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1.
Sci Rep ; 8(1): 14256, 2018 09 24.
Artículo en Inglés | MEDLINE | ID: mdl-30250036

RESUMEN

DNA barcoding, based on a fragment of cytochrome c oxidase I (COI) mtDNA, is as an effective molecular tool for identification, discovery, and biodiversity assessment for most animals. However, multiple gene markers coupled with more sophisticated analytical approaches may be necessary to clarify species boundaries in cases of cryptic diversity or morphological plasticity. Using 339 moths collected from mountains surrounding Beijing, China, we tested a pipeline consisting of two steps: (1) rapid morphospecies sorting and screening of the investigated fauna with standard COI barcoding approaches; (2) additional analyses with multiple molecular markers for those specimens whose morphospecies and COI barcode grouping were incongruent. In step 1, 124 morphospecies were delimited into 116 barcode units, with 90% of the conflicts being associated with specimens identified to the genus Hypena. In step 2, 55 individuals representing all 12 Hypena morphospecies were analysed using COI, COII, 28S, EF-1a, Wgl sequences or their combinations with the BPP (Bayesian Phylogenetics and Phylogeography) multigene species delimitation method. The multigene analyses supported the delimitation of 5 species, consistent with the COI analysis. We conclude that a two-step barcoding analysis pipeline is able to rapidly characterize insect biodiversity and help to elucidate species boundaries for taxonomic complexes without jeopardizing overall project efficiency by substantially increasing analytical costs.


Asunto(s)
Biodiversidad , Código de Barras del ADN Taxonómico/métodos , ADN Mitocondrial/genética , Mariposas Nocturnas/genética , Animales , Teorema de Bayes , China , Filogeografía , Especificidad de la Especie
2.
Mol Ecol Resour ; 18(3): 666-675, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29154499

RESUMEN

Species identification through DNA barcoding or metabarcoding has become a key approach for biodiversity evaluation and ecological studies. However, the rapid accumulation of barcoding data has created some difficulties: for instance, global enquiries to a large reference library can take a very long time. We here devise a two-step searching strategy to speed identification procedures of such queries. This firstly uses a Hidden Markov Model (HMM) algorithm to narrow the searching scope to genus level and then determines the corresponding species using minimum genetic distance. Moreover, using a fuzzy membership function, our approach also estimates the credibility of assignment results for each query. To perform this task, we developed a new software pipeline, FuzzyID2, using Python and C++. Performance of the new method was assessed using eight empirical data sets ranging from 70 to 234,535 barcodes. Five data sets (four animal, one plant) deployed the conventional barcode approach, one used metabarcodes, and two were eDNA-based. The results showed mean accuracies of generic and species identification of 98.60% (with a minimum of 95.00% and a maximum of 100.00%) and 94.17% (with a range of 84.40%-100.00%), respectively. Tests with simulated NGS sequences based on realistic eDNA and metabarcode data demonstrated that FuzzyID2 achieved a significantly higher identification success rate than the commonly used Blast method, and the TIPP method tends to find many fewer species than either FuzztID2 or Blast. Furthermore, data sets with tens of thousands of barcodes need only a few seconds for each query assignment using FuzzyID2. Our approach provides an efficient and accurate species identification protocol for biodiversity-related projects with large DNA sequence data sets.


Asunto(s)
Lógica Difusa , Cadenas de Markov , Programas Informáticos , Clasificación/métodos , Código de Barras del ADN Taxonómico
4.
Mitochondrial DNA A DNA Mapp Seq Anal ; 28(4): 458-472, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-27159695

RESUMEN

DNA barcoding was successfully used for the accurate identification of chondrichthyans in the Indian commercial marine fishery. About 528 specimens of 111 chondrichthyan species and 34 families, collected from the Indian EEZ, were barcoded for a 655 bp region of the mitochondrial gene cytochrome c oxidase subunit 1 (COI). Generally, five specimens per species were barcoded, but numbers ranged from 2 to 13. The average Kimura 2 parameter (K2P) distance separating individuals within species was 0.32%, and the average distance separating species within genera was 6.73%. Ten species were suggested as putative new species requiring formal descriptions. Based on the morphology and molecular support, 11 elasmobranch species were confirmed first records for Indian waters. The present study confirms the ability of DNA barcoding for the accurate identification of sharks, rays, and their products from Indian waters.


Asunto(s)
Código de Barras del ADN Taxonómico/métodos , Complejo IV de Transporte de Electrones/genética , Tiburones/clasificación , Rajidae/clasificación , Animales , ADN Mitocondrial/genética , Evolución Molecular , Proteínas de Peces/genética , Explotaciones Pesqueras , India , Filogenia , Tiburones/genética , Rajidae/genética , Especificidad de la Especie
5.
BMC Genomics ; 16: 428, 2015 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-26040695

RESUMEN

BACKGROUND: Pine moths (Lepidoptera; Bombycoidea; Lasiocampidae: Dendrolimus spp.) are among the most serious insect pests of forests, especially in southern China. Although COI barcodes (a standardized portion of the mitochondrial cytochrome c oxidase subunit I gene) can distinguish some members of this genus, the evolutionary relationships of the three morphospecies Dendrolimus punctatus, D. tabulaeformis and D. spectabilis have remained largely unresolved. We sequenced whole mitochondrial genomes of eight specimens, including D. punctatus wenshanensis. This is an unambiguous subspecies of D. punctatus, and was used as a reference for inferring the relationships of the other two morphospecies of the D. punctatus complex. We constructed phylogenetic trees from this data, including twelve published mitochondrial genomes of other Bombycoidea species, and examined the relationships of the Dendrolimus taxa using these trees and the genomic features of the mitochondrial genome. RESULTS: The eight fully sequenced mitochondrial genomes from the three morphospecies displayed similar genome structures as other Bombycoidea species in terms of gene content, base composition, level of overall AT-bias and codon usage. However, the Dendrolimus genomes possess a unique feature in the large ribosomal 16S RNA subunits (rrnL), which are more than 60 bp longer than other members of the superfamily and have a higher AC proportion. The eight mitochondrial genomes of Dendrolimus were highly conservative in many aspects, for example with identical stop codons and overlapping regions. But there were many differences in start codons, intergenic spacers, and numbers of mismatched base pairs of tRNA (transfer RNA genes). Our results, based on phylogenetic trees, genetic distances, species delimitation and genomic features (such as intergenic spacers) of the mitochondrial genome, indicated that D. tabulaeformis is as close to D. punctatus as is D. punctatus wenshanensis, whereas D. spectabilis evolved independently from D. tabulaeformis and D. punctatus. Whole mitochondrial DNA phylogenies showed that D. spectabilis formed a well-supported monophyletic clade, with a clear species boundary separating it from the other congeners examined here. However, D. tabulaeformis often clustered with D. punctatus and with the subspecies D. punctatus wenshanensis. Genetic distance analyses showed that the distance between D. tabulaeformis and D. punctatus is generally less than the intraspecific distance of D. punctatus and its subspecies D. punctatus wenshanensis. In the species delimitation analysis of Poisson Tree Processes (PTP), D. tabulaeformis, D. punctatus and D. punctatus wenshanensis clustered into a putative species separated from D. spectabilis. In comparison with D. spectabilis, D. tabulaeformis and D. punctatus also exhibit a similar structure in intergenic spacer characterization. These different types of evidence suggest that D. tabulaeformis is very close to D. punctatus and its subspecies D. punctatus wenshanensis, and is likely to be another subspecies of D. punctatus. CONCLUSIONS: Whole mitochondrial genomes possess relatively rich genetic information compared with the traditional use of single or multiple genes for phylogenetic purposes. They can be used to better infer phylogenetic relationships and degrees of relatedness of taxonomic groups, at least from the aspect of maternal lineage: caution should be taken due to the maternal-only inheritance of this genome. Our results indicate that D. spectabilis is an independent lineage, while D. tabulaeformis shows an extremely close relationship to D. punctatus.


Asunto(s)
Genoma Mitocondrial , Mitocondrias/genética , Mariposas Nocturnas/genética , Animales , Disparidad de Par Base , China , Codón Iniciador/genética , ADN Mitocondrial/análisis , ADN Mitocondrial/aislamiento & purificación , Evolución Molecular , Proteínas Mitocondriales/genética , Proteínas Mitocondriales/metabolismo , Mariposas Nocturnas/clasificación , Filogenia , ARN Ribosómico 16S/genética , ARN Ribosómico 16S/metabolismo , ARN de Transferencia/genética , ARN de Transferencia/metabolismo , Análisis de Secuencia de ADN
6.
Ecol Evol ; 4(12): 2472-87, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25360280

RESUMEN

DNA barcoding has become a promising means for the identification of organisms of all life-history stages. Currently, distance-based and tree-based methods are most widely used to define species boundaries and uncover cryptic species. However, there is no universal threshold of genetic distance values that can be used to distinguish taxonomic groups. Alternatively, DNA barcoding can deploy a "character-based" method, whereby species are identified through the discrete nucleotide substitutions. Our research focuses on the delimitation of moth species using DNA-barcoding methods. We analyzed 393 Lepidopteran specimens belonging to 80 morphologically recognized species with a standard cytochrome c oxidase subunit I (COI) sequencing approach, and deployed tree-based, distance-based, and diagnostic character-based methods to identify the taxa. The tree-based method divided the 393 specimens into 79 taxa (species), and the distance-based method divided them into 84 taxa (species). Although the diagnostic character-based method found only 39 so-identifiable species in the 80 species, with a reduction in sample size the accuracy rate substantially improved. For example, in the Arctiidae subset, all 12 species had diagnostics characteristics. Compared with traditional morphological method, molecular taxonomy performed well. All three methods enable the rapid delimitation of species, although they have different characteristics and different strengths. The tree-based and distance-based methods can be used for accurate species identification and biodiversity studies in large data sets, while the character-based method performs well in small data sets and can also be used as the foundation of species-specific biochips.

7.
Mol Endocrinol ; 28(12): 2025-37, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25333515

RESUMEN

Progesterone receptors (PRs) are phosphorylated on multiple sites, and a variety of roles for phosphorylation have been suggested by cell-based studies. Previous studies using PR-null mice have shown that PR plays an important role in female fertility, regulation of uterine growth, the uterine decidualization response, and proliferation as well as ductal side-branching and alveologenesis in the mammary gland. To study the role of PR phosphorylation in vivo, a mouse was engineered with homozygous replacement of PR with a PR serine-to-alanine mutation at amino acid 191. No overt phenotypes were observed in the mammary glands or uteri of PR S191A treated with progesterone (P4). In contrast, although PR S191A mice were fertile, litters were 19% smaller than wild type and the estrous cycle was lengthened slightly. Moreover, P4-dependent gene regulation in primary mammary epithelial cells (MECs) was altered in a gene-selective manner. MECs derived from wild type and PR S191A mice were grown in a three-dimensional culture. Both formed acinar structures that were morphologically similar, and proliferation was stimulated equally by P4. However, P4 induction of receptor activator of nuclear factor-κB ligand and calcitonin was selectively reduced in S191A cultures. These differences were confirmed in freshly isolated MECs. Chromatin immunoprecipitation analysis showed that the binding of S191A PR to some of the receptor activator of nuclear factor-κB ligand enhancers and a calcitonin enhancer was substantially reduced. Thus, the elimination of a single phosphorylation site is sufficient to modulate PR activity in vivo. PR contains many phosphorylation sites, and the coordinate regulation of multiple sites is a potential mechanism for selective modulation of PR function.


Asunto(s)
Receptores de Progesterona/química , Receptores de Progesterona/metabolismo , Serina/metabolismo , Animales , Femenino , Inmunohistoquímica , Ratones , Fosforilación , Receptores de Progesterona/genética , Serina/química
8.
PLoS One ; 8(5): e64428, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23741330

RESUMEN

With the ongoing loss of biodiversity, there is a great need for fast and effective ways to assess species richness and diversity: DNA barcoding provides a powerful new tool for this. We investigated this approach by focusing on the Tibetan plateau, which is one of the world's top biodiversity hotspots. There have been few studies of its invertebrates, although they constitute the vast majority of the region's diversity. Here we investigated species diversity of the lepidopteran family Noctuidae, across different environmental gradients, using measurements based on traditional morphology as well as on DNA barcoding. The COI barcode showed an average interspecific K2P distance of 9.45±2.08%, which is about four times larger than the mean intraspecific distance (1.85±3.20%). Using six diversity indices, we did not detect any significant differences in estimated species diversity between measurements based on traditional morphology and on DNA barcoding. Furthermore, we found strong positive correlations between them, indicating that barcode-based measures of species diversity can serve as a good surrogate for morphology-based measures in most situations tested. Eastern communities were found to have significantly higher diversity than Western ones. Among 22 environmental factors tested, we found that three (precipitation of driest month, precipitation of driest quarter, and precipitation of coldest quarter) were significantly correlated with species diversity. Our results indicate that these factors could be the key ecological factors influencing the species diversity of the lepidopteran family Noctuidae on the Tibetan plateau.


Asunto(s)
Biodiversidad , Código de Barras del ADN Taxonómico/métodos , Complejo IV de Transporte de Electrones/clasificación , Mariposas Nocturnas/clasificación , Filogenia , Animales , Teorema de Bayes , Complejo IV de Transporte de Electrones/genética , Femenino , Humedad , Masculino , Mariposas Nocturnas/anatomía & histología , Mariposas Nocturnas/genética , Estaciones del Año , Tibet
9.
Mol Ecol Resour ; 13(1): 32-42, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23006488

RESUMEN

Identification of taxonomical units underpins most biological endeavours ranging from accurate biodiversity estimates to the effective management of sustainably harvested, protected or endangered species. Successful species identification is now frequently based on a combination of approaches including morphometrics and DNA markers. Sequencing of the mitochondrial COI gene is an established methodology with an international campaign directed at barcoding all fishes. We employed COI sequencing alongside traditional taxonomic identification methods and uncovered instances of deep intraspecific genetic divergences among flathead species. Sixty-five operational taxonomic units (OTUs) were observed across the Indo-West Pacific from just 48 currently recognized species. The most comprehensively sampled taxon, Platycephalus indicus, exhibited the highest levels of genetic diversity with eight lineages separated by up to 16.37% genetic distance. Our results clearly indicate a thorough reappraisal of the current taxonomy of P. indicus (and its three junior synonyms) is warranted in conjunction with detailed taxonomic work on the other additional Platycephalidae OTUs detected by DNA barcoding.


Asunto(s)
Código de Barras del ADN Taxonómico/métodos , Peces/genética , Variación Genética/genética , Filogenia , Animales , Secuencia de Bases , Análisis por Conglomerados , Biología Computacional , Conservación de los Recursos Naturales/métodos , Complejo IV de Transporte de Electrones/genética , Océano Índico , Datos de Secuencia Molecular , Océano Pacífico , Análisis de Secuencia de ADN , Especificidad de la Especie
10.
Methods Mol Biol ; 858: 423-39, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22684969

RESUMEN

The FISH-BOL campaign was initiated in 2005, and currently has barcoded for the cytochrome c oxidase subunit I (COI) gene about 8,000 of the 31,000 fish species currently recognised. This includes the great majority of the world's most important commercial species. Results thus far show that about 98% and 93% of marine and freshwater species, respectively, are barcode distinguishable. One important issue that needs to be more fully addressed in FISH-BOL concerns the initial misidentification of a small number of barcode reference specimens. This is unsurprising considering the large number of fish species, some of which are morphologically very similar and others as yet unrecognised, but constant vigilance and ongoing attention by the FISH-BOL community is required to eliminate such errors. Once the reference library has been established, barcoding enables the identification of unknown fishes at any life history stage or from their fragmentary remains. The many uses of the FISH-BOL barcode library include detecting consumer fraud, aiding fisheries management, improving ecological analyses including food web syntheses, and assisting with taxonomic revisions.


Asunto(s)
Código de Barras del ADN Taxonómico , ADN/genética , Complejo IV de Transporte de Electrones/genética , Peces/clasificación , Peces/genética , Animales
11.
PLoS One ; 7(2): e30986, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22363527

RESUMEN

Species identification via DNA barcodes is contributing greatly to current bioinventory efforts. The initial, and widely accepted, proposal was to use the protein-coding cytochrome c oxidase subunit I (COI) region as the standard barcode for animals, but recently non-coding internal transcribed spacer (ITS) genes have been proposed as candidate barcodes for both animals and plants. However, achieving a robust alignment for non-coding regions can be problematic. Here we propose two new methods (DV-RBF and FJ-RBF) to address this issue for species assignment by both coding and non-coding sequences that take advantage of the power of machine learning and bioinformatics. We demonstrate the value of the new methods with four empirical datasets, two representing typical protein-coding COI barcode datasets (neotropical bats and marine fish) and two representing non-coding ITS barcodes (rust fungi and brown algae). Using two random sub-sampling approaches, we demonstrate that the new methods significantly outperformed existing Neighbor-joining (NJ) and Maximum likelihood (ML) methods for both coding and non-coding barcodes when there was complete species coverage in the reference dataset. The new methods also out-performed NJ and ML methods for non-coding sequences in circumstances of potentially incomplete species coverage, although then the NJ and ML methods performed slightly better than the new methods for protein-coding barcodes. A 100% success rate of species identification was achieved with the two new methods for 4,122 bat queries and 5,134 fish queries using COI barcodes, with 95% confidence intervals (CI) of 99.75-100%. The new methods also obtained a 96.29% success rate (95%CI: 91.62-98.40%) for 484 rust fungi queries and a 98.50% success rate (95%CI: 96.60-99.37%) for 1094 brown algae queries, both using ITS barcodes.


Asunto(s)
Inteligencia Artificial , Biología Computacional/métodos , Código de Barras del ADN Taxonómico/métodos , ADN/genética , Sistemas de Lectura Abierta/genética , Animales , Organismos Acuáticos , Secuencia de Bases , Canadá , Quirópteros/genética , ADN Espaciador Ribosómico/genética , Bases de Datos Genéticas , Complejo IV de Transporte de Electrones/genética , Peces/genética , Hongos/genética , Datos de Secuencia Molecular , Océano Pacífico , Phaeophyceae/genética , Especificidad de la Especie , Factores de Tiempo , Clima Tropical
12.
PLoS One ; 6(12): e28355, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22145038

RESUMEN

Humans with PROP1 mutations have multiple pituitary hormone deficiencies (MPHD) that typically advance from growth insufficiency diagnosed in infancy to include more severe growth hormone (GH) deficiency and progressive reduction in other anterior pituitary hormones, eventually including adrenocorticotropic hormone (ACTH) deficiency and hypocortisolism. Congenital deficiencies of GH, prolactin, and thyroid stimulating hormone have been reported in the Prop1(null) (Prop1(-/-)) and the Ames dwarf (Prop1(df/df)) mouse models, but corticotroph and pituitary adrenal axis function have not been thoroughly investigated. Here we report that the C57BL6 background sensitizes mutants to a wasting phenotype that causes approximately one third to die precipitously between weaning and adulthood, while remaining homozygotes live with no signs of illness. The wasting phenotype is associated with severe hypoglycemia. Circulating ACTH and corticosterone levels are elevated in juvenile and aged Prop1 mutants, indicating activation of the pituitary-adrenal axis. Despite this, young adult Prop1 deficient mice are capable of responding to restraint stress with further elevation of ACTH and corticosterone. Low blood glucose, an expected side effect of GH deficiency, is likely responsible for the elevated corticosterone level. These studies suggest that the mouse model differs from the human patients who display progressive hormone loss and hypocortisolism.


Asunto(s)
Hormona Adrenocorticotrópica/sangre , Envejecimiento/patología , Enanismo/genética , Hormona del Crecimiento/deficiencia , Proteínas de Homeodominio/fisiología , Animales , Glucemia/metabolismo , Corticosterona/sangre , Femenino , Homocigoto , Hipopituitarismo/genética , Técnicas para Inmunoenzimas , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Mutación/genética , Fenotipo , Prolactina/deficiencia , Radioinmunoensayo
14.
Mitochondrial DNA ; 22 Suppl 1: 21-6, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21271848

RESUMEN

BACKGROUND AND AIMS: DNA barcoding strongly suggests that specimens of the slender codling (Halargyreus johnsonii) from New Zealand and Tasmania belong to a different species to H. johnsonii reported from other areas. RESULTS: Sequence divergence between the two groups averaged 3.95%, much higher than within-group divergences of 0.03 and 0.02% for specimens, respectively, from New Zealand-Tasmania and from the North Pacific, Atlantic Ocean, and Southern Ocean. CONCLUSION: Meristic data for specimens from New Zealand and from the Southern Ocean north of the Ross Sea support the conclusion of two species. DNA barcodes for two sister taxa, Antimora rostrata and Antimora microlepis, show low intra-species (0.3-0.06%) and inter-species (0.23%) divergence.


Asunto(s)
Código de Barras del ADN Taxonómico/métodos , ADN Mitocondrial/genética , Evolución Molecular , Gadiformes/clasificación , Gadiformes/genética , Animales , Complejo IV de Transporte de Electrones/genética , Gadiformes/fisiología , Biología Marina , Nueva Zelanda , Océanos y Mares , Análisis de Secuencia de ADN , Especificidad de la Especie , Tasmania
15.
Zookeys ; (147): 85-97, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22379386

RESUMEN

A new species, Tetracha (Neotetracha) naviauxi, and a new subspecies, Tetracha (Tetracha) sobrina caicosensis, are described from the Turks and Caicos Islands. The key to Tetracha species in Naviaux (2007) is adapted to accommodate Tetracha naviauxi. Tetracha sobrina caicosensis is compared to other Caribbean subspecies of Tetracha sobrina.

17.
Biofactors ; 35(6): 528-36, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19904813

RESUMEN

Steroid receptors (SRs) are hormone-activated transcription factors important for a wide variety of cellular functions. Post-translational modifications of SRs, including phosphorylation, ubiquitination, acetylation, and sumoylation regulate their expression and function. The remarkable number of phosphorylation sites in these receptors and the wide variety of kinases shown to modulate phosphorylation influence the integration between cell-signaling pathways and SR action. These phosphorylation sites have been identified in all of the functional domains with the majority being located within the amino-terminal portions of the receptors. The regulation of function is receptor specific, site specific, and often dependent on the cellular context. Numerous roles for site-specific phosphorylation have been elucidated including sensitivity of hormone response, DNA binding, expression, stability, subcellular localization, dimerization, and protein-protein interactions that can determine the regulation of specific target genes. This review summarizes the current knowledge regarding receptor site-specific phosphorylation and regulation of function. As functional assays become more sophisticated, it is likely that additional roles for phosphorylation in receptor function will be identified.


Asunto(s)
Receptores de Esteroides/metabolismo , Animales , Humanos , Modelos Biológicos , Fosforilación , Receptores Androgénicos/metabolismo , Receptores de Estrógenos/metabolismo , Receptores de Glucocorticoides/metabolismo , Receptores de Progesterona/metabolismo
18.
Diabetes ; 58(10): 2292-302, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19587358

RESUMEN

OBJECTIVE: We showed that 17beta-estradiol (E(2)) favors pancreatic beta-cell survival via the estrogen receptor-alpha (ERalpha) in mice. E(2) activates nuclear estrogen receptors via an estrogen response element (ERE). E(2) also activates nongenomic signals via an extranuclear form of ERalpha and the G protein-coupled estrogen receptor (GPER). We studied the contribution of estrogen receptors to islet survival. RESEARCH DESIGN AND METHODS: We used mice and islets deficient in estrogen receptor-alpha (alphaERKO(-/-)), estrogen receptor-beta (betaERKO(-/-)), estrogen receptor-alpha and estrogen receptor-beta (alphabetaERKO(-/-)), and GPER (GPERKO(-/-)); a mouse lacking ERalpha binding to the ERE; and human islets. These mice and islets were studied in combination with receptor-specific pharmacological probes. RESULTS: We show that ERalpha protection of islet survival is ERE independent and that E(2) favors islet survival through extranuclear and membrane estrogen receptor signaling. We show that ERbeta plays a minor cytoprotective role compared to ERalpha. Accordingly, betaERKO(-/-) mice are mildly predisposed to streptozotocin-induced islet apoptosis. However, combined elimination of ERalpha and ERbeta in mice does not synergize to provoke islet apoptosis. In alphabetaERKO(-/-) mice and their islets, E(2) partially prevents apoptosis suggesting that an alternative pathway compensates for ERalpha/ERbeta deficiency. We find that E(2) protection of islet survival is reproduced by a membrane-impermeant E(2) formulation and a selective GPER agonist. Accordingly, GPERKO(-/-) mice are susceptible to streptozotocin-induced insulin deficiency. CONCLUSIONS: E(2) protects beta-cell survival through ERalpha and ERbeta via ERE-independent, extra-nuclear mechanisms, as well as GPER-dependent mechanisms. The present study adds a novel dimension to estrogen biology in beta-cells and identifies GPER as a target to protect islet survival.


Asunto(s)
Receptor alfa de Estrógeno/fisiología , Islotes Pancreáticos/citología , Receptores Acoplados a Proteínas G/fisiología , Animales , Apoptosis , Supervivencia Celular , Diabetes Mellitus Experimental/inducido químicamente , Diabetes Mellitus Experimental/genética , Estradiol/farmacología , Receptor alfa de Estrógeno/deficiencia , Receptor alfa de Estrógeno/genética , Receptor beta de Estrógeno/deficiencia , Receptor beta de Estrógeno/genética , Técnicas de Inactivación de Genes , Humanos , Inmunohistoquímica , Insulina/análisis , Células Secretoras de Insulina/citología , Células Secretoras de Insulina/efectos de los fármacos , Ratones , Ratones Noqueados , Páncreas/química , Páncreas/citología , Receptores de Estrógenos , Receptores Acoplados a Proteínas G/deficiencia , Receptores Acoplados a Proteínas G/genética , Estreptozocina/farmacología
19.
Mol Ecol Resour ; 9(4): 1077-85, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21564845

RESUMEN

COI DNA barcoding is increasingly recognized as a significant new tool for the recognition and identification of animal species. Here, publicly available barcode data are compiled and analysed for birds (657 species) and fishes (1088 species). The proportion of species that cannot be barcode-distinguished by this marker is approximately 6.4% for birds and 2.1-2.5% for fishes. At all hierarchical taxonomic levels (species, genera, family, order, class), fish show greater mean COI divergence than birds. If two samples are barcode-identical, then for both birds and fishes, the probability that they are from the same species is 98-99%. The probability of conspecificity rapidly drops as divergence increases. At 2% COI divergence, this probability approximates to 1% for birds and 3% for fishes. The apparent difference between birds and fishes might partially reflect currently unrecognized cryptic species complexes in the latter. These probability estimates derive from pooled samples of birds and pooled samples of fishes, and will not apply in all situations. Recently evolved species complexes will have higher proportions of species that are barcode-identical. As barcode data accumulate, more refined statistical analyses will become possible.

20.
Mol Ecol Resour ; 9 Suppl s1: 237-42, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-21564983

RESUMEN

With more than 15 000 described marine species, fishes are a conspicuous, diverse and increasingly threatened component of marine life. It is generally accepted that most large-bodied fishes have been described, but this conclusion presumes that current taxonomic systems are robust. DNA barcoding, the analysis of a standardized region of the cytochrome c oxidase 1 gene (COI), was used to examine patterns of sequence divergence between populations of 35 fish species from opposite sides of the Indian Ocean, chosen to represent differing lifestyles from inshore to offshore. A substantial proportion of inshore species showed deep divergences between populations from South African and Australian waters (mean = 5.10%), a pattern which also emerged in a few inshore/offshore species (mean = 0.84%), but not within strictly offshore species (mean = 0.26%). Such deep divergences, detected within certain inshore and inshore/offshore taxa, are typical of divergences between congeneric species rather than between populations of a single species, suggesting that current taxonomic systems substantially underestimate species diversity. We estimate that about one third of the 1000 fish species thought to bridge South African and Australian waters actually represent two taxa.

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