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Mohamed S Elnaggar - One of the best experts on this subject based on the ideXlab platform.
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two new triterpenoids and a new naphthoquinone derivative isolated from a hard coral derived fungus scopulariopsis sp
Fitoterapia, 2017Co-Authors: Zhen Liu, Mohamed S Elnaggar, Sherif S Ebada, Mohamed L Ashour, Weaam Ebrahim, Abdel Nasser B Singab, Wenhan Lin, Peter ProkschAbstract:Abstract Scopulariopsis sp. isolated from the Red Sea hard coral Stylophora sp. yielded two new triterpenoids (1–2) and a new naphthoquinone derivative (8) when cultured on white beans. In addition, fourteen known compounds including three triterpene analogues (3–5), two sesquiterpenoids (6–7), two polyketides (9–10) and seven nitrogenous compounds (11–17) were isolated. All structures were determined through extensive analysis of the NMR and MS data as well as by comparison with literature data. All isolated compounds were evaluated for their cytotoxic, antibacterial and antitubercular activities. However, none of them showed significant activity.
Chaolun Allen Chen - One of the best experts on this subject based on the ideXlab platform.
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physiological and biochemical performances of menthol induced aposymbiotic corals
PLOS ONE, 2012Co-Authors: Jihterng Wang, Kwee Siong Tew, Yiyun Chen, Peijei Meng, Chaolun Allen ChenAbstract:The unique mutualism between corals and their photosynthetic zooxanthellae (Symbiodinium spp.) is the driving force behind functional assemblages of coral reefs. However, the respective roles of hosts and Symbiodinium in this endosymbiotic association, particularly in response to environmental challenges (e.g., high sea surface temperatures), remain unsettled. One of the key obstacles is to produce and maintain aposymbiotic coral hosts for experimental purposes. In this study, a simple and gentle protocol to generate aposymbiotic coral hosts (Isopora palifera and Stylophora pistillata) was developed using repeated incubation in menthol/artificial seawater (ASW) medium under light and in ASW in darkness, which depleted more than 99% of Symbiodinium from the host within 4∼8 days. As indicated by the respiration rate, energy metabolism (by malate dehydrogenase activity), and nitrogen metabolism (by glutamate dehydrogenase activity and profiles of free amino acids), the physiological and biochemical performances of the menthol-induced aposymbiotic corals were comparable to their symbiotic counterparts without nutrient supplementation (e.g., for Stylophora) or with a nutrient supplement containing glycerol, vitamins, and a host mimic of free amino acid mixture (e.g., for Isopora). Differences in biochemical responses to menthol-induced bleaching between Stylophora and Isopora were attributed to the former digesting Symbiodinium rather than expelling the algae live as found in the latter species. Our studies showed that menthol could successfully bleach corals and provided aposymbiotic corals for further exploration of coral-alga symbioses.
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comparison of morphological and genetic analyses reveals cryptic divergence and morphological plasticity in Stylophora cnidaria scleractinia
Coral Reefs, 2011Co-Authors: Fabrizio Stefani, Francesca Benzoni, Sungyin Yang, Michel Pichon, Paolo Galli, Chaolun Allen ChenAbstract:A combined morphological and genetic study of the coral genus Stylophora investigated species boundaries in the Gulf of Aden, Yemen. Two mitochondrial regions, including the hypervariable IGS9 spacer and the control region, and a fragment of rDNA were used for phylogenetic analysis. Results were compared by multivariate analysis on the basis of branch morphology and corallite morphometry. Two species were clearly discriminated by both approaches. The first species was characterised by small corallites and a low morphological variability and was ascribed to a new geographical record of Stylophora madagascarensis on the basis of its phylogenetic distinction and its morphological similarity to the type material. The second species was characterised by larger corallite size and greater morphological variability and was ascribed to Stylophora pistillata. The analysis was extended to the intrageneric level for other S.pistillata populations from the Red Sea and the Pacific Ocean. Strong internal divergence was evident in the genus Stylophora. S. pistillata populations were split into two highly divergent Red Sea/Gulf of Aden and western Pacific lineages with significant morphological overlap, which suggests they represent two distinct cryptic species. The combined use of morphological and molecular approaches, so far proved to be a powerful tool for the re-delineation of species boundaries in corals, provided novel evidence of cryptic divergence in this group of marine metazoans.
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Unique Mitogenomic Features in the Scleractinian Family Pocilloporidae (Scleractinia: Astrocoeniina)
Marine Biotechnology, 2008Co-Authors: Chienhsun Chen, Chih-yung Chiou, Chaolun Allen ChenAbstract:The complete DNA sequences of three mitochondrial (mt) genomes were obtained from the scleractinian corals, Stylophora pistillata , Pocillopora damicornis , and Madracis mirabilis , and were compared to the published mt genomes to elucidate phylogenetically unique features of the family Pocilloporidae. The entire mt genomes of pocilloporid corals ranged from 16,951 to 17,425 bp with the A+T contents of their sense strands ranging from 68.4% to 70.2%. The gene order of protein-coding genes was identical to those of other scleractinian corals. The novel atp8 gene, first described in confamilial Seriatopora corals, was also confirmed using reverse transcription-polymerase chain reaction (RT-PCR), Northern blot, and sequence analyses in other genera of the Pocilloporidae. The intergenic spacer between atp6 and nad4 , containing distinct repeated elements, conserved sequence blocks and domains, and functional structures, possesses typical characteristics of a putative control region for the four coral genera. A duplicated trnW , detected in the region close to the cox1 gene and which shares the highly conserved primary and secondary structures of its original counterpart, was discovered in both Seriatopora and Stylophora . These molecular characteristics are unique and provide the phylogenetic information for future evaluation of the status of the family Pocilloporidae in the evolutionary history of scleractinian corals.
Proksch Peter - One of the best experts on this subject based on the ideXlab platform.
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Two new triterpenoids and a new naphthoquinone derivative isolated from a hard coral-derived fungus Scopulariopsis sp.
FITOTERAPIA, 2017Co-Authors: Elnaggar, Mohamed S., Ebada, Sherif S., Ashour, Mohamed L., Ebrahim Weaam, Singab Abdelnasser, Lin Wenhan, Liu Zhen, Proksch PeterAbstract:Scopulariopsis sp. isolated from the Red Sea hard coral Stylophora sp. yielded two new triterpenoids (1-2) and a new naphthoquinone derivative (8) when cultured on white beans. In addition, fourteen known compounds including three triterpene analogues (3-5), two sesquiterpenoids (6-7), two polyketides (9-10) and seven nitrogenous compounds (11-17) were isolated. All structures were determined through extensive analysis of the NMR and MS data as well as by comparison with literature data. All isolated compounds were evaluated for their cytotoxic, antibacterial and antitubercular activities. However, none of them showed significant activity. (C) 2016 Elsevier B.V. All rights reserved.Egyptian government (Ministry of Higher Education); Manchot-FoundationSCI(E)ARTICLE126-13011
Baruch Rinkevich - One of the best experts on this subject based on the ideXlab platform.
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marine silviculture incorporating ecosystem engineering properties into reef restoration acts
Ecological Engineering, 2015Co-Authors: Yael B Horoszowskifridman, Jeanclaude Brethes, Nathaele Rahmani, Baruch RinkevichAbstract:Abstract In the gardening approach for reef restoration, coral stocks are farmed in underwater nurseries (phase I) prior to their transplantation onto degraded reefs (phase II). The phase I aspects were already evaluated in the literature, but very little is known about the phase II outcomes. Assessing phase II feasibility, we transplanted 554 nursery-farmed colonies of two branching species (Stylophora pistillata, Pocillopora damicornis) onto five denuded knolls in Eilat (Red Sea). The performance of the transplants was compared for 17 months with 76 natal colonies and 217 colonies maintained at the coral-nursery. At the natural reef, rates of full/partial mortalities, detachment and fish herbivory were considerably higher than the nursery values. While corallivory on Pocillopora transplants was comparable to that observed in natal colonies, herbivory on Stylophora transplants increased 2.2 fold compared to natal controls. Their survivorship was similar to the survivorship observed in natal colonies in the 9 months post transplantation, but was 30% higher after 17 months. In contrast, no enhanced mortality was documented in Pocillopora transplants throughout the entire period. The detachment levels of the Stylophora and Pocillopora transplants were 3 and 10 times higher, respectively, than those observed in natal colonies, and the growth rates of the transplants were identical to the rates observed in the nursery control groups. Transplants showed a 2.5–3.3 fold increase in colonial ecological-volumes, resulting in enhanced acquired space/habitats for coral-dwelling species like Trapezia, Alpheus, Spirobranchus and Lithophaga. The successful integration of farmed transplants in Eilat’s degraded reef and their provision of new ecological niches for reef-associated fauna, coupled with economic assessments, indicate that transplantation of farmed corals is an easy, cost-effective mean to counteract degradation of coral reefs. Results also imply that the selection of coral species for reef restoration should take into consideration their autogenic/allogenic engineering properties, particularly if the aims are to restore the whole reef community, rather than simply focus on coral coverage.
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from isolated ramets to coral colonies the significanceof colony pattern formation in reef restoration practices
Basic and Applied Ecology, 2001Co-Authors: Nimrod Epstein, Baruch RinkevichAbstract:Summary Fragmentation in scleractinian corals has been recognized as an important facet in the life history portrait of many species. Fragments (ramets) isolated from existing genets may establish new colonies; a phenomenon that is widely used in a variety of management measures, including restoration of denuded coral reef areas. An analysis of regenerating branches of the Indo-Pacific coral Stylophora pistillata reveals that the architectural complexity of isolated branches may have a significant impact on the initiation of the regeneration process towards the typical structure and complexity of an intact colony. It is suggested that the 3-D structure complexity of isolated ramets should be taken into consideration when applying reef restoration practices. Die Fragmentierung bei skleraktinischen Korallen ist fur das Lebenzyklus-Portrait vieler Arten als wichtiges Merkmal erkannt worden. Fragmente (Rameten), die von existierenden genetischen Individuen (genets) isoliert wurden, konnen neue Kolonien etablieren; dies ist ein Phanomen, das bei Management-Messungen vielfach genutzt wird, zum Beispiel in der Restoration erodierter Riffe. Eine Analyse der sich regenerierenden Aste der indopazifischen Koralle Stylophora pistillata zeigte, dass die Komplexitat der Architektur isolierter Aste einen signifikanten Einfluss auf die Initiierung des Regenerationsprozesses im Hinblick auf die typische Struktur und Komplexitat einer intakten Kolonie hat. Es wird vorgeschlagen, dass die 3D-Struktur-Komplexitat von isolierten Rameten berucksichtigt werden wollte, wenn Riff-Restorations-Masnahmen angewandt werden.
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scyphozoan jellyfish s mesoglea supports attachment spreading and migration of anthozoans cells in vitro
Cell Biology International, 1999Co-Authors: Uri Frank, Baruch RinkevichAbstract:Mechanically and enzymatically dissociated cells from five anthozoan species were laid on seven substrates in vitro. Cells were taken from two sea anemones (Aiptasia sp. and Anemonia sulcata), a scleractinian coral (Stylophora pistillata) and two alcyonacean corals (Heteroxenia fuscescence and Nephthea sp). Substrates tested: glass (coverslips), plastic (uncoated tissue culture plates), type IV collagen, gelatin, fibronectin, mesoglea pieces from the scyphozoan jellyfish Rhopilema nomadica and acetic acid extract of jellyfish mesoglea. Except for the mesoglea pieces, cells did not respond to any one of the other substrates, retaining their rounded shape. Following contact with mesoglea pieces, cells attached and spread. Subsequently they migrated into the mesogleal matrix at a rate of 5-10 microm/h during the first 2-5 h. No difference was found between the behavior of cells from the five different cnidarian species.
Weaam Ebrahim - One of the best experts on this subject based on the ideXlab platform.
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two new triterpenoids and a new naphthoquinone derivative isolated from a hard coral derived fungus scopulariopsis sp
Fitoterapia, 2017Co-Authors: Zhen Liu, Mohamed S Elnaggar, Sherif S Ebada, Mohamed L Ashour, Weaam Ebrahim, Abdel Nasser B Singab, Wenhan Lin, Peter ProkschAbstract:Abstract Scopulariopsis sp. isolated from the Red Sea hard coral Stylophora sp. yielded two new triterpenoids (1–2) and a new naphthoquinone derivative (8) when cultured on white beans. In addition, fourteen known compounds including three triterpene analogues (3–5), two sesquiterpenoids (6–7), two polyketides (9–10) and seven nitrogenous compounds (11–17) were isolated. All structures were determined through extensive analysis of the NMR and MS data as well as by comparison with literature data. All isolated compounds were evaluated for their cytotoxic, antibacterial and antitubercular activities. However, none of them showed significant activity.
