45 research outputs found
Paralog-Specific Primers for the Amplification of Nuclear Loci in Tetraploid Barbels (Barbus: Cypriniformes)
Thirty paralog-specific primers were developed, following an intron-primed exon-crossing strategy, for S7 and growth hormone genes in Barbus (subgenera Barbus and Luciobarbus). We found that paralog-specific amplification requires the use of only one paralog-specific primer, allowing their simultaneous use with universal exon-primed intron-crossing primers of broad taxonomic applicability. This hybrid annealing strategy guarantees both specificity and generality of amplification reactions and represents a step forward in the amplification of duplicated nuclear loci in polyploid organisms and members of multigene families. Assays of several representative taxa identified high levels of segregating single nucleotide polymorphisms (SNPs) and nucleotide diversity within each of these subgenera. Additionally, several insertions-deletions (indels) that are diagnostic across species are found in intronic regions. Therefore, these primers provide a reliable source of valuable nuclear SNP and indel data for population and species level studies of barbels, such as applied conservation and basic evolutionary studie
O ‘Canto do Sertão’ na ‘Bachiana no. 4’: uma perspetiva sociomusicológica
O artigo traz um estudo da peça Coral Canto do Sertão, da Bachiana Brasileira no 4, de Heitor Villa- Lobos. Trata-se de uma análise intramusical (ritmos e melodias) e também extramusical, considerando os fatores externos, como caracterÃsticas fÃsicas do sertão nordestino, como essas são internalizadas e ressignificadas na música. O estudo desenvolveu-se a partir do exame da partitura a fim de explorá-la sob uma perspectiva crÃtica, indo além da própria música, sem, portanto, sair dela. Sob uma abordagem musicológica (KERMAN, 2010; LOPES, 2014), foram identificados trechos (tropos) e frases (tópicas) que conduziram o tema (AGAWU; RATTEN, 1980), sendo observados como se moviam na música a fim de conferir-lhe o tÃtulo sugerido: Canto do Sertão. Considerando a episteme musicológica e o exame documental, levantamos a discussão sobre até que ponto a música, em sua linguagem, pode trazer ou estabelecer pontos de identificação com a realidade da região abordada, o sertão nordestino
International Standardization of Common Names for Iberian Endemic Freshwater Fishes
Las especies de peces dulceacuÃcolas endémicas de la penÃnsula Ibérica carecen de nombres comunes en inglés, lo cual frecuentemente causa inconvenientes a los autores en el momento de publicar para una audiencia internacional. Con el objetivo de llenar este vacÃo, se presenta una lista actualizada de las especies de peces dulceacuÃcolas endémicas de la penÃnsula Ibérica con una propuesta razonada de designación internacional estandarizada junto con los nombres comunes en español y/o portugués adoptados en los Libros Rojos NacionalesIberian endemic freshwater fishes do not have standardized common names in English, which is usually a cause of inconveniences for authors when publishing for an international audience. With the aim to tackle this problem, an updated list of Iberian endemic freshwater fish species is presented with a reasoned proposition of a standard international designation along with Spanish and/or Portuguese common names adopted in the National Red Data BooksOs peixes dulciaquÃcolas endémicos da PenÃnsula Ibérica näo possuem um nome comum devidamente padronizado em Inglês, o que causa problemas aos investigadores quando publicam em revistas com uma audiência internacional. O presente trabalho procurou resolver esta questäo, incluindo uma lista actualizada das espécies piscÃcolas endémicas da PenÃnsula Ibérica e uma proposta fundamentada de nomes comuns em Inglês, juntamente com as designaçöes comuns em Espanhol e/ou Português adoptadas nos respectivos Livros Vermelhos Nacionai
Evidence of High Levels of Gene Flow in a Widely Distributed Catadromous Species: The Thin-Lippedgrey Mullet
The thin-lipped grey mullet Chelon ramada (Risso, 1827) is a catadromous species that is
distributed along the Northeast Atlantic, from the Norwegian coastline down to Mauritania, on the
African coast (20–60◦ N, 18◦ E–42º W), and displays diverse patterns of habitat use and migratory
behaviors. This widely distributed species is observed in large shoals throughout coastal areas and
in brackish and freshwater environments, yet no previous studies have addressed the population's
genetic structure. To study the patterns of genetic variation, gene flow and connectivity in the C.
ramada distribution range), 457 fin clips sampled from 14 locations (Portuguese coast, Bay of Biscay,
North seas, Celtic sea, Western Mediterranean and Eastern Mediterranean) were genotyped using
11 microsatellite DNA markers. No significant genetic differentiation among locations or geographic
clustering of samples was observed, which points towards the existence of a unique genetic group.
The results suggest strong gene flow from the Western Mediterranean to the Portuguese coast (Nm = 1)
and vice versa (Nm = 0.87). The Portuguese coast has displayed the highest values of gene flow
with all the sampling sites ([0.4–0.6]) whereas Northeast Atlantic coast and Eastern Mediterranean
maintained symmetrical lower values of gene flow that ranged between [0.20–0.30]. The present
study provides evidence that high levels of gene flow are maintained within the distribution range,
contributing to the existence of a panmictic population
The emerging role of the yeast Torulaspora delbrueckii in bread and wine production: using genetic manipulation to study molecular basis of physiological responses
Genetic Structure of Meagre (Argyrosomus regius) in Portugal: Implications for Fisheries Management
The meagre Argyrosomus regius (Asso, 1801) is a marine migratory species with a wide
distribution range encompassing the north-eastern and central-eastern Atlantic Ocean, the Mediter ranean Sea, and the western Black Sea. A. regius is one of the largest overexploited sciaenids, being a
valuable resource for aquaculture and fisheries along its distribution range. The Iberian Peninsula is
considered an intermediate area between two genetically distinct groups of A. regius populations, one
in the north-eastern Atlantic Ocean and one in the eastern Mediterranean Sea. The current knowledge
on the population dynamics and distribution of this species has been derived from commercial and
recreational fishery catches; therefore, little is known about the importance of the Iberian Peninsula
for the species’ management and conservation. The aim of this study is to evaluate the A. regius
population genetic structure along the Portuguese coast taking into consideration the north-eastern
Atlantic region. To achieve this goal, the genetic diversity, differentiation, populational structure
and demographic history of A. regius populations along the Atlantic coast were analyzed using
15 microsatellite loci. The detected populational structure indicates that A. regius species in Portugal
are divided into two distinct stocks, one across the Portuguese western coast, possibly related to the
Tagus spawning and nursery area, and another one on the southern coast. This study reveals the
need for A. regius-specific fishery management plans in Portugal and underlines the importance of
considering the genetic structure of A. regius populations when delineating such management plans
Historical food-web changes in invaded fish communities in the lower Guadiana basin
Freshwater ecosystems are increasingly being reshaped by biological invasions, leading to
biotic homogenization and biodiversity loss. However, the extent to which novel species may drive
changes in food-web structure over time remains poorly understood. Clarifying changes in historical
ecological processes is critical to inform conservation and restoration efforts in recipient ecosystems.
Here, we address food-web changes associated with fish invasions in the Lower Guadiana Basin
(LGB) over the past 40 years, by contrasting feeding relationships between museum-archived and
contemporary specimens, using stable carbon (δ13C) and nitrogen (δ15N) ratios. Specifically, trophic
niches of museum-archived fishes sampled throughout 1978–1987 and 1999–2004 corresponding to
the initial establishment and spread of non-native fishes, respectively, were compared with those of
fishes sampled in 2019, characterizing the integration of non-native species in the recipient ecosystem.
We focused on five native species (Anaecypris hispanica, Cobitis paludica, Iberochondrostoma lemmingii,
Squalius pyrenaicus and Squalius alburnoides) and four non-native species (Lepomis gibbosus, Australo heros facetus, Micropterus salmoides and Gambusia holbrooki) with potential to cover multiple trophic
positions in the food-webs. We approached historical baseline resources using prey items in gut con tents of the museum-archived fishes and characterized primary producers and macroinvertebrates in
2019. Prior to analysis, samples were normalized for high lipid content and corrected for preservation.
We found considerable asymmetries in niche partitioning among species as invasion progressed.
Over time, native species tended to be displaced to lower trophic levels, while non-native species
showed significantly higher trophic niches, driven mainly by increases in trophic (δ15N) range. Our
study highlights that stable isotopes may provide important insights on historical food-web structure
and particularly on processes underpinning ecological changes associated with anthropogenetic
pressures on freshwater ecosystems.info:eu-repo/semantics/publishedVersio
Evidence of Genetic Segregation among Meagre (Argyrosomus regius) Atlantic Spawning Areas
The meagre Argyrosomus regius, one of the largest sciaenidae in the world, is a valuable resource for fisheries and aquaculture. Despite its socioeconomic relevance, knowledge about population dynamics and wild stocks is still scarce, and conservation risks are associated with overexploitation. Two genetic distinct groups, one in the North Atlantic Ocean and one in the eastern Mediterranean Sea, were identified by previous studies. However, little is known about the genetic structure of the Atlantic group, where four important spawning areas have been identified. To assess if each spawning area is an independent breeding unit, the genetic diversity, populational structure, and demographic history of A. regius along the North–East and Eastern Central Atlantic coast were analyzed, using 15 microsatellite loci. Results corroborate the hypothesis tested, suggesting four genetic groups: a first group encompassing individuals from the Gironde spawning area, a second group encompassing individuals from the Tagus spawning area, a third group corresponding to individuals captured in the Algarve region, and a forth group gathering individuals from Morocco and Mauritania. This study reveals the need for specific fisheries management plans considering genetic structure information, and highlights the need for international cooperation.info:eu-repo/semantics/publishedVersio
Evidence of Genetic Segregation among Meagre (Argyrosomus regius) Atlantic Spawning Areas
The meagre Argyrosomus regius, one of the largest sciaenidae in the world, is a valuable resource for fisheries and aquaculture. Despite its socioeconomic relevance, knowledge about population dynamics and wild stocks is still scarce, and conservation risks are associated with overexploitation. Two genetic distinct groups, one in the North Atlantic Ocean and one in the eastern Mediterranean Sea, were identified by previous studies. However, little is known about the genetic structure of the Atlantic group, where four important spawning areas have been identified. To assess if each spawning area is an independent breeding unit, the genetic diversity, populational structure, and demographic history of A. regius along the North-East and Eastern Central Atlantic coast were analyzed, using 15 microsatellite loci. Results corroborate the hypothesis tested, suggesting four genetic groups: a first group encompassing individuals from the Gironde spawning area, a second group encompassing individuals from the Tagus spawning area, a third group corresponding to individuals captured in the Algarve region, and a forth group gathering individuals from Morocco and Mauritania. This study reveals the need for specific fisheries management plans considering genetic structure information, and highlights the need for international cooperation