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| Registros recuperados: 70 | |
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| Arntzen, J.W.; Jehle, R.; Bardakci, F.; Burke, T.; Wallis, G.P.. |
| Hybridization between divergent lineages often results in reduced hybrid viability. Here we report findings from a series of independent molecular analyses over several seasons on four life stages of F1 hybrids between the newts Triturus cristatus and T. marmoratus. These two species form a bimodal hybrid zone of broad overlap in France, with F1 hybrids making up about 4% of the adult population. We demonstrate strong asymmetry in the direction of the cross, with one class (cristatus-mothered) making up about 90% of F1 hybrids. By analyzing embryos and hatchlings, we show that this asymmetry is not due to prezygotic effects, as both classes of hybrid embryos are present at similar frequencies, implicating differential selection on the two hybrid classes... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Allozyme; Bateson–Dobzhansky–Muller incompatibility; Cytonuclear incompatibility; Hybridization; Microsatellite; MtDNA; Postzygotic isolation asymmetry; Triturus; 42.82. |
| Ano: 2008 |
URL: http://www.repository.naturalis.nl/record/289893 |
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| Azevedo,Cecília O.; Borba,Eduardo L.; Van Den Berg,Cássio. |
| Hybridization between B. involutum and B. weddellii (Orchidaceae) has been first observed in the Serra do Cipó, Minas Gerais State, Brazil, the hybrid being described as B. ×cipoense Borba & Semir. In this study, allozime electrophoresis was used to test the hypothesis of occurrence of hybridization between these two species, as suggested by morphological characters, in the Chapada Diamantina, Bahia State, Brazil. The lack of a diagnostic locus does not allow definite confirmation of the natural hybridization, although this hypotheses is reinforced by the absence of exclusive alleles in the putative hybrid individuals. The existence of several different genotypes points out to either population derived from multiple hybridization events or the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bulbophyllum; Genetic variability; Hybridization; Introgression; Orchidaceae. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042006000300008 |
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| Azevedo,MFC; Foresti,F.; Ramos,PRR; Jim,J. |
| Specimens of Bufo ictericus, Bufo paracnemis and a third type, considered an intermediate subgroup between these species, were cytogenetically studied by conventional Giemsa staining, C-banding and staining of the nucleolus organizer region (NOR). The nuclear DNA content and seroproteins were also analyzed to characterize these species, and verify the possibility of hybridization between them. Karyotypes and cytogenetic markers were essentially equal on the basis of the methods used. The DNA nuclear content found was 6.25 ± 0.30 pg/DNA in Bufo ictericus; 7.57 ± 0.40 pg/DNA in Bufo paracnemis and 7.04 ± 0.29 pg/DNA in the intermediate subgroup. Eletrophoresis of total blood serum in Bufo ictericus, Bufo paracnemis and the intermediate specimens revealed a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bufo; Hybridization; Cytogenetics; Nuclear DNA; Seroproteins. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572003000300012 |
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| Batista, Frederico; Ben-hamadou, Radhouan; Fonseca, Vera; Taris, Nicolas; Ruano, Francisco; Reis-henriques, Maria; Boudry, Pierre. |
| The taxonomic status of the cupped oysters Crassostrea angulata and C. gigas has received considerable attention in the last decades. Based on larval shell morphology, experimental hybridization, allozymes and nuclear DNA studies several authors have considered these two taxa as being synonymous. However, mitochondrial data showed clear genetic differences between the two taxa. In addition, microsatellite-based studies and cytogenetic studies have also provided evidence that supports their differentiation. Considerable differences have also been observed at the phenotypic level in terms of growth rate and ecophysiological parameters. In the present study, C. angulata from Sado estuary (Portugal) and C. gigas from Seudre estuary (France) were collected and... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Crassostrea angulata; Hybridization; Shell pigmentation; Shell morphology. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-3904.pdf |
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| Batista, Frederico; Boudry, Pierre; Lapegue, Sylvie; Heurtebise, Serge; Monteiro, C. C.. |
| The Portuguese oyster, Crassostrea angulata, was introduced from Portugal to the French Atlantic Coast in the 1860s. C. angulata quickly settled and expanded and leaded to the development of a new aquacultural industry in France. In the late 1960s, mortality associated with the detection of an iridovirus, led to the wipe out of C. angulata from French Atlantic waters and to the massive introduction of C. gigas to sustain production. In Southern Europe, similar symptoms were also observed in natural stocks of C. angulata from Sado River (Portugal) and from the area of Cadiz (Spain). Nowadays, only very few «pure» populations of C. angulata remain in southern Europe. These populations are potentially endangered by the current expansion of C. gigas... |
| Tipo: Text |
Palavras-chave: Selection; Hybridization; Settlement pattern; Population genetic; Genetic; Oysters; Crassostrea angulata; Crassostrea gigas. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/acte-3310.pdf |
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| Batista, Frederico; Fonseca, Vera; Ben-hamadou, Radhouan; Taris, Nicolas; Henriques, Maria; Boudry, Pierre. |
| Unlike in some crops, no large heterotic effects have been observed in most farmed animals. Interestingly, significant hybrid vigour for some traits has been reported in the Pacific oyster, Crassostrea gigas. Crossbreeding between closely related taxa can be seen as an efficient way to exploit the dominance component of the genetic variance of a trait. Factorial crosses between the Portuguese oyster C. angulata (from Sado estuary, Portugal) and C. gigas (from Seudre estuary, France) were done to evaluate the aquaculture potential of hybrids. Juveniles of the different progenies were reared in Ria Formosa (Portugal) under usual farming conditions. The genetic confirmation of all progenies was done using mitochondrial and nuclear markers in order to detect... |
| Tipo: Text |
Palavras-chave: Hybridization; Crassostrea angulata; Crassostrea gigas; Genetic; Oyster. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/acte-3429.pdf |
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| Boudry, Pierre; Barre, Marc; Gerard, Andre. |
| Despite the economic importance of shellfish, genetic improvement has not yet had a great impact on these species. Shellfish farming is traditionally based on wild species whose natural populations are often overexploited and do not fulfill market demand. Up to now, the most effective answer to disease problems or for the improvement of productivity has been the introduction of new species. However, the introduction of new species is constrained by their ecological impact and is also limited by the availability of suitable species. Genetic improvement of local species should therefore be of great importance as a viable alternative for the long term sustainability of the shellfish industry. The different approaches to genetic improvement include... |
| Tipo: Text |
Palavras-chave: Selective breeding; Hybridization; Polyplidy; Introduction; Oysters; Selection; Hybridation; Polyploidie; Introduction; Huitres. |
| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/1997/acte-3499.pdf |
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| Brito,Cíntia; Vilaça,Sibelle Torres; Lacerda,Ana Luzia; Maggioni,Rodrigo; Marcovaldi,Maria Ângela; Vélez-Rubio,Gabriela; Proietti,Maíra Carneiro. |
| Abstract Marine turtle hybridization is usually sporadic and involves reports of only a few individuals; however, Brazilian populations have high hybridization rates. Here we investigated the presence of hybrids in morphologically identified immature hawksbills (Eretmochelys imbricata) along the South Western Atlantic (SWA). We sequenced one mitochondrial (D-Loop) and three nuclear DNA (RAG1, RAG2, and CMOS) markers to better understand the patterns and characteristics of hybrids. We identified 22 hybrids (n = 270), 11 of them at the extreme South of the SWA. Uruguay had the highest hybrid frequency in the SWA (~37.5%) followed by southern Brazil with 30%. These are common areas for loggerheads (Caretta caretta) but uncommon for hawksbills, and these... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Hybridization; Cheloniidae; Genetic markers; Hybrid distribution; Conservation. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572020000400704 |
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| BRUSAMARELLO,A.P.; OLIVEIRA,P.H.; TREZZI,M.M.; XAVIER,E.; DALOSTO,E.D.. |
| ABSTRACT Weed resistance to herbicides is a major global problem for agriculture. In recent years, the increased use of herbicides, without proper planning, has led to a large increase in the number of cases of weed biotypes that are resistant to one or more herbicide mechanism of action. Wild poinsettia biotypes (Euphorbia heterophylla), discovered in the State of Paraná, with resistance to herbicides that inhibit protoporphyrinogen oxidase (PROTOX) and acetolactate synthase (ALS), are the first case to exhibit multiple resistance in Brazil. This study analyzed the genetic inheritance of PROTOX inhibiting herbicide resistance in E. heterophylla. Crosses were conducted between biotypes that were susceptible (female parent) and those carrying multiple... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Euphorbia heterophylla; Hybridization; Genetics; Herbicide. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582016000300575 |
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| Carneiro,Jeferson; Rodrigues-Filho,Luis Fernando da Silva; Schneider,Horacio; Sampaio,Iracilda. |
| Abstract Hybridization has been reported increasingly frequently in recent years, fueling the debate on its role in the evolutionary history of species. Some studies have shown that hybridization is very common in captive New World primates, and hybrid offspring have phenotypes and physiological responses distinct from those of the "pure" parents, due to gene introgression. Here we used the TA15 Alu insertion to investigate hybridization in the genus Saimiri. Our results indicate the hybridization of Saimiri boliviensis peruviensis with S. sciureus macrodon, and S. b. boliviensis with S. ustus. Unexpectedly, some hybrids of both S. boliviensis peruviensis and S. b. boliviensis were homozygous for the absence of the insertion, which indicates that the... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Saimiri; Squirrel monkeys; Alu elements; Hybridization. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572016000400539 |
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| Chen, C.-W.; Ngan, L.T.; Hidayat, A.; Evangelista, L.; Nooteboom, H.P.; Chiou, W.-L.. |
| Davallia repens and its close relatives have been identified as a species complex in this study because of the existence of continuously morphological variation. To decipher its evolutionary history, integrated methodologies were applied in this study including morphology, cytology, reproductive biology and molecular phylogeny. Analysis of morphological characters reveals several important discriminating characteristics, such as the shape of stipe scales, frond and indusium. Both diploid and polyploid forms are present in the complex and reproduce sexually and by apogamy, respectively. The incongruence between cpDNA and nDNA phylogeny indicates a hybrid origin for most polyploid individuals. Based on the present results, we hypothesize that there were at... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Apogamy; Davallia repens; Hybridization; Polyploidization. |
| Ano: 2014 |
URL: http://www.repository.naturalis.nl/record/525117 |
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| Registros recuperados: 70 | |
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