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| Registros recuperados: 117 | |
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| Ramirez-Gil,H.; Feldberg,E.; Almeida-Val,V.M.F.; Val,A.L.. |
| Karyological characteristics, i.e., diploid number, chromosome morphology and nucleolus organizer regions (NORs), biochemical characteristics, i.e., electrophoretic analysis of blood hemoglobin and the tissue enzymes lactate dehydrogenase (LDH), malate dehydrogenase (MDH), alcohol dehydrogenase (ADH), and phosphoglucose isomerase (PGI), and physiological characteristics, i.e., relative concentration of hemoglobin and intraerythrocytic concentrations of organic phosphates were analyzed for the species Callophysus macropterus collected from Marchantaria Island (white water system - Solimões River) and Anavilhanas Archipelago (black water system - Negro River). Karyological and biochemical data did not reveal significant differences between specimens... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Callophysus; Fish; Amazon; Population genetics; Adaptation. |
| Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998001100014 |
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| Gajardo, G.; Mercado, C.; Beardmore, J.A.; Sorgeloos, P.. |
| An <i>Artemia</i> population from a site recently described in Chile and located in a semi-arid and humid hydrographical zone (Torres del Paine National Park), was electrophoretically characterized and cross-bred (followed through <i>F</i><sub>3</sub>) to reference samples of <i>A. franciscana</i> (San Francisco Bay, California, USA) and <i>A. persimilis</i> (Buenos Aires, Argentina), which are the species most likely to be found in Chile. The population exhibited high levels of genetic variability as judged by the percentage of polymorphic loci (<i>P</i>=53.3), mean number of alleles per locus (<i>n</i>=2.2) and mean heterozygosity (<i>H</i>=0.176). Based on... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Allopatric populations; Allozymes; Genetic isolation; Hybridization; Population genetics; Chile. |
| Ano: 1999 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=4016 |
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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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| Shinn, A.P.; Banks, B.A.; Tange, N.; Bron, J.E.; Sommerville, C.; Aoki, T.; Wootten, R.. |
| Genetic differentiation within the salmon louse Lepeophtheirus salmonis (Krøyer, 1837), was investigated by the sequencing of specific nucleotide regions. Partial sequences of the 18S ribosomal RNA gene and the ribosomal internal transcribed spacer (ITS-1) region from single sea lice were amplified by the polymerase chain reaction (PCR). Lice were collected from wild and farmed Atlantic salmon ( Salmo salar L., 1758) from nine selected localities around the Scottish coastline. A 0.9kb fragment of the 18S ribosomal RNA gene was amplified and compared for several samples of lice which showed no observable differences between the lice from different collection sites confirming the absence of cryptic species. The 454 nucleotide ITS-1 sequence showed... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Sea louse; Copepod; Crustacea; Atlantic salmon; Sequencing; 18S ribosomal DNA; Internal transcribed spacer; Population genetics. |
| Ano: 2000 |
URL: http://www.repository.naturalis.nl/record/534343 |
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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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| CARSON,HAMPTON L.. |
| This is a personal essay commemorating Brncic as a keen naturalist/evolutionist in the best Darwinian sense. His innate curiosity, so important in a scientist, led him to the discovery of cenain unique drosophilid flies in Chile. The life cycle of one species of flower-fly (Drosophila flavopilosa) is of special interest. Females oviposit in fresh flowers of a solanaceous plant that is widespread in Chilean valleys. Twenty years of combined ecological and genetic work, carried out on this species, pioneers the use of a highly specialized Drosophila species in the study of population genetics and evolution. Many eco-genetic features are revealed that are important supplements to observations made on the widely-studied generalist species of the genus |
| Tipo: Journal article |
Palavras-chave: Flower-breeding Drosophila; Genetic specialization; Ecology; Population genetics; Evolution. |
| Ano: 2001 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2001000000008 |
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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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| Barcelos,Edson; Amblard,Philippe; Berthaud,Julien; Seguin,Marc. |
| The objective of this work was to evaluate the genetic diversity, its organization and the genetic relationships within oil palm (Elaeis oleifera (Kunth) Cortés, from America, and E. guineensis (Jacq.), from Africa) germplasm using Restriction Fragment Length Polymorphism (RFLP) and Amplified Fragment Length Polymorphism (AFLP). In complement to a previous RFLP study on 241 E. oleifera accessions, 38 E. guineensis accessions were analyzed using the same 37 cDNA probes. These accessions covered a large part of the geographical distribution areas of these species in America and Africa. In addition, AFLP analysis was performed on a sub-set of 40 accessions of E. oleifera and 22 of E. guineensis using three pairs of enzyme/primer combinations. Data were... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Elaeis oleifera; Elaeis guineensis; Population genetics; Palm species; Genetic resources; Molecular chacterization. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2002000800008 |
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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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| Boudry, Pierre; Launey, Sophie; Diaz-almela, A.; Naciri-graven, Yamama; Ledu, Christophe; Mira, S.; Taris, Nicolas; Bonhomme, Francois; Lapegue, Sylvie. |
| PCR-based DNA markers enable the study of diversity and differentiation of marine organisms at different stages of their life cycle. Our study of European fiat oyster (Ostrea edulis) populations 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. Similar patterns of variation were found using allozymes, microsatellites and mitochondrial DNA, aIl which support an isolation by distance model. High variability was observed in the range of diversity between populations using a mitochondrial marker, a reflection of small effective population sizes in sorne locations. A 10fold quantitative difference was observed in Fst,... |
| Tipo: Text |
Palavras-chave: Recruitment; Diversity; Molecular markers; Population genetics; Ostrea edulis; Flat oyster; Dynamique de recrutement; Diversité génétique; Microsatellites; Marqueurs moléculaires; Génétique des populations; Ostrea edulis; Huître plate. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-2851.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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| Registros recuperados: 117 | |
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