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Registros recuperados: 35 | |
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Arntzen, J.W.; García-París, M.. |
Three competing phylogenetic hypotheses for the genus Alytes (midwife toads) are evaluated. Based on quantitative coding of protein characters the most parsimonious solution shows a sister taxon relationship for Alytes dickhilleni and A. muletensis. The alternatives in which A. obstetricans has its sister group in either A. dickhilleni or A. muletensis lack support. Using calibrations derived from protein evolutionary rates, the vicariant events giving rise to A. obstetricans and the lineage leading to the A. muletensis and A. dickhilleni clade and the subsequent splitting between A. muletensis and A. dickhilleni cannot be placed much earlier than the Miocene-Pliocene boundary. Biogeographical scenarios invoking an earlier time of divergence should be... |
Tipo: Article / Letter to the editor |
Palavras-chave: Allozymes; Alytes; Biogeography; Midwife toads; Phylogenetics; Spain; Taxonomy; Vicariance. |
Ano: 1997 |
URL: http://www.repository.naturalis.nl/record/504096 |
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Arntzen, J.W.; García-París, M.. |
Allozyme variation in 31 to 50 presumptive loci of 12 populations of European midwife toads of the genus Alytes show appreciable genetic divergences (DiNe from 0.29 to 0.72) among four groups. These groups correspond to A. cisternasii Boscá, 1879, A. obstetricans (Laurenti, 1768), A. muletensis (Sanchiz & Adrover, 1979), and a new species from the Betic mountains described here as A. dickhilleni n. sp. Smaller divergences among geographic groups of populations of A. obstetricans (up to DNei = 0.17) support the existence of three geographic units in Europe corresponding to the previously recognized subspecies A. o. obstetricans and A. o. boscai Lataste, 1879, plus a third one described here under the designation of A. o. almogavarii n. ssp. The analysis... |
Tipo: Article / Letter to the editor |
Palavras-chave: Allozymes; Alytes; Midwife toads; Morphometry; Spain; Taxonomy. |
Ano: 1995 |
URL: http://www.repository.naturalis.nl/record/504393 |
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Arntzen, J.W.; Recuero, E.; Canestrelli, D.; Martínez-Solano, I.. |
Species delineation remains one of the most challenging tasks in the study of biodiversity, mostly owing to the application of different species concepts, which results in contrasting taxonomic arrangements. This has important practical consequences, since species are basic units in fields like ecology and conservation biology. We here review molecular genetic evidence relevant to the systematics of toads in the Bufo bufo species group (Anura, Bufonidae). Two studies recently published in this journal (Recuero et al., MPE 62: 71–86 and Garci´a-Porta et al., MPE 63: 113–130) addressed this issue but reached opposing conclusions on the taxonomy of the group (four versus two species). In particular, allozyme data in the latter paper were interpreted as... |
Tipo: Article / Letter to the editor |
Palavras-chave: Bufo bufo; Bufo spinosus; Molecular systematics; Bufo verrucosissimus; Phylogeny; Allozymes; 42.82. |
Ano: 2013 |
URL: http://www.repository.naturalis.nl/record/470065 |
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Arntzen, J.W.; Themudo, G. Espregueira; Wielstra, B.. |
Newts of the genus Triturus (Amphibia, Caudata, Salamandridae) are distributed across Europe and adjacent Asia. In spite of its prominence as a model system for evolutionary research, the phylogeny of Triturus has remained incompletely solved. Our aim was to rectify this situation, to which we employed nuclear encoded proteins (40 loci) and mitochondrial DNA-sequence data (mtDNA, 642 bp of the ND4 gene). We sampled up to four populations per species covering large parts of their ranges. Allozyme and mtDNA data were analyzed separately with parsimony, distance, likelihood and Bayesian methods of phylogenetic inference. Existing knowledge on taxonomic relationships was confirmed, including the monophyly of the genus and the groups of crested newts (four... |
Tipo: Article / Letter to the editor |
Palavras-chave: Allozymes; Historical biogeography; Mitochondrial DNA-sequences; Triturus macedonicus; Triturus marmoratus; Vicariance; 42.82. |
Ano: 2007 |
URL: http://www.repository.naturalis.nl/record/262648 |
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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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Chaieb, O.. |
La tortue marine, la caouanne (Caretta caretta), est une espèce en danger d’extinction. Elle est caractérisée par un cycle biologique complexe se basant sur une série de transitions écologiques et géographiques nécessitant des migrations sur de longues distances. En Tunisie, plusieurs études ont été réalisées sur les activités de nidification et les interactions avec les activités de pêche, mais, aucune n’a porté sur l’étude génétique de cette espèce. Dans ce travail, nous nous sommes intéressés à l’analyse génétique de la population nidifiante en Tunisie et des populations des tortues se développant dans les zones néritiques tunisiennes. La population nidifiante a été appréhendée par l’analyse des nouveau-nés échantillonnés durant une période de sept ans... |
Tipo: Theses and Dissertations |
Palavras-chave: Allozymes; DNA; Genetic diversity; Neritic province. |
Ano: 2013 |
URL: http://hdl.handle.net/1834/5923 |
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Cimmaruta, R; Scialanca, F; Luccioli, F; Nascetti, G. |
Allozyme electrophoresis has been used to analyse the genetic structure of ten populations of the killifish, Aphanius fasciatus, sampled from Italian coastal brackish lagoons or salterns. The goal of the study was to compare the genetic structure of samples obtained from habitats characterised by environmental stress of different kinds, with the aim of gaining a better understanding of the relationships between the genetic variation of natural populations and environmental disturbance, either natural or man-made. Therefore, the sampling scheme has been planned to provide samples from both brackish habitats, characterised by natural stress with seasonal marked fluctuations of chemical and physical parameters, and from coastal lagoons suffering from a high... |
Tipo: Text |
Palavras-chave: Aphanius fasciatus; Hétérozygotie; Allozymes; Eaux saumâtres; Stress du milieu; Aphanius fasciatus; Heterozygosity; Allozymes; Brackish waters; Environmental stress. |
Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00322/43290/43025.pdf |
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Cleary, Daniel F.R.; Descimon, Henri; Menken, Steph B.J.. |
Clear habitat separation between the sister species Colias alfacariensis and C. hyale is shown when occurring sympatrically. Colias hyale is found more often in moist cultivated pastures while Colias alfacariensis is more abundant in dry uncultivated habitat. Out of a total of 16 loci, no diagnostic loci were found between C. alfacariensis and C. hyale, and both species shared most major polymorphisms. Exceptions were the marked differences in allele frequencies at the HK locus and only C, hyale, but not C. alfacariensis was further invariable at the GOT2 locus, which is usually highly polymorphic in the Pieridae. Colias hyale has a significantly lower level of heterozygosity than its sister species C. alfacariensis. In Colias alfacariensis heterozygosity... |
Tipo: Article / Letter to the editor |
Palavras-chave: Lepidoptera; Pieridae; Allozymes; Population structure; Gene flow. |
Ano: 2002 |
URL: http://www.repository.naturalis.nl/record/534385 |
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Fassatoui, Ch.; Romdhane, M.S.. |
La variabilité génétique entre les classes d’âge du pageot commun, Pagellus erythrinus (Linnaeus, 1758 ; Sparidae) a été appréhendée par une analyse isoenzymatique. L’étude aà été portée sur 251 spécimens des côtes Nord de la Tunisie. L’âge des poissons a été estimé indirectement par analyse otolithométrique. Les quatorze systèmes enzymatiques utilisés sont codés par 21 loci dont 10 sont polymorphes au seuil de 99%. Le taux d’hétérozygotie attendu non biaisé moyen (Hnb = 0,048) est comparable à celui rapporté chez les espèces ichtyologiques, notamment les Sparidés. La vérification de l’équilibre de Hardy-Weinberg montre un écart significatif à la panmixie dans le sens d’un déficit en Hétérozygotes (FIS = 0,116, p < 0,001). L’indice de diversité... |
Tipo: Journal Contribution |
Palavras-chave: Genetic variation; Allozymes; Seabream fisheries. |
Ano: 2010 |
URL: http://hdl.handle.net/1834/4689 |
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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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Gusmão,Jaqueline; Lazoski,Cristiano; Solé-Cava,Antonio M.. |
Penaeid shrimps are important resources for worldwide fisheries and aquaculture. In the Southwest Atlantic, Farfantepenaeus brasiliensis, F. paulensis, F. subtilis, Farfantepenaeus sp. and Litopenaeus schmitti are among the most important commercially exploited species. Despite their high commercial value, there is little information available on the different aspects of their biology or genetics and almost no data on their stock structure. We used allozymes to estimate variability levels and population genetic structure of F. brasiliensis, F. paulensis, L. schmitti and the recently detected species Farfantepenaeus sp. along as much as 4,000 km of Brazilian coastline. No population heterogeneity was detected in F. brasiliensis or L. schmitti along the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Farfantepenaeus; Litopenaeus; Allozymes. |
Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572005000100029 |
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Ito,Kennya F.; Renesto,Erasmo; Zawadzki,Cláudio H.. |
Two syntopic morphotypes of the genus Hypostomus - H. nigromaculatus and H. cf. nigromaculatus (Atlântico Stream, Paraná State) - were compared through the allozyme electrophoresis technique. Twelve enzymatic systems (AAT, ADH, EST, GCDH, G3PDH, GPI, IDH, LDH, MDH, ME, PGM and SOD) were analyzed, attributing the score of 20 loci, with a total of 30 alleles. Six loci were diagnostic (Aat-2, Gcdh-1, Gpi-A, Idh-1, Ldh-A and Mdh-A), indicating the presence of interjacent reproductive isolation. The occurrence of few polymorphic loci acknowledge two morphotypes, with heterozygosity values He = 0.0291 for H. nigromaculatus and He = 0.0346 for H. cf. nigromaculatus. F IS statistics demonstrated fixation of the alleles in the two morphotypes. Genetic identity (I)... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Allozymes; Hypostomus nigromaculatus; Fish genetics; Genetic distance; Polymorphism. |
Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572009000100008 |
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Jolly, Mt; Jollivet, D; Gentil, F; Thiebaut, E; Viard, F. |
This study uses enzymatic and mitochondrial genes to infer the relative importance of historical processes and contemporary hydrodynamic features on the observed patterns of genetic structure in subdivided populations of Pectinaria koreni (Polychaeta: Pectinariidae) along the coasts of Brittany and the English Channel. Nucleotide sequence variation of a 603-bp fragment of the mtDNA cytochrome oxidase subunit I gene revealed a surprisingly deep phylogeographic break of about 16% divergence separating the Brittany and Channel populations, which coincides with a biogeographic boundary along the western coast of Brittany. Deep sequence divergence with fixed haplotype differences and the inversion of allele frequencies at two enzyme loci suggests the occurrence... |
Tipo: Text |
Palavras-chave: Phylogeography; Allozymes; MtDNA; Parapatric boundary; Cryptic species. |
Ano: 2005 |
URL: https://archimer.ifremer.fr/doc/00301/41250/40433.pdf |
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Lallias, Delphine; Taris, Nicolas; Boudry, Pierre; Bonhomme, Francois; Lapegue, Sylvie. |
he European flat oyster (Ostrea edulis L.) is a marine bivalve whose natural geographical distribution ranges along the European Atlantic coast from Norway to Morocco, in addition to the Mediterranean and Black Sea. Previous studies of allozymes, microsat-ellites and mitochondrial differentiation over the whole range concluded that a significant divergence existed between Mediterranean and Atlantic populations, together with an isolation-by-distance pattern. However, the average mitochondrial haplotypic diversity displayed a high among populations variance, reflecting smaller effective population size in some locations. Additionally, a ten-fold quantitative difference was observed in the same study in Fst between the mitochondrial and the nuclear genomes,... |
Tipo: Text |
Palavras-chave: Genotypes; Genetic diversity; Breeding success; Allozymes; Population genetics; Parentage analyses; Natural population; Ostrea edulis; Oyster. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/acte-3334.pdf |
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Registros recuperados: 35 | |
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