiella eucalyptigena from Eucalyptus brassiana and Strelitziana malaysiana from Acacia mangium. Furthermore, Stachybotrys sansevieriicola is described from Sansevieria ehrenbergii (Tanzania), Phacidium grevilleae from Grevillea robusta (Uganda), Graphium jumulu from Adansonia gregorii and Ophiostoma eucalyptigena from Eucalyptus marginata (Australia), Pleurophoma ossicola from bone and Plectosphaerella populi from Populus nigra (Germany), Colletotrichum neosansevieriae from Sansevieria trifasciata, Elsinoë othonnae from Othonna quinquedentata and Zeloasperisporium cliviae (Zeloasperisporiaceae fam. nov.) from Clivia sp. (South Africa), Neodevriesia pakbiae, Phaeophleospora hymenocallidis and Phaeophleospora hymenocallidicola on leaves of a fern (Thailand), Melanconium elaeidicola from Elaeis guineensis (Indonesia), Hormonema viticola from Vitis vinifera (Canary Islands), Chlorophyllum pseudoglobossum from a grassland (India), Triadelphia disseminata from an immunocompromised patient (Saudi Arabia), Colletotrichum abscissum from Citrus (Brazil), Polyschema sclerotigenum and Phialemonium limoniforme from human patients (USA), Cadophora vitícola from Vitis vinifera (Spain), Entoloma flavovelutinum and Bolbitius aurantiorugosus from soil (Vietnam), Rhizopogon granuloflavus from soil (Cape Verde Islands), Tulasnella eremophila from Euphorbia officinarum subsp. echinus (Morocco), Verrucostoma martinicensis from Danaea elliptica (French West Indies), Metschnikowia colchici from Colchicum autumnale (Bulgaria), Thelebolus microcarpus from soil (Argentina) and Ceratocystis adelpha from Theobroma cacao (Ecuador). Myrmecridium iridis (Myrmecridiales ord. nov., Myrmecridiaceae fam. nov.) is also

  14. Physiological responses to freezing in hatchlings of freeze-tolerant and -intolerant turtles.

    PubMed

    Costanzo, Jon P; Baker, Patrick J; Lee, Richard E

    2006-09-01

    Freeze tolerance is a complex cold-hardiness adaptation that has independently evolved in a diverse group of organisms, including several ectothermic vertebrates. Because little is known about the mechanistic basis for freeze tolerance in reptiles, we compared responses to experimental freezing in winter-acclimatized hatchlings representing nine taxa of temperate North American turtles, including ones that tolerated freezing and others that did not. Viability rates of hatchlings frozen to -3 degrees C for 72 h ranged from 0 to 100%. Tolerance to freezing was poor in Sternotherus odoratus, Graptemys geographica and Trachemys scripta, intermediate in Chelydra serpentina, and high in Emydoidea blandingii, Chrysemys picta bellii, C. p. marginata, Malaclemys terrapin, and Terrapene ornata, and generally reflected the winter thermal ecology of each taxon. Plasma activity of lactate dehydrogenase (LDH), a novel in vivo index of freeze/thaw damage, corroborated viability assessments and demonstrated that cryoinjury occurred even in surviving turtles. Irrespective of taxon, cryoinjury tended to be higher in smaller individuals and in those having relatively low water contents; however, bases for these associations were not apparent. Screening for certain organic osmolytes that might promote freezing survival by colligatively reducing ice content and limiting cell dehydration showed that the plasma of unfrozen (control) turtles contained small quantities of glucose (1.3-5.8 mmol l(-1)) and lactate (0.6-3.2 mmol l(-1)) and modest amounts of urea (range of mean values for all taxa 8.2-52.3 mmol l(-1)). Frozen/thawed turtles of all taxa accumulated modest amounts of glucose and lactate that jointly raised the plasma solute concentration by 30-100 mmol l(-1). We conclude that organic osmolytes accumulated both before and during freezing may promote survival in species that have evolved a tolerance to freezing, but are not necessarily accumulated for that purpose.

  15. Cold-water coral habitats of Rockall and Porcupine Bank, NE Atlantic Ocean: Sedimentary facies and benthic foraminiferal assemblages

    NASA Astrophysics Data System (ADS)

    Smeulders, G. G. B.; Koho, K. A.; de Stigter, H. C.; Mienis, F.; de Haas, H.; van Weering, T. C. E.

    2014-01-01

    The extent of the cold-water coral mounds in the modern ocean basins has been recently revealed by new state-of-the-art equipment. However, not much is known about their geological extent or development through time. In the facies model presented here seven different types of seabed substrate are distinguished, which may be used for reconstruction of fossil coral habitats. The studied substrates include: off-mound settings, (foram) sands, hardgrounds, dead coral debris, and substrates characterized by a variable density of living coral framework. Whereas sediment characteristics only provide a basis for distinguishing on- and off-mound habitats and the loci of most prolific coral growth, benthic foraminiferal assemblages are the key to identifying different mound substrates in more detail. Specific foraminiferal assemblages are distinguished that are characteristic of these specific environments. Assemblages from off-mound settings are dominated by (attached) epifaunal species such as Cibicides refulgens and Cibicides variabilis. The attached epibenthic species Discanomalina coronata is also common in off-mound sediments, but it is most abundant where hardgrounds have formed. In contrast, the settings with coral debris or living corals attract shallow infaunal species that are associated with more fine-grained soft sediments. The typical ‘living coral assemblage' is composed of Cassidulina obtusa, Bulimina marginata, and Cassidulina laevigata. The abundance of these species shows an almost linear increase with the density of the living coral cover. The benthic foraminifera encountered from off-mound to top-mound settings appear to represent a gradient of decreasing current intensity and availability of suspended food particles, and increasing availability of organic matter associated with fine-grained sediment trapped in between coral framework.

  16. Segment polarity gene expression in a myriapod reveals conserved and diverged aspects of early head patterning in arthropods.

    PubMed

    Janssen, Ralf

    2012-09-01

    Arthropods show two kinds of developmental mode. In the so-called long germ developmental mode (as exemplified by the fly Drosophila), all segments are formed almost simultaneously from a preexisting field of cells. In contrast, in the so-called short germ developmental mode (as exemplified by the vast majority of arthropods), only the anterior segments are patterned similarly as in Drosophila, and posterior segments are added in a single or double segmental periodicity from a posterior segment addition zone (SAZ). The addition of segments from the SAZ is controlled by dynamic waves of gene activity. Recent studies on a spider have revealed that a similar dynamic process, involving expression of the segment polarity gene (SPG) hedgehog (hh), is involved in the formation of the anterior head segments. The present study shows that in the myriapod Glomeris marginata the early expression of hh is also in a broad anterior domain, but this domain corresponds only to the ocular and antennal segment. It does not, like in spiders, represent expression in the posterior adjacent segment. In contrast, the anterior hh pattern is conserved in Glomeris and insects. All investigated myriapod SPGs and associated factors are expressed with delay in the premandibular (tritocerebral) segment. This delay is exclusively found in insects and myriapods, but not in chelicerates, crustaceans and onychophorans. Therefore, it may represent a synapomorphy uniting insects and myriapods (Atelocerata hypothesis), contradicting the leading opinion that suggests a sister relationship of crustaceans and insects (Pancrustacea hypothesis). In Glomeris embryos, the SPG engrailed is first expressed in the mandibular segment. This feature is conserved in representatives of all arthropod classes suggesting that the mandibular segment may have a special function in anterior patterning.

  17. Tracing latitudinal gradient, river discharge and water masses along the subtropical South American coast using benthic Foraminifera assemblages.

    PubMed

    Eichler, P P B; Rodrigues, A R; Eichler, B B; Braga, E S; Campos, E J D

    2012-08-01

    More than 30% of Buccella peruviana (D'Orbigny), Globocassidulina crassa porrecta (Earland & Heron-Allen), Cibicides mackannai (Galloway & Wissler) and C. refulgens (Montfort) indicate the presence of cold Sub Antarctic Shelf Water in winter, from 33.5 to 38.3º S, deeper than 100 m, in the southern part of the study area. In summer, the abundance of this association decreases to less than 15% around 37.5-38.9º S where two species (Globocassidulina subglobosa (Brady), Uvigerina peregrina (Cushman) take over. G. subglobosa, U. peregrina, and Hanzawaia boueana (D'Orbigny) are found at 27-33º S in both seasons in less than 55 m deep in the northern part, and are linked with warm Subtropical Shelf Water and Tropical Water. Freshwater influence was signalized by high silicate concentration and by the presence of Pseudononion atlanticum (Cushman), Bolivina striatula (Cushman), Buliminella elegantissima (D'Orbigny), Bulimina elongata (D'Orbigny), Elphidium excavatum (Terquem), E. poeyanum (D'Orbigny), Ammobaculites exiguus (Cushman & Brönnimann), Arenoparrella mexicana (Kornfeld), Gaudryina exillis (Cushman & Brönnimann), Textularia earlandi (Parker) and thecamoebians in four sectors of the shelf. The presence of Bulimina marginata (D'Orbigny) between 34.1-32.8º S in the winter and 34.2-32.7º S in the summer indicates that the influence of the Subtropical Shelf Front on the sediment does not change seasonally, otherwise, the presence of Angulogerina angulosa (Williamson) in the winter, only in Mar del Plata (38.9º S), show that Malvinas currents are not influencing the sediment in the summer.

  18. [A sarcoma-static new species of Pseudomonas, Pseudomonas jinanensis sp. nov].

    PubMed

    Cai, M Y; Lu, D S; Wang, D S; He, Z Z; Wang, J H

    1989-06-01

    A strain of Gram negative bacteria was isolated from the surface soil of Wuying Hill at Jinan, Shandong province with Gause's medium in 1973. It is a strain of antagonistic bacteria for hysterocervicoma, hepatoma and melanoma of mice screened from 2100 strains of bacteria. It is also antagonistic to Staphylococcus aureus, Bacillus subtilis and Micrococcus. It is a Gram negative bacterium with lophotrichous polar flagella. Straight rods in shape or with a little slightly curved rods, 0.5-0.6 X 1-2 microns, randomly arranged, poly-beta-hydroxybutyrate granules are accumulated in cells after 2-5 days cultivation. Water green soluble pigment and green fluorescent pigment are produced. Respiratory metabolism, chemoorganotroph, many carbon-containing organic compounds can be used as carbon sources, such as glucose, trehalose, ethanol, cellulobiose, fucose, arginine and betaine, but propionic acid or tartaric acid is not utilized. Inorganic nitrogen containing compounds can be used ae the sole source of nitrogen. No growth factor is necessary for growth. Gelatin is hydrolyzed. Starch and cellulose are not hydrolyzed. Nitrate is not reduced. Arginine dihydrolase is produced. Levan is produced from sucrose. Growth occurs from 7 degrees C to 37 degrees C and from pH 5.65-8.40. No growth occurs at 40 degrees C and at pH value below 4.86. It can not grow autotrophically with hydrogen. Its G + C contents in DNA is 58.1 mol%. DNA-DNA hybridization experiments reveals a relatedness value of 58.6% between this strain and Ps. fluorescens. The above evidence shows that this strain differs from all species known in Pseudomonas, such as Pseudomonas fluorescens group. Pseudomonas caryophylli, Pseudomonas cepacia, Pseudomonas marginata, Pseudomonas acidovorans, Pseudomonas testosteroni and Pseudomonas delafieldii.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Structure, diversity and evolution of myriapod hemocyanins.

    PubMed

    Pick, Christian; Scherbaum, Samantha; Hegedüs, Elöd; Meyer, Andreas; Saur, Michael; Neumann, Ruben; Markl, Jürgen; Burmester, Thorsten

    2014-04-01

    Oxygen transport in the hemolymph of many arthropods is mediated by hemocyanins, large copper-containing proteins that are well-studied in Chelicerata and Crustacea, but had long been considered unnecessary in the subphylum of Myriapoda. Only recently has it become evident that hemocyanins are present in Scutigeromorpha (Chilopoda) and Spirostreptida (Diplopoda). Here we present evidence for a more widespread occurrence of hemocyanin in the myriapods. By means of RT-PCR, western blotting and database searches, hemocyanins were identified in the symphylans Hanseniella audax and Symphylella vulgaris, the chilopod Scolopendra subspinipes dehaani and the diplopod Polydesmus angustus. No hemocyanins were found in the diplopods Polyxenus lagurus, Cylindroiulus punctatus, Glomeris marginata, Glomeris pustulata and Arthrosphaera brandtii, or the chilopods Lithobius forficatus, Geophilus flavus and Strigamia maritima. This suggests multiple independent losses in myriapod taxa. Two independent hemocyanin subunits were found that were already present in the myriapod stem line. We specifically investigated the structure of the hemocyanin of P. angustus, which consists of three distinct subunits that occur in an approximately equimolar ratio. As deduced by 3D electron microscopy, the quaternary structure is a 3 × 6-mer that resembles the half structure of the 6 × 6-mer hemocyanin from Scutigera coleoptrata. It was analyzed more closely by homology modeling of 1 × 6-mers and their rigid-body fitting to the electron density map of the 3 × 6-mer. In addition, we obtained the cDNA sequence of a putative myriapod phenoloxidase. Phenoloxidases are related to the arthropod hemocyanins, but diverged before radiation of the arthropod subphyla.

  20. The pattern of Distal-less expression in the mouthparts of crustaceans, myriapods and insects: new evidence for a gnathobasic mandible and the common origin of Mandibulata.

    PubMed

    Scholtz, G; Mittmann, B; Gerberding, M

    1998-09-01

    We examined embryos of representatives of crustaceans, myriapods and insects with respect to DII expression in the mouthparts. In order to examine the relationships between mandibular DII expression and the occurrence of a mandibular palp we compared amphipod, isopod and decapod crustacean species. In species with mandibular palps, DII expression is maintained throughout development and is restricted to the palps. The species lacking a palp as an adult show only transient DII expression in early embryonic stages. Furthermore, we studied mandibular DII expression in the myriapod Glomeris marginata that lacks like all myriapods mandibular palps as an adult. The expression pattern is similar to that in crustaceans lacking a palp as an adult. We examined entognathous and ectognathous insects. No sign of mandibular expression could be detected. It is shown that the distal parts of the mandibular appendage were reduced in several steps and lineages independently up to a total loss. Furthermore, we studied DII expression in the first and second maxillae. Except for Glomeris and the collembolans, the first maxillae of all species show a similar pattern of three lobes expressing DII: the outer expression marks the maxillary palp and the inner two mark the outgrowing endites (galea and lacinia of insects). In the first maxillae of collembolans only two expression areas could be detected. In palpless adult first maxillae of isopod crustaceans a transitory embryonic palp occurs which is also DII positive. In the second maxillae of insects, isopod and amphipod crustaceans only two DII-positive lobes occur. Our data suggest a gnathobasic character of the mandibles of crustaceans, myriapods and insects supporting the monophyly of Mandibulata sensu Snodgrass. The interpretation of DII expression patterns and its limits are critically evaluated.

  1. Expression of pair rule gene orthologs in the blastoderm of a myriapod: evidence for pair rule-like mechanisms?

    PubMed Central

    2012-01-01

    Background A hallmark of Drosophila segmentation is the stepwise subdivision of the body into smaller and smaller units, and finally into the segments. This is achieved by the function of the well-understood segmentation gene cascade. The first molecular sign of a segmented body appears with the action of the pair rule genes, which are expressed as transversal stripes in alternating segments. Drosophila development, however, is derived, and in most other arthropods only the anterior body is patterned (almost) simultaneously from a pre-existing field of cells; posterior segments are added sequentially from a posterior segment addition zone. A long-standing question is to what extent segmentation mechanisms known from Drosophila may be conserved in short-germ arthropods. Despite the derived developmental modes, it appears more likely that conserved mechanisms can be found in anterior patterning. Results Expression analysis of pair rule gene orthologs in the blastoderm of the pill millipede Glomeris marginata (Myriapoda: Diplopoda) suggests that these genes are generally involved in segmenting the anterior embryo. We find that the Glomeris pairberry-1 ( pby-1) gene is expressed in a pair rule pattern that is also found in insects and a chelicerate, the mite Tetraynchus urticae. Other Glomeris pair rule gene orthologs are expressed in double segment wide domains in the blastoderm, which at subsequent stages split into two stripes in adjacent segments. Conclusions The expression patterns of the millipede pair rule gene orthologs resemble pair rule patterning in Drosophila and other insects, and thus represent evidence for the presence of an ancestral pair rule-like mechanism in myriapods. We discuss the possibilities that blastoderm patterning may be conserved in long-germ and short-germ arthropods, and that a posterior double segmental mechanism may be present in short-germ arthropods. PMID:22595029

  2. Expression of myriapod pair rule gene orthologs

    PubMed Central

    2011-01-01

    Background Segmentation is a hallmark of the arthropods; most knowledge about the molecular basis of arthropod segmentation comes from work on the fly Drosophila melanogaster. In this species a hierarchic cascade of segmentation genes subdivides the blastoderm stepwise into single segment wide regions. However, segmentation in the fly is a derived feature since all segments form virtually simultaneously. Conversely, in the vast majority of arthropods the posterior segments form one at a time from a posterior pre-segmental zone. The pair rule genes (PRGs) comprise an important level of the Drosophila segmentation gene cascade and are indeed the first genes that are expressed in typical transverse stripes in the early embryo. Information on expression and function of PRGs outside the insects, however, is scarce. Results Here we present the expression of the pair rule gene orthologs in the pill millipede Glomeris marginata (Myriapoda: Diplopoda). We find evidence that these genes are involved in segmentation and that components of the hierarchic interaction of the gene network as found in insects may be conserved. We further provide evidence that segments are formed in a single-segment periodicity rather than in pairs of two like in another myriapod, the centipede Strigamia maritima. Finally we show that decoupling of dorsal and ventral segmentation in Glomeris appears already at the level of the PRGs. Conclusions Although the pair rule gene network is partially conserved among insects and myriapods, some aspects of PRG interaction are, as suggested by expression pattern analysis, convergent, even within the Myriapoda. Conserved expression patterns of PRGs in insects and myriapods, however, may represent ancestral features involved in segmenting the arthropod ancestor. PMID:21352542

  3. Diplectanids from Mycteroperca spp. (Epinephelidae) in the Mediterranean Sea: Redescriptions of six species from material collected off Tunisia and Libya, proposal for the 'Pseudorhabdosynochus riouxi group’, and a taxonomic key

    PubMed Central

    Neifar, Lassad; Justine, Jean-Lou

    2017-01-01

    Diplectanid monogeneans are gill parasites that can infect fish in huge numbers and thus become harmful, especially in maricultured fish. It is therefore useful to have taxonomic tools, such as keys, to identify species. The following diplectanid species from groupers of the Mediterranean Sea were studied: five species of Pseudorhabdosynochus Yamaguti, 1958, including P. riouxi (Oliver, 1986) Kritsky & Beverley-Burton, 1986 from the dusky grouper Mycteroperca marginata, P. enitsuji Neifar & Euzet, 2007, P. bouaini Neifar & Euzet, 2007, P. dolicocolpos Neifar & Euzet, 2007 and P. sinediscus Neifar & Euzet, 2007 from the goldblotch grouper M. costae, and Echinoplectanum echinophallus (Euzet & Oliver, 1965) Justine & Euzet, 2006 from the dusky grouper. New material was obtained from fish collected from off Tunisia and Libya and compared to the type-material and voucher specimens in museum collections. Identifications of fish were confirmed by barcoding of cytochrome c oxidase subunit I (COI) sequences. The sclerotized vagina was considered the most important structure for systematics. The three species P. riouxi, P. bouaini, and P. enitsuji share a common general structure of the sclerotized vagina with a conspicuous spherical secondary chamber. We thus propose the ‘Pseudorhabdosynochus riouxi group’ to accommodate them. Pseudorhabdosynochus dolicocolpos has an elongate vaginal structure that is completely different from all its congeneric species reported from the Mediterranean Sea, and Pseudorhabdosynochus sinediscus has a sclerotized vagina in which the secondary chamber is not visible, and a haptor without squamodiscs. A taxonomic key to diplectanid species on Mycteroperca spp. in the Mediterranean Sea is proposed; it includes ten species of Pseudorhabdosynochus and one species of Echinoplectanum. PMID:28152034

  4. Living (stained) benthic foraminifera from the Mozambique Channel (eastern Africa): Exploring ecology of deep-sea unicellular meiofauna

    NASA Astrophysics Data System (ADS)

    Fontanier, C.; Garnier, E.; Brandily, C.; Dennielou, B.; Bichon, S.; Gayet, N.; Eugene, T.; Rovere, M.; Grémare, A.; Deflandre, B.

    2016-09-01

    Live (Rose-Bengal stained) deep-sea foraminiferal faunas have been studied at four stations between 530 and 3200-m depth in the Mozambique Channel (eastern Africa) to understand how complex environmental conditions (e.g., organic matter, oxygenation) control their ecological structure (i.e., diversity, density, and microhabitats). Two upper-slope stations, located at 530- and 780-m depth off Madagascar, are bathed by well-oxygenated bottom waters. They are characterized by fine sediments enriched in highly degraded organic matter (low amino-acid bio-availability and reduced chlorophyllic freshness). Mineralization of organic compounds results in relatively moderate oxygen penetration depth (i.e., 15 and 30 mm) in sediment. Interestingly, foraminiferal species richness (S) is exceptionally high at both sites. The highest densities are observed in the 780-m deep station, where peculiar sedimentary facies of organic matter are recorded (OC >2.0% DW). Redox conditions and sedimentary organic matter control the composition and the vertical distribution (i.e. microhabitat) of benthic faunas at both upper-slope sites. Bolivina alata, Bulimina marginata, Haplophragmoides bradyi and Nouria compressa are relevant bio-indicators of enhanced burial of organic matter prevailing at the 780-m deep station (i.e., eutrophic conditions), whereas Uvigerina hispida and Uvigerina semiornata are dominant at the 530-m deep station (i.e., relatively mesotrophic conditions). Two other stations are located on well-ventilated terraces from the deep-sea canyons of Tsiribihina and Zambezi (>3000-m depth). They are characterized by carbonate ooze, which is depleted in degraded organic matter and, where oxygen penetration depth is relatively deep (i.e.,>80 mm). Because of food scarcity, S and densities are relatively low, and agglutinated and organic-walled taxa dominate foraminiferal faunas. Hospitella fulva, a foraminiferal species belonging to Allogromiida, occupies very deep infaunal

  5. rbcL and matK Earn Two Thumbs Up as the Core DNA Barcode for Ferns

    PubMed Central

    Li, Fay-Wei; Kuo, Li-Yaung; Rothfels, Carl J.; Ebihara, Atsushi; Chiou, Wen-Liang; Windham, Michael D.; Pryer, Kathleen M.

    2011-01-01

    Background DNA barcoding will revolutionize our understanding of fern ecology, most especially because the accurate identification of the independent but cryptic gametophyte phase of the fern's life history—an endeavor previously impossible—will finally be feasible. In this study, we assess the discriminatory power of the core plant DNA barcode (rbcL and matK), as well as alternatively proposed fern barcodes (trnH-psbA and trnL-F), across all major fern lineages. We also present plastid barcode data for two genera in the hyperdiverse polypod clade—Deparia (Woodsiaceae) and the Cheilanthes marginata group (currently being segregated as a new genus of Pteridaceae)—to further evaluate the resolving power of these loci. Principal Findings Our results clearly demonstrate the value of matK data, previously unavailable in ferns because of difficulties in amplification due to a major rearrangement of the plastid genome. With its high sequence variation, matK complements rbcL to provide a two-locus barcode with strong resolving power. With sequence variation comparable to matK, trnL-F appears to be a suitable alternative barcode region in ferns, and perhaps should be added to the core barcode region if universal primer development for matK fails. In contrast, trnH-psbA shows dramatically reduced sequence variation for the majority of ferns. This is likely due to the translocation of this segment of the plastid genome into the inverted repeat regions, which are known to have a highly constrained substitution rate. Conclusions Our study provides the first endorsement of the two-locus barcode (rbcL+matK) in ferns, and favors trnL-F over trnH-psbA as a potential back-up locus. Future work should focus on gathering more fern matK sequence data to facilitate universal primer development. PMID:22028918

  6. The importance of biotic factors in predicting global change effects on decomposition of temperate forest leaf litter.

    PubMed

    Rouifed, Soraya; Handa, I Tanya; David, Jean-François; Hättenschwiler, Stephan

    2010-05-01

    Increasing atmospheric CO(2) and temperature are predicted to alter litter decomposition via changes in litter chemistry and environmental conditions. The extent to which these predictions are influenced by biotic factors such as litter species composition or decomposer activity, and in particular how these different factors interact, is not well understood. In a 5-week laboratory experiment we compared the decomposition of leaf litter from four temperate tree species (Fagus sylvatica, Quercus petraea, Carpinus betulus and Tilia platyphyllos) in response to four interacting factors: elevated CO(2)-induced changes in litter quality, a 3 degrees C warmer environment during decomposition, changes in litter species composition, and presence/absence of a litter-feeding millipede (Glomeris marginata). Elevated CO(2) and temperature had much weaker effects on decomposition than litter species composition and the presence of Glomeris. Mass loss of elevated CO(2)-grown leaf litter was reduced in Fagus and increased in Fagus/Tilia mixtures, but was not affected in any other leaf litter treatment. Warming increased litter mass loss in Carpinus and Tilia, but not in the other two litter species and in none of the mixtures. The CO(2)- and temperature-related differences in decomposition disappeared completely when Glomeris was present. Overall, fauna activity stimulated litter mass loss, but to different degrees depending on litter species composition, with a particularly strong effect on Fagus/Tilia mixtures (+58%). Higher fauna-driven mass loss was not followed by higher C mineralization over the relatively short experimental period. Apart from a strong interaction between litter species composition and fauna, the tested factors had little or no interactive effects on decomposition. We conclude that if global change were to result in substantial shifts in plant community composition and macrofauna abundance in forest ecosystems, these interacting biotic factors could have

  7. Anatomy of nasal complex in the southern right whale, Eubalaena australis (Cetacea, Mysticeti).

    PubMed

    Buono, Mónica R; Fernández, Marta S; Fordyce, R Ewan; Reidenberg, Joy S

    2015-01-01

    The nasal region of the skull has undergone dramatic changes during the course of cetacean evolution. In particular, mysticetes (baleen whales) conserve the nasal mammalian pattern associated with the secondary function of olfaction, and lack the sound-producing specializations present in odontocetes (toothed whales, dolphins and porpoises). To improve our understanding of the morphology of the nasal region of mysticetes, we investigate the nasal anatomy, osteology and myology of the southern right whale, Eubalaena australis, and make comparisons with other mysticetes. In E. australis external deflection surfaces around the blowholes appear to divert water off the head, and differ in appearance from those observed in balaenopterids, eschrichtiids and cetotherids. In E. australis the blowholes are placed above hypertrophied nasal soft tissues formed by fat and nasal muscles, a pattern also observed in balaenopterids (rorqual mysticetes) and a cetotherid (pygmy right whale, Caperea marginata). Blowhole movements are due to the action of five nasofacial muscles: dilator naris superficialis, dilator naris profundus, depressor alae nasi, constrictor naris, and retractor alae nasi. The dilator naris profundus found in E. australis has not been previously reported in balaenopterids. The other nasofacial muscles have a similar arrangement in balaenopterids, with minor differences. A novel structure, not reported previously in any mysticete, is the presence of a vascular tissue (rete mirabile) covering the lower nasal passage. This vascular tissue could play a role in warming inspired air, or may engorge to accommodate loss of respiratory space volume due to gas compression from increased pressure during diving.

  8. Multigene phylogeny of the red algal subclass Nemaliophycidae.

    PubMed

    Lam, Daryl W; Verbruggen, Heroen; Saunders, Gary W; Vis, Morgan L

    2016-01-01

    The red algae (Rhodophyta) are a lineage of primary endosymbionts whose ancestors represent some of the first photosynthetic eukaryotes on the planet. They primarily inhabit marine ecosystems, with only ∼5% of species found in freshwater systems. The subclass Nemaliophycidae is very diverse in ecological and life history features and therefore a useful model to study these traits, but the phylogenetic relationships among the orders are, for the most part, poorly resolved. To elucidate the phylogeny of the Nemaliophycidae, we constructed a nine-gene dataset comprised of nuclear, plastid, and mitochondrial markers for 67 red algal specimens. The resulting maximum likelihood (ML) phylogeny confirmed the monophyly of all orders. The sister relationship of the Acrochaetiales and Palmariales received high support and the relationship of the Balliales with Balbianiales and Entwisleiales with Colaconematales was moderately supported. The Nemaliales, Entwisleiales, Colaconematales, Palmariales and Acrochaetiales formed a highly supported clade. Unfortunately, all other relationships among the orders had low bootstrap support. Although the ML analysis did not resolve many of the relationships, further analyses suggested that a resolution is possible. A Phycas analysis supported a dichotomously branching tree and Bayesian analysis showed a similar topology with all relationships highly supported. Simulations extrapolating the number of nucleotide characters beyond the current size of the dataset suggested that most nodes in the phylogeny would be resolved if more data become available. Phylogenomic approaches will be necessary to provide a well-supported phylogeny of this subclass with all relationships resolved such that the evolution of freshwater species from marine ancestors as well as reproductive traits can be explored.

  9. THE BIOGEOGRAPHIC ORIGIN OF ARCTIC ENDEMIC SEAWEEDS: A THERMOGEOGRAPHIC VIEW(1).

    PubMed

    Adey, Walter H; Lindstrom, Sandra C; Hommersand, Max H; Müller, Kirsten M

    2008-12-01

    The Arctic is geologically and biogeographically young, and the origin of its seaweed flora has been widely debated. The Arctic littoral biogeographic region dates from the latest Tertiary and Pleistocene. Following the opening of Bering Strait, about 3.5 mya, the "Great Trans-Arctic Biotic Interchange" populated the Arctic with a fauna strongly dominated by species of North Pacific origin. The Thermogeographic Model (TM) demonstrates why climate and geography continued to support this pattern in the Pleistocene. Thus, Arctic and Atlantic subarctic species of seaweeds are likely to be evolutionarily "based" in the North Pacific, subarctic species are likely to be widespread in the warmer Arctic, and species of Atlantic Boreal or warmer origin are unlikely in the Arctic and Subarctic. Although Arctic seaweeds have been thought to have a greater affinity with the North Atlantic, we have reanalyzed the Arctic endemic algal flora, using the Thermogeographic Model and evolutionary trees based on molecular data, to demonstrate otherwise. There are 35 congeneric species of the six, abundant Arctic Rhodophyta that we treat in this paper; 32 of these species (91%) occur in the North Pacific, two species (6%) occur in the Boreal or warmer Atlantic Ocean, and a single species is panoceanic, but restricted to the Subarctic. Laminaria solidungula J. Agardh, a kelp Arctic "endemic" species, has 18 sister species. While only eleven (61%) occur in the North Pacific, this rapidly dispersing and evolving genus is a terminal member of a diverse family and order (Laminariales) widely accepted to have evolved in the North Pacific. Thus, both the physical/time-based TM and the dominant biogeographic pattern of relatives of Arctic macrophytes suggest strong compliance with the evidence of zoology, geology, and paleoclimatology that the Arctic marine flora is largely of Pacific origin.

  10. Development of a cost-effective metabarcoding strategy for analysis of the marine phytoplankton community

    PubMed Central

    Yoon, Tae-Ho; Kang, Hye-Eun; Kang, Chang-Keun; Lee, Sang Heon; Ahn, Do-Hwan

    2016-01-01

    We developed a cost-effective metabarcoding strategy to analyze phytoplankton community structure using the Illumina MiSeq system. The amplicons (404–411 bp) obtained by end-pairing of two reads were sufficiently long to distinguish algal species and provided barcode data equivalent to those generated with the Roche 454 system, but at less than 1/20th of the cost. The original universal primer sequences targeting the 23S rDNA region and the PCR strategy were both modified, and this resulted in higher numbers of eukaryotic algal sequences by excluding non-photosynthetic proteobacterial sequences supporting effectiveness of this strategy. The novel strategy was used to analyze the phytoplankton community structure of six water samples from the East/Japan Sea: surface and 50 m depths at coastal and open-sea sites, with collections in May and July 2014. In total, 345 operational taxonomic units (OTUs) were identified, which covered most of the prokaryotic and eukaryotic algal phyla, including Dinophyta, Rhodophyta, Ochrophyta, Chlorophyta, Streptophyta, Cryptophyta, Haptophyta, and Cyanophyta. This highlights the importance of plastid 23S primers, which perform better than the currently used 16S primers for phytoplankton community surveys. The findings also revealed that more efforts should be made to update 23S rDNA sequences as well as those of 16S in the databases. Analysis of algal proportions in the six samples showed that community structure differed depending on location, depth and season. Across the six samples evaluated, the numbers of OTUs in each phylum were similar but their relative proportions varied. This novel strategy would allow laboratories to analyze large numbers of samples at reasonable expense, whereas this has not been possible to date due to cost and time. In addition, we expect that this strategy will generate a large amount of novel data that could potentially change established methods and tools that are currently used in the realms of

  11. The Complete Chloroplast and Mitochondrial Genomes of the Green Macroalga Ulva sp. UNA00071828 (Ulvophyceae, Chlorophyta)

    PubMed Central

    Melton, James T.; Leliaert, Frederik; Tronholm, Ana; Lopez-Bautista, Juan M.

    2015-01-01

    Sequencing mitochondrial and chloroplast genomes has become an integral part in understanding the genomic machinery and the phylogenetic histories of green algae. Previously, only three chloroplast genomes (Oltmannsiellopsis viridis, Pseudendoclonium akinetum, and Bryopsis hypnoides) and two mitochondrial genomes (O. viridis and P. akinetum) from the class Ulvophyceae have been published. Here, we present the first chloroplast and mitochondrial genomes from the ecologically and economically important marine, green algal genus Ulva. The chloroplast genome of Ulva sp. was 99,983 bp in a circular-mapping molecule that lacked inverted repeats, and thus far, was the smallest ulvophycean plastid genome. This cpDNA was a highly compact, AT-rich genome that contained a total of 102 identified genes (71 protein-coding genes, 28 tRNA genes, and three ribosomal RNA genes). Additionally, five introns were annotated in four genes: atpA (1), petB (1), psbB (2), and rrl (1). The circular-mapping mitochondrial genome of Ulva sp. was 73,493 bp and follows the expanded pattern also seen in other ulvophyceans and trebouxiophyceans. The Ulva sp. mtDNA contained 29 protein-coding genes, 25 tRNA genes, and two rRNA genes for a total of 56 identifiable genes. Ten introns were annotated in this mtDNA: cox1 (4), atp1 (1), nad3 (1), nad5 (1), and rrs (3). Double-cut-and-join (DCJ) values showed that organellar genomes across Chlorophyta are highly rearranged, in contrast to the highly conserved organellar genomes of the red algae (Rhodophyta). A phylogenomic investigation of 51 plastid protein-coding genes showed that Ulvophyceae is not monophyletic, and also placed Oltmannsiellopsis (Oltmannsiellopsidales) and Tetraselmis (Chlorodendrophyceae) closely to Ulva (Ulvales) and Pseudendoclonium (Ulothrichales). PMID:25849557

  12. XET Activity is Found Near Sites of Growth and Cell Elongation in Bryophytes and Some Green Algae: New Insights into the Evolution of Primary Cell Wall Elongation

    PubMed Central

    Van Sandt, Vicky S. T.; Stieperaere, Herman; Guisez, Yves; Verbelen, Jean-Pierre; Vissenberg, Kris

    2007-01-01

    Background and Aims In angiosperms xyloglucan endotransglucosylase (XET)/hydrolase (XTH) is involved in reorganization of the cell wall during growth and development. The location of oligo-xyloglucan transglucosylation activity and the presence of XTH expressed sequence tags (ESTs) in the earliest diverging extant plants, i.e. in bryophytes and algae, down to the Phaeophyta was examined. The results provide information on the presence of an XET growth mechanism in bryophytes and algae and contribute to the understanding of the evolution of cell wall elongation in general. Methods Representatives of the different plant lineages were pressed onto an XET test paper and assayed. XET or XET-related activity was visualized as the incorporation of fluorescent signal. The Physcomitrella genome database was screened for the presence of XTHs. In addition, using the 3′ RACE technique searches were made for the presence of possible XTH ESTs in the Charophyta. Key Results XET activity was found in the three major divisions of bryophytes at sites corresponding to growing regions. In the Physcomitrella genome two putative XTH-encoding cDNA sequences were identified that contain all domains crucial for XET activity. Furthermore, XET activity was located at the sites of growth in Chara (Charophyta) and Ulva (Chlorophyta) and a putative XTH ancestral enzyme in Chara was identified. No XET activity was identified in the Rhodophyta or Phaeophyta. Conclusions XET activity was shown to be present in all major groups of green plants. These data suggest that an XET-related growth mechanism originated before the evolutionary divergence of the Chlorobionta and open new insights in the evolution of the mechanisms of primary cell wall expansion. PMID:17098750

  13. Comprehensive Phylogenetic Analysis Sheds Light on the Diversity and Origin of the MLO Family of Integral Membrane Proteins

    PubMed Central

    Kusch, Stefan; Pesch, Lina; Panstruga, Ralph

    2016-01-01

    Mildew resistance Locus O (MLO) proteins are polytopic integral membrane proteins that have long been considered as plant-specific and being primarily involved in plant–powdery mildew interactions. However, research in the past decade has revealed that MLO proteins diverged into a family with several clades whose members are associated with different physiological processes. We provide a largely increased dataset of MLO amino acid sequences, comprising nearly all major land plant lineages. Based on this comprehensive dataset, we defined seven phylogenetic clades and reconstructed the likely evolution of the MLO family in embryophytes. We further identified several MLO peptide motifs that are either conserved in all MLO proteins or confined to one or several clades, supporting the notion that clade-specific diversification of MLO functions is associated with particular sequence motifs. In baker’s yeast, some of these motifs are functionally linked to transmembrane (TM) transport of organic molecules and ions. In addition, we attempted to define the evolutionary origin of the MLO family and found that MLO-like proteins with highly diverse membrane topologies are present in green algae, but also in the distinctly related red algae (Rhodophyta), Amoebozoa, and Chromalveolata. Finally, we discovered several instances of putative fusion events between MLO proteins and different kinds of proteins. Such Rosetta stone-type hybrid proteins might be instructive for future analysis of potential MLO functions. Our findings suggest that MLO is an ancient protein that possibly evolved in unicellular photosynthetic eukaryotes, and consolidated in land plants with a conserved topology, comprising seven TM domains and an intrinsically unstructured C-terminus. PMID:26893454

  14. Marine Invasion in the Mediterranean Sea: The Role of Abiotic Factors When There Is No Biological Resistance

    PubMed Central

    2012-01-01

    The tropical red alga Womersleyella setacea (Rhodomelaceae, Rhodophyta) is causing increasing concern in the Mediterranean Sea because of its invasive behavior. After its introduction it has colonized most Mediterranean areas, but the mechanism underlying its acclimatization and invasion process remains unknown. To understand this process, we decided i) to assess in situ the seasonal biomass and phenological patterns of populations inhabiting the Mediterranean Sea in relation to the main environmental factors, and ii) to experimentally determine if the tolerance of W. setacea to different light and temperature conditions can explain its colonization success, as well as its bathymetric distribution range. The bathymetric distribution, biomass, and phenology of W. setacea were studied at two localities, and related to irradiance and temperature values recorded in situ. Laboratory experiments were set up to study survival, growth and reproduction under contrasting light and temperature conditions in the short, mid, and long term.Results showed that, in the studied area, the bathymetric distribution of W. setacea is restricted to a depth belt between 25 and 40 m deep, reaching maximum biomass values (126 g dw m−2) at 30 m depth. In concordance, although in the short term W. setacea survived and grew in a large range of environmental conditions, its life requirements for the mid and long term were dim light levels and low temperatures. Biomass of Womersleyella setacea did not show any clear seasonal pattern, though minimum values were reported in spring. Reproductive structures were always absent. Bearing in mind that no herbivores feed on Womersleyella setacea and that its thermal preferences are more characteristic of temperate than of tropical seaweeds, low light (50 µmol photon m−2 s−1) and low temperature (12°C) levels are critical for W. setacea survival and growth, thus probably determining its spread and bathymetric distribution across the Mediterranean

  15. Effect of the dietary brominated phenol, lanasol, on chemical biotransformation enzymes in the gumboot chiton Cryptochiton stelleri (Middendorf, 1846).

    PubMed

    Debusk, B C; Chimote, S S; Rimoldi, J M; Schenk, D

    2000-09-01

    The effects of diet and other non-anthropogenic stressors on biochemical defenses and their relationship to susceptibility have been largely ignored in wildlife populations. Lanosol is a compound found in relatively high amounts in various marine species of Rhodophyta, including Odonthalia dentata. While previous studies demonstrated that lanosol is a feeding deterrent to several marine herbivores, Cryptochiton stelleri readily feeds upon O. dentata. To examine the effects of lanosol on the profile of biochemical defenses in C. stelleri, chitons were gavaged daily with 0, 1, 2.5, 5, or 10 mg/kg of lanosol. After three days of exposure, digestive gland microsomes were probed for expression of homologous isoforms of cytochromes P450 (CYP1A, CYP3A, and CYP2) and phase II enzymatic activities. Expression of a 43 kDa CYP3A-like protein was increased by approximately 45%, over control following 2.5, 5, and 10 mg/kg treatments. Estradiol hydroxylase activity tended to increase with the dose of lanosol. UDP-glucuronosyl transferase activity was highly variable but appeared to increase at the two highest treatments, while sulfotranserase activity was significantly decreased at the three highest doses. Kinetic studies of GST activity showed lanosol is a non-competitive inhibitor of both CDNB and GSH in the GST-mediated conjugation reaction. These results show that dietary exposure to the brominated-phenol, lanosol, may alter expression and activity of some phase I and II biotransformation enzymes in chitons, potentially providing a dietary advantage for the species.

  16. Physiologic and metagenomic attributes of the rhodoliths forming the largest CaCO3 bed in the South Atlantic Ocean

    PubMed Central

    Cavalcanti, Giselle S; Gregoracci, Gustavo B; dos Santos, Eidy O; Silveira, Cynthia B; Meirelles, Pedro M; Longo, Leila; Gotoh, Kazuyoshi; Nakamura, Shota; Iida, Tetsuya; Sawabe, Tomoo; Rezende, Carlos E; Francini-Filho, Ronaldo B; Moura, Rodrigo L; Amado-Filho, Gilberto M; Thompson, Fabiano L

    2014-01-01

    Rhodoliths are free-living coralline algae (Rhodophyta, Corallinales) that are ecologically important for the functioning of marine environments. They form extensive beds distributed worldwide, providing a habitat and nursery for benthic organisms and space for fisheries, and are an important source of calcium carbonate. The Abrolhos Bank, off eastern Brazil, harbors the world's largest continuous rhodolith bed (of ∼21 000 km2) and has one of the largest marine CaCO3 deposits (producing 25 megatons of CaCO3 per year). Nevertheless, there is a lack of information about the microbial diversity, photosynthetic potential and ecological interactions within the rhodolith holobiont. Herein, we performed an ecophysiologic and metagenomic analysis of the Abrolhos rhodoliths to understand their microbial composition and functional components. Rhodoliths contained a specific microbiome that displayed a significant enrichment in aerobic ammonia-oxidizing betaproteobacteria and dissimilative sulfate-reducing deltaproteobacteria. We also observed a significant contribution of bacterial guilds (that is, photolithoautotrophs, anaerobic heterotrophs, sulfide oxidizers, anoxygenic phototrophs and methanogens) in the rhodolith metagenome, suggested to have important roles in biomineralization. The increased hits in aromatic compounds, fatty acid and secondary metabolism subsystems hint at an important chemically mediated interaction in which a functional job partition among eukaryal, archaeal and bacterial groups allows the rhodolith holobiont to thrive in the global ocean. High rates of photosynthesis were measured for Abrolhos rhodoliths (52.16 μmol carbon m−2 s−1), allowing the entire Abrolhos rhodolith bed to produce 5.65 × 105 tons C per day. This estimate illustrates the great importance of the Abrolhos rhodolith beds for dissolved carbon production in the South Atlantic Ocean. PMID:23985749

  17. Exposure-driven macroalgal phase shift following catastrophic disturbance on coral reefs

    NASA Astrophysics Data System (ADS)

    Roff, George; Chollett, Iliana; Doropoulos, Christopher; Golbuu, Yimnang; Steneck, Robert S.; Isechal, Adelle L.; van Woesik, Robert; Mumby, Peter J.

    2015-09-01

    Environmental conditions play an important role in post-disturbance dynamics of ecosystems by modulating recovery of surviving communities and influencing patterns of succession. Here, we document the effects of wave exposure following a catastrophic disturbance on coral reefs in driving a phase shift to macroalgal dominance. In December 2012, a Category 5 super typhoon (`Typhoon Bopha') passed 50 km to the south of Palau (Micronesia), causing a major loss of reef corals. Immediately post-disturbance, a rapid and extensive phase shift of the macroalgae Liagora sp. (Rhodophyta) was observed at sites exposed to chronic wave exposure. To quantify the influence of biotic and abiotic drivers in modulating the extent of post-disturbance Liagora blooms, we compared benthic substrates and herbivore assemblages at sites surveyed pre- and post-disturbance across a gradient of wave exposure. Relative changes in herbivore biomass and coral cover before and after disturbance did not significantly predict the extent of Liagora cover, indicating that changes in herbivore biomass or reductions in grazing pressure were not directly responsible for driving the Liagora blooms. By contrast, the degree of wave exposure experienced at sites post-disturbance explained >90 % of model variance ( p < 0.001, R 2 = 0.69), in that Liagora was absent at low exposure sites, while most extensive blooms were observed at highly exposed sites. At regional scales, spatial maps of wave exposure accurately predicted the presence of Liagora at impacted sites throughout the Palau archipelago (>150 km distance), highlighting the predictive capacity of wave exposure as an explanatory variable and the deterministic nature of post-disturbance macroalgal blooms. Understanding how physical conditions modulate recovery of ecosystems after disturbance allows insight into post-disturbance dynamics and succession of communities, ultimately allowing management strategies to prioritise restoration efforts in regions

  18. INTERACTIONS BETWEEN OCEAN ACIDIFICATION AND WARMING ON THE MORTALITY AND DISSOLUTION OF CORALLINE ALGAE(1).

    PubMed

    Diaz-Pulido, Guillermo; Anthony, Kenneth R N; Kline, David I; Dove, Sophie; Hoegh-Guldberg, Ove

    2012-02-01

    Coralline algae are among the most sensitive calcifying organisms to ocean acidification as a result of increased atmospheric carbon dioxide (pCO2 ). Little is known, however, about the combined impacts of increased pCO2 , ocean acidification, and sea surface temperature on tissue mortality and skeletal dissolution of coralline algae. To address this issue, we conducted factorial manipulative experiments of elevated CO2 and temperature and examined the consequences on tissue survival and skeletal dissolution of the crustose coralline alga (CCA) Porolithon (=Hydrolithon) onkodes (Heydr.) Foslie (Corallinaceae, Rhodophyta) on the southern Great Barrier Reef (GBR), Australia. We observed that warming amplified the negative effects of high pCO2 on the health of the algae: rates of advanced partial mortality of CCA increased from <1% to 9% under high CO2 (from 400 to 1,100 ppm) and exacerbated to 15% under warming conditions (from 26°C to 29°C). Furthermore, the effect of pCO2 on skeletal dissolution strongly depended on temperature. Dissolution of P. onkodes only occurred in the high-pCO2 treatment and was greater in the warm treatment. Enhanced skeletal dissolution was also associated with a significant increase in the abundance of endolithic algae. Our results demonstrate that P. onkodes is particularly sensitive to ocean acidification under warm conditions, suggesting that previous experiments focused on ocean acidification alone have underestimated the impact of future conditions on coralline algae. Given the central role that coralline algae play within coral reefs, these conclusions have serious ramifications for the integrity of coral-reef ecosystems.

  19. Marine invasion in the Mediterranean Sea: the role of abiotic factors when there is no biological resistance.

    PubMed

    Cebrian, Emma; Rodríguez-Prieto, Conxi

    2012-01-01

    The tropical red alga Womersleyella setacea (Rhodomelaceae, Rhodophyta) is causing increasing concern in the Mediterranean Sea because of its invasive behavior. After its introduction it has colonized most Mediterranean areas, but the mechanism underlying its acclimatization and invasion process remains unknown. To understand this process, we decided i) to assess in situ the seasonal biomass and phenological patterns of populations inhabiting the Mediterranean Sea in relation to the main environmental factors, and ii) to experimentally determine if the tolerance of W. setacea to different light and temperature conditions can explain its colonization success, as well as its bathymetric distribution range. The bathymetric distribution, biomass, and phenology of W. setacea were studied at two localities, and related to irradiance and temperature values recorded in situ. Laboratory experiments were set up to study survival, growth and reproduction under contrasting light and temperature conditions in the short, mid, and long term. Results showed that, in the studied area, the bathymetric distribution of W. setacea is restricted to a depth belt between 25 and 40 m deep, reaching maximum biomass values (126 g dw m(-2)) at 30 m depth. In concordance, although in the short term W. setacea survived and grew in a large range of environmental conditions, its life requirements for the mid and long term were dim light levels and low temperatures. Biomass of Womersleyella setacea did not show any clear seasonal pattern, though minimum values were reported in spring. Reproductive structures were always absent. Bearing in mind that no herbivores feed on Womersleyella setacea and that its thermal preferences are more characteristic of temperate than of tropical seaweeds, low light (50 µmol photon m(-2) s(-1)) and low temperature (12°C) levels are critical for W. setacea survival and growth, thus probably determining its spread and bathymetric distribution across the Mediterranean

  20. Temporal mismatch between induction of superoxide dismutase and ascorbate peroxidase correlates with high H2O2 concentration in seawater from clofibrate-treated red algae Kappaphycus alvarezii.

    PubMed

    Barros, Marcelo P; Granbom, Malena; Colepicolo, Pio; Pedersén, Marianne

    2003-12-01

    Algal cells have developed different strategies to cope with the common environmentally promoted generation of H(2)O(2), which include induction of catalase (CAT) and ascorbate peroxidase (APX), massive H(2)O(2) release in seawater, and synthesis of volatile halocarbons by specific peroxidases. The antioxidant adaptability of the economically important carrageenophyte Kappaphycus alvarezii (Doty) Doty (Gigartinales: Rhodophyta) was tested here against exposure to clofibrate (CFB), a known promoter of peroxisomal beta-oxidation in mammals and plants. Possibly as a consequence of CFB-induced H2O2 peroxisomal production, the maximum concentration of H(2)O(2) in the seawater of red algae cultures was found to occur (120+/-17 min) after the addition of CFB, which was followed by a significant decrease in the photosynthetic activity of PSII after 24 h. Interestingly, 4 h after the addition of CFB, the total SOD activity was about 2.5-fold higher than in the control, whereas no significant changes were observed in lipoperoxidation levels (TBARS) or in CAT and APX activities. The two H(2)O(2)-scavenging enzymes were only induced later (after 72 h), whereupon CAT showed a dose-dependent response with increasing concentrations of CFB. A more pronounced increase of TBARS concentration than in the controls was evidenced when a 50 microM Fe(2+/3+) solution (3:2 ratio) was added to CFB-treated cultures, suggesting that the combination of exacerbated H(2)O(2) levels in the seawater-in this work, caused by CFB exposure-and Fenton-reaction catalyst (ferric/ferrous ions), imposes harsh oxidative conditions on algal cultures. The bulk of data suggests that K. alvarezii possesses little ability to promptly induce CAT and APX compared to the immediately responsive antioxidant enzyme SOD and, to avoid harmful accumulation of H(2)O(2), the red alga presumably releases H(2)O(2) into the surrounding medium as an alternative mechanism.

  1. Cloning and Functional Characterization of Cycloartenol Synthase from the Red Seaweed Laurencia dendroidea

    PubMed Central

    Arendt, Philipp; de Oliveira, Louisi Souza; Thompson, Cristiane; Soares, Angélica Ribeiro; Pereira, Renato Crespo; Goossens, Alain; Thompson, Fabiano L.

    2016-01-01

    The red seaweed Laurencia dendroidea belongs to the Rhodophyta, a phylum of eukaryotic algae that is widely distributed across the oceans and that constitute an important source of bioactive specialized metabolites. Laurencia species have been studied since 1950 and were found to contain a plethora of specialized metabolites, mainly halogenated sesquiterpenes, diterpenes and triterpenes that possess a broad spectrum of pharmacological and ecological activities. The first committed step in the biosynthesis of triterpenes is the cyclization of 2,3-oxidosqualene, an enzymatic reaction carried out by oxidosqualene cyclases (OSCs), giving rise to a broad range of different compounds, such as the sterol precursors cycloartenol and lanosterol, or triterpene precursors such as cucurbitadienol and β-amyrin. Here, we cloned and characterized the first OSC from a red seaweed. The OSC gene was identified through mining of a L. dendroidea transcriptome dataset and subsequently cloned and heterologously expressed in yeast for functional characterization, which indicated that the corresponding enzyme cyclizes 2,3-oxidosqualene to the sterol precursor cycloartenol. Accordingly, the gene was named L. dendroidea cycloartenol synthase (LdCAS). A phylogenetic analysis using OSCs genes from plants, fungi and algae revealed that LdCAS grouped together with OSCs from other red algae, suggesting that cycloartenol could be the common product of the OSC in red seaweeds. Furthermore, profiling of L. dendroidea revealed cholesterol as the major sterol accumulating in this species, implicating red seaweeds contain a ‘hybrid’ sterol synthesis pathway in which the phytosterol precursor cycloartenol is converted into the major animal sterol cholesterol. PMID:27832119

  2. The complete chloroplast and mitochondrial genomes of the green macroalga Ulva sp. UNA00071828 (Ulvophyceae, Chlorophyta).

    PubMed

    Melton, James T; Leliaert, Frederik; Tronholm, Ana; Lopez-Bautista, Juan M

    2015-01-01

    Sequencing mitochondrial and chloroplast genomes has become an integral part in understanding the genomic machinery and the phylogenetic histories of green algae. Previously, only three chloroplast genomes (Oltmannsiellopsis viridis, Pseudendoclonium akinetum, and Bryopsis hypnoides) and two mitochondrial genomes (O. viridis and P. akinetum) from the class Ulvophyceae have been published. Here, we present the first chloroplast and mitochondrial genomes from the ecologically and economically important marine, green algal genus Ulva. The chloroplast genome of Ulva sp. was 99,983 bp in a circular-mapping molecule that lacked inverted repeats, and thus far, was the smallest ulvophycean plastid genome. This cpDNA was a highly compact, AT-rich genome that contained a total of 102 identified genes (71 protein-coding genes, 28 tRNA genes, and three ribosomal RNA genes). Additionally, five introns were annotated in four genes: atpA (1), petB (1), psbB (2), and rrl (1). The circular-mapping mitochondrial genome of Ulva sp. was 73,493 bp and follows the expanded pattern also seen in other ulvophyceans and trebouxiophyceans. The Ulva sp. mtDNA contained 29 protein-coding genes, 25 tRNA genes, and two rRNA genes for a total of 56 identifiable genes. Ten introns were annotated in this mtDNA: cox1 (4), atp1 (1), nad3 (1), nad5 (1), and rrs (3). Double-cut-and-join (DCJ) values showed that organellar genomes across Chlorophyta are highly rearranged, in contrast to the highly conserved organellar genomes of the red algae (Rhodophyta). A phylogenomic investigation of 51 plastid protein-coding genes showed that Ulvophyceae is not monophyletic, and also placed Oltmannsiellopsis (Oltmannsiellopsidales) and Tetraselmis (Chlorodendrophyceae) closely to Ulva (Ulvales) and Pseudendoclonium (Ulothrichales).

  3. Implementation of a ground truth process for development of a submerged aquatic vegetation (SAV) mapping protocol using hyperspectral imagery

    NASA Astrophysics Data System (ADS)

    Hall, Carlton R.; Bostater, Charles R., Jr.; Virnstein, Robert W.

    2006-09-01

    Protocol development for science based mapping of submerged aquatic vegetation (SAV) requires comprehensive ground truth data describing the full range of variability observed in the target. The Indian River Lagoon, Florida, extends along 250 km of the east central Florida coast adjacent to the Atlantic Ocean. The lagoon crosses the transition zone between the Caribbean and Carolinian zoogeographic provinces making it highly diverse. For large scale mapping and management of SAV four common and three uncommon species of seagrass (Tracheophyta) and three broad groups of macroalgae; red algae (Rhodophyta), green algae (Chlorophyta), and brown algae (Phaeophyta) are recognized. Based on technical and cost limitations we established twenty, 7-10 km long flight transects for collection of 1.2 m2 spatial resolution hyperspectral imagery covering the length of the lagoon. Emphasis was placed on the area near the Sebastian River and adjacent Sebastian Inlet. Twenty six 40 m long ground truth transects were established in the lagoon using 1 m2 white panels to mark each transect end. Each transect target was located in the field using high precision GPS. Transects were positioned to cover a range of depths, SAV densities, mixed and monotypic species beds, water quality conditions and general sediment types. A 3 m wide by 30 m long grid was centered on each transect to avoid spectral influences of the white targets. Water depth, species of seagrasses, estimates of vegetation cover percentage, estimates of epiphytic density, and measured canopy height were made for each 1 m2 (n=90). This target based grid arrangement allows for identification and extraction of pixel based hyperspectral signatures corresponding to individual ground truth grid cells without significant concern for rectification and registration error.

  4. Phaeocystis globosa Scherffel, a harmful microalga, and its production of dimethylsulfoniopropionate

    NASA Astrophysics Data System (ADS)

    Shen, Pingping; Qi, Yuzao; Wang, Yan; Huang, Liangmin

    2011-07-01

    The production of dimethylsulfoniopropionate (DMSP) and its cleavage products (DMS) are well studied in phytoplankton worldwide. However, less is known about their sources, distributions, and impacts in the coast of China. We examined the production of DMSP and DMS in Phaeocystis globosa Scherffel and other benthic macroalgae from the South China coast in relation to environmental conditions. P. globosa was a harmful marine microalgal species and its bloom took place in the eutrophic waters along the South China Sea frequently. It also produced high content of DMSP at different growth stages, with the highest concentration usually observed in the stationary period. Moreover, the production of DMSP in P. globosa was significantly affected by salinity and temperature with the highest contents associated with high salinity (e.g. 40) and low temperature (e.g. 20°C). In field benthic macroalgae, there was also a marked difference in the DMSP of various species or different samples of the same species. Chlorophyll a contents were also determined for each macroalgal species. The highest chlorophyll a (238.7 ng/g fresh weight) was recorded in Chlorophyta Ulva lactuca at Guishan Island (Zhuhai), while the lowest value (1.5 ng/g fresh weight) was found in Rhodophyta Gracilaria tenuistipitata in Zhanjiang. Further correlation analysis indicated that there was no significant relationship between the content of DMSP and chl- a in macroalgae samples ( P > 0.05). All the results suggested that the production of DMSP in marine algae was not only species- and stage-related, but also greatly affected by various environmental factors.

  5. Cultivation and conversion of marine macroalgae. [Gracilaria and Ulva

    SciTech Connect

    Ryther, J.H.; DeBusk, T.A.; Blakeslee, M.

    1984-05-01

    Research was conducted on the development of an alternative ocean energy farm concept that would not be dependent upon deep ocean water or other extraneous sources for its nutrient supply and that could be located in shallow, near shore, and protected coastal ocean areas. There are five tasks reported in this document: determination of the annual yield of Ulva in non-intensive cultures; evaluation of the effect of carbon concentration on Gracilaria and Ulva yields; evaluation of spray/mist culture of Ulva and Gracilaria; species screening for the production of petroleum replacement products; and synthesis analysis, and economic energy evaluation of culture data. An alternative concept to open ocean culture is a land-based energy production system utilizing saline waters from underground aquifers or enclosed coastal areas. Research was performed to evaluate growth and biomass production of all macroscopic algal species that could be obtained in adequate quantity in the central Florida area. A total of 42 species were grown in specially adapted burial vaults. These included 16 green algae (Garcilaria 4 weekshlorophyta), 2 brown algae (Phaeophyta), and 18 red algae (Rhodophyta). Of these, the most successful and suitable species were a strain of Gracilaria (a red seaweed) and Ulva (a green seaweed). These two species have a high carbohydrate content that may be anaerobically digested to methane gas. Well-nourished Gracilaria will double its biomass in 1 to 4 weeks, depending on the season, water flow, and other variables. After its biomass has doubled (i.e., from 2 to 4 kg/m/sup 2/) the incremental growth is harvested to return the crop to a starting density. Enrichment of the new starting crop following harvest could conceivably be accomplished onsite at the seaweed farm, but the rapid uptake and storage of nutrients by depleted seaweeds makes possible a simpler process, known as pulse fertilization.

  6. Comprehensive Phylogenetic Analysis Sheds Light on the Diversity and Origin of the MLO Family of Integral Membrane Proteins.

    PubMed

    Kusch, Stefan; Pesch, Lina; Panstruga, Ralph

    2016-03-26

    Mildew resistanceLocusO(MLO) proteins are polytopic integral membrane proteins that have long been considered as plant-specific and being primarily involved in plant-powdery mildew interactions. However, research in the past decade has revealed that MLO proteins diverged into a family with several clades whose members are associated with different physiological processes. We provide a largely increased dataset of MLO amino acid sequences, comprising nearly all major land plant lineages. Based on this comprehensive dataset, we defined seven phylogenetic clades and reconstructed the likely evolution of the MLO family in embryophytes. We further identified several MLO peptide motifs that are either conserved in all MLO proteins or confined to one or several clades, supporting the notion that clade-specific diversification of MLO functions is associated with particular sequence motifs. In baker's yeast, some of these motifs are functionally linked to transmembrane (TM) transport of organic molecules and ions. In addition, we attempted to define the evolutionary origin of the MLO family and found that MLO-like proteins with highly diverse membrane topologies are present in green algae, but also in the distinctly related red algae (Rhodophyta), Amoebozoa, and Chromalveolata. Finally, we discovered several instances of putative fusion events between MLO proteins and different kinds of proteins. Such Rosetta stone-type hybrid proteins might be instructive for future analysis of potential MLO functions. Our findings suggest that MLO is an ancient protein that possibly evolved in unicellular photosynthetic eukaryotes, and consolidated in land plants with a conserved topology, comprising seven TM domains and an intrinsically unstructured C-terminus.

  7. Identification of potential internal control genes for real-time PCR analysis during stress response in Pyropia haitanensis

    NASA Astrophysics Data System (ADS)

    Wang, Xia; Feng, Jianhua; Huang, Aiyou; He, Linwen; Niu, Jianfeng; Wang, Guangce

    2017-01-01

    Pyropia haitanensis has prominent stress-resistance characteristics and is endemic to China. Studies into the stress responses in these algae could provide valuable information on the stress-response mechanisms in the intertidal Rhodophyta. Here, the effects of salinity and light intensity on the quantum yield of photosystem II in Py. haitanensis were investigated using pulse-amplitude-modulation fluorometry. Total RNA and genomic DNA of the samples under different stress conditions were isolated. By normalizing to the genomic DNA quantity, the RNA content in each sample was evaluated. The cDNA was synthesized and the expression levels of seven potential internal control genes were evaluated using qRT-PCR method. Then, we used geNorm, a common statistical algorithm, to analyze the qRT-PCR data of seven reference genes. Potential genes that may constantly be expressed under different conditions were selected, and these genes showed stable expression levels in samples under a salinity treatment, while tubulin, glyceraldehyde-3-phosphate dehydrogenase and actin showed stability in samples stressed by strong light. Based on the results of the pulse amplitude-modulation fluorometry, an absolute quantification was performed to obtain gene copy numbers in certain stress-treated samples. The stably expressed genes as determined by the absolute quantification in certain samples conformed to the results of the geNorm screening. Based on the results of the software analysis and absolute quantification, we proposed that elongation factor 3 and 18S ribosomal RNA could be used as internal control genes when the Py. haitanensis blades were subjected to salinity stress, and that α-tubulin and 18S ribosomal RNA could be used as the internal control genes when the stress was from strong light. In general, our findings provide a convenient reference for the selection of internal control genes when designing experiments related to stress responses in Py. haitanensis.

  8. Role of Recruitment Processes in Structuring Coralligenous Benthic Assemblages in the Northern Adriatic Continental Shelf.

    PubMed

    Fava, Federica; Ponti, Massimo; Abbiati, Marco

    2016-01-01

    Coralligenous biogenic reefs are among the most diverse marine habitats in the Mediterranean Sea. The northern Adriatic mesophotic coralligenous outcrops host very rich and diverse epibenthic assemblages. Several studies quantified the low temporal variability and high spatial heterogeneity of these habitats, while processes driving structuring and differentiation are still poorly understood. To shed light on these processes, temporal and spatial patterns of colonisation were investigated using travertine tiles deployed on three coralligenous outcrops, corresponding to the main typologies of benthic assemblages described in previous studies. Three years after deployment, assemblages colonising travertine tiles resembled the differentiation among sites revealed by the natural assemblages in terms of major ecological groups. Processes structuring and maintaining species diversity have been explored. Pioneer species with high reproduction rate, long distance larval dispersal and fast growth (e.g. the serpulid polychaete Spirobranchus triqueter and the bivalve Anomia ephippium), were the most abundant in the early stages of recruitment on the two outcrops further away from the coast and with lower sedimentation. Their success may vary according to larval availability and environmental conditions (e.g., sedimentation rates). At these sites early-stage lasted 10-12 months, during which even species from natural substrates began colonising tiles by settlement of planktonic propagules (e.g., encrusting calcareous Rhodophyta) and lateral encroachment (e.g., sponges and ascidians). On coastal outcrop, exposed to a higher sedimentation rates, tiles were colonised by fast-growing algal turfs. Resilience of northern Adriatic coralligenous assemblages, and maintenance of their diversity, appeared largely entrusted to asexual reproduction. Exploring the mechanisms that underlie the formation and maintenance of the species diversity is crucial to improve our understanding of

  9. Wenyingzhuangia gracilariae sp. nov., a novel marine bacterium of the phylum Bacteroidetes isolated from the red alga Gracilaria vermiculophylla.

    PubMed

    Yoon, Jaewoo; Oku, Naoya; Kasai, Hiroaki

    2015-06-01

    A Gram-negative, strictly aerobic, beige-pigmented, non-motile, rod-shaped bacterial strain designated N5DB13-4(T) was isolated from the red alga Gracilaria vermiculophylla (Rhodophyta) collected at Sodegaura Beach, Chiba, Japan. Phylogenetic analyses based on the 16S rRNA gene sequence revealed that the novel isolate is affiliated with the family Flavobacteriaceae within the phylum Bacteroidetes and that it showed highest sequence similarity (97.3 %) to Wenyingzhuangia heitensis H-MN17(T). The hybridization values for DNA-DNA relatedness between the strains N5DB13-4(T) and W. heitensis H-MN17(T) were 34.1 ± 3.5 %, which is below the threshold accepted for the phylogenetic definition of a novel prokaryotic species. The DNA G+C content of strain N5DB13-4(T) was determined to be 31.8 mol%; MK-6 was identified as the major menaquinone; and the presence of iso-C15:0, iso-C15:0 3-OH and iso-C17:0 3-OH as the major (>10 %) cellular fatty acids. A complex polar lipid profile was present consisting of phosphatidylethanolamine, two unidentified glycolipids and four unidentified lipids. From the distinct phylogenetic position and combination of genotypic and phenotypic characteristics, the strain is considered to represent a novel species of the genus Wenyingzhuangia for which the name Wenyingzhuangia gracilariae sp. nov. is proposed. The type strain of W. gracilariae sp. nov. is N5DB13-4(T) (=KCTC 42246 (T)=NBRC 110602(T)).

  10. Effects of Coral Reef Benthic Primary Producers on Dissolved Organic Carbon and Microbial Activity

    PubMed Central

    Haas, Andreas F.; Nelson, Craig E.; Wegley Kelly, Linda; Carlson, Craig A.; Rohwer, Forest; Leichter, James J.; Wyatt, Alex; Smith, Jennifer E.

    2011-01-01

    Benthic primary producers in marine ecosystems may significantly alter biogeochemical cycling and microbial processes in their surrounding environment. To examine these interactions, we studied dissolved organic matter release by dominant benthic taxa and subsequent microbial remineralization in the lagoonal reefs of Moorea, French Polynesia. Rates of photosynthesis, respiration, and dissolved organic carbon (DOC) release were assessed for several common benthic reef organisms from the backreef habitat. We assessed microbial community response to dissolved exudates of each benthic producer by measuring bacterioplankton growth, respiration, and DOC drawdown in two-day dark dilution culture incubations. Experiments were conducted for six benthic producers: three species of macroalgae (each representing a different algal phylum: Turbinaria ornata – Ochrophyta; Amansia rhodantha – Rhodophyta; Halimeda opuntia – Chlorophyta), a mixed assemblage of turf algae, a species of crustose coralline algae (Hydrolithon reinboldii) and a dominant hermatypic coral (Porites lobata). Our results show that all five types of algae, but not the coral, exuded significant amounts of labile DOC into their surrounding environment. In general, primary producers with the highest rates of photosynthesis released the most DOC and yielded the greatest bacterioplankton growth; turf algae produced nearly twice as much DOC per unit surface area than the other benthic producers (14.0±2.8 µmol h−1 dm−2), stimulating rapid bacterioplankton growth (0.044±0.002 log10 cells h−1) and concomitant oxygen drawdown (0.16±0.05 µmol L−1 h−1 dm−2). Our results demonstrate that benthic reef algae can release a significant fraction of their photosynthetically-fixed carbon as DOC, these release rates vary by species, and this DOC is available to and consumed by reef associated microbes. These data provide compelling evidence that benthic primary producers differentially influence reef

  11. Physiologic and metagenomic attributes of the rhodoliths forming the largest CaCO3 bed in the South Atlantic Ocean.

    PubMed

    Cavalcanti, Giselle S; Gregoracci, Gustavo B; dos Santos, Eidy O; Silveira, Cynthia B; Meirelles, Pedro M; Longo, Leila; Gotoh, Kazuyoshi; Nakamura, Shota; Iida, Tetsuya; Sawabe, Tomoo; Rezende, Carlos E; Francini-Filho, Ronaldo B; Moura, Rodrigo L; Amado-Filho, Gilberto M; Thompson, Fabiano L

    2014-01-01

    Rhodoliths are free-living coralline algae (Rhodophyta, Corallinales) that are ecologically important for the functioning of marine environments. They form extensive beds distributed worldwide, providing a habitat and nursery for benthic organisms and space for fisheries, and are an important source of calcium carbonate. The Abrolhos Bank, off eastern Brazil, harbors the world's largest continuous rhodolith bed (of ∼21,000 km(2)) and has one of the largest marine CaCO3 deposits (producing 25 megatons of CaCO3 per year). Nevertheless, there is a lack of information about the microbial diversity, photosynthetic potential and ecological interactions within the rhodolith holobiont. Herein, we performed an ecophysiologic and metagenomic analysis of the Abrolhos rhodoliths to understand their microbial composition and functional components. Rhodoliths contained a specific microbiome that displayed a significant enrichment in aerobic ammonia-oxidizing betaproteobacteria and dissimilative sulfate-reducing deltaproteobacteria. We also observed a significant contribution of bacterial guilds (that is, photolithoautotrophs, anaerobic heterotrophs, sulfide oxidizers, anoxygenic phototrophs and methanogens) in the rhodolith metagenome, suggested to have important roles in biomineralization. The increased hits in aromatic compounds, fatty acid and secondary metabolism subsystems hint at an important chemically mediated interaction in which a functional job partition among eukaryal, archaeal and bacterial groups allows the rhodolith holobiont to thrive in the global ocean. High rates of photosynthesis were measured for Abrolhos rhodoliths (52.16 μmol carbon m(-2 )s(-1)), allowing the entire Abrolhos rhodolith bed to produce 5.65 × 10(5) tons C per day. This estimate illustrates the great importance of the Abrolhos rhodolith beds for dissolved carbon production in the South Atlantic Ocean.

  12. Activated chemical defenses suppress herbivory on freshwater red algae.

    PubMed

    Goodman, Keri M; Hay, Mark E

    2013-04-01

    The rapid life cycles of freshwater algae are hypothesized to suppress selection for chemical defenses against herbivores, but this notion remains untested. Investigations of chemical defenses are rare for freshwater macrophytes and absent for freshwater red algae. We used crayfish to assess the palatability of five freshwater red algae relative to a palatable green alga and a chemically defended aquatic moss. We then assessed the roles of structural, nutritional, and chemical traits in reducing palatability. Both native and non-native crayfish preferred the green alga Cladophora glomerata to four of the five red algae. Batrachospermum helminthosum, Kumanoa holtonii, and Tuomeya americana employed activated chemical defenses that suppressed feeding by 30-60 % following damage to algal tissues. Paralemanea annulata was defended by its cartilaginous structure, while Boldia erythrosiphon was palatable. Activated defenses are thought to reduce ecological costs by expressing potent defenses only when actually needed; thus, activation might be favored in freshwater red algae whose short-lived gametophytes must grow and reproduce rapidly over a brief growing season. The frequency of activated chemical defenses found here (three of five species) is 3-20× higher than for surveys of marine algae or aquatic vascular plants. If typical for freshwater red algae, this suggests that (1) their chemical defenses may go undetected if chemical activation is not considered and (2) herbivory has been an important selective force in the evolution of freshwater Rhodophyta. Investigations of defenses in freshwater rhodophytes contribute to among-system comparisons and provide insights into the generality of plant-herbivore interactions and their evolution.

  13. Lipid Composition, Fatty Acids and Sterols in the Seaweeds Ulva armoricana, and Solieria chordalis from Brittany (France): An Analysis from Nutritional, Chemotaxonomic, and Antiproliferative Activity Perspectives

    PubMed Central

    Kendel, Melha; Wielgosz-Collin, Gaëtane; Bertrand, Samuel; Roussakis, Christos; Bourgougnon, Nathalie; Bedoux, Gilles

    2015-01-01

    Lipids from the proliferative macroalgae Ulva armoricana (Chlorophyta) and Solieria chordalis (Rhodophyta) from Brittany, France, were investigated. The total content of lipids was 2.6% and 3.0% dry weight for U. armoricana and S. chordalis, respectively. The main fractions of S. chordalis were neutral lipids (37%) and glycolipids (38%), whereas U. armoricana contained mostly neutral lipids (55%). Polyunsaturated fatty acids (PUFA) represented 29% and 15% of the total lipids in U. armoricana and S. chordalis, respectively. In both studied algae, the phospholipids were composed of PUFA for 18%. In addition, PUFA were shown to represent 9% and 4.5% of glycolipids in U. armoricana and S. chordalis, respectively. The essential PUFA were 16:4n-3, 18:4n-3, 18:2n-3, 18:2n-6, and 22:6n-3 in U. armoricana, and 20:4n-6 and 20:5n-3 in S. chordalis. It is important to notice that six 2-hydroxy-, three 3-hydroxy-, and two monounsaturated hydroxy fatty acids were also identified and may provide a chemotaxonomic basis for algae. These seaweeds contained interesting compounds such as squalene, α-tocopherol, cholest-4-en-3-one and phytosterols. The antiproliferative effect was evaluated in vitro on human non-small-cell bronchopulmonary carcinoma line (NSCLC-N6) with an IC50 of 23 μg/mL for monogalactosyldiacylglycerols isolated from S. chordalis and 24 μg/mL for digalactosyldiacylglycerols from U. armoricana. These results confirm the potentialities of valorization of these two species in the fields of health, nutrition and chemotaxonomy. PMID:26404323

  14. Effects of coral reef benthic primary producers on dissolved organic carbon and microbial activity.

    PubMed

    Haas, Andreas F; Nelson, Craig E; Wegley Kelly, Linda; Carlson, Craig A; Rohwer, Forest; Leichter, James J; Wyatt, Alex; Smith, Jennifer E

    2011-01-01

    Benthic primary producers in marine ecosystems may significantly alter biogeochemical cycling and microbial processes in their surrounding environment. To examine these interactions, we studied dissolved organic matter release by dominant benthic taxa and subsequent microbial remineralization in the lagoonal reefs of Moorea, French Polynesia. Rates of photosynthesis, respiration, and dissolved organic carbon (DOC) release were assessed for several common benthic reef organisms from the backreef habitat. We assessed microbial community response to dissolved exudates of each benthic producer by measuring bacterioplankton growth, respiration, and DOC drawdown in two-day dark dilution culture incubations. Experiments were conducted for six benthic producers: three species of macroalgae (each representing a different algal phylum: Turbinaria ornata--Ochrophyta; Amansia rhodantha--Rhodophyta; Halimeda opuntia--Chlorophyta), a mixed assemblage of turf algae, a species of crustose coralline algae (Hydrolithon reinboldii) and a dominant hermatypic coral (Porites lobata). Our results show that all five types of algae, but not the coral, exuded significant amounts of labile DOC into their surrounding environment. In general, primary producers with the highest rates of photosynthesis released the most DOC and yielded the greatest bacterioplankton growth; turf algae produced nearly twice as much DOC per unit surface area than the other benthic producers (14.0±2.8 µmol h⁻¹ dm⁻²), stimulating rapid bacterioplankton growth (0.044±0.002 log10 cells h⁻¹) and concomitant oxygen drawdown (0.16±0.05 µmol L⁻¹ h⁻¹ dm⁻²). Our results demonstrate that benthic reef algae can release a significant fraction of their photosynthetically-fixed carbon as DOC, these release rates vary by species, and this DOC is available to and consumed by reef associated microbes. These data provide compelling evidence that benthic primary producers differentially influence reef microbial

  15. Role of Recruitment Processes in Structuring Coralligenous Benthic Assemblages in the Northern Adriatic Continental Shelf

    PubMed Central

    Abbiati, Marco

    2016-01-01

    Coralligenous biogenic reefs are among the most diverse marine habitats in the Mediterranean Sea. The northern Adriatic mesophotic coralligenous outcrops host very rich and diverse epibenthic assemblages. Several studies quantified the low temporal variability and high spatial heterogeneity of these habitats, while processes driving structuring and differentiation are still poorly understood. To shed light on these processes, temporal and spatial patterns of colonisation were investigated using travertine tiles deployed on three coralligenous outcrops, corresponding to the main typologies of benthic assemblages described in previous studies. Three years after deployment, assemblages colonising travertine tiles resembled the differentiation among sites revealed by the natural assemblages in terms of major ecological groups. Processes structuring and maintaining species diversity have been explored. Pioneer species with high reproduction rate, long distance larval dispersal and fast growth (e.g. the serpulid polychaete Spirobranchus triqueter and the bivalve Anomia ephippium), were the most abundant in the early stages of recruitment on the two outcrops further away from the coast and with lower sedimentation. Their success may vary according to larval availability and environmental conditions (e.g., sedimentation rates). At these sites early-stage lasted 10–12 months, during which even species from natural substrates began colonising tiles by settlement of planktonic propagules (e.g., encrusting calcareous Rhodophyta) and lateral encroachment (e.g., sponges and ascidians). On coastal outcrop, exposed to a higher sedimentation rates, tiles were colonised by fast-growing algal turfs. Resilience of northern Adriatic coralligenous assemblages, and maintenance of their diversity, appeared largely entrusted to asexual reproduction. Exploring the mechanisms that underlie the formation and maintenance of the species diversity is crucial to improve our understanding of

  16. Non-methylene interrupted and hydroxy fatty acids in polar lipids of the alga Grateloupia turuturu over the four seasons.

    PubMed

    Kendel, Melha; Barnathan, Gilles; Fleurence, Joël; Rabesaotra, Vony; Wielgosz-Collin, Gaëtane

    2013-05-01

    Phospholipids (PL) and glycolipids (GL) FA in the edible Rhodophyta Grateloupia turuturu, from Brittany, France, were investigated over four seasons. The major lipid class was GL in all seasons (around 45 %). More than 80 FA occurred in polar lipids, with chains from C12 to C26, identified as methyl esters and N-acyl pyrrolidides by gas chromatography-mass spectrometry (GC-MS). PUFA occurred at up to 47.1 % (summer) in PL, and up to 43.6 % (summer) in GL. The major PUFA were 20:5n-3 (12.2 % in PL and 29.0 % in GL) and 20:4n-6 (25.6 % in PL and 10.4 % in GL). The unusual 18:3n-7 acid was identified in PL up to 2.2 %. Several minor unsaturated FA were identified in PL and are previously unreported in seaweeds, namely 14-tricosenoic, 15-tetracosenoic, 5,11-octadecadienoic and 5,9-nonadecadienoic. Also unprecedented in seaweeds, ten 2-hydroxy and three 3-hydroxy FA occurred mainly in PL, 13.9 % in spring with the 3-hydroxyhexadecanoic acid as the major one (8.1 % winter). Three n-9 monounsaturated 2-hydroxy FA occurred in PL. The 2-hydroxy-15-tetracosenoic acid was characterized as the dimethyl disulfide adduct of its methyl ester. The 2-hydroxy-16-pentacosenoic and 2-hydroxy-17-hexacosenoic acids were identified by comparison of mass spectra and GC mobilities with those of the 2-hydroxy-15-tetracosenoic acid, and of other homogeneous FA series. These rare n-9 monounsaturated 2-hydroxy FA are unprecedented in seaweeds.

  17. Applying DNA barcoding to red macroalgae: a preliminary appraisal holds promise for future applications

    PubMed Central

    Saunders, Gary W

    2005-01-01

    Marine macroalgae, especially the Rhodophyta, can be notoriously difficult to identify owing to their relatively simple morphology and anatomy, convergence, rampant phenotypic plasticity, and alternation of heteromorphic generations. It is thus not surprising that algal systematists have come to rely heavily on genetic tools for molecular assisted alpha taxonomy. Unfortunately the number of suitable marker systems in the three available genomes is enormous and, although most workers have settled on one of three or four models, the lack of an accepted standard hinders the comparison of results between laboratories. The advantages of a standard system are obvious for practical purposes of species discovery and identification; as well, compliance with a universal marker, such as cox1 being developed under the label ‘DNA barcode’, would allow algal systematists to benefit from the rapidly emerging technologies. Novel primers were developed for red algae to PCR amplify and sequence the 5′ cox1 ‘barcode’ region and were used to assess three known species-complex questions: (i) Mazzaella species in the Northeast Pacific; (ii) species of the genera Dilsea and Neodilsea in the Northeast Pacific; and (iii) Asteromenia peltata from three oceans. These models were selected because they have all caused confusion with regards to species number, distribution, and identification in the field, and because they have all been studied with molecular tools. In all cases the DNA barcode resolved accurately and unequivocally species identities and, with the enhanced sampling here, turned up a variety of novel observations in need of further taxonomic investigation. PMID:16214745

  18. Phylogenetic analysis of proteins involved in the stringent response in plant cells.

    PubMed

    Ito, Doshun; Ihara, Yuta; Nishihara, Hidenori; Masuda, Shinji

    2017-03-16

    The nucleotide (p)ppGpp is a second messenger that controls the stringent response in bacteria. The stringent response modifies expression of a large number of genes and metabolic processes and allows bacteria to survive under fluctuating environmental conditions. Recent genome sequencing analyses have revealed that genes responsible for the stringent response are also found in plants. These include (p)ppGpp synthases and hydrolases, RelA/SpoT homologs (RSHs), and the pppGpp-specific phosphatase GppA/Ppx. However, phylogenetic relationship between enzymes involved in bacterial and plant stringent responses is as yet generally unclear. Here, we investigated the origin and evolution of genes involved in the stringent response in plants. Phylogenetic analysis and primary structures of RSH homologs from different plant phyla (including Embryophyta, Charophyta, Chlorophyta, Rhodophyta and Glaucophyta) indicate that RSH gene families were introduced into plant cells by at least two independent lateral gene transfers from the bacterial Deinococcus-Thermus phylum and an unidentified bacterial phylum; alternatively, they were introduced into a proto-plant cell by a lateral gene transfer from the endosymbiotic cyanobacterium followed by gene loss of an ancestral RSH gene in the cyanobacterial linage. Phylogenetic analysis of gppA/ppx families indicated that plant gppA/ppx homologs form an individual cluster in the phylogenetic tree, and show a sister relationship with some bacterial gppA/ppx homologs. Although RSHs contain a plastidial transit peptide at the N terminus, GppA/Ppx homologs do not, suggesting that plant GppA/Ppx homologs function in the cytosol. These results reveal that a proto-plant cell obtained genes for the stringent response by lateral gene transfer events from different bacterial phyla and have utilized them to control metabolism in plastids and the cytosol.

  19. YCF1: A Green TIC?

    PubMed Central

    de Vries, Jan; Sousa, Filipa L.; Bölter, Bettina; Soll, Jürgen; Gould, Sven B.

    2015-01-01

    A pivotal step in the transformation of an endosymbiotic cyanobacterium to a plastid some 1.5 billion years ago was the evolution of a protein import apparatus, the TOC/TIC machinery, in the common ancestor of Archaeplastida. Recently, a putative new TIC member was identified in Arabidopsis thaliana: TIC214. This finding is remarkable for a number of reasons: (1) TIC214 is encoded by ycf1, so it would be the first plastid-encoded protein of this apparatus; (2) ycf1 is unique to the green lineage (Chloroplastida) but entirely lacking in glaucophytes (Glaucophyta) and the red lineage (Rhodophyta) of the Archaeplastida; (3) ycf1 has been shown to be one of the few indispensable plastid genes (aside from the ribosomal machinery), yet it is missing in the grasses; and (4) 30 years of previous TOC/TIC research missed it. These observations prompted us to survey the evolution of ycf1. We found that ycf1 is not only lacking in grasses and some parasitic plants, but also for instance in cranberry (Ericaceae). The encoded YCF proteins are highly variable, both in sequence length and in the predicted number of N-terminal transmembrane domains. The evolution of the TOC/TIC machinery in the green lineage experienced specific modifications, but our analysis does not support YCF1 to be a general green TIC. It remains to be explained how the apparent complete loss of YCF1 can be tolerated by some embryophytes and whether what is observed for YCF1 function in a member of the Brassicaceae is also true for, e.g., algal and noncanonical YCF1 homologs. PMID:25818624

  20. The mineralogical responses of marine calcifiers to CO2-induced ocean acidification

    NASA Astrophysics Data System (ADS)

    Ries, J. B.; Cohen, A. L.; McCorkle, D. C.

    2008-12-01

    We have conducted 6-month laboratory experiments to investigate the effect of pCO2-induced reductions in seawater CaCO3 saturation state on biocalcification by 18 aragonitic and calcitic (low-high Mg) taxa representing eight of the major marine calcifying groups: Chlorophyta; Rhodophyta; Crustacea; Bivalvia; Gastropoda; Annelida; Cnidaria; and Echinodermata. The CaCO3 saturation states of the experimental seawaters, constrained by intercalibrated determinations of pH, alkalinity, and DIC, were attained with bubbled air-CO2 mixtures of 400 (ambient), 600, 900, and 2850 ppm pCO2, yielding Ωarag of 2.5 (ambient), 2.0, 1.5, 0.7, respectively. We previously showed that while rates of net calcification obtained from buoyant weighing declined with increasing pCO2 for nearly half of the species investigated, a nearly equal number exhibited constant or, in some cases, increased calcification under moderately (600 ppm) or extremely (900 or 2850 ppm) elevated pCO2. The organisms' investigated in this study secrete various forms of CaCO3, which differ in crystallographic structure and therefore solubility: aragonite and high-Mg are generally more soluble than low-Mg calcite. We have employed powder x-ray diffraction, Raman spectroscopy, inductively-coupled-plasma mass-spectrometry, and scanning electron microscopy to quantify changes in the organisms' skeletal mineralogy (aragonite:calcite ratio) and Mg-content (MgCO3:CaCO3 ratio) that occurred in response to the prescribed reductions in seawater CaCO3 saturation state. We will compare calcification and mineralogical response patterns amongst the organisms to elucidate the role of mineral lability in driving species-specific responses to CO2-induced ocean acidification.

  1. Pseudorhabdosynochus species (Monogenoidea, Diplectanidae) parasitizing groupers (Serranidae, Epinephelinae, Epinephelini) in the western Atlantic Ocean and adjacent waters, with descriptions of 13 new species.

    PubMed

    Kritsky, Delane C; Bakenhaster, Micah D; Adams, Douglas H

    2015-01-01

    ; Pseudorhabdosynochus beverleyburtonae (Oliver, 1984) Kritsky & Beverley-Burton, 1986 from dusky grouper Mycteroperca marginata; Pseudorhabdosynochus mizellei n. sp. from red hind Epinephelus guttatus; Pseudorhabdosynochus williamsi n. sp. from rock hind Epinephelus adscensionis; Pseudorhabdosynochus bunkleywilliamsae n. sp. from Nassau grouper Epinephelus striatus; Pseudorhabdosynochus mycteropercae n. sp. from tiger grouper Mycteroperca tigris; and Pseudorhabdosynochus tumeovagina n. sp. from speckled hind Epinephelus drummondhayi. Pseudorhabdosynochus woodi n. sp. from red hind Epinephelus guttatus is described based on specimens from the US National Parasite Collection (USNPC). Drawings of the haptoral and copulatory sclerites of the type specimens in the USNPC of Pseudorhabdosynochus monaensis Dyer, Williams & Bunkley-Williams, 1994 from rock hind Epinephelus adscensionis are presented. Finally, a note confirming Pseudorhabdosynochus epinepheli Yamaguti, 1958 rather than its senior synonym Pseudorhabdosynochus epinepheli (Yamaguti, 1938) Kritsky & Beverley-Burton, 1986 as the type species of Pseudorhabdosynochus is provided.

  2. Conservation, loss, and redeployment of Wnt ligands in protostomes: implications for understanding the evolution of segment formation

    PubMed Central

    2010-01-01

    Background The Wnt genes encode secreted glycoprotein ligands that regulate a wide range of developmental processes, including axis elongation and segmentation. There are thirteen subfamilies of Wnt genes in metazoans and this gene diversity appeared early in animal evolution. The loss of Wnt subfamilies appears to be common in insects, but little is known about the Wnt repertoire in other arthropods, and moreover the expression and function of these genes have only been investigated in a few protostomes outside the relatively Wnt-poor model species Drosophila melanogaster and Caenorhabditis elegans. To investigate the evolution of this important gene family more broadly in protostomes, we surveyed the Wnt gene diversity in the crustacean Daphnia pulex, the chelicerates Ixodes scapularis and Achaearanea tepidariorum, the myriapod Glomeris marginata and the annelid Platynereis dumerilii. We also characterised Wnt gene expression in the latter three species, and further investigated expression of these genes in the beetle Tribolium castaneum. Results We found that Daphnia and Platynereis both contain twelve Wnt subfamilies demonstrating that the common ancestors of arthropods, ecdysozoans and protostomes possessed all members of all Wnt subfamilies except Wnt3. Furthermore, although there is striking loss of Wnt genes in insects, other arthropods have maintained greater Wnt gene diversity. The expression of many Wnt genes overlap in segmentally reiterated patterns and in the segment addition zone, and while these patterns can be relatively conserved among arthropods and the annelid, there have also been changes in the expression of some Wnt genes in the course of protostome evolution. Nevertheless, our results strongly support the parasegment as the primary segmental unit in arthropods, and suggest further similarities between segmental and parasegmental regulation by Wnt genes in annelids and arthropods respectively. Conclusions Despite frequent losses of Wnt gene

  3. Investigation of the calcification response of foraminifera and pteropods to high CO2 environments in the Pleistocene, Paleogene and Cretaceous

    NASA Astrophysics Data System (ADS)

    Hart, M.; Pettit, L.; Wall-Palmer, D.; Smart, C.; Hall-Spencer, J.; Medina-Sanchez, A.; Prol Ledesma, R. M.; Rodolfo-Metalpa, R.; Collins, P.

    2012-04-01

    Ocean acidification is regarded as a current problem and there is an extensive literature on how various organisms are responding to changes in oceanic pH: the result of increasing atmospheric pCO2. Acidification is, however, not just a recent phenomenon and there are times in the geological record where pCO2 has been higher than present day levels (especially in the Cretaceous and Paleogene). Understanding the response of various microfossil groups to the changes in oceanic pH is on-going as part of a major investigation of ocean acidification in both modern and 'fossil' environments. Extensive carbon dioxide vents have recently been described in the Wagner Basin (northern Gulf of California, Mexico), which cause dramatic changes in carbonate chemistry. The pHT decreased from 7.88 to 7.55 near the most active vents where the lowest saturation states of aragonite (ΩArag) and calcite (ΩCalc) were 0.95 and 1.47 respectively. Foraminifera (unicellular protists) present in the top 2 cm of the sediment (both living and dead individuals) had a range of mainly calcareous taxa (including Bolivina acuminata, B. acutula, Bulimina marginata and Nonionella basispinata). This is a normal composition for these water depths. The lack of dissolution features and the generally good preservation of the tests, even when viewed under a scanning electron microscope, were striking. With no evidence of breakage caused by transportation, it is assumed that this composition is representative in terms of numbers of individuals and taxa represented. Benthic foraminifera from CO2 vents around the island of Ischia (Italy) have shown dramatic long-term effects of ocean acidification. The foraminifera of the Wagner Basin appear to be surviving in high CO2 environments comparable to those that occurred during the Cretaceous-Paleogene "greenhouse" world where atmospheric pCO2 was much higher, but with calcareous foraminifera apparently thriving. In the Pleistocene, pCO2 levels are known to have

  4. Pseudorhabdosynochus species (Monogenoidea, Diplectanidae) parasitizing groupers (Serranidae, Epinephelinae, Epinephelini) in the western Atlantic Ocean and adjacent waters, with descriptions of 13 new species

    PubMed Central

    Kritsky, Delane C.; Bakenhaster, Micah D.; Adams, Douglas H.

    2015-01-01

    ; Pseudorhabdosynochus beverleyburtonae (Oliver, 1984) Kritsky & Beverley-Burton, 1986 from dusky grouper Mycteroperca marginata; Pseudorhabdosynochus mizellei n. sp. from red hind Epinephelus guttatus; Pseudorhabdosynochus williamsi n. sp. from rock hind Epinephelus adscensionis; Pseudorhabdosynochus bunkleywilliamsae n. sp. from Nassau grouper Epinephelus striatus; Pseudorhabdosynochus mycteropercae n. sp. from tiger grouper Mycteroperca tigris; and Pseudorhabdosynochus tumeovagina n. sp. from speckled hind Epinephelus drummondhayi. Pseudorhabdosynochus woodi n. sp. from red hind Epinephelus guttatus is described based on specimens from the US National Parasite Collection (USNPC). Drawings of the haptoral and copulatory sclerites of the type specimens in the USNPC of Pseudorhabdosynochus monaensis Dyer, Williams & Bunkley-Williams, 1994 from rock hind Epinephelus adscensionis are presented. Finally, a note confirming Pseudorhabdosynochus epinepheli Yamaguti, 1958 rather than its senior synonym Pseudorhabdosynochus epinepheli (Yamaguti, 1938) Kritsky & Beverley-Burton, 1986 as the type species of Pseudorhabdosynochus is provided. PMID:26272242

  5. Sedimentary archives of climate and sea-level changes during the Holocene in the Rhône prodelta (NW Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    Fanget, Anne-Sophie; Bassetti, Maria-Angela; Fontanier, Christophe; Tudryn, Alina; Berné, Serge

    2016-12-01

    A 7.38 m long sediment core was collected from the eastern section of the Rhône prodelta (NW Mediterranean) at 67 m water depth. A multi-proxy study (including sedimentary facies, benthic foraminifera, ostracods, and clay mineralogy) provides a multi-decadal to century-scale record of climate and sea-level changes during the Holocene. The early Holocene is marked by alternative silt and clay layers interpreted as distal tempestites deposited in a context of rising sea level. This interval contains shallow infra-littoral benthic meiofauna (e.g., Pontocythere elongata, Elphidium spp., Quinqueloculina lata) and formed between ca. 20 and 50 m water depth. The middle Holocene (ca. 8.3 to 4.5 ka cal. BP) is characterized, at the core site, by a period of sediment starvation (accumulation rate of ca. 0.01 cm yr-1) resulting from the maximum landward shift of the shoreline and the Rhône outlet(s). From a sequence stratigraphic point of view, this condensed section, about 35 cm thick, can be identified on seismic profiles as a maximum flooding surface that marks the transition between delta retrogradation and delta progradation. The transition between the early Holocene deposits and the middle Holocene condensed section is marked by a gradual change in all proxy records. Following the stabilization of sea level at a global scale, the late Holocene is marked by the establishment of prodeltaic conditions at the core site, as shown by the lithofacies and by the presence of benthic meiofauna typical of the modern Rhône prodelta (e.g., Valvulineria bradyana, Cassidulina carinata, Bulimina marginata). Several periods of increased fluvial discharge are also emphasized by the presence of species commonly found in brackish and shallow-water environments (e.g., Leptocythere spp.). Some of these periods correspond to the multi-decadal to centennial late Holocene humid periods recognized in Europe (i.e., the 2.8 ka event and the Little Ice Age). Two other periods of increased

  6. Does leaf water efficiency vary among eucalypts in water-limited environments?

    PubMed

    Hatton, Tom; Reece, Peter; Taylor, Peter; McEwan, Kerryn

    1998-01-01

    There is a need to generalize water use behavior of eucalypts to facilitate bioengineering and landscape remediation programs in a wide range of Australian environments. A critical question can be stated as a null hypothesis: tree water use per unit leaf area (leaf efficiency) is independent of eucalypt species. This is implicitly equivalent to the hydrological equilibrium hypothesis that states that leaf area is a function of climate, at least in cases where transpiration and growth are limited by soil water. Failure to reject this null hypothesis simplifies (a) the selection of tree species for water balance management, (b) the generation of regional-scale expectations of leaf area index, and (c) the estimation (monitoring) of the effectiveness of plantations in controlling site water balance. The hypothesis was tested with tree water use data collected in natural multi-species stands across Australia, including sites in the wet-dry season tropical woodlands of the Northern Territory, the Mediterranean climate forests of Western Australia, and a woodland system in southern New South Wales receiving an even distribution of rainfall throughout the year. We also tested the hypothesis in a multi-species tree plantation growing on a saline gradient. In each case, we could not reject the hypothesis of constant leaf efficiency among eucalypts. In every case there was a common, strong, linear relationship among tree leaf area and mean daily water use by all tree species in a sample. Single factor (species) analysis of variance did not detect significant differences between leaf water efficiencies of species. For the jarrah forest (Eucalyptus marginata J. Donn ex Sm., E. calophylla R. Br. ex Lindl.), the null hypothesis held in both spring (wet) and autumn (dry) conditions. The null hypothesis held in the mixed species woodland of New South Wales (E. macrorhynca F.J. Muell. ex Benth., E. blakelyi Maiden., E. polyanthemos Schauer.) under summer and autumn conditions, and

  7. Foraminifera eco-biostratigraphy of the southern Evoikos outer shelf, central Aegean Sea, during MIS 5 to present

    NASA Astrophysics Data System (ADS)

    Drinia, Hara; Antonarakou, Assimina; Tsourou, Theodora; Kontakiotis, George; Psychogiou, Maria; Anastasakis, George

    2016-09-01

    The South Evoikos Basin is a marginal basin in the Aegean Sea which receives little terrigenous supply and its sedimentation is dominated by hemipelagic processes. Late Quaternary benthic and planktonic foraminifera from core PAG-155 are investigated in order to understand their response to the glacial-interglacial cycles in this region. The quantitative analysis of planktonic foraminifera, coupled with accelerator mass spectrometry (14C-AMS) radiocarbon date measurements, provide an integrated chrono-stratigraphic time framework over the last 90 ka (time interval between late Marine Isotopic Stages 5 and 1; MIS5-MIS1). The temporary appearance and disappearance as well as several abundance peaks in the quantitative distribution of selected climate-sensitive planktonic species allowed the identification of several eco-bioevents, useful to accurately mark the boundaries of the eco-biozones widely recognized in the Mediterranean records and used for large-scale correlations. The established bio-ecozonation scheme allows a detailed palaecological reconstruction for the late Pleistocene archive in the central Aegean, and furthermore provides a notable contribution for palaeoclimatic studies, facilitating intercorrelations between various oceanographic basins. The quantitative analyses of benthic foraminifera identify four distinct assemblages, namely Biofacies: Elphidium spp., Haynesina spp. Biofacies, characterized by neritic species, dominated during the transition from MIS 5 to MIS 4; Cassidulina laevigata/carinata Biofacies dominated till 42 ka (transgressive trend from MIS 4 to MIS 3); Bulimina gibba Biofacies dominated from 42 ka to 9.5 ka (extensive regression MIS 3,2 through lowstand and early transgression; beginning of MIS 1); Bulimina marginata, Uvigerina spp. Biofacies dominated from 9.5 ka to the present (late transgression through early highstand; MIS 1)., This study showed that the South Evoikos Basin which is characterized by its critical depths and

  8. Characterization of bottom hydrodynamic conditions on the central western Portuguese continental shelf based on benthic foraminifera and sedimentary parameters.

    PubMed

    Martins, Maria Virgínia Alves; Quintino, Victor; Tentúgal, Rita Marques; Frontalini, Fabrizio; Miranda, Paulo; Mattos Laut, Lazaro Luiz; Martins, Roberto; Rodrigues, Ana Maria

    2015-08-01

    Dead benthic foraminiferal assemblages from the central western Portuguese continental shelf have been studied to identify the prevalent oceanographic processes in the study area. Sediment samples collected at 46 stations along transepts perpendicular to the coastal line, between the latitudes of 38-40 °N and 17-190 m water depth, in April/May 2008, were analysed for selected physicochemical parameters (temperature, redox potential), grain size, organic matter content, and benthic foraminifera. Statistical analysis identified two main groups of stations, the Inshore/Offshore groups, which are not only defined by their geographical positions, but easily distinguishable by different hydrodynamic conditions. The Offshore Group is mainly represented by deeper stations characterized by a higher percentage of fines and TOM, negative values of redox potential and by the higher foraminiferal density and species diversity than the Inshore one. Foraminiferal assemblages of the Offshore Group are dominated/represented by species (such as Cassidulina laevigata/Cassidulina carinata, Bolivina spathulata, Bolivina ordinaria, Globocassidulina minuta, Bulimina elongata/Bulimina gibba and Bulimina marginata) common in areas with significant concentrations of organic matter. The benthic foraminiferal assemblages of the Inshore Group are instead characterized by epifaunal species such as Lobatula lobatula, Cibicides ungerianus, Planorbulina mediterranensis, Gavelinopsis praegeri and Quinqueloculina seminula. Both the sedimentary and foraminiferal results suggest that this group of stations is subjected to stronger bottom hydrodynamic conditions, caused by waves and swell activity and coastal currents, than the Offshore Group. Bray-Curtis similarity comparison between the stations of both groups reveals that the Offshore Group has a higher internal similarity than the Inshore Group. These differences seem to stem from topographic forcing, from the presence of rocky outcrops, from

  9. Penultimate and last glacial cycles in the western Bering Sea: evidence from micropaleontological and sedimentary records

    NASA Astrophysics Data System (ADS)

    Ovsepyan, Ekaterina; Ivanova, Elena; Murdmaa, Ivar

    2014-05-01

    lling/Allerød and Early Holocene with the corresponding weakening of the bottom water oxygenation are well-pronounced in the studied record. We argue that the peaks of PF and BF abundance, as well as high percentages of the high-productivity species Bulimina marginata and Bolivina seminuda reflecting an increase in bioproductivity during the Bølling/Allerød and Early Holocene, were mainly related to an intensified advection of nutrients by the surface currents from the gradually flooded northeastern Bering Sea shelf during the glacioeustatic sea level rise.

  10. Methods for DNA barcoding photosynthetic protists emphasizing the macroalgae and diatoms.

    PubMed

    Saunders, Gary W; McDevit, Daniel C

    2012-01-01

    This chapter outlines the current practices used in our laboratory for routine DNA barcode analyses of the three major marine macroalgal groups, viz., brown (Phaeophyceae), red (Rhodophyta), and green (Chlorophyta) algae, as well as for the microscopic diatoms (Bacillariophyta). We start with an outline of current streamlined field protocols, which facilitate the collection of substantial (hundreds to thousands) specimens during short (days to weeks) field excursions. We present the current high-throughput DNA extraction protocols, which can, nonetheless, be easily modified for manual molecular laboratory use. We are advocating a two-marker approach for the DNA barcoding of protists with each major lineage having a designated primary and secondary barcode marker of which one is always the LSU D2/D3 (divergent domains D2/D3 of the nuclear ribosomal large subunit DNA). We provide a listing of the primers that we currently use in our laboratory for amplification of DNA barcode markers from the groups that we study: LSU D2/D3, which we advocate as a eukaryote-wide barcode marker to facilitate broad ecological and environmental surveys (secondary barcode marker in this capacity); COI-5P (the standard DNA barcode region of the mitochondrial cytochrome c oxidase 1 gene) as the primary barcode marker for brown and red algae; rbcL-3P (the 3' region of the plastid large subunit of ribulose-l-5-bisphosphate carboxylase/oxygenase) as the primary barcode marker for diatoms; and tufA (plastid elongation factor Tu gene) as the primary barcode marker for chlorophytan green algae. We outline our polymerase chain reaction and DNA sequencing methodologies, which have been streamlined for efficiency and to reduce unnecessary cleaning steps. The combined information should provide a helpful guide to those seeking to complete barcode research on these and related "protistan" groups (the term protist is not used in a phylogenetic context; it is simply a catch-all term for the bulk of

  11. A molecular timescale of eukaryote evolution and the rise of complex multicellular life

    NASA Technical Reports Server (NTRS)

    Hedges, S. Blair; Blair, Jaime E.; Venturi, Maria L.; Shoe, Jason L.

    2004-01-01

    BACKGROUND: The pattern and timing of the rise in complex multicellular life during Earth's history has not been established. Great disparity persists between the pattern suggested by the fossil record and that estimated by molecular clocks, especially for plants, animals, fungi, and the deepest branches of the eukaryote tree. Here, we used all available protein sequence data and molecular clock methods to place constraints on the increase in complexity through time. RESULTS: Our phylogenetic analyses revealed that (i) animals are more closely related to fungi than to plants, (ii) red algae are closer to plants than to animals or fungi, (iii) choanoflagellates are closer to animals than to fungi or plants, (iv) diplomonads, euglenozoans, and alveolates each are basal to plants+animals+fungi, and (v) diplomonads are basal to other eukaryotes (including alveolates and euglenozoans). Divergence times were estimated from global and local clock methods using 20-188 proteins per node, with data treated separately (multigene) and concatenated (supergene). Different time estimation methods yielded similar results (within 5%): vertebrate-arthropod (964 million years ago, Ma), Cnidaria-Bilateria (1,298 Ma), Porifera-Eumetozoa (1,351 Ma), Pyrenomycetes-Plectomycetes (551 Ma), Candida-Saccharomyces (723 Ma), Hemiascomycetes-filamentous Ascomycota (982 Ma), Basidiomycota-Ascomycota (968 Ma), Mucorales-Basidiomycota (947 Ma), Fungi-Animalia (1,513 Ma), mosses-vascular plants (707 Ma), Chlorophyta-Tracheophyta (968 Ma), Rhodophyta-Chlorophyta+Embryophyta (1,428 Ma), Plantae-Animalia (1,609 Ma), Alveolata-plants+animals+fungi (1,973 Ma), Euglenozoa-plants+animals+fungi (1,961 Ma), and Giardia-plants+animals+fungi (2,309 Ma). By extrapolation, mitochondria arose approximately 2300-1800 Ma and plastids arose 1600-1500 Ma. Estimates of the maximum number of cell types of common ancestors, combined with divergence times, showed an increase from two cell types at 2500 Ma to

  12. Trace Elements in Calcifying Marine Invertebrates Indicate Diverse Sensitivities to the Seawater Carbonate System

    NASA Astrophysics Data System (ADS)

    Doss, W. C.

    2015-12-01

    Surface ocean absorption of anthropogenic CO2 emissions resulting in ocean acidification may interfere with the ability of calcifying marine organisms to biomineralize, since the drop in pH is accompanied by reductions in CaCO3 saturation state. However, recent experiments show that net calcification rates of cultured benthic invertebrate taxa exhibit diverse responses to pCO2-induced changes in saturation state (Ries et al., 2009). Advancement of geochemical tools as biomineralization indicators will enable us to better understand these results and therefore help predict the impacts of ongoing and future decrease in seawater pH on marine organisms. Here we build upon previous work on these specimens by measuring the elemental composition of biogenic calcite and aragonite precipitated in four pCO2 treatments (400; 600; 900; and 2850 ppm). Element ratios (including Sr/Ca, Mg/Ca, Li/Ca, B/Ca, U/Ca, Ba/Ca, Cd/Ca, and Zn/Ca) were analyzed in 18 macro-invertebrate species representing seven phyla (crustacea, cnidaria, echinoidea, rhodophyta, chlorophyta, gastropoda, bivalvia, annelida), then compared to growth rate data and experimental seawater carbonate system parameters: [CO32-], [HCO3-], pH, saturation state, and DIC. Correlations between calcite or aragonite composition and seawater carbonate chemistry are highly taxa-specific, but do not resemble trends observed in growth rate for all species. Apparent carbonate system sensitivities vary widely by element, ranging from strongly correlated to no significant response. Interpretation of these results is guided by mounting evidence for the capacity of individual species to modulate pH and/or saturation state at the site of calcification in response to ambient seawater chemistry. Such biomineralization pathways and strategies in turn likely influence elemental fractionation during CaCO3 precipitation. Ries, J.B., A.L. Cohen, A.L., and D.C. McCorkle (2009), Marine calcifiers exhibit mixed responses to CO2-induced ocean

  13. Water quality of the Crescent River basin, Lake Clark National Park and Preserve, Alaska, 2003-2004

    USGS Publications Warehouse

    Brabets, Timothy P.; Ourso, Robert T.

    2006-01-01

    relatively small number of ovigerous (egg-bearing) individuals. Cyclops sp. are one of the primary food sources for rearing sockeye salmon juveniles and were most prevalent in the July sampling. Qualitative-Multi-Habitat algae samples were collected from two surface-water sites. A total of 59 taxa were found and were comprised of 4 phyla: Rhodophyta (red algae), Cyanophyta (blue-green algae), Chlorophyta (green algae), and Chrysophyta (diatoms). Twenty-two algal taxa were collected from the upper site, North Fork Crescent River, whereas twice as many taxa were collected from the downstream site, Crescent River near the mouth.

  14. Benthic faunal assemblages from the Holocene middle shelf of the South Evoikos Gulf, central Greece, and their palaeoenvironmental implications

    NASA Astrophysics Data System (ADS)

    Asimina Louvari, Markella; Tsourou, Theodora; Drinia, Hara; Anastasakis, George

    2013-04-01

    South Evoikos Gulf is an elongate, WNW - ESE trending basin, 60 km long and 15 km wide. Its floor slopes towards the south-east where the basin connects with the Aegean Sea across a 55 m deep sill. The hydrographic network of the area is characterized by Asopos river the small Lilas River and some other ephemeral streams. A sedimentary record spanning the last 13000 calyr BP was recovered at N 38°12'23.1228" E 24°8'14.2404", water depth 70 m, in this gulf. A total of 52 samples from the lower half of the core were quantitatively analyzed for micropalaeontological (benthic foraminifera and ostracods) study in order to reconstruct palaeoenvironmental conditions. This work contributes to the evaluation of the modern environmental problems in South Evoikos Gulf (hypoxia, ecosystem changes, subaquatic vegetation die-off, metal pollution) within the context of the palaeoenvironmental record. In the investigated core, the benthic microfaunal assemblages indicate a marine coastal environment with a gradual transition from a circalittoral to an infralittoral restricted environment. The basal part of the record is characterized by Haynesina depressula Assemblage, which is composed of Haynesina depressula, Textularia agglutinans and Bulimina aculeata.The abundance of Haynesina depressula could be associated with normal marine conditions, but always with periodic brackish water influence. The species composed this assemblage, which are almost all typically infaunal, characterize sediments with a high or medium-high muddy fraction, rich in organic matter available for the organisms that live within the sediment, and low salinity bottom water. Samples from the upper unit of the core indicate a nearshore, inner-shelf facies less than 50 m deep. Common inner-shelf species in these samples include Ammonia beccarii together with Bulimina marginata (Sgarrella & Moncharmont Zei, 1993). The highest abundance of A. beccarii is found between 15 and 20 m water-depth in samples with

  15. Checklist of copepods from Gulf of Nicoya, Coronado Bay and Golfo Dulce, Pacific coast of Costa Rica, with comments on their distribution.

    PubMed

    Morales-Ramírez, A

    1996-12-01

    also observed, but the separation of the species was not so evident. Outer stations were represented by oceanic species like Paracalanus aculeatus, Pleuromamma gracilis, Lucicutia ovalis, Candacia catula, Euchaeta wolfendeni and Oncaea mediterranea, while the inner station, located at the upper part of the Gulf, was more characterized by a mixed copepod group, with both neritic species like Pseudodiaptomus wrigthi, Acartia danae, A. clausi, Canthocalanus pauper as well as oceanic species like Scolicithricella marginata, Saphirina nicromaculata or Oncaea conifera. Two species of Coryceaus, C. flaccus and C. speciosus, were identified in the outer stations of Golfo Dulce, while C. brehmi was found in inner stations of Gulf of Nicoya. The majority of copepods found are typical of the east Pacific. This paper constitutes an additional work about the copepods in the Gulf of Nicoya and the first report of copepod species for Coronado Bay and Golfo Dulce.

  16. Living and dead benthic foraminiferal assemblages from bathyal environment in the Pontine Archipelago (Tyrrhenian Sea, Italy)

    NASA Astrophysics Data System (ADS)

    Di Bella, Letizia; Frezza, Virgilio; Ingrassia, Michela; Latino Chiocci, Francesco; Martorelli, Eleonora

    2016-04-01

    (0-66.7%), whereas agglutinated foraminifera are substantially absent. Biloculinella depressa, Biloculinella labiata, Miliolinella subrotunda and Quinqueloculina pygmaea are the more abundant species. As regard the dead assemblages, the Faunal Density is really high (1733-6273 specimens/gr). A total of 89 species were classified, with a range of 42-52 species in each core-interval. The α-Fisher index shows values from 14.21 to 22.06 while Shannon index ranges between 2.92-3.31. In the dead assemblage, perforate taxa are very abundant, with percentages between 74.0 and 85.5%. In this case, imperforate (12.3-18.6%) and agglutinated (1.0-7.4%) tests are accessories. Bulimina marginata, Cassidulina carinata, Cassidulina crassa, Globocassidulina subglobosa and Uvigerina mediterranea are the main constituent of benthic assemblage. In conclusion, miliolids dominate in the living assemblages while calcareous perforate taxa are more abundant in the dead assemblages.

  17. Current understanding on Villosiclava virens, a unique flower-infecting fungus causing rice false smut disease.

    PubMed

    Fan, Jing; Yang, Juan; Wang, Yu-Qiu; Li, Guo-Bang; Li, Yan; Huang, Fu; Wang, Wen-Ming

    2016-12-01

    ornamented with prominent irregularly curved spines, which are 200-500 nm in length. The sclerotia are black, horseshoe-shaped and irregular oblong or flat, ranging from 2 to 20 mm. Nested polymerase chain reaction (PCR) and quantitative PCR have been developed to specifically detect Vv presence in rice tissues and other biotic and abiotic samples in fields. Host range: Rice is the primary host for Vv. Natural infection by Vv has been found on several paddy field weeds, including Digitaria marginata, Panicum trypheron, Echinochloa crusgalli and Imperata cylindrica. However, the occurrence of infection in these potential alternative hosts is very rare. Life cycle: Vv infects rice spikelets at the late rice booting stage, and produces false smut balls covered with dark-green chlamydospores. Occasionally, sclerotia form on the surface of false smut balls in late autumn when the temperature fluctuates greatly between day and night. Both chlamydospores and sclerotia may serve as primary infection sources. Rainfall at the rice booting stage is a major environmental factor resulting in epidemics of rice false smut disease. Disease control: The use of fungicides is the major approach for the control of Vv. Several fungicides, such as cuproxat SC, copper oxychloride, tebuconazole, propiconazole, difenoconazole and validamycin, are often applied. However, the employment of resistant rice cultivars and genes has been limited, because of the poor understanding of rice resistance to Vv. Useful websites: Villosiclava virens genome sequence: http://www.ncbi.nlm.nih.gov/Traces/wgs/?val=JHTR01#contigs.

  18. Fungal Planet description sheets: 469-557.

    PubMed

    Crous, P W; Wingfield, M J; Burgess, T I; Hardy, G E St J; Crane, C; Barrett, S; Cano-Lira, J F; Le Roux, J J; Thangavel, R; Guarro, J; Stchigel, A M; Martín, M P; Alfredo, D S; Barber, P A; Barreto, R W; Baseia, I G; Cano-Canals, J; Cheewangkoon, R; Ferreira, R J; Gené, J; Lechat, C; Moreno, G; Roets, F; Shivas, R G; Sousa, J O; Tan, Y P; Wiederhold, N P; Abell, S E; Accioly, T; Albizu, J L; Alves, J L; Antoniolli, Z I; Aplin, N; Araújo, J; Arzanlou, M; Bezerra, J D P; Bouchara, J-P; Carlavilla, J R; Castillo, A; Castroagudín, V L; Ceresini, P C; Claridge, G F; Coelho, G; Coimbra, V R M; Costa, L A; da Cunha, K C; da Silva, S S; Daniel, R; de Beer, Z W; Dueñas, M; Edwards, J; Enwistle, P; Fiuza, P O; Fournier, J; García, D; Gibertoni, T B; Giraud, S; Guevara-Suarez, M; Gusmão, L F P; Haituk, S; Heykoop, M; Hirooka, Y; Hofmann, T A; Houbraken, J; Hughes, D P; Kautmanová, I; Koppel, O; Koukol, O; Larsson, E; Latha, K P D; Lee, D H; Lisboa, D O; Lisboa, W S; López-Villalba, Á; Maciel, J L N; Manimohan, P; Manjón, J L; Marincowitz, S; Marney, T S; Meijer, M; Miller, A N; Olariaga, I; Paiva, L M; Piepenbring, M; Poveda-Molero, J C; Raj, K N A; Raja, H A; Rougeron, A; Salcedo, I; Samadi, R; Santos, T A B; Scarlett, K; Seifert, K A; Shuttleworth, L A; Silva, G A; Silva, M; Siqueira, J P Z; Souza-Motta, C M; Stephenson, S L; Sutton, D A; Tamakeaw, N; Telleria, M T; Valenzuela-Lopez, N; Viljoen, A; Visagie, C M; Vizzini, A; Wartchow, F; Wingfield, B D; Yurchenko, E; Zamora, J C; Groenewald, J Z

    2016-12-01

    Novel species of fungi described in this study include those from various countries as follows: Australia: Apiognomonia lasiopetali on Lasiopetalum sp., Blastacervulus eucalyptorum on Eucalyptus adesmophloia, Bullanockia australis (incl. Bullanockia gen. nov.) on Kingia australis, Caliciopsis eucalypti on Eucalyptus marginata, Celerioriella petrophiles on Petrophile teretifolia, Coleophoma xanthosiae on Xanthosia rotundifolia, Coniothyrium hakeae on Hakea sp., Diatrypella banksiae on Banksia formosa, Disculoides corymbiae on Corymbia calophylla, Elsinoë eelemani on Melaleuca alternifolia, Elsinoë eucalyptigena on Eucalyptus kingsmillii, Elsinoë preissianae on Eucalyptus preissiana, Eucasphaeria rustici on Eucalyptus creta, Hyweljonesia queenslandica (incl. Hyweljonesia gen. nov.) on the cocoon of an unidentified microlepidoptera, Mycodiella eucalypti (incl. Mycodiella gen. nov.) on Eucalyptus diversicolor, Myrtapenidiella sporadicae on Eucalyptus sporadica, Neocrinula xanthorrhoeae (incl. Neocrinula gen. nov.) on Xanthorrhoea sp., Ophiocordyceps nooreniae on dead ant, Phaeosphaeriopsis agavacearum on Agave sp., Phlogicylindrium mokarei on Eucalyptus sp., Phyllosticta acaciigena on Acacia suaveolens, Pleurophoma acaciae on Acacia glaucoptera, Pyrenochaeta hakeae on Hakea sp., Readeriella lehmannii on Eucalyptus lehmannii, Saccharata banksiae on Banksia grandis, Saccharata daviesiae on Daviesia pachyphylla, Saccharata eucalyptorum on Eucalyptus bigalerita, Saccharata hakeae on Hakea baxteri, Saccharata hakeicola on Hakea victoria, Saccharata lambertiae on Lambertia ericifolia, Saccharata petrophiles on Petrophile sp., Saccharata petrophilicola on Petrophile fastigiata, Sphaerellopsis hakeae on Hakea sp., and Teichospora kingiae on Kingia australis.Brazil: Adautomilanezia caesalpiniae (incl. Adautomilanezia gen. nov.) on Caesalpina echinata, Arthrophiala arthrospora (incl. Arthrophiala gen. nov.) on Sagittaria montevidensis, Diaporthe caatingaensis (endophyte from

  19. Impact of paleoceanographic changes at glacial/interglacial transitions on benthic foraminiferal faunas of the eastern North Atlantic (IODP Expedition 339, Site U1385)

    NASA Astrophysics Data System (ADS)

    Grunert, Patrick; Hodell, David; Alvarez Zarikian, Carlos; Hernández-Molina, F. Javier; Stow, Dorrik A. V.

    2014-05-01

    the later phase of the terminations. While the evaluation on the generic level indicates repetitive paleoenvironmental changes for the studied transitions, the taxonomic analysis on the species level reveals significant differences between the terminations. These differences primarily concern the H-events and the early phase of the terminations. H 1 differs from other such events by showing the highest abundances of deep infaunal like Globobulimina affinis. In contrast, H 11 is characterized by high abundances of Bulimina marginata and Cassidulina laevigata/teretis which are rare to absent during H 1. A similar pattern is observed for a H-event associated with the onset of Termination IV. In contrast, the H-event preceding Termination IV shows high abundances of Bolivinita quadrilatera, a species absent all other samples. The explanation of the faunal differences between the terminations despite a rather comparable environmental framework (poor ventilation and/or high export productivity) indicates that the nature of short-term events is fairly diverse and an individual perspective has to be put on each these events. E.g., in the case of H 1, increased primary productivity and/or severely reduced AMOC compared to other such events might provide explanations. For the other, less well known events new isotopic results are expected to help with the explanation.

  20. Carbon isotopic fractionation in macroalgae from Cádiz Bay (Southern Spain): Comparison with other bio-geographic regions

    NASA Astrophysics Data System (ADS)

    Mercado, Jesús M.; de los Santos, Carmen B.; Lucas Pérez-Lloréns, J.; Vergara, Juan J.

    2009-11-01

    The 13C signature of forty-five macroalgal species from intertidal zones at Cádiz Bay was analysed in order to research the extension of diffusive vs. non-diffusive utilisation of dissolved inorganic carbon (DIC) and to perform a comparison with data published for other bio-geographic regions. The ∂ 13C values ranged from -6.8‰ to -33‰, although the span of variation was different depending on the taxa. Thus, ∂ 13C for Chlorophyta varied from -7‰ ( Codium adhaerens) to -29.6‰ ( Flabellia petiolata), while all the Phaeophyceae (excepting Padina pavonica with ∂ 13C higher than -10‰) had values between -10‰, and -20‰. The widest variation range was recorded in Rhodophyta, from values above -10‰ ( Liagora viscida) to values lower than -30‰ obtained in three species belonging to the subclass Rhodymeniophycidae. Accordingly, the mean ∂ 13C value calculated for red algae (-20.2‰) was significantly lower than that for brown (-15.9‰) and green algae (-15.6‰). Most of the analysed red algae were species inhabiting crevices and the low intertidal fringe which explains that, on average, the shaded-habitat species had a ∂ 13C value lower than those growing fully exposed to sun (i.e. in rockpools or at the upper intertidal zone). The comparison between the capacity for non-diffusive use of DIC (i.e. active or facilitated transport of HCO 3- and/or CO 2) and the ∂ 13C values reveals that values more negative than -30‰ indicate that photosynthesis is dependent on CO 2 diffusive entry, whereas values above this threshold would not indicate necessary the operation of a non-diffusive DIC transport mechanism. Furthermore, external carbonic anhydrase activity ( extCA) and ∂ 13C values were negatively correlated indicating that the higher the dependence of the photosynthesis on the CO 2 supplied from HCO 3- via extCA, the lower the ∂ 13C in the algal material. The comparison between the ∂ 13C values obtained for the analysed species and those

  1. Taxocoenosis of epibenthic dinoflagellates in the coastal waters of the northern Yucatan Peninsula before and after the harmful algal bloom event in 2011-2012.

    PubMed

    Aguilar-Trujillo, Ana C; Okolodkov, Yuri B; Herrera-Silveira, Jorge A; Merino-Virgilio, Fany Del C; Galicia-García, Citlalli

    2017-03-22

    Eutrophication causes the major impact in the coastal waters of the state of Yucatan. In general, loss of water quality and biological communities and massive development of toxic microorganisms are some of the consequences of this phenomenon. To reveal changes in species composition and cell abundance of the taxocoenosis of epibenthic dinoflagellates before and after a harmful algal bloom event in the water column that lasted about 150days (August-December 2011) in the Dzilam - San Crisanto area (northern Yucatan Peninsula, southeastern Gulf of Mexico) were the main objectives of the present study. In August 2011 and September 2012, sampling along 20 transects perpendicular to the coastline along the entire northern Yucatan coast, starting from 20 sampling sites from El Cuyo in the east to Celestún in the west, at a distance of 50, 150 and 250m from the coast, was carried out. Physicochemical characteristics measured before and after the bloom were within the ranges previously reported in the study area. Salinity was the most stable characteristic, with mean values of 36.25 and 36.42 in 2011 and 2012, respectively. Phosphates were the only parameter that showed a wide range with higher values before the bloom (0.03-0.54μM/l). A total of 168 macrophyte (seaweeds and seagrasses), sponge and sediment samples (105 in 2011 and 63 in 2012) that included associated microphytobenthos were taken by snorkeling from 0.7 to 5m depth. Six substrate types were distinguished: Chlorophyta, Phaeophyceae, Rhodophyta, Angiospermae (seagrasses), Demospongiae (sponges) and sediment. Chlorophytes dominated the collected samples: 38 samples in 2011 and 23 in 2012. Avrainvillea longicaulis f. laxa predominated before the bloom and Udotea flabellum after it. In total, 25 epibenthic dinoflagellate species from 11 genera were found. The genus Prorocentrum was the most representative in terms of the number of species. The highest total dinoflagellate cell abundances were observed in the

  2. Evaluation of biological data, Guanella Pass Area, Clear Creek and Park counties, Colorado, water years 1995-97

    USGS Publications Warehouse

    Cox-Lillis, Jennifer R.

    2000-01-01

    density, were Cyanophyta (blue-green algae), Chrysophyta (diatoms), Chlorophyta (green algae), Rhodophyta (red algae), and Euglenophyta (euglenoids). In general, diatom biovolumes dominated the algal assemblage, followed by blue-green algae, green algae, red algae, and euglenoids. Algal densities ranged from 3.1 X 102 to more than 4.7 X 106 cells per square centimeter, and algal biovolume ranged from 2.3 X 104 to 4.6 X 109 cells per cubic centimeter. Diversity values for diatoms ranged from 1.5 to 4.9. The pollution tolerance index (PTI) for diatoms ranged from 1.8 to 3.0. Sensitive diatoms were present at each site and ranged from 21 to 97 percent. The percentage of motile diatoms ranged from 0 to 13 percent. The presence of acid-tolerant diatoms ranged from less than 0.5 to greater than 20 percent. The percentage of community similarity between site pairs ranged from 1 to 97 percent. Overall, the biotic metrics that were evaluated during this study indicate that the macroinvertebrate and algal communities in the streams on Guanella Pass are not degraded by the existing road. Erosion may cause some localized effects but may not affect the overall health of the whole stream system. The degraded condition of Geneva Creek probably is due to natural effects as opposed to road effects. Although upper South Clear Creek, upstream from Naylor Creek, is located downstream from several sources of road runoff, the biological community at this site does not seem to be negatively affected.

  3. The extreme environments and their microbes as models for extraterrestrial life

    NASA Astrophysics Data System (ADS)

    Seckbach, J.; Oren, A.; Chela-Flores, J.

    2008-09-01

    British Penetrator Consortium (Smith et al., 2008), a modest penetration depth of penetrators (instruments in the process of development to be deployed on planetary bodies such as the Moon to bury themselves into the surface) into the icy surface of Europa would be sufficient to obtain samples that can be used to correctly interpret isotopic abundances of sulfur. When derived from the activity of putative S-reducing microbes, the sulfur can be used as a biomarker, based on its characteristic isotopic composition, not influenced by radiation interference. References Blanc, M. and the LAPLACE consortium (2008). LAPLACE: a mission to Europa and the Jupiter System, Astrophysical Instruments and Methods, in press. (The LAPLACE Consortium: http://www.ictp.it/~chelaf/ss164.html). Chela-Flores, J. (2006). The sulphur dilemma: Are there biosignatures on Europa's icy and patchy surface? International Journal of Astrobiology 5: 17-22. Chela-Flores, J. and Kumar, N. (2008). Returning to Europa: Can traces of surficial life be detected? International Journal of Astrobiology, in press. Dudeja, S., Bhattacherjee, A.B. and Chela-Flores, J. (2008). Manuscript in preparation. Greenberg, R. (2005). Europa - The Ocean Moon. Springer and Praxia Publishing, Chichester, 328 pp. Oren, A. (2002). Halophilic Microorganisms and their Environments. Kluwer Scientific Publishers, Dordrecht, 575 pp. Oren, A. (2008). Life at low water activity. Halophilic micro-organisms and their adaptations. The Biochemist, in press. Seckbach, J. (1994). The natural history of Cyanidium (Geitler 1933): past and present perspectives. in: Seckbach, J. (ed.), Evolutionary Pathways and Enigmatic Algae: Cyanidium caldarium (Rhodophyta) and Related Cells, Kluwer Academic Publishers, Dordrecht, pp. 99-112. Seckbach, J., Baker, F.A. and Shugarman, P.M. (1970). Algae thrive under pure CO2. Nature 227: 744-745. Seckbach, J. and Chela-Flores, J. (2007). Extremophiles and chemotrophs as contributors to astrobiological signatures