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Leonid L. Moroz - One of the best experts on this subject based on the ideXlab platform.
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complete dna sequence of the mitochondrial genome of the sea slug aplysia californica conservation of the gene order in euthyneura
Molecular Phylogenetics and Evolution, 2006Co-Authors: Leonid L. Moroz, Bjarne Knudsen, Andrea B Kohn, Ben Nahir, Catherine S McfaddenAbstract:We have sequenced and characterized the complete mitochondrial genome of the sea slug, Aplysia californica, an important model organism in experimental biology and a representative of Anaspidea (Opisthobranchia, Gastropoda). The mitochondrial genome of Aplysia is in the small end of the observed sizes of animal mitochondrial genomes (14,117 bp, NCBI Accession No. NC_005827). The Aplysia genome, like most other mitochondrial genomes, encodes genes for 2 ribosomal subunit RNAs (small and large rRNAs), 22 tRNAs, and 13 protein subunits (cytochrome c oxidase subunits 1-3, cytochrome b apoenzyme, ATP synthase subunits 6 and 8, and NADH dehydrogenase subunits 1-6 and 4L). The gene order is virtually identical between Opisthobranchs and pulmonates, with the majority of differences arising from tRNA translocations. In contrast, the gene order from representatives of basal gastropods and other molluscan classes is significantly different from Opisthobranchs and pulmonates. The Aplysia genome was compared to all other published molluscan mitochondrial genomes and phylogenetic analyses were carried out using a concatenated protein alignment. Phylogenetic analyses using maximum likelihood based analyses of the well aligned regions of the protein sequences support both monophyly of Euthyneura (a group including both the pulmonates and Opisthobranchs) and Opisthobranchia (as a more derived group). The Aplysia mitochondrial genome sequenced here will serve as an important platform in both comparative and neurobiological studies using this model organism.
Rhanor Gillette - One of the best experts on this subject based on the ideXlab platform.
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systemic serotonin sulfate in Opisthobranch mollusks
Journal of Neurochemistry, 2004Co-Authors: Jeffrey N Stuart, Rhanor Gillette, Jason D Ebaugh, Ashley L Copes, Nathan G Hatcher, Jonathan V SweedlerAbstract:Serotonin (5-hydroxytryptamine, 5-HT) is a ubiquitous modulatory neurotransmitter with roles as a neurohormone and neurotransmitter. However, few studies have been performed characterizing this molecule and its related metabolites in circulating fluids. Here, we demonstrate native 5-HT sulfate, but much lower levels of 5-HT, in hemolymph of the marine mollusk Pleurobranchaea californica. The metabolite 5-HT sulfate forms from 5-HT uptake and metabolism in central ganglia of Aplysia californica and in the visceral nerve and eye of Pleurobranchaea, but not in hemolymph itself. In addition, 5-hydroxyindole acetic acid (5-HIAA), while not detected in hemolymph, forms in higher quantities than does 5-HT sulfate in the eye and visceral nerve, and γ-glu-5-HT is also observed in this area but never in hemolymph. As systemic 5-HT sulfate appears not to originate from the optic region or from systemic 5-HT, 5-HT sulfate likely derives from the nervous system. Circulating 5-HT sulfate is at least 10-fold higher during the light portion of a 12 : 12-h light/dark cycle than during the dark portion (p 0.3) in Pleurobranchaea. 5-HT in mollusks is associated with general arousal state; thus, diurnal systemic changes in a 5-HT catabolite may reflect a regulatory role for indole catabolism in behavioral rhythms.
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Central pattern generator for escape swimming in the notaspid sea slug Pleurobranchaea californica.
Journal of Neurophysiology, 1999Co-Authors: Jian Jing, Rhanor GilletteAbstract:Central pattern generator for escape swimming in the notaspid sea slugPleurobranchaea californica. Escape swimming in the notaspid Opisthobranch Pleurobranchaea is an episode of alternating dorsal ...
Angel R De Lera - One of the best experts on this subject based on the ideXlab platform.
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synthesis of haminol a and haminol b polyenic alarm pheromones of cephalaspidean molluscs
Tetrahedron-asymmetry, 1998Co-Authors: Rosana Alvarez, Angel R De LeraAbstract:Abstract Two stereocontrolled palladium-catalyzed cross-couplings of 1-alkenyl boronic acids and aryl/alkenyl halides (the Suzuki–Miyaura reaction) are the key steps in an enantioselective approach to the polyene fragment of haminols A and B, alarm pheromones isolated from Haminoea navicula , a Cephalaspidean Opisthobranch mollusc. Chirality rested on the use of ( S )-propylene oxide as the starting material.
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stereoselective synthesis of polyenic alarm pheromones of cephalaspidean molluscs
Tetrahedron, 1998Co-Authors: Rosana Alvarez, Maria Teresa Herrero, Susana Lopez, Angel R De LeraAbstract:Abstract The stereospecific thallium-accelerated palladium-catalyzed cross-coupling of 1-alkenyl boronic acids and 1-alkenyl iodides (the Suzuki reaction) is the key step in an efficient approach to several polyenic pheromones isolated from cephalaspidean Opisthobranch molluscs.
Benoit Dayrat - One of the best experts on this subject based on the ideXlab platform.
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ten new complete mitochondrial genomes of pulmonates mollusca gastropoda and their impact on phylogenetic relationships
BMC Evolutionary Biology, 2011Co-Authors: Tracy R White, Michele M Conrad, Roger Tseng, Shaina Balayan, Rosemary E Golding, Antonio M De Frias Martins, Benoit DayratAbstract:Reconstructing the higher relationships of pulmonate gastropods has been difficult. The use of morphology is problematic due to high homoplasy. Molecular studies have suffered from low taxon sampling. Forty-eight complete mitochondrial genomes are available for gastropods, ten of which are pulmonates. Here are presented the new complete mitochondrial genomes of the ten following species of pulmonates: Salinator rhamphidia (Amphiboloidea); Auriculinella bidentata, Myosotella myosotis, Ovatella vulcani, and Pedipes pedipes (Ellobiidae); Peronia peronii (Onchidiidae); Siphonaria gigas (Siphonariidae); Succinea putris (Stylommatophora); Trimusculus reticulatus (Trimusculidae); and Rhopalocaulis grandidieri (Veronicellidae). Also, 94 new pulmonate-specific primers across the entire mitochondrial genome are provided, which were designed for amplifying entire mitochondrial genomes through short reactions and closing gaps after shotgun sequencing. The structural features of the 10 new mitochondrial genomes are provided. All genomes share similar gene orders. Phylogenetic analyses were performed including the 10 new genomes and 17 genomes from Genbank (outgroups, Opisthobranchs, and other pulmonates). Bayesian Inference and Maximum Likelihood analyses, based on the concatenated amino-acid sequences of the 13 protein-coding genes, produced the same topology. The pulmonates are paraphyletic and basal to the Opisthobranchs that are monophyletic at the tip of the tree. Siphonaria, traditionally regarded as a basal pulmonate, is nested within Opisthobranchs. Pyramidella, traditionally regarded as a basal (non-euthyneuran) heterobranch, is nested within pulmonates. Several hypotheses are rejected, such as the Systellommatophora, Geophila, and Eupulmonata. The Ellobiidae is polyphyletic, but the false limpet Trimusculus reticulatus is closely related to some ellobiids. Despite recent efforts for increasing the taxon sampling in euthyneuran (Opisthobranchs and pulmonates) molecular phylogenies, several of the deeper nodes are still uncertain, because of low support values as well as some incongruence between analyses based on complete mitochondrial genomes and those based on individual genes (18S, 28S, 16S, CO1). Additional complete genomes are needed for pulmonates (especially for Williamia, Otina, and Smeagol), as well as basal heterobranchs closely related to euthyneurans. Increasing the number of markers for gastropod (and more broadly mollusk) phylogenetics also is necessary in order to resolve some of the deeper nodes -although clearly not an easy task. Step by step, however, new relationships are being unveiled, such as the close relationships between the false limpet Trimusculus and ellobiids, the nesting of pyramidelloids within pulmonates, and the close relationships of Siphonaria to sacoglossan Opisthobranchs. The additional genomes presented here show that some species share an identical mitochondrial gene order due to convergence.
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crawling through time transition of snails to slugs dating back to the paleozoic based on mitochondrial phylogenomics
Marine Genomics, 2011Co-Authors: Mónica Medina, Yvonne Valles, Tori L Takaoka, Benoit Dayrat, Jeffrey L Boore, Terrence M GoslinerAbstract:Sea slugs (Gastropoda: Opisthobranchia) are characterized by extensive morphological homoplasy. In particular, reduced or absent shells are predominant throughout the group. This trend towards shell loss has resulted in a poor fossil record. DNA-based phylogenies have been helpful in improving our understanding of the evolution of this group and major clades are emerging. We report 13 new complete Opisthobranch mitochondrial genomes that provide robust support for some of these emerging nodes. We name three new clades within the Opisthobranchia, the Actopleura (Acteonoidea plus Nudipleura), Placoesophaga (Cephalaspidea plus Anaspidea), and Siphoglossa (Sacoglossa plus the Siphonaria). Finally we use molecular clock dating that suggests an earlier Opisthobranch divergence than previously reported. The implications of this evolutionary scenario are discussed.
Guido Cimino - One of the best experts on this subject based on the ideXlab platform.
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structure and cytotoxicity of phidianidines a and b first finding of 1 2 4 oxadiazole system in a marine natural product
Organic Letters, 2011Co-Authors: Marianna Carbone, Guido Cimino, Ernesto Mollo, Carlo Irace, Antonio Di Pascale, Francesco Castelluccio, Yan Li, Rita Santamaria, Margherita GavagninAbstract:Two indole alkaloids, phidianidines A (1) and B (2), exhibiting an uncommon 1,2,4-oxadiazole ring linked to the indole system, have been isolated from the marine Opisthobranch mollusk Phidiana militaris. The structures of the two metabolites have been elucidated by spectroscopic techniques. Phidianidines exhibit high cytotoxicity against tumor and nontumor mammalian cell lines in in vitro assays.
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Structure and synthesis of a unique isocyanide serinol-like lipid isolated from the marine mollusk Actinocyclus papillatus
'American Chemical Society (ACS)', 2011Co-Authors: Emiliano Manzo, Guido Cimino, M. Letizia Ciavatta, Ernesto Mollo, Carlo Irace, Antonio Di Pascale, M. Carbone, Y.w. Guo, Margherita GavagninAbstract:(-)-Actisonitrile, a lipid based on a serinol ether skeleton, was isolated from the Opisthobranch mollusk Actinocyclus papillatus. The structure was established by spectroscopic methods whereas the absolute configuration of the chiral centre was determined by comparing the optical properties of natural actisonitrile with those of (+)- and (-)-synthetic enantiomers, opportunely prepared. In a preliminary in vitro cytotoxicity bioassay, both (-)- and (+) -actisonitrile enantiomers showed cytotoxic activity against tumor and non tumor mammalian cells
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molluscs from chemo ecological study to biotechnological application
2006Co-Authors: Guido Cimino, Margherita GavagninAbstract:Molluscan Natural Products as Biological Models: Chemical Ecology, Histology, and Laboratory Culture.- Shellfish Poisons.- Bivalve Molluscs as Vectors of Marine Biotoxins Involved in Seafood Poisoning.- Hyperhydroxylation: A New Strategy for Neuronal Targeting by Venomous Marine Molluscs.- The Chemistry of Marine Pulmonate Gastropods.- Secondary Metabolites from the Marine Gastropod Molluscs of Antarctica, Southern Africa and South America.- Marine Mollusks from Australia and New Zealand: Chemical and Ecological Studies.- Chemical Diversity in Opisthobranch Molluscs from Scarcely Investigated Indo-Pacific Areas.- Selected Bioactive Compounds from Japanese Anaspideans and Nudibranchs.- Bioactive Molecules from Sea Hares.- Trisoxazole Macrolides from Hexabranchus Nudibranchs and Other Marine Invertebrates.- Sequestration and Possible Role of Dietary Alkaloids in the Sponge-Feeding Mollusk Tylodina perversa.- Skin Chemistry of Nudibranchs from the West Coast of North America.- Biogenetic Proposals and Biosynthetic Studies on Secondary Metabolites of Opisthobranch Molluscs.- Total Synthesis of Bioactive Peptides and Depsipeptides from Marine Opisthobranch Molluscs.- Kahalalide F and ES285: Potent Anticancer Agents from Marine Molluscs.
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Biosynthesis in Opisthobranch molluscs: General outline in the light of recent use of stable isotopes
Phytochemistry Reviews, 2004Co-Authors: Guido Cimino, Angelo Fontana, Adele Cutignano, Margherita GavagninAbstract:The use of stable isotopes has been recently introduced in the biosynthetic studies of metabolites produced by Opisthobranch molluscs. This methodology offers numerous advantages since it avoids the complex and tedious manipulations of potentially dangerous radioactive compounds and gives unequivocal evidence for the incorporation. In these studies, high field NMR spectroscopy is a particularly useful tool to localize the labeled atoms in the molecule. This chapter updates the biosynthetic studies on Opisthobranch molluscs with particular attention to the recent experiments with precursors labeled with stable isotopes. Opisthobranchs are able to biosynthesize de novo a wide array of chemical skeletons including polyketides, polypropionates, acetogenins, and terpenoids. The studies regarding this latter class is proposed in the light of the recent debate about classical and independent mevalonate pathway.
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hodgsonal a new drimane sesquiterpene from the mantle of the antarctic nudibranch bathydoris hodgsoni
Tetrahedron Letters, 1998Co-Authors: Katrin Iken, Maria Letizia Ciavatta, Angelo Fontana, Conxita Avila, Guido CiminoAbstract:Abstract A new drimane sesquiterpene, hodgsonal ( 1 ), has been isolated from the mantle extract of the Antarctic Opisthobranch mollusc Bathydoris hodgsoni . The structure of 1 , including the absolute stereochemistry, has been elucidated by spectroscopic and chemical methods. The localization of 1 in the mantle and the analogies with related drimane compounds may indicate a defensive role against predators.