A Genetic Approach to Spanish Populations of the Threatened Austropotamobius italicus Located at Three Different Scenarios

Spanish freshwater ecosystems are suffering great modification and some macroinvertebrates like Austropotamobius italicus, the white-clawed crayfish, are threatened. This species was once widely distributed in Spain, but its populations have shown a very strong decline over the last thirty years, due to different factors. Three Spanish populations of this crayfish—from different scenarios—were analysed with nuclear (microsatellites) and mitochondrial markers (COI and 16S rDNA). Data analyses reveal the existence of four haplotypes at mitochondrial level and polymorphism for four microsatellite loci. Despite this genetic variability, bottlenecks were detected in the two natural Spanish populations tested. In addition, the distribution of the mitochondrial haplotypes and SSR alleles show a similar geographic pattern and the genetic differentiation between these samples is mainly due to genetic drift. Given the current risk status of the species across its range, this diversity offers some hope for the species from a management point of view

A complex landscape favours the abundance and species richness of syrphids (Diptera: Syrphidae) in olive groves

1. Sustainability of agroecosystems depends on the ecosystem services, provided by beneficial organisms, such as the syrphids (Diptera: Syrphidae) acting as other-insect predators and pollinators in different crops. In the case of olive groves, syrphids are predators of important pests and are endangered by the continuous intensification of agriculture, including landscape simplification. In this work, the effect of landscape structure on the abundance and species richness of syrphids in the olive agroecosystem of central Spain is assessed. 2. Adult syrphids were sampled in 2015 and 2016 in the centre of circular areas of 15 olive grove landscapes (from 250 to 1500 m radius) representing a gradient of landscape complexity, in the province of Madrid, central Spain. 3. The syrphid assemblage was made up of 57 species, although Eupeodes corollae, Eristalis tenax, Eristalis similis and Chrysotoxum intermedium made up 76% of the captures. 4. Syrphid abundance and species richness were favoured in complex landscapes, with low olive grove area (CAO). Other landscape indices showed also this trend although their effect was not as strong and consistent as that of CAO. The area of scrublands (CAS) favoured syrphids in spring, but was unfavourable in autumn. The effect of Shannon's Evenness Index (SHEI) and mean shape index (MSI) was less consistent. The effect of CAO increased with increasing buffers radii, while the effect of CAS, SHEI and MSI was detected in general at smaller radii, indicating these indices affect different processes. 5. Redundancy analysis (RDA) detected some differences between species regarding their abundance in spring versus autumn, and their relationship with landscape indices. 6. This work provides new evidence that maintenance of complex landscapes is essential for maintaining functional biodiversity in the olive agroecosystem.This work was supported by the the Ministerio de Economía y Competitividad of Spain and the European Regional Development Fund by project RTA2013-00039-C03-03 and the “Vicerrectorado de Investigación y Transferencia del Conocimiento” was funded by Antonio Ricarte's position at the University of Alicante (Ref. UATALENTO17-08). This study is within the framework of the “Fauna Ibérica” project (PGC2018-095851-A-C65) of the “Ministerio de Ciencia, Innovación y Universidades” of Spain

Specific and sensitive primers for the detection of predated olive fruit flies, Bactrocera oleae (Diptera: Tephritidae)

Bactrocera oleae, the olive fruit fly, is a major pest of olive (Olea europaea L.) trees worldwide. Its presence can cause important losses, with consequences for the economies of countries that produce and export table olives and olive oil. Efforts to control olive fruit fly populations have, however, been insufficient. Now more than ever, environmentally friendly alternatives need to be considered in potential control programs. Generalist predators could provide a way of managing this pest naturally. However, the identification of candidate predator species is essential if such a management system is to be introduced. The present paper describes a set of species-specific primers for detecting the presence of B. oleae DNA in the gut of predatory arthropods. All primers were tested for checking cross-reactive amplification of other fruit fly DNA and evaluated in heterospecific mixes of nucleic acids. All were found to be very sensitive for B. oleae. Subsequent feeding trials were conducted using one of the most abundant species of ground dwelling carabids in olive groves in south-eastern Madrid, Spain. These trials allowed determining that 253F-334R and 334F-253R primer pairs had the highest detection efficiency with an ID50 of around 78 h. These primers therefore provide a very useful tool for screening the gut contents of potential predators of B. oleae, and can thus reveal candidate species for the pest's biological control

Molecular detection of Philaenus spumarius DNA in predators gut

X. fastidiosa is one of the most destructive pathogens of olive orchards. Its recent arrival to Europe can cause important losses, with possible drastic consequences for the sector. Philaenus spumarius (Linnaeus 1758) was identified as vector of X. fastidiosa in Europe and finding candidate natural enemies of P. spumarius is essential to design environmentally friendly control strategies against X. fastidiosa. Generalist predators, such as spiders, arise as important potential biocontrol agents. In this context, a set of species-specific primers for detecting the presence of P. spumarius DNA in the gut of predatory arthropods is being developed. All primers will be tested for checking cross-reactive amplification of arthropods DNA and evaluated in heterospecific mixes of nucleic acids. Subsequent feeding trials will be conducted using Synemaglobosum (Fabricius 1775), an important spider species in olive groves from Mirandela, Portugal. These trials will allow determining the detection efficiency of the primers designed and also they will be the starting point to detect predation in field trials. These primers therefore provide a very useful tool for screening the gut contents of potential predators of P. spumarius, and can thus reveal candidate species for this species biological control.This work has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement N. 727987 “Xylella fastidiosa Active Containment Through a multidisciplinary-Oriented Research Strategy XF-ACTORS”.info:eu-repo/semantics/publishedVersio

Phylogeography of organophosphate resistant ace alleles in spanish olive fruit fly populations: a mediterranean perspective in the global change context

The olive fruit fly (olf) Bactrocera oleae is the most damaging olive pest. The intensive use of organophosphates (OPs) to control it, led to an increase in resistance in field populations. This study assesses the presence and distribution of three mutations at the ace gene related to target site insensitivity to OPs in Spain. Samples from other Mediterranean countries were included as external references. Resistance-conferring alleles (from exons IV and VII of the ace gene) reached almost an 80% frequency in olf Spanish populations. In total, 62% of them were homozygous (RR/RR), this being more common in eastern mainland Spain. High frequencies of RR/RR individuals were also found in North Mediterranean samples. Conversely, in Tunisia, only sensitive alleles were detected. Finally, the exon X mutation ∆Q3 had an extremely low frequency in all samples. The high frequency of genotype RR/RR in Spain indicates high fitness in an agroecosystem treated with pesticides, in contrast to ∆Q3. At exon IV all flies carried the same haplotype for the allele conferring resistance. The sequence analysis at this exon suggests a unique origin and fast expansion of the resistant allele. These results provide evidence that OPs appropriate use is needed and prompt the search for alternative methods for olf pest control

Herramientas de aprendizaje para estudiantes de secundaria: Aplicación de la Genética y la Genómica

Depto. de Genética, Fisiología y MicrobiologíaFac. de Ciencias BiológicasFALSEsubmitte

Laboratorio en abierto: aPrendiendo a CopiaR el ADN

El objetivo principal del proyecto es la puesta a punto de recursos educativos en abierto (REA) dirigidos a los alumnos de secundaria. El punto de partida será plantear diferentes retos y situaciones que se pueden resolver utilizando distintos recursos científicos, para decidir qué recurso es el más adecuado y cómo se aplica. En esta propuesta la resolución de los problemas planteados estaría basada en la aplicación de una herramienta que ha revolucionado la genética y biología, la reacción en Cadena de la Polimerasa, conocida como PCR

Análisis genético de las poblaciones españolas del cangrejo de río "Austropotamobius italicus" (Faxon, 1914)

El cangrejo de río Austropotamobius pallipes sensu lato es una especie autóctona en Europa que en las últimas décadas está sufriendo una drástica regresión poblacional, especialmente en España. Por ello actualmente está protegida tanto a nivel europeo como español y se están desarrollando planes para su conservación, los cuales desafortunadamente no incluyen información genética sobre la especie. Mediante dos marcadores mitocondriales y microsatélites nucleares hemos analizado más de 250 ejemplares de cangrejos ibéricos pertenecientes a 10 cuencas hidrográficas. En conjunto hemos identificado 19 haplotipos mitocondriales y probado que todos los loci SSR estudiados son polimórficos en las poblaciones españolas. Los niveles de variabilidad haplotípica y nucleotídica detectados son 0,77 y 0,00074, respectivamente y la heterocigosis media 0,186. Valores dentro del rango descrito para la especie. Estos resultados concuerdan con severas restricciones del tamaño poblacional y la acción de la deriva genética. Esta variación genética no se distribuye homogéneamente en nuestro país sino que podemos distinguir dos grandes grupos genéticos denominados `Norte¿ y `Centro¿. En el grupo `Norte¿ se distinguen además las poblaciones de la Cordillera Cantábrica de las localizadas en los Montes Vascos y en el grupo `Centro¿, las poblaciones de la cuenca del Ebro de las restantes. La estructura genética detectada podría estar influenciada por factores actuales, tales como las migraciones ¿ naturales o antropogénicas ¿, los cuellos de botella causados por enfermedades o alteraciones del hábitat y, en definitiva, los efectos de la deriva genética. También por los cambios climáticos pasados, especialmente la última glaciación, ya que el análisis exhaustivo de los marcadores mitocondriales revela que la especie lleva largo tiempo establecida en España, al menos desde el Pleistoceno. Con fines de conservación las poblaciones españolas parecen constituir una ESU diferenciada. Esta ESU estaría compuesta por dos MU, coincidentes con los grupos genéticos `Norte¿ y `Centro¿. Para facilitar la inclusión de información genética en la gestión de estas poblaciones hemos puesto a punto la técnica de PCR ¿ RFLP. Mediante el análisis de los cangrejos con dos enzimas de restricción, HpaI y CviAII, es posible asignarlos una de las dos MU propuestas y además, identificar el subgrupo genético al que pertenecen. Dada la controversia que aún prevalece sobre el estatus taxonómico del complejo de especies Austropotamobius pallipes, una especie en peligro en todo su rango de distribución, también hemos evaluado las consideraciones taxonómicas que se desprenden del estudio de la variabilidad genética. Estudiando la práctica totalidad de la información disponible en las bases de datos genéticas sobre este organismo con los marcadores 16S y COI, se pueden diferenciar claramente las dos especies reconocidas en este género, A. torrentium y A. pallipes sensu lato. El umbral que proponemos para diferenciarlas es de 7,6 por ciento con el gen 16S y 12,5 por ciento con el gen COI. A su vez A. pallipes sensu lato parece estar compuesto por A. pallipes sensu estricto y A. italicus, que podrían haber empezado a diferenciarse hace unos 9,2 ¿ 8,2 MA, y aun no habrían completado el proceso de especiación. Por último en A. italicus podemos distinguir dos subgrupos genéticos, A. i. italicus y A. i. carsicus. Ambos subgrupos tienen un marcado patrón de distribución geográfica y las diferencias genéticas encontradas entre ambas podrían deberse a adaptaciones locales

PCR Species-Specific Primers for Molecular Gut Content Analysis to Determine the Contribution of Generalist Predators to the Biological Control of the Vector of Xylella fastidiosa

The European Union (EU) is facing the recent arrival of the bacterium Xylella fastidiosa. Its fast spread has caused great alarm because of the economic impact it implies for the agroeconomy of European countries. Among its insect vectors, Philaenus spumarius has been demonstrated to transmit the bacterium from infected to uninfected trees in the EU, where different measures have been established to control it. One of the proposals to manage this vector is the augmentation of natural enemy populations. However, the identification of candidate predator species is essential if such a management system is to be introduced. The present paper describes a set of species-specific primers designed to detect the presence of P. spumarius DNA in soil arthropod fauna generalist predators’ gut which can reveal candidate species for the pest’s biological control. Such primers have been proven to be a useful and reliable taxonomic tool for P. spumarius identification at any life stage, i.e., nymphs. This rapid and accurate identification is essential for control strategies designed to avoid the spread of the pest and consequently the considerable economic losses it causes in crops

Vast Gene Flow among the Spanish Populations of the Pest Bactrocera oleae (Diptera, Tephritidae), Phylogeography of a Metapopulation to Be Controlled and Its Mediterranean Genetic Context

Spain is the leading producer of olives and olive oil. Ninety-five percent of world production originate from Spain and other regions of the Mediterranean Basin. However, these olive-growing countries face a major problem, the harmful fly Bactrocera oleae, the main pest of olive crops. To improve its control, one of the challenges is the further knowledge of the species and populations dynamics in this area. A phylogeographic work is necessary to further characterise the levels and distribution patterns of genetic diversity of the Spanish populations and their genetic relationships with other Mediterranean populations. A 1151 bp fragment of the mitochondrial cytochrome oxidase subunit I (COI) gene has been analysed in over 250 specimens of the six main Mediterranean countries via sequencing. Genetic diversity parameters were high; 51 new haplotypes have been identified showing a geographical pattern across the Mediterranean area. The data revealed that olive fruit fly populations have been long time established in the Mediterranean Basin with two genetic groups. Gene flow seems to be the main process in shaping this genetic structure as well as fly’s colonisation routes that have paralleled those of the olive tree