Read by QxMD icon Read


Jose Montalvo-Proaño, Patrick Buerger, Karen D Weynberg, Madeleine J H van Oppen
The coral-Symbiodinium association is a critical component of coral reefs as it is the main primary producer and builds the reef's 3-dimensional structure. A breakdown of this endosymbiosis causes a loss of the dinoflagellate photosymbiont, Symbiodinium, and/or its photosynthetic pigments from the coral tissues (i.e., coral bleaching), and can lead to coral mortality. Coral bleaching has mostly been attributed to environmental stressors, and in some cases to bacterial infection. Viral lysis of Symbiodinium has been proposed as another possible cause of some instances of coral bleaching, but this hypothesis has not yet been experimentally confirmed...
2017: Frontiers in Microbiology
Chiara Lauritano, Daniele De Luca, Alberto Ferrarini, Carla Avanzato, Andrea Minio, Francesco Esposito, Adrianna Ianora
Dinoflagellates are phytoplanktonic organisms found in both freshwater and marine habitats. They are often studied because related to harmful algal blooms but they are also known to produce bioactive compounds for the treatment of human pathologies. The aim of this study was to sequence the full transcriptome of the dinoflagellate Amphidinium carterae in both nitrogen-starved and -replete culturing conditions (1) to evaluate the response to nitrogen starvation at the transcriptional level, (2) to look for possible polyketide synthases (PKSs) in the studied clone (genes that may be involved in the synthesis of bioactive compounds), (3) if present, to evaluate if nutrient starvation can influence PKS expression, (4) to look for other possible enzymes of biotechnological interest and (5) to test strain cytotoxicity on human cell lines...
September 15, 2017: Scientific Reports
Elisabet Alacid, Albert Reñé, Jordi Camp, Esther Garcés
Dinoflagellate blooms are natural phenomena that often occur in coastal areas, which in addition to their large number of nutrient-rich sites are characterized by highly restricted hydrodynamics within bays, marinas, enclosed beaches, and harbors. In these areas, massive proliferations of dinoflagellates have harmful effects on humans and the ecosystem. However, the high cell density reached during blooms make them vulnerable to parasitic infections. Under laboratory conditions parasitoids are able to exterminate an entire host population...
2017: Frontiers in Microbiology
Oliviero Andreussi, Ingrid Guarnetti Prandi, Marco Campetella, Giacomo Prampolini, Benedetta Mennucci
Classical molecular dynamics is more and more often coupled to quantum mechanical based techniques as statistical tool to sample configurations of molecular systems embedded in complex environments. Nonetheless, the classical potentials describing the molecular systems are seldom parameterized to reproduce electronic processes, such as electronic excitations, which are instead very sensitive to the underlining description of the molecular structure. Here we analyze the challenging case of the peridinin molecule, a natural apocarotenoid responsible for the light-harvesting process in the PCP antenna protein of dinoflagellates...
September 14, 2017: Journal of Chemical Theory and Computation
Bo Song, David Morse, Yue Song, Yuan Fu, Xin Lin, Wenliang Wang, Shifeng Cheng, Wenbin Chen, Xin Liu, Senjie Lin
Gene retroposition is an important mechanism of genome evolution but the role it plays in dinoflagellates, a critical player in marine ecosystems, is not known. Until recently, when the genomes of two coral-symbiotic dinoflagellate genomes, Symbiodinium kawagutii and S. minutum, were released, it has not been possible to systematically study these retrogenes. Here we examine the abundant retrogenes (∼23% of the total genes) in these species. The hallmark of retrogenes in the genome is the presence of DCCGTAGCCATTTTGGCTCAAG, a spliced leader (DinoSL) constitutively trans-spliced to the 5'-end of all nucleus-encoded mRNAs...
August 1, 2017: Genome Biology and Evolution
F Joseph Pollock, Sefano M Katz, Jeroen A J M van de Water, Sarah W Davies, Margaux Hein, Gergely Torda, Mikhail V Matz, Victor H Beltran, Patrick Buerger, Eneour Puill-Stephan, David Abrego, David G Bourne, Bette L Willis
Here we describe an efficient and effective technique for rearing sexually-derived coral propagules from spawning through larval settlement and symbiont uptake with minimal impact on natural coral populations. We sought to maximize larval survival while minimizing expense and daily husbandry maintenance by experimentally determining optimized conditions and protocols for gamete fertilization, larval cultivation, induction of larval settlement by crustose coralline algae, and inoculation of newly settled juveniles with their dinoflagellate symbiont Symbiodinium...
2017: PeerJ
Lorenzo López-Rosales, Francisco García-Camacho, Asterio Sánchez-Mirón, Antonio Contreras-Gómez, Emilio Molina-Grima
The shear-sensitive dinoflagellate microalga Karlodinium veneficum was grown in a sparged bubble column photobioreactor. The influence of mass transfer and shear stress on cell growth and physiology (concentration of reactive oxygen species, membrane fluidity and photosynthetic efficiency) was studied, and a model describing cell growth in term of mass transfer and culture parameters (nozzle sparger diameter, air flow rate, and culture height) was developed. The results show that mass transfer limits cell growth at low air-flow rates, whereas the shear stress produced by the presence of bubbles is critically detrimental for air flow rates above 0...
August 31, 2017: Bioresource Technology
Jason C Macrander, James L Dimond, Brian L Bingham, Adam M Reitzel
There is a growing body of literature using transcriptomic data to study how tropical cnidarians and their photosynthetic endosymbionts respond to environmental stressors and participate in metabolic exchange. Despite these efforts, our understanding of how essential genes function to facilitate symbiosis establishment and maintenance remains limited. The inclusion of taxonomically and ecologically diverse endosymbionts will enhance our understanding of these interactions. Here we characterize the transcriptomes of two very different symbionts found within the temperate sea anemone Anthopleura elegantissima: the chlorophyte Elliptochloris marina and the dinoflagellate Symbiodinium muscatinei...
September 6, 2017: Marine Genomics
Masayuki Iwamoto, Ayumi Sumino, Eri Shimada, Masanao Kinoshita, Nobuaki Matsumori, Shigetoshi Oiki
Amphidinol 3 (AM3) is an anti-fungal polyene extracted from a marine dinoflagellate. Here, we examined the ion channel activity and membrane-embedded structure of AM3 using a lipid bilayer method and atomic force microscopy (AFM). AM3 exhibited large-conductance (~1 nS) and non-selective single-channel activity only when sterols were present in the membrane leaflet of the AM3-added side. The variable conductance suggests the formation of a multimeric barrel-stave pore. At high AM3 concentrations, giant-conductance "jumbo" channels (~40 nS) emerged...
September 7, 2017: Scientific Reports
Thomas Cavalier-Smith
In 1981 I established kingdom Chromista, distinguished from Plantae because of its more complex chloroplast-associated membrane topology and rigid tubular multipartite ciliary hairs. Plantae originated by converting a cyanobacterium to chloroplasts with Toc/Tic translocons; most evolved cell walls early, thereby losing phagotrophy. Chromists originated by enslaving a phagocytosed red alga, surrounding plastids by two extra membranes, placing them within the endomembrane system, necessitating novel protein import machineries...
September 5, 2017: Protoplasma
Yanrong Li, Yamin Lou, Tong Mu, Aiying Ke, Zhaoshou Ran, Jilin Xu, Juanjuan Chen, Chengxu Zhou, Xiaojun Yan, Qingshan Xu, Yinghong Tan
Sphingolipid compositions are crucial for the structural and physiological properties of microalgae membranes. In the present study, we developed a quadrupole time-of-flight (Q-TOF) mass spectrometric method based on MS(E) data collection for the identification of sphingolipids with high efficiency, selectivity, sensitivity and mass accuracy and applied this method for precise structural identification and quantitative profiling of ceramides and glycosphingolipids in total lipid extracts from 17 strains of microalgae, including 11 strains of diatom, 3 strains of dinoflagellate and 3 strains of haptophyta...
September 15, 2017: Analytica Chimica Acta
Laura Núñez-Pons, Iacopo Bertocci, Garen Baghdasarian
Warming oceans menace reef ecosystems by disrupting symbiosis between cnidarians and Symbiodinium zooxanthellae, thus triggering bleach episodes. Temperature fluctuations promote adjustments in physiological variables and symbiont composition, which can cause stress responses, but can also yield adaptation if fitter host-symbiont homeostasis are achieved. To understand such processes manipulative studies are required, but many reef-building cnidarians pose limitations to experimental prospects. We exposed Exaiptasia anemones to Gradual Thermal Stress (GTS) and Heat Shock (HS) exposures and monitored chlorophyll and symbiont dynamics to test the phenotypic plasticity of these photosynthetic holobionts...
August 24, 2017: Marine Environmental Research
Masakazu Katsumata, Ichiro Takeuchi
We examined the effect of two herbicides (Irgarol 1051 and Diuron) on symbiotic dinoflagellates in the hard coral Acropora digitifera using delayed fluorescence (DF), specifically assessing changes in molecular membrane transport, i.e. inflow and outflow rates, and the binding of the herbicides to target proteins in photosystem II. The DF approach is rapid (e.g. measurement time, 60 s) and non-invasive, and can provide data on the extent of a photosynthetic system and the activity of its electron carriers. The DF of A...
August 30, 2017: Marine Pollution Bulletin
Kenneth Neil Mertens, Haifeng Gu, Vera Pospelova, Nicolas Chomérat, Elisabeth Nézan, Pieter Roger Gurdebeke, Kara Bogus, Henk Vrielinck, Myriam Rumebe, Claire Meteigner
The resting cysts of the benthic dinoflagellate Prorocentrum leve from a natural reservoir in Gujan-Mestras (Gironde, France) were described in this study. The incubated urn-shaped cysts gave rise to cells of Prorocentrum leve. Morphological observations through light microscopy and scanning electron microscopy, particularly of the periflagellar platelets, combined with large subunit ribosomal DNA sequences obtained through single-cell analysis confirm their affinity to the species Prorocentrum leve. The cysts are characterized by a specific shape and the presence of an anterior plug...
September 2, 2017: Journal of Phycology
Stefano Accoroni, Luciana Tartaglione, Emma Dello Iacovo, Salvatore Pichierri, Mauro Marini, Alessandra Campanelli, Carmela Dell'Aversano, Cecilia Totti
Intense blooms of the toxic dinoflagellate Ostreopsis have been a recurrent phenomenon along several Mediterranean coasts. Blooms have been associated with noxious effects on human health and mortality of marine organisms, due to the production of palytoxin-like compounds. We analyzed the toxin concentrations throughout an O. cf. ovata bloom to highlight their relationships with environmental parameters in the Conero Riviera, northern Adriatic Sea. High temperature and balanced nutrient conditions were the optimal environmental conditions to start and sustain blooms as well as to maximize toxin production...
August 29, 2017: Marine Pollution Bulletin
Nils Rädecker, Claudia Pogoreutz, Maren Ziegler, Ananya Ashok, Marcelle M Barreto, Veronica Chaidez, Carsten G B Grupstra, Yi Mei Ng, Gabriela Perna, Manuel Aranda, Christian R Voolstra
The productivity of coral reefs in oligotrophic tropical waters is sustained by an efficient uptake and recycling of nutrients. In reef-building corals, the engineers of these ecosystems, this nutrient recycling is facilitated by a constant exchange of nutrients between the animal host and endosymbiotic photosynthetic dinoflagellates (zooxanthellae), bacteria, and other microbes. Due to the complex interactions in this so-called coral holobiont, it has proven difficult to understand the environmental limitations of productivity in corals...
August 2017: Ecology and Evolution
Hao Luo, Xin Lin, Ling Li, Lingxiao Lin, Chao Zhang, Senjie Lin
The ability to utilize dissolved organic phosphorus (DOP) is important for phytoplankton to survive the scarcity of dissolved inorganic phosphorus (DIP), and alkaline phosphatase (AP) has been the major research focus as a facilitating mechanism. Here we employed a unique molecular ecological approach and conducted a broader search for underpinning molecular mechanisms of adenosine triphosphate (ATP) utilization. Cultures of the dinoflagellate Karenia mikimotoi were set up in L1 medium (+P), DIP-depleted L1 medium (-P), and ATP-replacing-DIP medium (ATP)...
August 30, 2017: Environmental Microbiology
Mathieu Beauchemin, David Morse
Dinoflagellate chromatin is unique among eukaryotes, as the chromosomes are permanently condensed in a liquid crystal state instead of being packed in nucleosomes. However, how it is organized is still an unsolved mystery, in part due to the lack of a comprehensive catalog of dinoflagellate nuclear proteins. Here, we report the results of CHromatin Enrichment for Proteomics (CHEP) followed by shotgun mass spectrometry sequencing of the chromatin-associated proteins from the dinoflagellate Lingulodinum polyedra...
August 29, 2017: Chromosoma
David J Suggett, Mark E Warner, William Leggat
Coral reefs have entered an era of 'ecological crisis' as climate change drives catastrophic reef loss worldwide. Coral growth and stress susceptibility are regulated by their endosymbiotic dinoflagellates (genus Symbiodinium). The phylogenetic diversity of Symbiodinium frequently corresponds to patterns of coral health and survival, but knowledge of functional diversity is ultimately necessary to reconcile broader ecological success over space and time. We explore here functional traits underpinning the complex biology of Symbiodinium that spans free-living algae to coral endosymbionts...
August 23, 2017: Trends in Ecology & Evolution
Hisaaki Onoue, Riho Marubayashi, Erina Ishikawa, Keiichi Konoki, Kohei Torikai, Makoto Ebine, Michio Murata, Tohru Oishi
Structure-activity relationship studies of maitotoxin (MTX), a marine natural product produced by an epiphytic dinoflagellate, were conducted using chemically synthesized model compounds corresponding to the partial structures of MTX. Both enantiomers of the LMNO ring system were synthesized via aldol reaction of the LM ring aldehyde and the NO ring ketone. These fragments were derived from a common cis-fused pyranopyran intermediate prepared through a sequence involving Nozaki-Hiyama-Kishi reaction, intramolecular oxa-Michael addition, and Pummerer rearrangement...
September 6, 2017: Journal of Organic Chemistry
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"