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1.
Ylenia Chiari Pablo Orozco-terWengel Miguel Vences David R. Vieites Augustin Sarovy Jasmin E. Randrianirina Axel Meyer Edward Louis Jr. 《Conservation Genetics》2006,7(4):473-482
Dyscophus antongilii and D. guineti are two morphologically very similar microhylid frogs from Madagascar of uncertain taxonomy. D. antongilii is currently included in Appendix I of the Convention on the International Trade in Endangered Species (CITES) and its exportation is banned completely. In contrast, D. guineti does not receive any legal protection and it is regularly exported. Field data on ecology and behaviour are to a large extent lacking. Here we report on a genetic survey of D. antongilii and D. guineti using nuclear and mitochondrial DNA markers. Sequences of a fragment of 501 bp of the mitochondrial cytochrome b gene from one population of D. antongilii and two populations of D. guineti resulted in a single haplotype network, without haplotype sharing among the populations. However, haplotypes of D.␣guineti were only 1–4 mutational steps from those of D. antongilii, and did not form a clade. The analysis of eight microsatellites newly developed and standardized for D. antongilii revealed an excess of homozygotes and the absence of Hardy–Weinberg equilibrium. The microsatellite data clearly distinguished between D. antongilii and D. guineti, and fixed differences were observed at one locus. Although confirmation of the status of Dyscophus antongilii and D. guineti as separate species requires further data, our study supports the definition of these two taxa as different evolutionary significant units under the adaptive evolutionary conservation concept. 相似文献
2.
The compulsory dispute settlement regime included in the 1982 Law of the Sea Convention is recognized as one of the most comprehensive in a modern international convention. Yet, in the recent application of this regime, the question has arisen as to whether the procedural prerequisites associated with the LOS Convention's compulsory dispute settlement mechanism are so arduous as to avoid binding and compulsory jurisdiction in most instances. This article addresses that question by examining, in particular, the reasoning of the Southern Bluefin Tuna arbitration tribunal, which found Article 281 of Section 1 of the LOS Convention to bar jurisdiction to the compulsory dispute settlement mechanism prescribed by the Convention, and offers suggestions as to how states might distinguish or overcome the barriers imposed by the Southern Bluefin Tuna tribunal in future cases. 相似文献
3.
María-Eugenia Guazzaroni Florian-Alexander Herbst Iván Lores Javier Tamames Ana Isabel Peláez Nieves López-Cortés María Alcaide Mercedes V Del Pozo José María Vieites Martin von Bergen José Luis R Gallego Rafael Bargiela Arantxa López-López Dietmar H Pieper Ramón Rosselló-Móra Jesús Sánchez Jana Seifert Manuel Ferrer 《The ISME journal》2013,7(1):122-136
Microbial metabolism in aromatic-contaminated environments has important ecological implications, and obtaining a complete understanding of this process remains a relevant goal. To understand the roles of biodiversity and aromatic-mediated genetic and metabolic rearrangements, we conducted ‘OMIC'' investigations in an anthropogenically influenced and polyaromatic hydrocarbon (PAH)-contaminated soil with (Nbs) or without (N) bio-stimulation with calcium ammonia nitrate, NH4NO3 and KH2PO4 and the commercial surfactant Iveysol, plus two naphthalene-enriched communities derived from both soils (CN2 and CN1, respectively). Using a metagenomic approach, a total of 52, 53, 14 and 12 distinct species (according to operational phylogenetic units (OPU) in our work equivalent to taxonomic species) were identified in the N, Nbs, CN1 and CN2 communities, respectively. Approximately 10 out of 95 distinct species and 238 out of 3293 clusters of orthologous groups (COGs) protein families identified were clearly stimulated under the assayed conditions, whereas only two species and 1465 COGs conformed to the common set in all of the mesocosms. Results indicated distinct biodegradation capabilities for the utilisation of potential growth-supporting aromatics, which results in bio-stimulated communities being extremely fit to naphthalene utilisation and non-stimulated communities exhibiting a greater metabolic window than previously predicted. On the basis of comparing protein expression profiles and metagenome data sets, inter-alia interactions among members were hypothesised. The utilisation of curated databases is discussed and used for first time to reconstruct ‘presumptive'' degradation networks for complex microbial communities. 相似文献
4.
Aurélien Miralles Jörn Köhler David R. Vieites Frank Glaw Miguel Vences 《Organisms Diversity & Evolution》2011,11(2):135-150
In squamate reptiles the rostral shield constitutes one of the most advanced cases of reduction in the number of scales in
the rostral region, an evolutionary trend clearly associated with a burrowing lifestyle. This structure is characterized by
the fusion of the rostral scale with all adjacent scales into a large, smooth and conical plate covering the snout, totally
encompassing the nostrils, with a horizontal groove running posteriorly from either nostril. In lizards this structure evolved
several times independently, in various lineages of limbless skinks and in the family Dibamidae. We performed a multilocus
phylogenetic analysis of combined mitochondrial and nuclear DNA sequences from the fossorial genus Paracontias, including P. vermisaurus, a new species described herein under an integrative taxonomic approach. The resulting phylogeny supports monophyly of Paracontias, with the following internal topology: [P. kankana (P. vermisaurus sp. n. (((P. minimus + P. brocchii) (P. manify + P. hildebrandti)) (P. rothschildi + P. fasika)))]. The molecular data, coupled with a comparative morphological study, allows us to investigate the evolution of the snout
scales into a single large rostral shield in Paracontias. We discuss the evolutionary processes through which the rostral shield may have originated (e.g. fusion of scales, number
and order of steps involved), and conclude that intuitive and apparently obvious hypotheses for scale homologies based on
position and size only (as usually formulated in squamate taxonomy) may be highly misleading, even in closely related species.
We develop the hypothesis that the rostral shield may provide several functional advantages for fossorial species in facilitating
burrowing and protecting the head from strong physical stress, e.g. smoother surface reducing friction between the tegument
and the substrate, reduction in the number of flexible sutures resulting in strengthened tegument, and the rostral tip likely
playing a role as a shock-absorbing buffer. 相似文献
5.
Carolina Urquiola Marisol Vieites María H. Torre Mauricio Cabrera María Laura Lavaggi Hugo Cerecetto Mercedes González Adela López de Cerain Antonio Monge Pablo Smircich Beatriz Garat Dinorah Gambino 《Bioorganic & medicinal chemistry》2009,17(4):1623-1629
Four new palladium(II) complexes with the formula Pd(L)2, where L are quinoxaline-2-carbonitrile N1,N4-dioxide derivatives, were synthesized as a contribution to the chemistry and pharmacology of metal compounds with this class of pharmacologically interesting bioreductive prodrugs. Compounds were characterized by elemental, conductometric and thermogravimetric analyses, fast atom bombardment mass spectrometry (FAB-MS) and electronic, Fourier transform infrared (FTIR) and 1H-nuclear magnetic resonance spectroscopies. The complexes were subjected to cytotoxic evaluation on V79 cells in hypoxic and aerobic conditions. In addition, a preliminary study on interaction with plasmid DNA in normoxia was performed. Complexes showed different in vitro biological behavior depending on the nature of the substituent on the quinoxaline ring. Pd(L1)2 and Pd(L2)2, where L1 is 3-aminoquinoxaline-2-carbonitrile N1,N4-dioxide and L2 is 3-amino-6(7)-methylquinoxaline-2-carbonitrile N1,N4-dioxide, showed non selective cytotoxicity, being cytotoxic either in hypoxic or in aerobic conditions. On the other hand, Pd(L3)2, where L3 is 3-amino-6(7)-chloroquinoxaline-2-carbonitrile N1,N4-dioxide, resulted in vitro more potent cytotoxin in hypoxia (P = 5.0 μM) than the corresponding free ligand (P = 9.0 μM) and tirapazamine (P = 30.0 μM), the first bioreductive cytotoxic drug introduced into clinical trials. In addition, it showed a very good selective cytotoxicity in hypoxic conditions, being non-cytotoxic in normoxia. Its hypoxic cytotoxicity relationship value, HCR, was of the same order than those of other hypoxia selective cytotoxins (i.e., Mitomycine C, Misonidazole and the N-oxide RB90740). Interaction of the complexes with plasmid DNA in normoxia showed dose dependent ability to relax the negative supercoiled forms via different mechanisms. Pd(L2)2 introduced a scission event in supercoiled DNA yielding the circular relaxed form. Meanwhile, both Pd(L1)2 and Pd(L3)2 produced the loss of negative supercoils rendering a family of topoisomers with reduced electrophoretic mobility. Pd(L3)2 showed a more marked effect than Pd(L1)2. Indeed, for the highest doses assayed, Pd(L3)2 was even able to introduce positive supercoils on the plasmid DNA. 相似文献
6.
7.
Cynthia Sarniguet Jeannette Toloza Micaella Cipriani Michel Lapier Marisol Vieites Yanis Toledano-Magaña Juan Carlos García-Ramos Lena Ruiz-Azuara Virtudes Moreno Juan Diego Maya Claudio Olea Azar Dinorah Gambino Lucía Otero 《Biological trace element research》2014,159(1-3):379-392
Parasitic illnesses are major causes of human disease and misery worldwide. Among them, both amebiasis and Chagas disease, caused by the protozoan parasites, Entamoeba histolytica and Trypanosoma cruzi, are responsible for thousands of annual deaths. The lack of safe and effective chemotherapy and/or the appearance of current drug resistance make the development of novel pharmacological tools for their treatment relevant. In this sense, within the framework of the medicinal inorganic chemistry, metal-based drugs appear to be a good alternative to find a pharmacological answer to parasitic diseases. In this work, novel ruthenium complexes [RuCl2(HL)(HPTA)2]Cl2 with HL = bioactive 5-nitrofuryl containing thiosemicarbazones and PTA?=?1,3,5-triaza-7-phosphaadamantane have been synthesized and fully characterized. PTA was included as co-ligand in order to modulate complexes aqueous solubility. In fact, obtained complexes were water soluble. Their activity against T. cruzi and E. histolytica was evaluated in vitro. [RuCl2(HL4)(HPTA)2]Cl2 complex, with HL4?=?N-phenyl-5-nitrofuryl-thiosemicarbazone, was the most active compound against both parasites. In particular, it showed an excellent activity against E. histolytica (half maximal inhibitory concentration (IC50)?=?5.2 μM), even higher than that of the reference drug metronidazole. In addition, this complex turns out to be selective for E. histolytica (selectivity index (SI) >38). The potential mechanism of antiparasitic action of the obtained ruthenium complexes could involve oxidative stress for both parasites. Additionally, complexes could interact with DNA as second potential target by an intercalative-like mode. Obtained results could be considered a contribution in the search for metal compounds that could be active against multiple parasites. 相似文献
8.
9.
Jason L. Brown Neftali Sillero Frank Glaw Parfait Bora David R. Vieites Miguel Vences 《PloS one》2016,11(1)
Madagascar has become a model region for testing hypotheses of species diversification and biogeography, and many studies have focused on its diverse and highly endemic herpetofauna. Here we combine species distribution models of a near-complete set of species of reptiles and amphibians known from the island with body size data and a tabulation of herpetofaunal communities from field surveys, compiled up to 2008. Though taxonomic revisions and novel distributional records arose since compilation, we are confident that the data are appropriate for inferring and comparing biogeographic patterns among these groups of organisms. We observed species richness of both amphibians and reptiles was highest in the humid rainforest biome of eastern Madagascar, but reptiles also show areas of high richness in the dry and subarid western biomes. In several amphibian subclades, especially within the Mantellidae, species richness peaks in the central eastern geographic regions while in reptiles different subclades differ distinctly in their richness centers. A high proportion of clades and subclades of both amphibians and reptiles have a peak of local endemism in the topographically and bioclimatically diverse northern geographic regions. This northern area is roughly delimited by a diagonal spanning from 15.5°S on the east coast to ca. 15.0°S on the west coast. Amphibian diversity is highest at altitudes between 800–1200 m above sea-level whereas reptiles have their highest richness at low elevations, probably reflecting the comparatively large number of species specialized to the extended low-elevation areas in the dry and subarid biomes. We found that the range sizes of both amphibians and reptiles strongly correlated with body size, and differences between the two groups are explained by the larger body sizes of reptiles. However, snakes have larger range sizes than lizards which cannot be readily explained by their larger body sizes alone. Range filling, i.e., the amount of suitable habitat occupied by a species, is less expressed in amphibians than in reptiles, possibly reflecting their lower dispersal capacity. Taxonomic composition of communities assessed by field surveys is largely explained by bioclimatic regions, with communities from the dry and especially subarid biomes distinctly differing from humid and subhumid biomes. 相似文献
10.
José María Vieites Azam Ghazi Ana Beloqui Julio Polaina José M. Andreu Olga V. Golyshina Taras Y. Nechitaylo Agnes Waliczek Michail M. Yakimov Peter N. Golyshin Manuel Ferrer 《Microbial biotechnology》2010,3(1):48-58
Carboxyl esterases (CE) exhibit various reaction specificities despite of their overall structural similarity. In present study we have exploited functional metagenomics, saturation mutagenesis and experimental protein evolution to explore residues that have a significant role in substrate discrimination. We used an enzyme, designated 3A6, derived from the earthworm gut metagenome that exhibits CE and feruloyl esterase (FAE) activities with p-nitrophenyl and cinnamate esters, respectively, with a [(kcat/Km)]CE/[(kcat/Km)]FAE factor of 17. Modelling-guided saturation mutagenesis at specific hotspots (Lys281, Asp282, Asn316 and Lys317) situated close to the catalytic core (Ser143/Asp273/His305) and a deletion of a 34-AA–long peptide fragment yielded mutants with the highest CE activity, while cinnamate ester bond hydrolysis was effectively abolished. Although, single to triple mutants with both improved activities (up to 180-fold in kcat/Km values) and enzymes with inverted specificity ((kcat/Km)CE/(kcat/Km)FAE ratio of ∼0.4) were identified, no CE inactive variant was found. Screening of a large error-prone PCR-generated library yielded by far less mutants for substrate discrimination. We also found that no significant changes in CE activation energy occurs after any mutation (7.3 to −5.6 J mol−1), whereas a direct correlation between loss/gain of FAE function and activation energies (from 33.05 to −13.7 J mol−1) was found. Results suggest that the FAE activity in 3A6 may have evolved via introduction of a limited number of ‘hot spot’ mutations in a common CE ancestor, which may retain the original hydrolytic activity due to lower restrictive energy barriers but conveys a dynamic energetically favourable switch of a second hydrolytic reaction. 相似文献