Huntington's disease (HD) is a fatal neurodegenerative disease caused by expansion of CAG repeats in the Huntingtin gene (). Neither its pathogenic mechanisms nor the normal functions of HTT are well understood. To model HD in humans, we engineered a genetic allelic series of isogenic human embryonic stem cell (hESC) lines with graded increases in CAG repeat length. Neural differentiation of these lines unveiled a novel developmental HD phenotype: the appearance of giant multinucleated telencephalic neurons at an abundance directly proportional to CAG repeat length, generated by a chromosomal instability and failed cytokinesis over multiple rounds of DNA replication. We conclude that disrupted neurogenesis during development is an important, unrecognized aspect of HD pathogenesis. To address the function of normal HTT protein we generated and lines. Surprisingly, the same phenotype emerged in but not lines. We conclude that HD is a developmental disorder characterized by chromosomal instability that impairs neurogenesis, and that HD represents a genetic dominant-negative loss of function, contrary to the prevalent gain-of-toxic-function hypothesis. The consequences of developmental alterations should be considered as a new target for HD therapies.

We intended to evaluate the effects of different explants and growth regulators on callus induction and plant regeneration in garlic (Allium sativum L.). Furthermore, we intended to differentiate among different morphological types of callus by light microscopy and to relate them with their abilities to regenerate plants in the redgarlic cultivar 069. A factorial design with BDS-basal Dunstan and Short (1977)-medium, as a control and supplemented with 0.042, 0.42 and 4.24 lM picloram or with 0.045, 0.45 and 4.5 lM 2,4-D, in both cases with and without 4.43 lM N 6 -benzylaminopurine (BAP), was used. The cultures were grown in darkness at 25 ± 2°C and they were subcultured over a 6-month period. Basal plates and meristems were highly responsive explants, while immature umbels and roottips were less responsive ones, as indicated by percentage of induced callus, growing callus and regenerating callus. The best response was 41% regenerating callus with 0.045 lM 2,4-D and BAP

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El propóleos constituye, gracias a sus propiedades antimicrobianas, una alternativa para el control de fitopatógenos. En este trabajo se realizó, mediante técnicas convencionales, la caracterización sensorial y físico-química de cuatro muestras de propóleos provenientes de diferentes regiones de Argentina y de sus respectivos extractos hidroalcohólicos. Asimismo, se evaluó in vitro la actividad antifúngica de los extractos sobre el hongo Penicillium sp. causante de la «mufa del ajo» (Allium sativum). Los propóleos en bruto presentaron aroma resinoso, coloración marrón con diferentes tintes y aspecto de trozos irregulares. El análisis de las muestras evidenció diferencias significativas en los parámetros ceras (9,43-31,16 %), pérdidas por calentamiento (1,04-1,46 %), cenizas (0,98-7,18 %) y temperatura media de fusión (63,16-67,5 °C). En los extractos hidroalcohólicos de propóleos también se detectaron diferencias estadísticas en el extracto seco (5,50-9,30 %), contenido de fenoles (23,44-53,91 mg eq gálico/g propóleos), flavonoides totales (11,23-15,88 mg eq quercetina/g propóleos) e índice de oxidación (2,25-4,33 segundos). Todos los tratamientos a base de extractos de propóleos tuvieron un efecto inhibidor superior al 99 % sobre el desarrollo de unidades formadoras de colonias fúngicas. Los resultados permiten concluir que, si bien los propóleos y extractos analizados en este trabajo presentaron diferentes características, coincidieron en la excelente actividad antifúngica sobre Penicillium sp. Esto demuestra la potencialidad de los propóleos para el desarrollo de un biofungicida de uso agrícola.

Aims This study aimed to evaluate in vitro individual and combined antifungal activity of propolis extract (PE) and oregano essential oil (OEO) against Penicillium allii, causal agent of blue mould disease. The chemical characterization of both products was also included. Methods and Results Chromatographic analysis of PE and OEO confirmed the presence of bioactive compounds. The antifungal susceptibility assays showed that PE and OEO were highly active against the mycelial growth and conidial germination of P. allii. PE and OEO MICs were 12·5 and 1·5 μl ml−1, respectively. The MFCs of these products were 50 and 3·1 μl ml−1, respectively. PE acted mainly through diffusion, while OEO acted by a mixed contribution of vapour and diffusion. Synergism and additive effect between both products were found in some combination ratios. Conclusion PE and OEO, both natural products with different chemical composition, have a strong antifungal activity against P. allii and show a favourable interaction causing synergism. Significance and Impact of the Study The results of this study indicated the potential use of PE combined with OEO as a non‐conventional strategy towards the formulation of a biofungicide to control blue mould disease in garlic seed‐cloves.

Temperate deciduous fruit trees survive winter temperatures by entering a dormant phase in their aerial meristematic organs. Release from bud dormancy occurs after chill requirements (CR) have been satisfied, whereas bud burst/flowering follows heat requirement (HR) fulfillment. The physiological basis behind these metrics remains elusive. In this study, we are presenting the first multidisciplinary dormancy progression analysis in northern Patagonia, linking (1) forcing/field phenology, (2) bud anatomical development, and (3) soluble sugar (sucrose, glucose, and fructose) dynamics in Juglans regia L. CR and HR were determined for ‘Chandler’ and ‘Franquette,’ two walnut cultivars with markedly different CR, in artificial chill/forced heat trials (three seasons) and in-field chill/forced heat tests (five seasons) using excised twigs either with or without apical buds (non-decapitated and decapitated). The soluble sugar dynamics of ‘Chandler’ (high-performance liquid chromatography) and the anatomical changes of the buds (light microscopy) of the two cultivars were analyzed during endo-ecodormancy progression in one and two seasons, respectively. The CR defined by artificial chill tests proved to be an overestimation compared to the field determinations. Moreover, HR was the main driver in the phenology dynamics, as expected for a high-chill region. ‘Chandler’ showed an average of 10.3 field chill portions (CP) and 2,163 Growing Degree Hours (GDH°C) less than ‘Franquette’ for dormancy release and bud burst, respectively. These results were consistent with the transition of the shoot apex from the vegetative to the reproductive phase and the soluble sugar profile. The decrease in sucrose between 15 and 30 days after CR fulfillment could be a reliable biological marker for endodormancy release in walnut, while the increase in fructose and glucose is likely an osmolyte and cellulosic carbon source in pre-sprouting. In addition, we discuss the effect of paradormancy thanks to our apical bud experiment (with or without). Our results improve the current understanding of endo-ecodormancy progression in walnut and provide insightful results for walnut production (i.e., cultivation practices such as pruning) as well as for further application in dormancy modeling, to infer the ideotypes that should be bred for future climate conditions.