Reprogramming of rye rDNA in triticale during microsporogenesis

To test the hypothesis that interspecific genomic and chromosome interactions leading to nucleolar dominance could be reprogrammed in meiosis, we compared the expression of distinct nucleolar organizing region (NOR) loci in hexaploid triticale root tip meristematic cells, pollen mother cells and young pollen grains. Interphase and metaphase cells were silver stained to quantify nucleoli and active NOR loci respectively. A marked difference in the ribosomal RNA gene activity of each locus was observed when different types of cells were compared: in somatic and pollen mother cells, rRNA gene activity was mainly restricted to major wheat NORs (1B and 6B) with only a small contribution from rye NORs (1R). In contrast, in young pollen grains, all NORs present, including the 1R NORs, were consistently active. The expression of all NORs just after meiosis is considered to be a consequence of meiotic reprogramming of rye origin rDNA. Gene reprogramming mediated by the resetting of methylation patterns established early in embryogenesis is suggested to be responsible for the differential expression of the NORs of rye origin in distinct developmental stages of triticale

Genetic diversity of the grapevine (Vitis vinifera L.) cultivars most utilized for wine production in Portugal

Portugal is very rich in grapevine biodiversity but nowadays only a small number of cultivars (13 black and 3 white) with defined enological characteristics are being used. However, there are still 51 cultivars with significant expression in the country which have a great potential to be used in the establishment of new vineyards. Considering the importance of identifying and understanding the genetic relatedness of the main cultivars used for wine making in Portugal, those cultivars were genotyped with the 6 SSRs loci VVMD5, VVMD7, VVMD27, VrZag62, VrZag79 and VVS2 that are recommended by the Office de la Vigne et du Vin for the elaboration of the worldwide database containing the alleles of all the known grapevine cultivars. A total of 49 alleles were detected with an average allele number of 8.17 per locus. The SSR profile of the 51 cultivars, at the 6 evaluated loci, indicates that all can be distinguished from each other. In addition, this study produces information on the relationship of these 51 grapevine cultivars with cultivars of other important Mediterranean wine producing regions

Interplay of ribosomal DNA Loci in nucleolar dominance: dominant NORs are up-regulated by chromatin dynamics in the wheat-rye system

Background: Chromatin organizational and topological plasticity, and its functions in gene expression regulation, have been strongly revealed by the analysis of nucleolar dominance in hybrids and polyploids where one parental set of ribosomal RNA (rDNA) genes that are clustered in nucleolar organizing regions (NORs), is rendered silent by epigenetic pathways and heterochromatization. However, information on the behaviour of dominant NORs is very sparse and needed for an integrative knowledge of differential gene transcription levels and chromatin specific domain interactions. Methodology/Principal Findings: Using molecular and cytological approaches in a wheat-rye addition line (wheat genome plus the rye nucleolar chromosome pair 1R), we investigated transcriptional activity and chromatin topology of the wheat dominant NORs in a nucleolar dominance situation. Herein we report dominant NORs up-regulation in the addition line through quantitative real-time PCR and silver-staining technique. Accompanying this modification in wheat rDNA trascription level, we also disclose that perinucleolar knobs of ribosomal chromatin are almost transcriptionally silent due to the residual detection of BrUTP incorporation in these domains, contrary to the marked labelling of intranucleolar condensed rDNA. Further, by comparative confocal analysis of nuclei probed to wheat and rye NORs, we found that in the wheat-rye addition line there is a significant decrease in the number of wheat-origin perinucleolar rDNA knobs, corresponding to a diminution of the rDNA heterochromatic fraction of the dominant (wheat) NORs. Conclusions/Significance: We demonstrate that inter-specific interactions leading to wheat-origin NOR dominance results not only on the silencing of rye origin NOR loci, but dominant NORs are alsomodified in their transcriptional activity and interphase organization. The results show a cross-talk between wheat and rye NORs, mediated by ribosomal chromatin dynamics, revealing a conceptual shift from differential amphiplasty to ‘mutual amphiplasty’ in the nucleolar dominance process.This work was supported by the Fundação para a Ciência e Tecnologia (projects POCI/BIA-BDE/57575/2004 to M.S. and POCI/BIA-BCM/59389/2004 to N.N.

Different numbers of rye B chromosomes induce identical compaction changes in distinct A chromosome domains

In rye each B chromosome (B) represents 5.5% of the diploid A genome. Rye Bs have several nuclear to whole plant effects although they seem to bear no genes except for the ones that lead to their maintenance within a population. In this context, and considering that rye Bs are enriched in repetitive non-coding regions that build up heterochromatin (het), we investigated the influence of Bs on the organization of two chromatin fractions, namely the ribosomal DNA (facultative het) and satellite (non-het) domain of rye chromosome 1 by silver staining on root tip metaphase cells. The results show that rye Bs cause condensation both in the NOR and in the chromosome 1 satellite domain. Since the silver staining technique used is indicative of the transcriptional activity of the NORs, the condensation observed at those loci demonstrates that the rRNA gene arrays are down-regulated in the presence of Bs, regardless of their number per individual. Furthermore, the organizational changes of metaphase NORs find parallel with the interphase organization of ribosomal chromatin, since the frequency of cells with intranucleolar condensed rDNA regions increases drastically and nuclear matrix attachment pattern is altered in the presence of the Bs. Our results show an identical effect of the Bs on the organization of two distinct chromosome domains displaying a presence/absence dichotomyFCT - Fundação para a Ciência e Tecnologi

Risk management in providing specialized care for people living with AIDS

OBJETIVO Analisar a oferta de ações relacionadas ao manejo de risco clínico na gestão do cuidado especializado a pessoas vivendo com aids. MÉTODO Estudo transversal realizado em ambulatório de referência na Paraíba, com amostra de 150 adultos com aids. Os dados foram coletados por meio de fontes primárias e secundárias utilizando-se de formulário estruturado, e analisados através de estatística descritiva, análise de correspondência múltipla e modelo de regressão logística para averiguar a associação entre "oferta" e "risco clínico". RESULTADOS As ações de oferta satisfatória expressam foco biologicista do cuidado; as dimensões que mais contribuíram para o julgamento satisfatório da oferta foram "avaliação clínica e laboratorial" e "prevenção e estímulo ao autocuidado"; 45,3% dos participantes foram categorizados em risco clínico alto, 34% em risco clínico médio, e 20,7% em risco clínico baixo; e verificou-se associação positiva entre oferta e risco clínico. CONCLUSÃO Ficou evidente a necessidade da utilização de tecnologias de classificação de risco para direcionar o planejamento da oferta local, considerando-se as necessidades, e assim qualificar o cuidado produzido nestes espaços.OBJETIVO Analizar la oferta de acciones relacionadas con el manejo de riesgo clínico en la gestión del cuidado especializado a personas viviendo con SIDA. MÉTODO Estudio transversal realizado en ambulatorio de referencia en el Estado de Paraíba, con muestra de 150 adultos con SIDA. Los datos fueron recolectados por medio de fuentes primarias y secundarias utilizándose formulario estructurado y analizados mediante estadística descriptiva, análisis de correspondencia múltiple y modelo de regresión logística para averiguar la asociación entre "oferta" y "riesgo clínico". RESULTADOS Las acciones de oferta satisfactoria expresan enfoque biologicista del cuidado; las dimensiones que más contribuyeron al juicio satisfactorio de la oferta fueron "evaluación clínica y de laboratorio" y "prevención y estímulo al autocuidado"; el 45,3% de los participantes fueron categorizados en riesgo clínico alto, el 34% en riesgo clínico medio y el 20,7% en riesgo clínico bajo; y se verificó asociación positiva entre oferta y riesgo clínico. CONCLUSIÓN Resultó evidente la necesidad de la utilización de tecnologías de clasificación de riesgo para dirigir la planificación de la oferta local, considerándose las necesidades, y así calificar el cuidado producido en esos espacios.OBJECTIVE Analyzing the provision of actions related to managing clinical risk in managing specialized care for people living with AIDS. METHOD A cross-sectional study carried out in a reference outpatient clinic in Paraíba, with a sample of 150 adults with AIDS. Data were collected through primary and secondary sources using a structured questionnaire, analyzed using descriptive statistics, multiple correspondence analysis and logistic regression model to determine the association between "providing care" and "clinical risk." RESULTS Actions with satisfactory provision express a biological care focus; the dimensions that most contributed to a satisfactory assessment of care provision were "clinical and laboratory evaluations" and "prevention and self-care incentivization"; 45.3% of participants were categorized into high clinical risk, 34% into average clinical risk, and 20.7% into low clinical risk; a positive association between providing care and clinical risk was found. CONCLUSION The need to use risk classification technologies to direct the planning of local care provision became evident considering its requirements, and thus qualifying the care provided in these areas