Histomorphological study of the digestive tract of the oyster Crassostrea angulata (Lamarck, 1819), and distribution of carbohydrates

We present a histomorphological description of the digestive tract of the oyster Crassostrea angulata (Lamarck, 1819), as well as a histochemical study of its carbohydrate distribution. The study shows that, in general, glycogen is found in the connective tissue, and neutral mucopolysaccharides/glycoproteins and/or acid mucosubstances in the epithelium and basal cell layers. Glycogen was not detected in the digestive gland, possibly because of its mobilization to the connective tissue for reproduction.Se realiza una descripción histomorfológica del aparato digestivo del ostión Crassostrea angulata (Lamarck, 1819) y se pone de manifiesto la distribución de carbohidratos mediante técnicas histoquímicas. La pauta general observada es la presencia de glucógeno en el tejido conjuntivo y de mucopolisacáridos/glicoproteínas neutras y/o ácidas en las membranas basales y el epitelio. En la glándula digestiva no se observa glucógeno debido, posiblemente, a su movilización hacia el tejido conjuntivo para su posterior uso con fines reproductivos.Instituto Español de Oceanografí

Cross-sectoral implications of the implementation of irrigation water use efficiency policies in Spain: A nexus footprint approach

One technical solution often suggested for alleviating water scarcity is to increase the efficiency of irrigation water use. In Spain, several plans have been launched since 2000 to upgrade irrigation infrastructures and thereby achieve water savings equivalent to 2500 hm3/year and promote rural development. The present study uses a footprint approach to evaluate the impacts on land, water, energy, and carbon emissions of the implementation of irrigation modernization policies in agriculture in Spain between 2005 and 2011. The results show that during the period studied, the irrigated area remained stable (+0.3%), although there was a shift in crop patterns, with low-value non-permanent crops being replaced by high-value permanent crops. The water demand for irrigation decreased by 21%; half of this is explained by the shift in crop patterns and the reduction of the consumptive fraction (i.e., blue water footprint), and the other half by the cutback of return flows associated with the higher efficiency of the irrigation infrastructure. Changes in water demand have been accompanied by a progressive substitution of surface water for groundwater. Reduced water demand for irrigation has brought a reduction of 13% in water’s energy footprint and 25% in its carbon footprint. In relative terms, water efficiency (m3 consumed/m3 irrigated) has increased by 8%, although this has also increased the energy intensity (kWh/m3) to 9%. The emission rate (kgCO2 equiv/m3 irrigated) has decreased by 12% as a result of the drop in the emission factor of electricity production. Overall, irrigation modernization policies in Spain have supported the transition from an irrigation sector that is less technified and heavily dependent on surface water into one that is more productive and groundwater-based. From a resource-use perspective, such transition has contributed to stabilizing or even decreasing the irrigated land, and surpass the annual water savings target of 2500 hm3, although it has also made the sector more energy-dependent. Despite the overall positive outcomes, the observed water savings are masked by various synergistic factors, including favorable climatological conditions toward the end of the study period, which contributed strongly to curbing overall irrigation water demand. In the light of the higher frequency of observed droughts in Spain, the investments done so far do not guarantee that the planned water saving targets can be sustained if not complemented with additional measures like restricting irrigated area and/or setting caps for water intensive crops

A landscape genetics approach to unravel the complex evolutionary history of the Iberian honey bee hybrid zone

While landscape genetics is in its infancy, it is a rapidly growing research field in part owing to the increasing availability of powerful molecular and analytical tools. By integrating landscape ecology, spatial statistics and population genetics, landscape genetics is allowing an unprecedented understanding of the microevolutionary processes shaping genetic variation, which has important implications for the advance of ecological and evolutionary knowledge. The Iberian honey bee provides a great model system to address evolutionary questions using a landscape genetics framework. First, previous studies suggest that the Iberian honey bee has a hybrid origin and hybrid zones have been favored by evolutionary biologists as powerful natural laboratories to study evolutionary processes. Second, with the publication of the honey bee genome and development of high‐density SNP markers, powerful tools are now available to dissect the relative importance of neutral and adaptive forces in shaping the Iberian honey bee hybrid zone, a goal of central importance as it leads to more robust inferences of demographic history and to identification of adaptive divergence. Herein, we will present an ongoing research project on the Iberian honey bee hybrid zone where the tools of landscape genetics and population genomics will be combined to unravel the challenging evolutionary history of the Iberian honey bee

Signatures of selection in the Iberian honey bee: a genome wide approach using single nucleotide polymorphisms (SNPs)

Dissecting genome-wide (expansions, contractions, admixture) from genome-specific effects (selection) is a goal of central importance in evolutionary biology because it leads to more robust inferences of demographic history and to identification of adaptive divergence. The publication of the honey bee genome and the development of high-density SNPs genotyping, provide us with powerful tools, allowing us to identify signatures of selection in the honey bee genome. These signatures will be an important first step towards understanding the transition of genotype into phenotype and the basis of adaptive divergence. The Iberian Peninsula harbours the greatest honey bee genetic diversity and complexity in Europe. The challenge of deciphering the mechanisms underlying such complexity has led to numerous morphological and molecular marker-based surveys of the Iberian honey bee. Yet, in spite of the numerous studies, the evolutionary processes underlying patterns of Iberian honey bee genetic diversity remain poorly understood. The evolutionary process in the Iberian Peninsula has been dynamic and the genetic consequences are too complex to be addressed piecemeal, using few markers with unknown or poorly known linkage relationships. Accordingly, in 2010 more than 650 honey bee colonies were sampled across latitudinal and longitudinal clines in the Iberian Peninsula. The 650 honey bee samples were genotyped for 1536 SNPs – all equally distributed across the honey bee genome and all with known linkage relationships, based on the latest honey bee genome assembly. Herein we show the preliminary results of this genotyping, focusing on an Iberian honey bee genome inquiry on recent selective sweeps. We provide new insights into the evolutionary processes shaping the Iberian honey bee patterns

Signatures of selection in the Iberian honey bee: a genome wide approach using single nucleotide polymorphisms (SNPs)

Dissecting genome-wide (expansions, contractions, admixture) from genome-specific effects (selection) is a goal of central importance in evolutionary biology because it leads to more robust inferences of demographic history and to identification of adaptive divergence. The publication of the honey bee genome and the development of high-density SNPs genotyping, provide us with powerful tools, allowing us to identify signatures of selection in the honey bee genome. These signatures will be an important first step towards understanding the transition of genotype into phenotype and the basis of adaptive divergence. The Iberian Peninsula harbours the greatest honey bee genetic diversity and complexity in Europe. The challenge of deciphering the mechanisms underlying such complexity has led to numerous morphological and molecular marker-based surveys of the Iberian honey bee. Yet, in spite of the numerous studies, the evolutionary processes underlying patterns of Iberian honey bee genetic diversity remain poorly understood. The evolutionary process in the Iberian Peninsula has been dynamic and the genetic consequences are too complex to be addressed piecemeal, using few markers with unknown or poorly known linkage relationships. Accordingly, in 2010 more than 650 honey bee colonies were sampled across latitudinal and longitudinal clines in the Iberian Peninsula. The 650 honey bee samples were genotyped for 1536 SNPs – all equally distributed across the honey bee genome and all with known linkage relationships, based on the latest honey bee genome assembly. Herein we show the preliminary results of this genotyping, focusing on an Iberian honey bee genome inquiry on recent selective sweeps. We provide new insights into the evolutionary processes shaping the Iberian honey bee patterns

Intercontinental long-distance seed dispersal across the Mediterranean Basin explains population genetic structure of a bird-dispersed shrub.

Long-distance dispersal (LDD) is a pivotal process for plants determining their range of distribution and promoting gene flow among distant populations. Most fleshy-fruited species rely on frugivorous vertebrates to disperse their seeds across the landscape. While LDD events are difficult to record, a few ecological studies have shown that birds move a sizeable number of ingested seeds across geographic barriers, such as sea straits. The foraging movements of migrant frugivores across distant populations, including those separated by geographic barriers, creates a constant flow of propagules that in turn shapes the spatial distributions of the genetic variation in populations. Here, we have analysed the genetic diversity and structure of 74 populations of Pistacia lentiscus, a fleshy-fruited shrub widely distributed in the Mediterranean Basin, to elucidate whether the Mediterranean Sea acts as a geographic barrier or alternatively whether migratory frugivorous birds promote gene flow among populations located on both sides of the sea. Our results show reduced genetic distances among populations, including intercontinental populations, and they show a significant genetic structure across an eastern-western axis. These findings are consistent with known bird migratory routes that connect the European and African continents following a north-southwards direction during the fruiting season of many fleshy-fruited plants. Further, Approximate Bayesian Analysis failed to explain the observed patterns as a result of historical population migrations at the end of Last Glacial Maximum. Therefore, anthropic and/or climatic changes that would disrupt the migratory routes of frugivorous birds might have genetic consequences for the plant species they feed upon

Spatial patterns of genetic variation in the Iberian honey bee hybrid zone: a comparison between mitochondrial and nuclear DNA

The Iberian honey bee (Apis mellifera iberiensis) has been intensely surveyed for genetic variation with different markers ranging from morphology, allozymes, mitochondrial DNA (mt DNA), to microsatellites. Some of these markers have revealed non-concordant complex patterns of genetic variation, which led scientists to evoke competing hypotheses for the origin of Iberian honey bees. While complex patterns and underlying historical processes are typical of hybrid zones, the use of more powerful molecular and analytical tools and the fine-scale sampling promised to help dissecting the complexities of the Iberian hybrid zone. In this study, we conducted a genome-wide sampling by genotyping over 384 SNPs (single nucleotide polymorphisms) and sequenced an intergenic fragment of the mt DNA in 711 georeferenced honey bee samples collected across three North-South transects in the Iberian Peninsula. Both mt DNA and SNP datasets were analyzed using spatial tools to represent the structure generated by both types of molecular markers. We found concordant spatial patterns between markers which led to rejection of the standing hypothesis of recent human introductions and selection as the processes shaping Iberian honey bees patterns. This study shows that the fine-scale genomic and spatial analyses can reveal patterns which would otherwise had been undetected.Fundação para a Ciência e Tecnologi

Padrões de variação genética em loci sob selecção na abelha ibérica: comparação da selecção balanceada e direccional

A Península Ibérica tem sido reconhecida como um "hotspot" de diversidade c endemismo para diversas espécies quer animais quer vegetais. Em parte esta grande diversidade encontrada na Península Ibérica deve-se ao flicto de este local ter sido utilizado como refúgio por diferentes espécies durante as glaciaçôes A abelha é um dos muitos casos onde este processo aconteceu. Na verdade, a Península Ibérica é umas das regiões da Europa onde esta espécie apresenta uma maior diversidade c complexidade genética. A abelha ibérica que está distribuída pela Península Ibérica é o fruto de uma hibridação natural entre a linhagem Africana c a linhagem da Europa ocidental. O estudo de zonas híbridas tem sido muito importante para compreender os processos evolutivos que levaram à complexidade genética tão característica dos refúgios O objectivo deste trabalho é fazer uma abordagem inicial para perceber como é que os diferentes tipos de selecção (balanceadora e direccional) influenciam a diversidade genética das abelhas na Península Ibérica e tentar perceber qual o papel da selecção na divergência adaptativa das populações. Para tal foram calculadas algumas cstatisticas sumárias e também toram utilizados diversos sothvares que implementam algoritmos Bayesianos de forma a verificar que estrutura é captada ao utilizar-se as regiões do genoma sob diferentes tipos de selecção (balanceadora ou direccional). No total foram detectados 22 loci sob selecção usando o Bayescan, 9 dos quais apresentavam aparentam estar sob de uma selecção balanceada c 13 sob selecção direccional. Neste trabalho é representado o padrão obtido utilizado software "STRUCTURE

Patrones de diversidad neutral y adaptativa de la abeja Ibérica

La península ibérica es conocida como un importante foco (hotspot) de diversidad y endemismos de numerosas especies de plantas y animales representando por ello una de las regiones prioritarias por la conservación en Europa. Varios factores geomorfológicos y ambientales contribuyen a esta riqueza, concretamente: la localización geográfica en el extremo sudoeste de Europa, el aislamiento en relación al resto de Europa por la barrera geográfica de los Pirineos, la complejidad fisiográfica y la diversidad climática resultante de la heterogeneidad fisiográfica y de las distintas influencias del Atlántico y del Mediterráneo. Una conjugación de estos factores hacen de la península ibérica no solo uno cuna de diferenciación y especiación sino también un importante refugio que albergó durante varios periodos glaciales del Pleistoceno muchas de las especies de plantos y animales que hoy colonizan el Norte y el Centra de Europa {Hewitt, 1999).Fundação para a Ciência e Tecnologi