Noggin induce un destino neurale corticale nelle cellule staminali embrionali murine antagonizzando Bone Morphogenetic Proteins (BMPs) secrete in maniera autocrina.

Le cellule staminali embrionali (ESC) rappresentano uno strumento utile per lo studio in coltura del potenziale differenziativo di cellule pluripotenti. Il differenziamento di ESC in mezzi di coltura chimicamente definiti permette di individuare i fattori necessari e sufficienti all’induzione di specifici destini cellulari. Abbiamo studiato il differenziamento di ESC murine, coltivate come monostrato aderente, in un mezzo minimo privo di fattori di crescita. La coltura di ESC in queste condizioni porta al differenziamento di neuroni caratterizzati da un profilo di espressione genica tipico delle regioni prosencefalo-mesencefaliche. Il lavoro dimostra che le ESC durante il loro differenziamento secernono BMPs (Bone Morphogenetic Proteins) e che l’inibizione di questa via di segnale per mezzo di Noggin rafforza l’abilità delle ESC di generare neuroni con un repertorio genico corticale. Tali neuroni sono stati caratterizzati mediante l’analisi di espressione di marcatori antero-posteriori e dorso-ventrali dello sviluppo del sistema nervoso. Inoltre abbiamo comparato mediante microarray l’espressione genica globale delle cellule ottenute dal differenziamento di ESC con quella del prosencefalo, mesencefalo e romboencefalo embrionale murino. Nell’insieme i dati suggeriscono, per le ESC murine, la presenza di un programma differenziativo di default in senso neurale corticale

Seedless Fruit Production by Hormonal Regulation of Fruit Set

Seed and fruit development are intimately related processes controlled by internal signals and environmental cues. The absence of seeds is usually appreciated by consumers and producers because it increases fruit quality and fruit shelf-life. One method to produce seedless fruit is to develop plants able to produce fruits independently from pollination and fertilization of the ovules. The onset of fruit growth is under the control of phytohormones. Recent genomic studies have greatly contributed to elucidate the role of phytohormones in regulating fruit initiation, providing at the same time genetic methods for introducing seedlessness in horticultural plants

Percepción dispersa: Arquitectura y tactilidad en la sociedad de la comunicación

El tema de la tesis se centra en el pensamiento de Walter Benjamin y en el concepto de percepción distraída, desarrollado en el ensayo La obra de arte en la época de su reproducibilidad técnica (1936). El título percepción dispersa deriva de una profundización de los conceptos benjaminianos en términos lingüísticos, adoptando otros significados de la palabra distracción que relacionan este concepto a cuestiones de ámbito espacial y atmosférico. Benjamin sostiene que la arquitectura, en una época en la que se desarrollan y se difunden nuevas técnicas de reproducción/ comunicación, no se puede percibir solo de manera visual sino también táctil, interrelacionando la difusión de nuevas técnicas de reproducción, la tensión entre diferentes modalidades perceptivas y la arquitectura: según él, la dispersión de la vista a favor de la percepción táctil/háptica es un rasgo característico de una sociedad en la que se desarrollan y se difunden nuevas técnicas de reproducción. La tesis profundiza en estos temas, actualizando el concepto de distracción/dispersión para valorar las repercusiones de esta intuición en el ámbito de una parte de la producción arquitectónica contemporánea: se propone una contextualización histórica y una conceptual, relativas a los proyectos recientes de algunos de los autores que profundizan en el impacto de las nuevas tecnologías en el ámbito del proyecto de arquitectura. La hipótesis que se quiere demostrar es que se está desarrollando una tendencia que lleva proyectos o edificios de alto nivel tecnológico y informático desde un ámbito de (supuesto) predominio de la percepción visual, hasta una arquitectura que proporciona experiencias multisensoriales: espacios que se pueden medir con el movimiento, los músculos y el tacto, que desarrollan un conjunto de sensaciones táctiles/hápticas y no solo visuales. Finalmente se quiere verificar si, revertiendo siglos de evolución visual, la visión táctil y cercana siga siendo uno de los polos dialécticos que estructuran la experiencia de la arquitectura, como previsto por Benjamin hace 75 años. ABSTRACT The thesis focuses on the thought of Walter Benjamin and the concept of distracted perception, developed in the essay The Work of Art in the Age of Mechanical Reproduction (1936). The title derives from a linguistic approach to this concept which further explores the meaning of the word distraction, finally relating this kind of perception to spatial and atmospheric issues. Benjamin argues that architecture, thanks to the development of new reproduction/communication technologies, cannot be perceived exclusively in a visual way but also in a tactile way, interrelating new technologies of reproduction, perceptual modalities and architecture: according to him, the dispersion of the view in favor of tactile/ haptic perception is a fundamental characteristic of a technologically developed society. The thesis explores these issues, updating the concept of distraction/dispersion to assess its implications in the works of some architects that are exploring with their buildings the impact of new communication technologies in the field of architectural design. The hypothesis at the base of this work is that we are facing a new trend in this particular field: many of the most advanced buildings provide multisensory experience, and define spaces that can be better perceived with the sense of touch (haptic sense), going beyond a mere visual perception. Finally the thesis wants to verify if, reversing centuries of visual evolution, tactile and close vision remains one of the dialectical poles that stay at the base of the experience of architecture, as foreseen by Benjamin 75 years ago. ABSTRACT La tesi si basa sul pensiero di Walter Benjamin e sul concetto di percezione distratta, sviluppato nel saggio La opera d’arte nell’epoca della sua riproducibilità tecnica (1936). Il titolo, percezione dispersa, deriva da un approfondimento dei concetti benjaminiani in termini linguistici, adottando ulteriori significati della parola che il filosofo utilizza per indicare la distrazione e che relazionano questo termine a questioni di ambito spaziale ed atmosferico. Benjamin sostiene che l’architettura, in un’epoca nella quale si sviluppano e si diffondono nuove tecniche di riproduzione (o meglio: nuove tecnologie di comunicazione), non possa essere percepita solamente in maniera visuale, ma anche tattile, mettendo in relazione la diffusione di nuove tecnologie, la tensione tra differenti modalità percettive e l’architettura: secondo Benjamin, la dispersione della vista a favore di una ricezione tattile/aptica della realtà è una caratteristica tipica di quei momenti storici nei quali si manifestano grandi trasformazioni di ambito sociale e culturale dovute allo sviluppo di nuove tecnologie di comunicazione. La tesi approfondisce questi temi, aggiornando il concetto di distrazione/dispersione per valutarne le ripercussioni su una certa parte della produzione architettonica contemporanea: si propone una contestualizzazione storica ed una concettuale, relative ai progetti di alcuni architetti che lavorano da tempo sull’impatto delle nuove tecnologie nell’ambito del progetto di architettura. La ipotesi che si dimostra con questa tesi è che si sta sviluppando una contro-tendenza tattile, a seguito della quale molti degli edifici tecnologicamente ed informaticamente più avanzati strutturano la relazione con i propri utenti sulla base di esperienze multisensoriali, definendo spazi che possono essere percepiti attraverso una percezione aptica, piuttosto che visuale. In definitiva la tesi verifica che, superando secoli di evoluzione visuale, la visione tattile e ravvicinata e - più in generale - una percezione di tipo aptico continuano ad essere uno dei poli dialettici che strutturano l’esperienza dell’architettura, come previsto da Benjamin più di 75 anni fa

Narrating Cases: a Storytelling Approach to Case Study Analysis in the Field of Lifelong Learning Policies

The paper aims to discuss the narrative approach to case study analysis, drawing on the research carried out within the H2020 European Project YOUNG_ ADULLLT. It aimed to analyse Lifelong Learning (LLL) policies targeted to young adults in Europe, particularly those in situations of social exclusion, focusing on the different ways in which the policies are socially embedded in specific local contexts across Europe. By a multimethod and multilevel perspective, the research sought to explore the interplay between structural, institutional and individual levels to understand the relationship and complementarity between the LLL policies and the young people\u2019s social conditions, needs and expectations. The paper focuses on the narrative approach, namely the \u201cstorytelling strategy\u201d, adopted to examine the Lifelong Learning policies chosen as case studies in their social, political and economic realities. Different examples of storytelling and their contribution to analyse LLL policies are explored. Lastly, we critically discuss whether the narrative approach allowed to build a dense portrait able to yield the complexity and the specificity of the cases, reconstructing the story of the meaning of Lifelong Learning in different constellations. Epistemological and methodological considerations on the use of narrative approach in social science are provided, highlighting its opportunities and limits

Genetic transformation of Vitis vinifera via organogenesis

BACKGROUND: Efficient transformation and regeneration methods are a priority for successful application of genetic engineering to vegetative propagated plants such as grape. The current methods for the production of transgenic grape plants are based on Agrobacterium-mediated transformation followed by regeneration from embryogenic callus. However, grape embryogenic calli are laborious to establish and the phenotype of the regenerated plants can be altered. RESULTS: Transgenic grape plants (V. vinifera, table-grape cultivars Silcora and Thompson Seedless) were produced using a method based on regeneration via organogenesis. In vitro proliferating shoots were cultured in the presence of increasing concentrations of N(6)-benzyl adenine. The apical dome of the shoot was removed at each transplantation which, after three months, produced meristematic bulk tissue characterized by a strong capacity to differentiate adventitious shoots. Slices prepared from the meristematic bulk were used for Agrobacterium-mediated transformation of grape plants with the gene DefH9-iaaM. After rooting on kanamycin containing media and greenhouse acclimatization, transgenic plants were transferred to the field. At the end of the first year of field cultivation, DefH9-iaaM grape plants were phenotypically homogeneous and did not show any morphological alterations in vegetative growth. The expression of DefH9-iaaM gene was detected in transgenic flower buds of both cultivars. CONCLUSIONS: The phenotypic homogeneity of the regenerated plants highlights the validity of this method for both propagation and genetic transformation of table grape cultivars. Expression of the DefH9-iaaM gene takes place in young flower buds of transgenic plants from both grape cultivars

Expression profile analysis of early fruit development in iaaM-parthenocarpic tomato plants

<p>Abstract</p> <p>Background</p> <p>Fruit normally develops from the ovary after pollination and fertilization. However, the ovary can also generate seedless fruit without fertilization by parthenocarpy. Parthenocarpic fruit development has been obtained in tomato (<it>Solanum lycopersicum</it>) by genetic modification using auxin-synthesising gene(s) (<it>DefH9-iaaM</it>; <it>DefH9-RI-iaaM</it>) expressed specifically in the placenta and ovules.</p> <p>Findings</p> <p>We have performed a cDNA Amplified Fragment Length Polymorphism (cDNA-AFLP) analysis on pre-anthesis tomato flower buds (0.5 cm long) collected from <it>DefH9-iaaM </it>and <it>DefH9-RI-iaaM </it>parthenocarpic and wild-type plants, with the aim to identify genes involved in very early phases of tomato fruit development. We detected 212 transcripts differentially expressed in auxin-ipersynthesising pre-anthesis flower buds, 65 of them (31%) have unknown function. Several differentially expressed genes show homology to genes involved in protein trafficking and protein degradation via proteasome. These processes are crucial for auxin cellular transport and signaling, respectively.</p> <p>Conclusion</p> <p>The data presented might contribute to elucidate the molecular basis of the fruiting process and to develop new methods to confer parthenocarpy to species of agronomic interest. In a recently published work, we have demonstrated that one of the genes identified in this screening, corresponding to #109 cDNA clone, regulates auxin-dependent fruit initiation and its suppression causes parthenocarpic fruit development in tomato.</p

Auxin and nitric oxide control indeterminate nodule formation

<p>Abstract</p> <p>Background</p> <p>Rhizobia symbionts elicit root nodule formation in leguminous plants. Nodule development requires local accumulation of auxin. Both plants and rhizobia synthesise auxin. We have addressed the effects of bacterial auxin (IAA) on nodulation by using <it>Sinorhizobium meliloti </it>and <it>Rhizobium leguminosarum </it>bacteria genetically engineered for increased auxin synthesis.</p> <p>Results</p> <p>IAA-overproducing <it>S. meliloti </it>increased nodulation in <it>Medicago </it>species, whilst the increased auxin synthesis of <it>R. leguminosarum </it>had no effect on nodulation in <it>Phaseolus vulgaris</it>, a legume bearing determinate nodules. Indeterminate legumes (<it>Medicago </it>species) bearing IAA-overproducing nodules showed an enhanced lateral root development, a process known to be regulated by both IAA and nitric oxide (NO). Higher NO levels were detected in indeterminate nodules of <it>Medicago </it>plants formed by the IAA-overproducing rhizobia. The specific NO scavenger cPTIO markedly reduced nodulation induced by wild type and IAA-overproducing strains.</p> <p>Conclusion</p> <p>The data hereby presented demonstrate that auxin synthesised by rhizobia and nitric oxide positively affect indeterminate nodule formation and, together with the observation of increased expression of an auxin efflux carrier in roots bearing nodules with higher IAA and NO content, support a model of nodule formation that involves auxin transport regulation and NO synthesis.</p

Expression of self-complementary hairpin RNA under the control of the rolC promoter confers systemic disease resistance to plum pox virus without preventing local infection

BACKGROUND: Homology-dependent selective degradation of RNA, or post-transcriptional gene silencing (PTGS), is involved in several biological phenomena, including adaptative defense mechanisms against plant viruses. Small interfering RNAs mediate the selective degradation of target RNA by guiding a multicomponent RNAse. Expression of self-complementary hairpin RNAs within two complementary regions separated by an intron elicits PTGS with high efficiency. Plum pox virus (PPV) is the etiological agent of sharka disease in Drupaceae, although it can also be transmitted to herbaceous species (e.g. Nicotiana benthamiana). Once inside the plant, PPV is transmitted via plasmodesmata from cell to cell, and at longer distances, via phloem. The rolC promoter drives expression in phloem cells. RolC expression is absent in both epidermal and mesophyll cells. The aim of the present study was to confer systemic disease resistance without preventing local viral infection. RESULTS: In the ihprolC-PP197 gene (intron hair pin rolC PPV 197), a 197 bp sequence homologous to the PPV RNA genome (from base 134 to 330) was placed as two inverted repeats separated by the DNA sequence of the rolA intron. This hairpin construct is under the control of the rolC promoter.N. benthamiana plants transgenic for the ihprolC-PP197 gene contain siRNAs homologous to the 197 bp sequence. The transgenic progeny of ihprolC-PP197 plants are resistant to PPV systemic infection. Local infection is unaffected. Most (80%) transgenic plants are virus free and symptomless. Some plants (20%) contain virus in uninoculated apical leaves; however they show only mild symptoms of leaf mottling. PPV systemic resistance cosegregates with the ihprolC-PP197 transgene and was observed in progeny plants of all independent transgenic lines analyzed. SiRNAs of 23–25 nt homologous to the PPV sequence used in the ihprolC-PP197 construct were detected in transgenic plants before and after inoculation. Transitivity of siRNAs was observed in transgenic plants 6 weeks after viral inoculation. CONCLUSIONS: The ihprolC-PP197 transgene confers systemic resistance to PPV disease in N. benthamiana. Local infection is unaffected. This transgene and/or similar constructs could be used to confer PPV resistance to fruit trees where systemic disease causes economic damage