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| Registros recuperados: 117 | |
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| Huvet, Arnaud; Lapegue, Sylvie; Magoulas, A; Boudry, Pierre. |
| The respective status of the Portuguese oyster, Crassostrea angulata, and the Pacific oyster, Crassostrea gigas, has long been a matter of controversy. Morphological and physiological similarities, homogeneity of allozyme allelic frequencies between populations of the two taxa and the demonstration of hybridization lead most authors to suggest that they should be regrouped within the same species. The risk of introgression and the present expansion of C. gigas aquaculture in Europe raises the question of the need for preservation of C. angulata in Europe, as only a few populations remain. We studied European and Asian populations of C. gigas and C. angulata using microsatellite and mitochondrial DNA markers to estimate their genetic diversity and... |
| Tipo: Text |
Palavras-chave: Phylogeography; Population genetics; Microsatellites; Crassostrea gigas; Crassostrea angulata. |
| Ano: 2000 |
URL: https://archimer.ifremer.fr/doc/2000/publication-707.pdf |
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| Faust, Ellika; Andre, Carl; Meurling, Sara; Kochmann, Judith; Christiansen, Henrik; Jensen, Lasse Fast; Charrier, Gregory; Laugen, Ane T.; Strand, Asa. |
| Identifying the routes and rates of introductions is fundamental for the understanding of marine invasions. Recurring introductions over the last 50 yr have led to the establishment of feral Pacific oyster Crassostrea gigas populations throughout Europe. In the northern countries, Sweden and Norway, the species first occurred in large numbers in 2006. Here, we investigated the relative importance of introduction via re-laying of cultured oysters imported for consumption from France, Ireland or the Netherlands, and dispersal of oyster larvae by ocean currents from wild oyster populations in Denmark. Using microsatellite DNA markers, we estimated genetic differentiation among Pacific oysters collected at 4 Swedish locations, 3 Norwegian locations and 9... |
| Tipo: Text |
Palavras-chave: Population genetics; Microsatellites; Range expansion; Non-native species; Aquaculture; Connectivity; Scandinavia; Skagerrak. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00395/50627/72574.pdf |
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| Lapegue, Sylvie; Boudry, Pierre. |
| Oysters are among the most familiar of all marine invertebrate taxa. However our knowledge of oyster phylogeny and systematics is fragmentary. This is principally due to the plastic growth patterns of these animals, which result in a wide range of overlapping, ecophenotypic variants that greatly reduce the value of analysis based on shell morphology. Besides that, many intentional or accidental anthropogenic transfers have emphasised this situation. In several cases of misclassification or misidentification of oysters, DNA molecular data, have provided valuable new insights on the tracing of introductions or more generally on the phylogeographic relationships between oyster species. We will illustrate this issue with recent case studies from our lab on... |
| Tipo: Text |
Palavras-chave: Genetic; Ostreola stentina; Crassostrea honkongensis; Crassostrea gigas; Crassostrea angulata; Oysters; Population genetics. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/acte-3475.pdf |
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| Souza,Maria Isabel Ferreira de; Salgueiro,Fabiano; Carnavale-Bottino,Mariana; Félix,Durvalina Benedita; Alves-Ferreira,Marcio; Bittencourt,Juliana Vitoria Messias; Margis,Rogério. |
| Habitat fragmentation and a decrease in population size may lead to a loss in population genetic diversity. For the first time, the reduction in genetic diversity in the northernmost limit of natural occurence (southeastern Brazil) of Araucaria angustifolia in comparison with populations in the main area of the species continuous natural distribution (southern Brazil), was tested. The 673 AFLPs markers revealed a high level of genetic diversity for the species (Ht = 0.27), despite anthropogenic influence throughout the last century, and a decrease of H in isolated populations of southeastern Brazil (H = 0.16), thereby indicating the tendency for higher genetic diversity in remnant populations of continuous forests in southern Brazil, when compared to... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Araucariaceae; Relict populations; Araucaria forest; Population genetics; AFLP. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572009000300018 |
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| da Silva Santos,Anelisie; Trigo,Tatiane Campos; de Oliveira,Tadeu Gomes; Silveira,Leandro; Eizirik,Eduardo. |
| Abstract The pampas cat is a small felid that occurs in open habitats throughout much of South America. Previous studies have revealed intriguing patterns of morphological differentiation and genetic structure among its populations, as well as molecular evidence for hybridization with the closely related L. tigrinus. Here we report phylogeographic analyses encompassing most of its distribution (focusing particularly on Brazilian specimens, which had been poorly sampled in previous studies), using a novel dataset comprising 2,143 bp of the mitogenome, along with previously reported mtDNA sequences. Our data revealed strong population strutucture and supported a west-to-east colonization process in this species’ history. We detected two population expansion... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Phylogeography; Population genetics; Mitochondrial DNA; Conservation genetics; Historical demography. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572018000200273 |
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| Frederico,Renata G.; Farias,Izeni P.; Araújo,Maria Lúcia Góes de; Charvet-Almeida,Patricia; Alves-Gomes,José A.. |
| The family Potamotrygonidae is monophyletic comprising three genera: Paratrygon Duméril, Potamotrygon Garman and Plesiotrygon Rosa, Castello & Thorson. The distribution of most species in this family is restricted to a single basin or fluvial system. Only Potamotrygon motoro, Potamotrygon orbignyi and Paratrygon aiereba are found in more than one river basin. In this study we investigate genetic structuring of Paratrygon aiereba, from five rivers of the Amazon region: Negro, Solimões-Amazon-Estuary system, Tapajós, Xingu and Araguaia. Sixty-three individuals were sequenced for ATPase 6, and a representative subsample of 27 individuals was sequenced for COI. The COI dataset analysis indicated that Paratrygon is sister to all other potamotrygonid... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazon basin; ATPase; COI; Population genetics. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252012000100007 |
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| Ben Amor, M. M.; Ben Salem, M.; Capapé, C.. |
| De juin 2002 à juin 2005, 267 syngnathes aiguilles, <Syngnathus acus> Linnaeus, 1758, ont été récoltés dans les eaux tunisiennes: 204 dans Bahiret El Biban (Tunisie méridionale), 24 dans la lagune Sud de Tunis et 39 devant La Goulette (Tunisie septentrionale). Trois types d'études ont été effectués à partir de l’ensemble des variables biométriques: la première repose sur l'analyse de la variance et de la moyenne à l'aide du test "F" de Ficher et du test "t" de Student; la deuxième est fondée sur l’analyse de la multivariance (ANOVA); et la troisième est fondée sur des analyses multidimensionnelles. La première et la deuxième études ont montré des différences significatives dans les variances et les moyennes pour la plupart des caractères examinés,... |
| Tipo: Journal Contribution |
Palavras-chave: Biometrics; Biopolymorphism; Population genetics; Statistical analysis. |
| Ano: 2008 |
URL: http://hdl.handle.net/1834/4234 |
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| Packer, Laurence; York University; bugsrus@yorku.ca; Owen, Robin; Mount Royal College and University of Calgary; rowen@mtroyal.ab.ca. |
| We reviewed the theory of conservation genetics, with special emphasis on the influence of haplodiploidy and other aspects of bee biology upon conservation genetic parameters. We then investigated the possibility that pollinator decline can be addressed in this way, using two meta-analytical approaches on genetic data from the Hymenoptera and the Lepidoptera. First, we compared levels of heterozygosity between the orders. As has been found previously, the haplodiploid Hymenoptera had markedly lower levels of genetic variation than the Lepidoptera. Bees had even lower levels, and bumble bees, in particular, often seemed almost monomorphic genetically. However, the statistically confounding effects of phylogeny render detailed interpretation of such data... |
| Tipo: Peer-Reviewed Reports |
Palavras-chave: Bumble bees; Effective population size; Gene flow; Haplodiploidy; Heterozygosity; Hymenoptera; Lepidoptera; Meta-analysis; Pollinator decline; Population fragmentation; Population genetics. |
| Ano: 2001 |
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| Tacuatiá,Luana Olinda; Eggers,Lilian; Kaltchuk-Santos,Eliane; Souza-Chies,Tatiana T.. |
| Sisyrinchium micranthum Cav. is a member of the family Iridaceae, which is distributed over the American continent. In Brazil, this species is found, not only in disturbed areas and coastal regions, but is also very common in urban centers, such as public parks, during the spring. Chromosome counts for North American specimens are 2n = 32 and 2n = 48, whereas in southern Brazil, there is a polyploidy series with three chromosome numbers, 2n = 16, 2n = 32, and 2n = 48. Population analyses using DNA molecular markers are inexistent for this species, in spite of its wide distribution and morphological variation. To study the genetic population structure of S. micranthum, five natural populations were accessed in a conservation park within the Atlantic Rain... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Iridaceae; ISSR-PCR; Mating system; Population genetics; Sisyrinchium micranthum. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572012000100014 |
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| Boudry, Pierre; Launey, Sophie; Diaz-almela, E.; Naciri-graven, Yamama; Ledu, Christophe; Mira, Sara; Taris, Nicolas; Bonhomme, Francois; Lapegue, Sylvie. |
| Nowadays, PCR-based DNA markers allow the study of diversity and differentiation of marine organisms at different stages of their life cycle. Our study of European flat oyster (Ostrea edulis) populations has aimed to describe their spatial and temporal dynamics. First, we analyzed adults sampled over the natural range of the species. An Atlantic/Mediterranean differentiation pattern was observed. Results were congruent between allozymes, microsatellites and mitochondrial DNA and support an isolation by distance model. High variability was observed in the breadth of diversity between populations using a mitochondrial marker, this highlights the small effective population sizes in some locations. A 10-fold quantitative difference was observed in Fst... |
| Tipo: Text |
Palavras-chave: Larvae; Reproduction; Genetic; Ostrea edulis; European flat oyster; Population genetics. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/acte-3493.pdf |
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| Boraschi,Daniele; Del Lama,Marco Antonio. |
| Gene variation and population genetic structure of the Neotropical sawfly Digelasinus diversipes were measured by allozyme analyses using starch gel electrophoresis. Cocoon masses were collected in Eugenia glazioviana (Myrtaceae) stems, in two areas of the "Estação Ecológica Jataí" (Luiz Antônio, SP, Brazil - 21°25' S, 47°50' W), in 2000 and 2001. The average heterozygosity observed in this species (Hobs = 0.094 ± 0.025) was not significantly different from other Symphyta groups; it was, however, significantly higher than in other Hymenoptera populations. No significant levels of inbreeding were found (F IS = 0.062; chi2 = 29.9; p > 0.05), but the population was subdivided (F ST = 0.070; chi2 = 458.9; p < 0.05), suggesting the absence of a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Genetic variability; Population genetics; Digelasinus diversipes; Neotropical sawfly; Allozymes. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572004000300013 |
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| Pinto,Luciana Rossini; Vieira,Maria Lucia Carneiro; Souza Jr.,Claudio Lopes de; Souza,Anete Pereira de. |
| A modified reciprocal recurrent selection (RRS) method, which employed one cycle of high-intensity selection, was applied to two tropical maize (Zea mays L.) populations, BR-105 and BR-106, originating the improved synthetics IG-3 and IG-4, respectively. In the present study the effects of this kind of selection on the genetic structure of these populations and their synthetics were investigated at 30 microsatellite (SSR) loci. A total of 125 alleles were revealed. A reduction in the number of alleles was observed after selection, as well as changes in allele frequencies. In nearly 13% (BR-105) and 7% (BR-106) of the loci evaluated, the changes in allele frequencies were not explained, exclusively due to the effects of genetic drift. The effective... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Population genetics; Plant breeding; Molecular markers. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572003000300022 |
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| Registros recuperados: 117 | |
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