Comparative analysis of two genomic regions among four strains of Buchnera aphidicola, primary endosymbiont of aphids.

Preliminary analysis of two selected genomic regions of Buchnera aphidicola BCc, the primary endosymbiont of the cedar aphid Cinara cedri, has revealed a number of interesting features when compared with the corresponding homologous regions of the three B. aphidicola genomes previously sequenced, that are associated with different aphid species. Both regions exhibit a significant reduction in length and gene number in B. aphidicola BCc, as it could be expected since it possess the smallest bacterial genome. However, the observed genome reduction is not even in both regions, as it appears to be dependent on the nature of their gene content. The region fpr-trxA, that contains mainly metabolic genes, has lost almost half of its genes (45.6%) and has reduced 52.9% its length. The reductive process in the region rrl-aroK, that contains mainly ribosomal protein genes, is less dramatic, since it has lost 9.3% of genes and has reduced 15.5% of its length. Length reduction is mainly due to the loss of protein-coding genes, not to the shortening of ORFs or intergenic regions. In both regions, G+C content is about 4% lower in BCc than in the other B. aphidicola strains. However, when only conserved genes and intergenic regions of the four B. aphidicola strains are compared, the G+C reduction is higher in the fpr-trxA region

Plasmids in the aphid endosymbiont Buchnera aphidicola with the smallest genomes. A puzzling evolutionary story.

Buchnera aphidicola, the primary endosymbiont of aphids, has undergone important genomic and biochemical changes as an adaptation to intracellular life. The most important structural changes include a drastic genome reduction and the amplification of genes encoding key enzymes for the biosynthesis of amino acids by their translocation to plasmids. Molecular characterization through different aphid subfamilies has revealed that the genes involved in leucine and tryptophan biosynthesis show a variable fate, since they can be located on plasmids or on the chromosome in different lineages. This versatility contrasts with the genomic stasis found in three distantly related B. aphidicola strains already sequenced. We present the analysis of three B. aphidicola strains (BTg, BCt and BCc) belonging to aphids from different tribes of the subfamily Lachninae, that was estimated to harbour the bacteria with the smallest genomes. The presence of both leucine and tryptophan plasmids in BTg, a chimerical leucine-tryptophan plasmid in BCt, and only a leucine plasmid in BCc, indicates the existence of many recombination events in a recA minus bacterium. In addition, these B. aphidicola plasmids are the simplest described in this species, indicating that plasmids are also involved in the genome shrinkage process

De lo abyecto en el cuerpo humano y sus relaciones con el Arte y la Semiótica

Esta tesis doctoral ha sido abarcada de una forma panorámica, tratándose de una tesis teórica ; que trata temas contemporáneos abarcados de forma científica. Tiene por objeto examinar cómo el concepto de abyecto en el cuerpo humano es utilizado en el arte y la semiótica. Tenemos por objetivos concretos: establecer cómo aplicamos el juicio del gusto estético y lo subjetivo del término abyecto. Para ello recurriremos a la crítica del juicio kantiana. Puesto que es de vital importancia estudiar cómo enjuiciamos los objetos y que factores intervienen en ello. Establecer el marco ético y moral en el que nos movemos para determinar que entendemos por abyecto. Demostrar la existencia del lenguaje abyecto por asociación de cosas comunes y cotidianas v.g. Das unheimlich, como lo definió Freud. Dándonos cuenta que surgió una teoría después de la lectura de una obra literaria. Quedándonos patente que el principio de realidad, muchas veces surge del arte. Así cómo la necesidad de tener un arte transgresor para poder desarrollar las sociedades. Los textos de Julia Kristeva, Michel Foucault y Umberto Eco; han representado un grado de confrontación importante para acercarnos al estado de la cuestión. Con esta investigación nos hemos propuesto demostrar la siguiente tesis: el concepto de abyecto es real , puesto que lo encontramos en la existencia del ser,( el cuerpo) y por extensión en el arte. (convención social de expresión), con un lenguaje propio y su propia semántica lingüística con sus propios semas -signos- y con su propia semiótica visual. Lo abyecto sirve para cruzar los límites y jugar con las prohibiciones, más concretamente en transgredir. Lo abyecto perturba, el orden, el sistema y la identidad. Por ello es tan interesante, porque nos hace reflexionar, lo preestablecido, la hermenéutica del cuerpo, como sujeto, activo y pasivo. Además de ser absolutamente necesario, porque sin los deshechos, no existe el cuerpo, se deben eliminar los residuos para poder seguir vivo. Encontramos un paralelismo claro con el arte, es necesario eliminar los elementos residuales para crear la obra. Está dividida en tres partes; la primera parte de la investigación ha estudiado y analizado en profundidad el cuerpo abyecto, la abyección en la sociedad, en la cultura. La segunda parte ha analizado y estudiado lo abyecto en los principales movimientos artísticos, citando ejemplos. La tercera parte la componen las conclusiones y la bibliografía. PALABRAS CLAVE: Abyección, cuerpo, arte, semiótica, cultura.Latorre Romero, A. (2014). De lo abyecto en el cuerpo humano y sus relaciones con el Arte y la Semiótica [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/39309TESI

UTILIZACIÓN DEL CUERPO ABYECTO DE LA MUJER REAL Y VIRTUAL EN EL ARTE

[EN] Never a society had been so immersed in stereotypes and pursue personal success, beyond ethics, understood and applied so far. Increased even more if possible, with a sense of belonging to a certain type of body and ideological aesthetics. It is observed in the body the yearning for true communication, understanding and belonging to a world that continually puts mirrors in front of the body. We consider, in this case, the body as an enemy, we do not want to be seen or captured in any way. The relationship of women with abjection is strangely contradictory, takes wrong with the mother's body, but not with the idea of being a mother. This concept is explained particularly well in the book Powers of Horror, Julia Kristeva. As she points out the food is the oral –abject--‐ object opposes me, the relationship between oneself and others. The aim of this paper is to reflect on the use of the abject body of real and virtual women in art.[ES] Nunca una sociedad se había visto tan inmersa en perseguir estereotipos corporales y de éxito, más allá de la ética, comprendida y aplicada hasta ahora. Acrecentada, aún más si cabe, con el sentido de pertenencia a un cierto tipo de estética corporal e ideológica. Se observa en el cuerpo el anhelo de la comunicación verdadera, el entendimiento y la pertenencia a un mundo que pone continuamente espejos delante del cuerpo. Consideramos, en este caso, el cuerpo como enemigo, que no queremos que sea observado o plasmado de ninguna de las maneras. La relación de la mujer con la abyección es extrañamente contradictoria, se lleva mal con el cuerpo materno, pero no así con la idea de ser madre. Este concepto se explica particularmente bien en el libro Poderes del horror, de Julia Kristeva. Para ella, la comida es el objeto -abyecto- oral que se opone al yo, la relación de uno mismo con los otros. El objetivo de esta comunicación es reflexionar sobre la utilización del cuerpo abyecto de la mujer real y virtual en el arte.Latorre Romero, A. (2015). UTILIZACIÓN DEL CUERPO ABYECTO DE LA MUJER REAL Y VIRTUAL EN EL ARTE. En II CONGRESO INTERNACIONAL DE INVESTIGACIÓN DE ARTES VISUALES. Editorial Universitat Politècnica de València. 385-389. https://doi.org/10.4995/ANIAV2015.1074OCS38538

Abiezione nell'arte postmoderna come risultato di una cultura post-traumatica

Obiettivo di questo articolo è identificare gli elementi che permettono di costruire un punto di vista storico-artistico e critico a partire dall'Olocausto fino ad arrivare alla questione dell'abietto. Se il concetto di abietto è stato, nel corso del Novecento, sia nella storia dell'arte che nell'estetica o nella semiotica, alla base del superamento dei limiti simbolici, psichici e culturali, per tentare di trasgredire o di perturbare i sistemi identitari sia individuali che collettivi, nell'abiezione nell'arte tali questioni si presentano in form estremamente originali. Lo studio cerca dunque di dimostrare, anche attraverso una linea teorica che Julia Kristeva ha trattato nel suo libro Pouvoirs de l'horreur, che il discorso si costruisce su concetti e poetiche connessi all'abiezione. Partendo da queste considerazioni sarà interessante riconoscere la presenza di immagini dell'abietto

The generalist inside the specialist: gut bacterial communities of two insect species feeding on toxic plants are dominated by enterococcus sp.

Some specialist insects feed on plants rich in secondary compounds, which pose a major selective pressure on both the phytophagous and the gut microbiota. However, microbial communities of toxic plant feeders are still poorly characterized. Here, we show the bacterial communities of the gut of two specialized Lepidoptera, Hyles euphorbiae and Brithys crini, which exclusively feed on latex-rich Euphorbia sp. and alkaloid-rich Pancratium maritimum, respectively. A metagenomic analysis based on high-throughput sequencing of the 16S rRNA gene revealed that the gut microbiota of both insects is dominated by the phylum Firmicutes, and especially by the common gut inhabitant Enterococcus sp. Staphylococcus sp. are also found in H. euphorbiae though to a lesser extent. By scanning electron microscopy, we found a dense ring-shaped bacterial biofilm in the hindgut of H. euphorbiae, and identified the most prominent bacterium in the biofilm as Enterococcus casseliflavus through molecular techniques. Interestingly, this species has previously been reported to contribute to the immobilization of latex-like molecules in the larvae of Spodoptera litura, a highly polyphagous lepidopteran. The E. casseliflavus strain was isolated from the gut and its ability to tolerate natural latex was tested under laboratory conditions. This fact, along with the identification of less frequent bacterial species able to degrade alkaloids and/or latex, suggest a putative role of bacterial communities in the tolerance of specialized insects to their toxic diet.Financial support was provided by grant BFU2012-39816-C02-01 (Ministerio de Ciencia e Innovación, Spain) co-financed by FEDER funds to Amparo Latorre and CGL2008-00605 (Ministerio de Ciencia e Innovación) to Joaquín Baixeras. Cristina Vilanova is a recipient of a FPU fellowship from the Ministerio de Educación (Spain).Peer reviewe

Accelerated evolution in bacterial endosymbionts of aphids

When compared with free living bacteria, it is proposed that there are at least two endosymbiotic processes in aphids based on the A + T content as well as the increased evolutionary rate of the b-subunit of the F-ATPase complex in different endosymbiotic bacteria. The first well established process corresponds to the integration of Buchnera aphidicola more than 150 million years ago. The other is postulated to correspond to new endosymbiotic processes in which the bacteria involved contain less A + T and show a lower increase of evolutionary rates when compared with B. aphidicola. It is proposed, therefore, that endosymbioses are active processes in aphid evolution

New Insights on the Evolutionary History of Aphids and Their Primary Endosymbiont Buchnera aphidicola

Since the establishment of the symbiosis between the ancestor of modern aphids and their primary endosymbiont, Buchnera aphidicola, insects and bacteria have coevolved. Due to this parallel evolution, the analysis of bacterial genomic features constitutes a useful tool to understand their evolutionary history. Here we report, based on data from B. aphidicola, the molecular evolutionary analysis, the phylogenetic relationships among lineages and a comparison of sequence evolutionary rates of symbionts of four aphid species from three subfamilies. Our results support previous hypotheses of divergence of B. aphidicola and their host lineages during the early Cretaceous and indicate a closer relationship between subfamilies Eriosomatinae and Lachninae than with the Aphidinae. They also reveal a general evolutionary pattern among strains at the functional level. We also point out the effect of lifecycle and generation time as a possible explanation for the accelerated rate in B. aphidicola from the Lachninae

Coexistence of Wolbachia with Buchnera aphidicola and a secondary symbiont in the aphid Cinara cedri.

Intracellular symbiosis is very common in the insect world. For the aphid Cinara cedri, we have identified by electron microscopy three symbiotic bacteria that can be characterized by their different sizes, morphologies, and electrodensities. PCR amplification and sequencing of the 16S ribosomal DNA (rDNA) genes showed that, in addition to harboring Buchnera aphidicola, the primary endosymbiont of aphids, C. cedri harbors a secondary symbiont (S symbiont) that was previously found to be associated with aphids (PASS, or R type) and an alpha-proteobacterium that belongs to the Wolbachia genus. Using in situ hybridization with specific bacterial probes designed for symbiont 16S rDNA sequences, we have shown that Wolbachia was represented by only a few minute bacteria surrounding the S symbionts. Moreover, the observed B. aphidicola and the S symbionts had similar sizes and were housed in separate specific bacterial cells, the bacteriocytes. Interestingly, in contrast to the case for all aphids examined thus far, the S symbionts were shown to occupy a similarly sized or even larger bacteriocyte space than B. aphidicola. These findings, along with the facts that C. cedri harbors the B. aphidicola strain with the smallest bacterial genome and that the S symbionts infect all Cinara spp. analyzed so far, suggest the possibility of bacterial replacement in these species

The Active Human Gut Microbiota Differs from the Total Microbiota

The human gut microbiota is considered one of the most fascinating reservoirs of microbial diversity hosting between 400 to 1000 bacterial species distributed among nine phyla with Firmicutes, Bacteroidetes and Actinobacteria representing around of the diversity. One of the most intriguing issues relates to understanding which microbial groups are active players in the maintenance of the microbiota homeostasis