Academic literature on the topic 'Stylophora'
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Journal articles on the topic "Stylophora"
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Parsley, R. L. "The echinoderm classes Stylophora and Homoiostelea: non Calcichordata." Paleontological Society Papers 3 (October 1997): 225–48. http://dx.doi.org/10.1017/s1089332600000279.
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Stylophora and Homoiostelea are the largest classes of the subphylum Homalozoa. They have also been placed in the Calcichordata but that position is herein rejected. Stylophorans are divided into two orders the Cornuta and Ankyroida: cornutes have asymmetrical thecae, aulacophores with stylocones and cover plates over the food groove that open widely; ankyroids have essentially bilaterally symmetrical thecae, aulacophores with styloids and in most the cover plates do not open widely. Epispires, cothurnopores, and lamellipores in cornutes are respiratory structures not atypical of early echinoderms and are only superficially similar to chordate gill slits. The superior and inferior faces of cornute and ankyroid thecae and the aulacophores are homologous. There is no evidence that ‘mitrates’ (most ankyroids) are inverted or their aulacophores(calcichordate tail) have been lost and re-evolved.Homoiosteles are superficially similar to stylophorans: the column or stele resembles the aulacophore and the theca in younger genera develope distinct marginal and somatic plate patterns. The earliest homoiosteles are attached by a holdfast, at least in juvenile stages, and this fixation may have imprinted some morphological features on steles of vagile genera. Earliest homoiosteles share significant characters with coeval species of the eocrinoid Gogia and it serves as outgroup.Cladograms for Stylophora and Homoiostelea were generated by NONA, a phylogenetic program for personal computers.
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Sheu, Shih-Yi, Sing-Rong Jiang, Chaolun Allen Chen, Jih-Terng Wang, and Wen-Ming Chen. "Vibrio stylophorae sp. nov., isolated from the reef-building coral Stylophora pistillata." International Journal of Systematic and Evolutionary Microbiology 61, no. 9 (September 1, 2011): 2180–85. http://dx.doi.org/10.1099/ijs.0.026666-0.
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A bacterial strain designated KTW-12T was isolated from a reef-building coral in Kenting, Taiwan, and was characterized using a polyphasic taxonomic approach. Strain KTW-12T was Gram-negative, semi-transparent, slightly curved rod-shaped, and non-motile. Growth occurred at 15–35 °C (optimum, 30 °C), at pH 6.0–9.0 (optimum, pH 7.0–8.0), and with 0.5–6.0 % NaCl (optimum, 2 %). The major cellular fatty acids were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C14 : 0 and C16 : 0. The DNA G+C content was 47.8 mol%. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain KTW-12T was most closely related to Vibrio porteresiae MSSRF30T, with 94.8 % gene sequence similarity. Further multilocus sequence analysis using rpoA, recA and pyrH genes also revealed low levels of sequence similarity (74.6–85.0 %) with all species of the genus Vibrio with validly published names. A multigene phylogenetic tree using concatenated sequences of the four genes (16S rRNA, rpoA, recA and pyrH) elucidated that strain KTW-12T occupied a distinct phylogenetic position, forming a long branch that was not clustered with any other known species of the genus Vibrio. Strain KTW-12T differed from V. porteresiae MSSRF30T in the ability to reduce nitrate to nitrite, hydrolysis of chitin, fermentation of sorbitol and production of arginine dihydrolase, valine arylamidase, cystine arylamidase and N-acetyl-β-glucosaminidase. On the basis of phenotypic, chemotaxonomic and phylogenetic distinctiveness, strain KTW-12T should be classified as representing a novel species, for which the name Vibrio stylophorae sp. nov. is proposed. The type strain is KTW-12T ( = BCRC 80105T = LMG 25357T).
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Sheu, Shih-Yi, Sing-Rong Jiang, Chaolun Allen Chen, Jih-Terng Wang, and Wen-Ming Chen. "Paracoccus stylophorae sp. nov., isolated from the reef-building coral Stylophora pistillata." International Journal of Systematic and Evolutionary Microbiology 61, no. 9 (September 1, 2011): 2221–26. http://dx.doi.org/10.1099/ijs.0.028035-0.
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A bacterial strain, designated KTW-16T, was isolated from the reef-building coral Stylophora pistillata, collected from southern Taiwan. Strain KTW-16T was a Gram-negative, facultatively anaerobic, pale-yellow, non-motile short rod. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain KTW-16T belonged to the genus Paracoccus in the Alphaproteobacteria and exhibited 93.7–96.9 % 16S rRNA gene sequence similarity with type strains of species of the genus Paracoccus (96.9 % with Paracoccus alcaliphilus JCM 7364T). Strain KTW-16T grew at 15–40 °C (optimum 35 °C), at pH 6.0–10.0 (optimum pH 8.0) and with 0–9 % NaCl (optimum 5 %). The predominant cellular fatty acids were C18 : 1ω7c, C19 : 0 cyclo ω8c and C18 : 0. The major respiratory quinone was Q-10 and the DNA G+C content was 69.1 mol%. The polar lipid profile consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine and several unknown polar lipids. The physiological and biochemical tests allowed clear phenotypic differentiation of the isolate from the type strains of already described Paracoccus species. It is evident from the genotypic, phenotypic and chemotaxonomic analysis that strain KTW-16T should be classified in a novel species of the genus Paracoccus, for which the name Paracoccus stylophorae sp. nov. is proposed. The type strain is KTW-16T ( = LMG 25392T = BCRC 80106T).
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Chen, Ming-Hui, Shih-Yi Sheu, Chaolun Allen Chen, Jih-Terng Wang, and Wen-Ming Chen. "Oceanicaulis stylophorae sp. nov., isolated from the reef-building coral Stylophora pistillata." International Journal of Systematic and Evolutionary Microbiology 62, Pt_9 (September 1, 2012): 2241–46. http://dx.doi.org/10.1099/ijs.0.036780-0.
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A bacterial strain designated GISW-4T was isolated from the reef-building coral Stylophora pistillata, collected from seawater off the coast of southern Taiwan, and was characterized in this taxonomic study using a polyphasic approach. Strain GISW-4T was Gram-stain-negative, aerobic, beige, rod-shaped, and dimorphic, either non-motile with stalks (or prosthecae), or non-stalked and motile by means of a single polar flagellum. 16S rRNA gene sequence studies showed that the novel strain clustered with Oceanicaulis alexandrii C116-18T (98.9 % 16S rRNA gene sequence similarity). Strain GISW-4T exhibited optimal growth at 35–40 °C, 1–2 % (w/v) NaCl and at pH 7–9. The predominant cellular fatty acids (>10 %) were C18 : 0, C18 : 1ω7c and C18 : 1ω7c 11-methyl. The predominant polar lipids were phosphatidylglycerol, sulfoquinovosyl diacylglycerol and two unknown phospholipids (PL1–2). The major respiratory quinones were ubiquinone Q-10 and Q-9, and the DNA G+C content was 61.6 mol%. The results of physiological and biochemical tests allowed clear phenotypic differentiation of strain GISW-4T from the type strain of O. alexandrii . It is evident from the genotypic, phenotypic and chemotaxonomic data that the isolate should be classified as a novel species of the genus Oceanicaulis . The name proposed for this taxon is Oceanicaulis stylophorae sp. nov., with the type strain GISW-4T ( = LMG 25723T = BCRC 80207T).
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Chen, Ming-Hui, Shih-Yi Sheu, Chaolun Allen Chen, Jih-Terng Wang, and Wen-Ming Chen. "Corallomonas stylophorae gen. nov., sp. nov., a halophilic bacterium isolated from the reef-building coral Stylophora pistillata." International Journal of Systematic and Evolutionary Microbiology 63, Pt_3 (March 1, 2013): 982–88. http://dx.doi.org/10.1099/ijs.0.043208-0.
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A heterotrophic marine bacterium, designated strain KTSW-6T, was isolated from the reef-building coral Stylophora pistillata in Kenting, Taiwan. Cells of strain KTSW-6T were Gram-stain-negative, facultatively anaerobic, halophilic, non-motile rods surrounded by a thick glycocalyx-like coat and forming creamy white colonies. Growth occurred at 15–37 °C (optimum, 25–30 °C), at pH 7.0–9.0 (optimum, pH 7.5–8.0) and with 0.5–7 % NaCl (optimum, 3–4 %). Polar lipids comprised phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an uncharacterized aminophospholipid and three uncharacterized phospholipids (PL1–PL3). The respiratory quinones of strain KTSW-6T were Q-8 (62 %) and Q-7 (38 %). Major cellular fatty acids were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c, 29.6 %), C18 : 1ω7c (27.6 %) and C16 : 0 (19.5 %). The major cellular hydroxy fatty acid was C10 : 0 3-OH. The DNA G+C content of strain KTSW-6T was 48.6 mol%. 16S rRNA gene sequence analysis indicated that strain KTSW-6T belongs to the family Oceanospirillaceae of the order Oceanospirillales , class Gammaproteobacteria . Strain KTSW-6T shared 92.7 % 16S rRNA gene sequence similarity with Neptuniibacter caesariensis MED92T and 92.0 % with Neptunomonas naphthovorans NAG-2N-126T. On the basis of the genotypic and phenotypic data, strain KTSW-6T represents a novel species of a new genus of the Oceanospirillaceae , for which the name Corallomonas stylophorae gen. nov., sp. nov. is proposed. The type strain of Corallomonas stylophorae is KTSW-6T ( = BCRC 80176T = LMG 25553T).
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Bockel and Rinkevich. "Rapid Recruitment of Symbiotic Algae into Developing Scleractinian Coral Tissues." Journal of Marine Science and Engineering 7, no. 9 (September 4, 2019): 306. http://dx.doi.org/10.3390/jmse7090306.
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While the early acquisition of Symbiodiniaceae algae into coral host tissues has been extensively studied, the dynamics of the migration of algal cells into rapidly expanding coral tissues still lacks a systematic study. This work examined two Red Sea branching coral species, Pocillopora damicornis and Stylophora pistillata, as they were growing and expanding their tissue laterally on glass slides (January–June, 2014; 450 assays; five colonies/species). We measured lateral tissue expansion rates and intratissue dinoflagellate migration rates. Tissue growth rates significantly differed between the two species (with Stylophora faster than Pocillopora), but not between genotypes within a species. Using a “flow-through coral chamber” under the microscope, the migration of dinoflagellates towards the peripheral edges of the expanding coral tissue was quantified. On a five-day timescale, the density of the endosymbiotic dinoflagellate cells, presenting within a 90 µm region of expanding coral tissue (outer edge), increased by a factor of 23.6 for Pocillopora (from 1.2 × 104 cells cm‒² to 2.4 × 105 cells cm‒²) and by a factor of 6.8 for Stylophora (from 3.6 × 104 cells cm‒² to 2.4 × 105 cells cm‒²). The infection rates were fast (5.2 × 104 and 4.1 × 104 algal cells day-1 cm‒², respectively), further providing evidence of an as yet unknown pathway of algal movement within coral host tissues.
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Lefebvre, B. "A critical comment on ‘ankyroids’ (Echinodermata, Stylophora)." Geobios 34, no. 6 (January 2001): 597–627. http://dx.doi.org/10.1016/s0016-6995(01)80024-3.
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Liew, Yi Jin, Manuel Aranda, Adrian Carr, Sebastian Baumgarten, Didier Zoccola, Sylvie Tambutté, Denis Allemand, Gos Micklem, and Christian R. Voolstra. "Identification of MicroRNAs in the Coral Stylophora pistillata." PLoS ONE 9, no. 3 (March 21, 2014): e91101. http://dx.doi.org/10.1371/journal.pone.0091101.
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Grover, Renaud, Jean-François Maguer, Denis Allemand, and Christine Ferrier-Pagés. "Nitrate uptake in the scleractinian coral Stylophora pistillata." Limnology and Oceanography 48, no. 6 (November 2003): 2266–74. http://dx.doi.org/10.4319/lo.2003.48.6.2266.
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Karako-Lampert, Sarit, Didier Zoccola, Mali Salmon-Divon, Mark Katzenellenbogen, Sylvie Tambutté, Anthony Bertucci, Ove Hoegh-Guldberg, Emeline Deleury, Denis Allemand, and Oren Levy. "Transcriptome Analysis of the Scleractinian Coral Stylophora pistillata." PLoS ONE 9, no. 2 (February 13, 2014): e88615. http://dx.doi.org/10.1371/journal.pone.0088615.
Full textDissertations / Theses on the topic "Stylophora"
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Liew, Yi Jin. "Small RNA studies in Drosophila melanogaster, Stylophora pistillata and Symbiodinium sp." Thesis, University of Cambridge, 2013. https://www.repository.cam.ac.uk/handle/1810/268035.
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Small non-coding RNAs such as microRNAs (miRNAs), small interfering RNAs (siRNAs) and Piwi-interacting RNAs (piRNAs) play a big role in regulating gene expression in cells. In my work, I focus primarily on miRNAs, which represses the expression of the mRNA targets post-transcriptionally. For Drosophila melanogaster, I predicted the tissue-specific expression of several miRNAs based on the expression levels of the predicted mRNA targets in those tissues. The computational predictions are then followed up by quantitative PCR validation of miRNA expression levels in dissected fly tissues. For Stylophora pistillata (a species of coral found in the Red Sea) and Symbiodinium sp. (a photosynthetic, symbiotic algae present in the coral cell), my collaborators and I strived to study the genome, transcriptome and proteome of both organisms. At present, there is another coral genome available — from Acropora digitifera — but the large evolutionary distance between both corals (about 240 million years apart) warrants in-depth study of our coral of interest. On the other hand, our Symbiodinium genome will be the first of its kind for any dinoflagellate. My role in the project was to investigate the small RNAome of both organisms via small RNAseq. As the presence of a thick cell wall in Symbiodinium sp. poses a unique challenge to RNA extraction, and compounded by the dearth of literature regarding RNA extraction from the dinoflagellate, we optimised a procedure that consistently produced high quality RNA for downstream sequencing. From our draft proteome, I showed that the RNA interference (RNAi) machinery is very likely to be present in both organisms. Based on our short RNAseq data, I predicted miRNAs in both organisms. Two of the predicted miRNAs in S. pistillata have been identified in other organisms, while all of the predicted miRNAs in Symbiodinium sp. were novel.
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Tibbits, Matthew A. Budd Ann F. "The effects of decling environmental pH on coral microstructure and morphology." [Iowa City, Iowa] : University of Iowa, 2009. http://ir.uiowa.edu/etd/445.
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Gattuso, Jean-Pierre. "Ecomorphologie, métabolisme, croissance et calcification du scléractiniaire à zooxanthelles Stylophora pistillata (Golfe d'Agaba, Mer Rouge) influence de l'éclairement /." Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37605301r.
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Bertucci, Anthony. "Etudes moléculaire et physiologique des mécanismes permettant l'utilisation du carbone inorganique chez le corail Scléractiniaire Stylophora pistillata (Esper, 1797)." Thesis, Aix-Marseille 2, 2010. http://www.theses.fr/2010AIX22112/document.
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La formation d’un squelette de CaCO3 par les coraux Scléractiniaires est à la base de l’édification des récifs coralliens. Nombre de ces coraux constructeurs de récif vivent en symbiose avec des Dinoflagellés photosynthétiques. Ces deux processus reposent sur le transport et l’utilisation de carbone inorganique (Ci) provenant de l’eau de mer pour la photosynthèse, et du métabolisme animal pour la calcification. Cette thèse s’est intéressée à l’étude moléculaire et physiologique des mécanismes, permettant l’utilisation de ce carbone inorganique.Malgré l’importance des transports de HCO3-, aucun transporteur n’a été caractérisé à cejour et leur implication dans la physiologie des coraux n’est que suggérée par la pharmacologie. Durant cette thèse nous avons cloné un gène codant pour un transporteur deHCO3- chez le corail Acropora sp. La conversion de ce HCO3- en CO2 pour la photosynthèse est facilitée par l’acidification de l’environnement proche du Dinoflagellé dans la cellule animale. Cette acidification est causée par une H+-ATPase de type P que nous avons caractérisée. Ce gène est le premier à montrer une expression dépendante de la vie en symbiose chez le symbiote.Nous avons aussi cloné et localisé deux anhydrases carboniques (AC). L’une impliquée dans la calcification et l’autre dans la régulation du pH intracellulaire et l’équilibre entre leCO2 et HCO3-. Une étude pharmacologique de ces deux AC, a identifié des molécules inhibitrices et activatrices qui ont permis des expériences de physiologie in vivo. Celles-ci permettent une analyse plus discriminante du rôle des AC dans la calcificationCoral reefs edification is based on the formation of a calcium carbonate skeleton byscleractinian corals. Many of these reef-building corals establish a symbiotic association with photosynthetic Dinoflagellates. Both processes involve the transport and utilization of inorganic carbon (Ci) coming from seawater for photosynthesis, and from animal metabolismfor calcification. This work focused on the molecular and physiological study of poorlyknown mechanisms that allow the utilization of Ci.Despite the importance of bicarbonate transport, no transporter has been characterized and their role in coral physiology is only suggested by pharmacological experiments. We have cloned a gene encoding a bicarbonate transporter in the coral Acropora sp. The conversion of this bicarbonate into CO2 for photosynthesis is mediated by the acidification of the are asurrounding the Dinoflagellate in the animal cell. This is performed by a P type H+-ATPasethat we characterized here. This is the first gene with a symbiosis-dependent expression in the symbiont.This work also allowed the cloning and the localization of two carbonic anhydrases (CA).The first one is involved in calcification, the second one plays a role in the intracellular pHregulation and the CO2 / HCO3- equilibrium. A pharmacological study of these two enzymes identified inhibitor and activator compounds that have been then used in physiology experiments. This last approach represents a more accurate study of the role of CAs incalcification
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Tambutté, Eric. "Processus de calcification d'un scleractinaire hermatypique stylophora pistillata (esper, 1797). Etude de la croissance in situ sur l'atoll de mururoa." Nice, 1996. http://www.theses.fr/1996NICE5056.
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L'utilisation conjointe d'un nouveau modele biologique, la microcolonie de corail de stylophora pistillata, et d'un nouveau protocole utilisant le #4#5ca a permis de caracteriser les mecanismes cellulaires impliques dans la calcification des scleractiniaires hermatypiques. Lors de l'utilisation de radioisotopes, les problemes d'adsorption non specifique sont elimines. Ce protocole est caracterise par une phase d'efflux a la fin de l'incubation qui permet de vidanger un compartiment extracellulaire. Quatre compartiments ont ete mis en evidence. Le premier est extracellulaire et correspond au clenteron. Le second, correspondant a la totalite des tissus, est caracterise par un t#1#/#2 de 20 min (ca #t#o#t: 7 nmol ca. Mg#-#1 proteine), son intervention dans le transport du calcium utilise pour la calcification semble indirecte. Le troisieme, implique dans la synthese du squelette (t#1#/#2: 2 min), correspond vraisemblablement a l'ectoderme calicoblastique dont les cellules possedent des canaux calcium sensibles aux inhibiteurs des canaux calcium de type l. La caracterisation moleculaire d'un canal calcium de type l a permis grace a des anticorps de le localiser sur les deux ectodermes. Le transport de calcium dans ce compartiment est de type transcellulaire et est couple probablement a des ca#2#+-atpases. Le quatrieme, correspondant au squelette, est un flux unidirectionnel de 975 pmol ca. Mg#-#1 proteine. Min#-#1. L'etude de l'incorporation de la matrice organique a montre qu'elle est couplee a l'incorporation de calcium dans le squelette. Le tbt, compose present dans certaines peintures anti-salissures, pourrait alterer la calcification en inhibant la synthese de la matrice organique. Une approche en microscopie electronique a permis de confirmer la nature cellulaire des structures d'ancrage, les desmocytes. L'etude de la croissance in situ sur l'atoll de mururoa a permis de correler la croissance a la temperature mais non avec le rayonnement. Dans la zone subsidee, la croissance lineaire est superieure a la zone controle
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Moya, Aurélie. "Approches physiologique et moléculaire de la calcification et de la "light-enhanced calcification" chez le corail Scléractiniaire Stylophora pistillata (Esper, 1797)." Aix-Marseille 2, 2007. http://theses.univ-amu.fr.lama.univ-amu.fr/2007AIX22073.pdf.
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Les récifs coralliens, majoritairement édifiés par les coraux Scléractiniaires, constituent la plus importante construction biologique à l’échelle mondiale. De nombreux coraux Scléractiniaires établissent une symbiose avec un Dinobionte photosynthétique. Cette symbiose est responsable, entre autres, d’une stimulation de la calcification des coraux en présence de lumière, phénomène décrit sous le terme de “light-enhanced calcification” (LEC). Malgré de nombreuses recherches, les mécanismes responsables de ce phénomène de LEC restent méconnus. Ma thèse a consisté en l’étude de la calcification et du phénomène de LEC chez le corail Stylophora pistillata par une double approche physiologique (caractérisation du phénomène chez cette espèce, cycle journalier, temps de transition) et moléculaire (caractérisation moléculaire et localisation tissulaire d’une anhydrase carbonique impliquée dans le processus de calcification, régulation transcriptionnelle entre les conditions "Jour" et "Nuit")Scleractinian corals are the main calcifying organisms of coral reefs. Most scleractinian corals establish a symbiotic relationship with phototrophic Dinoflagellates. This symbiosis is responsible for the stimulation of coral calcification by light, a phenomenon called “light enhanced calcification” (LEC). Despite numerous studies performed on this subject, the mechanisms linking photosynthesis of the symbionts to coral calcification remain largely unknown. The aim of the present work is to gain a better understanding of the calcification process and of the “light-enhanced calcification” phenomenon in the scleractinian coral Stylophora pistillata (Esper, 1797), using both physiological (characterization of the LEC phenomenon in S. Pistillata, daily cycle, time transitions) and molecular approaches (molecular characterization and tissular localization of a carbonic anhydrase involved in the calcification process, transcriptional regulation between light and dark conditions)
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Marchioretti, Manuel. "Nouvelles données écophysiologiques chez les scléractiniaires à zooxanthelles du genre stylophora(Schweigger,1819) : perspectives d'applications à la restauration des récifs coralliens." Nice, 1999. http://www.theses.fr/1999NICE5271.
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Tremblay, Pascale. "Relations entre auto- et hétérotrophie chez les coraux scléractiniaires symbiotiques." Paris 6, 2012. http://www.theses.fr/2012PA066298.
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Les coraux scléractiniaires sont des organismes hétérotrophes, qui capturent du plancton, et autotrophes, de par leur symbiose avec des dinoflagellés photosynthétiques, qui transfèrent à l’hôte la majeure partie du carbone fixé (photosynthétats). L’acquisition et l’allocation de ces nutriments sont deux processus clés expliquant l’expansion des coraux dans des milieux oligotrophes. Malgré l’importance de ces processus, de nombreuses zones d’ombre existent. Les enjeux de cette thèse, réalisée sur un corail tropical (Stylophora pistillata) et un tempéré (Cladocora caespitosa) ont donc été : 1) de développer un modèle permettent de quantifier le transfert de carbone autotrophe des symbiotes à l’hôte et d’estimer le budget de ce carbone; 2) d’estimer l’importance de l’hétérotrophie, notamment lorsque les apports autotrophes sont diminués. Les résultats obtenus ont montré que le transfert de photosynthétats varie de 50 à 90 % selon les conditions environnementales (lumière, nutrition, et pH de l’eau de mer), ce qui influe sur le budget de carbone de la symbiose. Cependant, lorsque la production photosynthétique diminue suite à un stress, le transfert de photosynthétats tend à augmenter, afin de fournir la même quantité de carbone à l’hôte. L’hétérotrophie, chez S. Pistillata, ne permet pas de compenser la privation d’autotrophie lors d’un blanchissement (perte des symbiotes), car les colonies diminuent aussi leur prédation sur le zooplancton. Chez C. Caespitosa, par contre, l’hétérotrophie joue un rôle majeur dans le budget de carbone. Cette espèce s’acclimate aussi très bien à une large gamme de lumières, ce qui la rend autant autotrophe que les espèces tropicalesScleractinian corals are both heterotroph, since they capture planktonic prey, and autotroph, via their symbiosis with photosynthetic dinoflagellates, which translocate most of the photosynthates to the coral host for its own needs. The acquisition and allocation of these nutrients are key processes explaining the functioning and development of corals in oligotrophic waters. Despite the importance of these processes, many gaps still exist. The aims of this thesis, performed on a tropical (Stylophora pistillata) and a temperate (Cladocora caespitosa) species, were to: 1) develop a model to estimate the autotrophic carbon budget, as well as the rates of photosynthate translocation from the symbionts to the host; 2) assess the importance of heterotrophy, especially in situations where autotrophy is impacted. Results have shown that photosynthate translocation varies between 50 and 90% depending on environmental conditions (irradiance, feeding, and seawater pH), and affects the global carbon budget of the symbiotic association. However, when a stress decreases the photosynthetic production, photosynthate translocation increases to allocate the same amount of carbon to the host. For S. Pistillata, heterotrophy does not compensate for the loss of autotrophy during a bleaching event (loss of symbionts), because the coral colonies also decrease their predation on zooplankton. In contrast, for C. Caespitosa, heterotrophy plays an important role in the carbon budget. Since this species is also very well acclimatised to a wide range of irradiances, it is as autotroph as the tropical species
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Bernardet, Coralie. "Physiologie des transports ioniques et moléculaires chez les coraux, implications environnementales." Electronic Thesis or Diss., Sorbonne université, 2019. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2019SORUS496.pdf.
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Les coraux tropicaux constructeurs de récifs sont à l’origine d’écosystèmes extrêmement riches dont dépendent de nombreuses espèces, y compris l’Homme. Aujourd’hui, les changements climatiques représentent toutefois une menace pour la survie des coraux. Afin de comprendre la réponse de ces espèces aux modifications environnementales, il est essentiel d’avoir des informations sur la physiologie de ces espèces-clé. Les travaux conduits au cours de ma thèse ont ainsi permis de caractériser, au niveau mécanistique, les processus affectés par des changements de température chez l’espèce Stylophora pistillata. Pour cela, j’ai employé des approches multiples en partant de l’animal jusqu’au gène. Mes résultats ont montré : 1) que les taux de calcification, de photosynthèse et de respiration sont drastiquement réduits aux extrémités de la fenêtre thermique, 2) l’existence d’un phénomène de « light-enhanced calcification », excepté à basse température, 3) la sous-expression d’un groupe de gènes impliqué dans le transport du carbone inorganique lorsque les taux de calcification sont réduits (stress thermiques et la nuit), 4) la stabilité du pH dans le milieu extracellulaire calcifiant dans tous les traitements, et 5) l’augmentation de la perméabilité paracellulaire conjointement à l’augmentation de la calcification (25°C et le jour). En plus de leur intérêt en recherche fondamentale, ces informations peuvent constituer des outils utiles pour de futures recherches sur le terrain dans le but d’évaluer l’état de santé des coraux et prédire leur devenir dans un monde qui changeTropical reef-building corals are at the basis of extremely biodiverse ecosystems on which many species depend, including human beings. Today, climate change represents a threat for the future survival of corals, and it is becoming crucial to better understand the physiology of these key species and the mechanisms underlying their responses to environmental change. The work conducted during my PhD focused on the characterization of the processes affected by temperature changes in Stylophora pistillata. For this purpose, I used multiple approaches from the animal to the gene. My results showed that: 1) calcification, photosynthesis and respiration declined drastically at the extremes of the thermal performance window, 2) light-enhanced calcification occurs across the thermal performance window except at low temperature, 3) a group of genes involved in inorganic carbon transport is under-expressed when calcification is reduced (thermal stress and during night), 4) pH in the extracellular calcifying medium remains stable at low and high temperatures, 5) paracellular permeability is highest when calcification increases (25°C and during the day). Information gained from this lab-based study will be useful in guiding further research in the field in order to evaluate coral health and predict the future of coral reefs in a changing world
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Rouan, Alice. "Étude des variations de la taille des télomères chez le corail Stylophora pistillata et dans les populations sauvages des genres Pocillopora sp., Porites sp., et Millepora sp. récoltés sur 32 systèmes insulaires de l’Océan Pacifique au cours de l’expédition TARA-Pacifique." Electronic Thesis or Diss., Université Côte d'Azur, 2020. http://theses.univ-cotedazur.fr/2020COAZ6050.
Full textAbstract:
La linéarité des chromosomes eucaryotes implique la présence d’une chromatine à la structure particulière, appelée télomère, pour contrôler la stabilité du génome et conserver sa fonction. Des changements dans la structure des télomères peuvent déterminer la longévité, la résistance au stress et la susceptibilité de développer certaines pathologies. Notre compréhension sur la contribution des facteurs environnementaux sur la longueur des télomères n’en est qu’à ses balbutiements, tout comme notre connaissance de la diversité des mécanismes de régulation de la taille des télomères dans l’arbre de la vie. Les coraux constructeurs de récifs sont à cet égard des modèles de choix, leurs conditions de vie fixée les empêchant de fuir des conditions défavorables et leur endosymbiose obligatoire avec une micro-algue photosynthétique les exposant à un stress oxydant quotidien. Leurs télomères ne sont pourtant que peu étudiés. Dans ce travail de thèse, j’ai combiné une large étude de terrain sur 3 genres de coraux (deux scléractiniaires, Pocillopora sp. et Porites sp., et un hydrozoaire Millepora sp.) et une étude en conditions contrôlées sur l’espèce modèle Stylophora pistillata dans le but de comprendre le lien entre la variation de la taille des télomères et l'environnement. J’ai observé que la taille des télomères des coraux ne diminuait pas avec l’âge, ni avec la taille des colonies, mais qu’une rupture de la symbiose induite à l’obscurité pouvait induire un raccourcissement des télomères. J’ai aussi montré que des espèces avec des stratégies évolutives différentes avaient des régulations de leurs tailles de télomères différentes, le genre Pocillopora sp. étant contraint à la fois par la génétique et l'environnement tandis que le genre Porites sp. démontrant un incroyable maintien de la taille des télomères en dépit des variations génétiques ou des catégories d'environnements. Cependant, malgré leurs différentes stratégies, la taille des télomères des deux genres étaient négativement corrélées aux variations environnementales, mettant à jour ce paramètre comme crucial et potentiellement perturbateur des mécanismes de maintien de la taille des télomèresThe linearity of eukaryotic chromosomes requires the presence of a particular terminal chromatin structure, named telomere, to control the stability and function of genomes. Changes in telomere structure during life can determine longevity, stress resistance and disease susceptibility. Our knowledge on the contribution of environmental factors on telomere length (TL) variability remains at its infancy, as well as the diversity of telomere maintenance mechanisms and ageing strategies existing in the tree of life. In this regard reef building corals are an interesting but yet poorly investigated model to tackle the question of telomere response to environment. Indeed those long lived animals cannot escape external environmental stressors due to their fixed life mode nor internal ones due to the symbiosis, within their gastrodermal cells, with a photosynthetic microalgae. Here I combined an extensive field case study on 3 coral genera (two scleractinians, Pocillopora sp. and Porites sp. and the hydrozoan Millepora sp.) as well as controlled conditions test on the coral model Stylophora pistillata to unravel the possible links between telomere DNA length variation and environmental stress. I found that an absence of TL shortening with age and size in all the investigated corals. I observed a possible impact of dark induced bleaching on TL and different TL dynamics in wild populations. Pocillopora sp. mean TL is constrained both by genetic and environment while Porites sp. has a remarkable ability to maintain its TL regardless of size, genetic and some environment disturbance. Yet both of genera TLs were negatively correlated with seasonal deviations, identifying this environmental parameter as a factor overcoming TL maintenance in genera with different TL dynamics and life-history strategies
Books on the topic "Stylophora"
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Review of selected North American mitrate stylophorans (homalozoa--echinodermata). Ithaca, N.Y., U.S.A: Paleontological Research Institution, 1991.
Find full textBook chapters on the topic "Stylophora"
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Lefebvre, B., S. Régnault, H. Lardeux, J. Kundura, and P. Roussel. "New Ordovician mitrates (Echinodermata, Stylophora) from the Ancenis Basin (South Armorican Domain, France)." In Echinoderms: Durham, 37–44. CRC Press, 2009. http://dx.doi.org/10.1201/9780203869543-c6.
Full textConference papers on the topic "Stylophora"
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Reid, Mhairi, Wendy L. Taylor, Emese Bordy, and Carlton E. Brett. "TAPHONOMY AND PALEOECOLOGY OF AN OPHIUROID-STYLOPHORAN OBRUTION DEPOSIT FROM THE LOWER DEVONIAN BOKKEVELD GROUP, SOUTH AFRICA." In GSA Annual Meeting in Denver, Colorado, USA - 2016. Geological Society of America, 2016. http://dx.doi.org/10.1130/abs/2016am-285839.
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