Sobre la Presencia del Género Ibalia Latreille en España (Hymenoptera, Cynipoidea: Ibaliidae)

2 paginasPeer reviewe

MicroRNA degradation by a conserved target RNA regulates animal behavior

International audiencemicroRNAs (miRNAs) repress target transcripts through partial complementarity. By contrast, highly complementary miRNA-binding sites within viral and artificially engineered transcripts induce miRNA degradation in vitro and in cell lines. Here, we show that a genome-encoded transcript harboring a near-perfect and deeply conserved miRNA-binding site for miR-29 controls zebrafish and mouse behavior. This transcript originated in basal vertebrates as a long noncoding RNA (lncRNA) and evolved to the protein-coding gene NREP in mammals, where the miR-29-binding site is located within the 3′ UTR. We show that the near-perfect miRNA site selectively triggers miR-29b destabilization through 3′ trimming and restricts its spatial expression in the cerebellum. Genetic disruption of the miR-29 site within mouse Nrep results in ectopic expression of cerebellar miR-29b and impaired coordination and motor learning. Thus, we demonstrate an endogenous target-RNA-directed miRNA degradation event and its requirement for animal behavio

Comparative Analysis of Serine/Arginine-Rich Proteins across 27 Eukaryotes: Insights into Sub-Family Classification and Extent of Alternative Splicing

Alternative splicing (AS) of pre-mRNA is a fundamental molecular process that generates diversity in the transcriptome and proteome of eukaryotic organisms. SR proteins, a family of splicing regulators with one or two RNA recognition motifs (RRMs) at the N-terminus and an arg/ser-rich domain at the C-terminus, function in both constitutive and alternative splicing. We identified SR proteins in 27 eukaryotic species, which include plants, animals, fungi and “basal” eukaryotes that lie outside of these lineages. Using RNA recognition motifs (RRMs) as a phylogenetic marker, we classified 272 SR genes into robust sub-families. The SR gene family can be split into five major groupings, which can be further separated into 11 distinct sub-families. Most flowering plants have double or nearly double the number of SR genes found in vertebrates. The majority of plant SR genes are under purifying selection. Moreover, in all paralogous SR genes in Arabidopsis, rice, soybean and maize, one of the two paralogs is preferentially expressed throughout plant development. We also assessed the extent of AS in SR genes based on a splice graph approach (http://combi.cs.colostate.edu/as/gmap_SRgenes). AS of SR genes is a widespread phenomenon throughout multiple lineages, with alternative 3′ or 5′ splicing events being the most prominent type of event. However, plant-enriched sub-families have 57%–88% of their SR genes experiencing some type of AS compared to the 40%–54% seen in other sub-families. The SR gene family is pervasive throughout multiple eukaryotic lineages, conserved in sequence and domain organization, but differs in gene number across lineages with an abundance of SR genes in flowering plants. The higher number of alternatively spliced SR genes in plants emphasizes the importance of AS in generating splice variants in these organisms

Regulation of microRNA biogenesis and turnover by animals and their viruses

Item does not contain fulltextMicroRNAs (miRNAs) are a ubiquitous component of gene regulatory networks that modulate the precise amounts of proteins expressed in a cell. Despite their small size, miRNA genes contain various recognition elements that enable specificity in when, where and to what extent they are expressed. The importance of precise control of miRNA expression is underscored by functional studies in model organisms and by the association between miRNA mis-expression and disease. In the last decade, identification of the pathways by which miRNAs are produced, matured and turned-over has revealed many aspects of their biogenesis that are subject to regulation. Studies in viral systems have revealed a range of mechanisms by which viruses target these pathways through viral proteins or non-coding RNAs in order to regulate cellular gene expression. In parallel, a field of study has evolved around the activation and suppression of antiviral RNA interference (RNAi) by viruses. Virus encoded suppressors of RNAi can impact miRNA biogenesis in cases where miRNA and small interfering RNA pathways converge. Here we review the literature on the mechanisms by which miRNA biogenesis and turnover are regulated in animals and the diverse strategies that viruses use to subvert or inhibit these processes

Long non-coding RNAs and cancer: a new frontier of translational research?

Author manuscriptTiling array and novel sequencing technologies have made available the transcription profile of the entire human genome. However, the extent of transcription and the function of genetic elements that occur outside of protein-coding genes, particularly those involved in disease, are still a matter of debate. In this review, we focus on long non-coding RNAs (lncRNAs) that are involved in cancer. We define lncRNAs and present a cancer-oriented list of lncRNAs, list some tools (for example, public databases) that classify lncRNAs or that scan genome spans of interest to find whether known lncRNAs reside there, and describe some of the functions of lncRNAs and the possible genetic mechanisms that underlie lncRNA expression changes in cancer, as well as current and potential future applications of lncRNA research in the treatment of cancer.RS is supported as a fellow of the TALENTS Programme (7th R&D Framework Programme, Specific Programme: PEOPLE—Marie Curie Actions—COFUND). MIA is supported as a PhD fellow of the FCT (Fundação para a Ciência e Tecnologia), Portugal. GAC is supported as a fellow by The University of Texas MD Anderson Cancer Center Research Trust, as a research scholar by The University of Texas System Regents, and by the Chronic Lymphocytic Leukemia Global Research Foundation. Work in GAC’s laboratory is supported in part by the NIH/ NCI (CA135444); a Department of Defense Breast Cancer Idea Award; Developmental Research Awards from the Breast Cancer, Ovarian Cancer, Brain Cancer, Multiple Myeloma and Leukemia Specialized Programs of Research Excellence (SPORE) grants from the National Institutes of Health; a 2009 Seena Magowitz–Pancreatic Cancer Action Network AACR Pilot Grant; the Laura and John Arnold Foundation and the RGK Foundation

The Coupling of Alternative Splicing and Nonsense-Mediated mRNA Decay

Most human genes exhibit alternative splicing, but not all alternatively spliced transcripts produce functional proteins. Computational and experimental results indicate that a substantial fraction of alternative splicing events in humans result in mRNA isoforms that harbor a premature termination codon (PTC). These transcripts are predicted to be degraded by the nonsense-mediated mRNA decay (NMD) pathway. One explanation for the abundance of PTC-containing isoforms is that they represent splicing errors that are identified and degraded by the NMD pathway. Another potential explanation for this startling observation is that cells may link alternative splicing and NMD to regulate the abundance of mRNA transcripts. This mechanism, which we call "Regulated Unproductive Splicing and Translation" (RUST), has been experimentally shown to regulate expression of a wide variety of genes in many organisms from yeast to human. It is frequently employed for autoregulation of proteins that affect the splicing process itself. Thus, alternative splicing and NMD act together to play an important role in regulating gene expression

Los insectos de la isla de Coiba (Panamá). Abundancia y dinámica estacional. Análisis del caso de los himenópteros (Hexapoda Hymenoptera)

18 paginas, 7 figuras y 11 tablesInsects: Generallntroduction. Abundance and seasonal dynamícs of insects in Coiba. The case of the hymenoptera. An introduction to the insects is presented withln the global flora and fauna project of inventory of the National Park of lhe 1 land of Coiba (Panama). Preliminary results on entomology are conrribulcd in four artieles: One first work i devoted to investigate the abundance and temporal dynamic ' of insecls, cspecially hymenoplera, as measured by Malaise traps catches, in North of Coiba island. A second work presents faunistical results of the inventory of selected families of Hymenoptera parasítica Cynipoidea and Chalcidoidea: Figitidae, Chalcididae, Encyrtidae and Eucharitidae. A thlrd artiele deals with the butterflies of Coiba and fmally, the fourth work, presents a list of Odonata from the island. Field work data comes from three collecting trips to Coiba (two-five weeks long) between 1994 and 1996. Wet and dry seasons were sampled. Thirty one sites in the National Park were sampled representing almo. l aJl the main terrestrial habitats of Coiba. Sampling methods used were: Malai e trap, weep nct, yellow pan traps, pitfall traps and light trap, but most colIected dlUa come from Ihe rwo first techniques. Local abundance of insect orders and famílies of Hymenoptera, measured by Malaise traps samples from the north of the Coiba island, was investigated and the results compared with data from the Iiterature and unpublished author's Malaise traps data from two sítes in the centre of the Iberian Península. Local abundance of insects was comparatively higher than that registered in other tropicallocalities and intermediate in relatíon to the two sites in the Iberian Península. Local abundance of Hymenoptera was in average higher than those indicated by bibliographical data for other sites and countries but it was equal or lower in relation to the two sites in the lberian Península. Seasonal dynamícs of Ihe families of Hymenoptera: Eucoilidae, Figitidae, Chalcididae, Eucharitidae, Pteromalidae and Symphyta were investígaled from samples of a single Malaise trap operatíng along the whole 1994 annual cycle. Figitidae and Symphyta showed short phenological cycles from May to August and the other farnilies presented flight activity along the whole year. Eucoilidae, Chalcididae y Eucharitidae were, along one full year, more abundant in Coiba, as a whole, than in the two sites in central Spain; Pteromalidae y Figitidae showed an intermediate abundance in comparison with that localities and Symphyta was much less abundant in Coiba islandEste trabajo ha sido posible gracias a la colaboración de muchas personas a las que, desde aquí, queremo expre ar nuestro agradecimiento. En primer lugar a Santiago Castroviejo a quien debemos la invitación para participar en el proyecto de inventario de Coiba y la ayuda prestada en todo momento. Carmen Moreno y Timoteo Guijarro de la AECI en Panamá pusieron los medios, en la financiación, y todo su esfuerzo, eficacia y amabilidad en la logística de las expedición a la isla. Raúl Brenes, director del Parque Nacional Coiba y Juan Cuadras, como guía de la expedición fueron de inestimable ayuda. En especial queremos agradecer la e laboración del recluso Mali Mali por atender la operatividad de la trampa Malaise instalada en la estación Biológica a lo largo de todo el año 1994. Elvira Mingo, Vicenta Llorente Mª Paz Martín, Arabia Sánchez y Florita Tordesillas del MNCN colaboraron en la tarea de separación de ordenes de insectos en las muestras de Trampas Malaise, Carmen Rey en la separación de Hymenoptera Aculeata e /chneumonoidea y Ma Luisa Hinojosa en el montaje de ejemplares.Peer reviewe

Estudio Comparado de Diversidad de Eucoilinos Paleárticos (El ventorrillo, España ) y Neotropicales (P. N. Coiba, Panamá) (Hymenoptera, Cynipoidea, Figitidae, Eucoilinae)

51 páginas, 15 figuras, 7 tables[EN] The composition, richness and diversity of two eucoiline communities (Hymenoptera, Cynipoidea, Figitidae, Eucoilinae) are studied and compared for the first time. The sites and period of study were the Biogeological Station of El Ventorrillo, in the Sierra de Guadarrama mountains (Spain), from 1988 to 1991, and the Coiba Island National Park (Panama), in the the Central American sector of the Pacific Ocean, from 1994 to 1999. The Malaise trap was the main monitoring method, although sweep nets, yellow pan traps and ultraviolet light traps were used as complementary sampling methods. It is the first time eucoilines have been caught with ultraviolet light traps. 1,547 specimens of 123 species were collected, 29 species of 10 genera at El Ventorrillo and 95 species of 21 genera at Coiba. At the Mediterranean locality Kleidotoma, with 13 species, and Trybliographa, with 4, were the genera with the biggest number of species; 7 genera are recorded for the first time from the Iberian Peninsula: Diglyphosema, Disorygma, Ganaspis, Glauraspidia, Gronotoma, Hexacola and Kleidotoma. At Coiba Ganaspis, with 17 species, and Leptopilina with 13, were the genera with the most species; 11 genera are recorded for the first time from Panama: Bewelda, Coneucoela, Didyctium, Dieucoila, Hexacola, Kleidotoma, Leptopilina, Micreriodes (first record for the Neotropical Region), Nordlandiella, Striatovertex and Triplasta, and 16 species are stated as new to science but not formally described yet. Only 4 genera (Ganaspis, Hexacola, Kleidotoma and Rhoptromeris) and 1 species (Hexacola hexatoma (Htg)) were found at both localities. At El Ventorrillo shared genera were dominant (40% of shared genera versus 20% of exclusive genera), while Coiba showed the reverse situation (81.8% of exclusive genera versus 18.2% of shared genera). Differences in the composition of the two studied communities are discussed in terms of the possible tropical origin of the eucoilines and the environmental relative humidity as a likely limiting ecological factor to eucoiline dispersion. Results from cumulative species curves indicate that the sampling effort was sufficient and that the number of species found is representative of eucoiline diversity at both localities. Several ecological parameters are used in the description and discussion of functional and structural characteristics of the two studied eucoiline communities. Malaise trap data from one entire annual cycle year indicate that the El Ventorrillo inventory of eucoilines was more exhaustive than the Coiba inventory, although many species not caught by Malaise traps were collected by other sampling methods, especially by sweeping. We conclude that to obtain exhaustive inventories of 52 eucoilines from Palaearctic ecosystems, the joint use of Malaise traps and sweeping is advisable, but it is essential at tropical sites. It is the first study where the eucoilines, as representative of a hyperdiverse group of microhymenoptera, are used to check the RESTAR functions approach (or the higher taxa richness approach) to estimate the diversity of an ecosystem. Proven monophyletic supraspecific categories are used to calculate the RESTAR functions for the first time. This approach is shown as a valid methodology to estimate the diversity of eucoiline communities, both for the Palaearctic and Neotropical Regions. It is much more useful when we confirm a better fit using monophyletic genera-groups than with genera and for Neotropical communities, more difficult to monitor (higher values of β) than Palaearctic ones.[ES] Se estudia y compara por primera vez la composición, riqueza y diversidad de dos comunidades de eucoilinos (Hymenoptera, Cynipoidea, Figitidae, Eucoilinae), una paleártica, en España, y otra neotropical, en Panamá. Las localidades estudiadas fueron la Estación Biogeológica de El Ventorrillo en la Sierra de Guadarrama, en la España central, desde 1988 a 1991, y el Parque Nacional de la Isla de Coiba (Panamá), en el Pacífico centroamericano, desde 1994 hasta 1999. El método de muestreo principal fue la trampa Malaise, complementado con otros métodos como la red entomológica de barrido, las trampas bandeja coloreadas y trampas de luz ultravioleta, siendo la primera vez que se cogen eucoilinos con trampas de luz. Fueron capturados 1.547 individuos para un total de 123 especies inventariadas, 29 de 10 géneros en El Ventorrillo y 95 de 21 géneros en Coiba . En El Ventorillo los géneros con más especies fueron Kleidotoma, con 13, y Trybliographa, con 4. 7 géneros se citan por primera vez para la Península Ibérica: Diglyphosema, Disorygma, Ganaspis, Glauraspidia, Gronotoma, Hexacola y Kleidotoma. En Coiba los géneros más especiados fueron Ganaspis, con 17 especies, y Leptopilina, con 13. 11 géneros se citan por primera vez para Panamá: Bewelda, Coneucoela, Didyctium, Dieucoila, Hexacola, Kleidotoma, Leptopilina, Micreriodes (primera cita para la Región Neotropical), Nordlandiella, Striatovertex, Triplasta, y 16 son probables especies nuevas para la ciencia, aún no descritas. Únicamente cuatro géneros (Ganaspis, Hexacola, Kleidotoma y Rhoptromeris) y una especie (Hexacola hexatoma (Htg)) se obtuvieron en las dos localidades. En El Ventorrillo predominan los géneros compartidos entre las dos comunidades (un 40% de similitud, frente a un 20% de exclusividad), mientras que en Coiba el componente mayoritario es el de géneros exclusivos (un 81.8% de exclusividad, frente a un 18.2% de similitud). Las diferencias en la composición de las dos comunidades se discuten en función del posible origen tropical de los eucoilinos y de la variable de la humedad relativa ambiental como probable factor limitante. Los resultados de las curvas de acumulación de especies muestran que el esfuerzo de muestreo ha sido suficiente y las especies encontradas son representativas de la diversidad de eucoilinos de las dos localidades. Se describen y discuten las características estructurales y funcionales de las dos comunidades estudiadas en función del análisis de distintos parámetros ecológicos. Los datos de muestreo con trampa Malaise, correspondientes a un ciclo anual completo, indican que el inventario de eucoilinos resulta más exhaustivo para el ecosistema paleártico que para el neotropical, si bien un alto porcentaje de las especies no capturadas con trampa Malaise se consiguen capturar con otras técnicas de muestreo, especialmente con red de barrido; se concluye que complementar el método de la trampa Malaise con el de red de barrido es recomendable en ecosistemas paleárticos, pero imprescindible en ecosistemas neotropicales, si se quiere contar con inventarios significativos de la diversidad de eucoilinos. Este es el primer estudio que ensaya la utilización de los eucoilinos, como grupo de microhimenópteros hiperdiversos, para probar el método de las funciones RESTAR (o the higher taxa richness approach) para estimar la diversidad de los ecosistemas. Por vez primera se utilizan categorías supraespecíficas de naturaleza monofilética demostrada en el cálculo de las funciones RESTAR. Se demuestra que las funciones RESTAR son un método válido para estimar la diversidad de comunidades de eucoilinos, tanto en el Paleártico como en el Neotrópico. Este método resulta aún más valioso cuando comprobamos que las comunidades neotropicales, más costosas de inventariar (mayor β) que las paleárticas, presentan mejor ajuste con grupos de géneros monofiléticos que con géneros.Este trabajo se ha beneficiado de la financiación de la Consejería de educación de la Comunidad de Madrid (proyecto C188/91 de la AECI en Panamá (proyecto Coiba) y de la DGES, fondos del proyecto PB97-1241, concedidos a J.L.N.A.Peer reviewe