Caracterización molecular de algunas especies y variedades de ñame presentes en la costa atlántica colombiana

En Colombia el ñame (Dioscorea data y Dioscorea rotundata) es un cultivo de importancia para los pequeños productores de la Costa Atlántica. El Programa Colombiano de Biotecnología Agrícola (PBA) de Ñame tiene el objetivo de incrementar la sostenibilidad de grupos de campesinos de la región, adelantando investigaciones participativas en diferentes aspectos relacionados con el cultivo. En el presente trabajo, el objetivo principal fue caracterizar molecularmente las ocho variedades de ñame utilizadas en el PBA, a través de marcadores moleculares tipo AFLP para determinar si existe concordancia entre la taxonomía morfológica establecida para la clasificación de las especies y variedades con la discriminación y agrupación de los individuos por sus perfiles de bandas moleculares aportados por los AFLP Para la obtención de los patrones de AFLP se utilizaron los kits de Gibco-BRL, New York Analysis System I y Analysis System II, siguiendo los manuales de instrucción. Para el análisis estadístico se realizaron matrices de presencia ausencia, se determinaron las similitudes a partir del índice de similaridad de Dice con el paquete estadístico Gel Stats. Posteriormente, las matrices se transformaron en matrices de distancia, y a partir de éstas se construyeron los dendogramas utilizando como estrategia de agrupamientos UPGMA (Unweighted Pare Group Method Averange). Finalmente se realizó una comparación entre matrices utilizando el análisis de permutaciones de Mantel. Los resultados muestran que de las siete variedades de Dioscorea alata analizadas solamente tres de ellas presentan polimorfismos que permiten diferenciarlas. Las otras cuatro se agruparon como una sola variedad.Seven varieties of the Dioscorea alata specie (but only one variety of the Dioscorea rotundata specie) have been morphologically characterised in Colombia. These varieties have been used in the Colombian Yam Agricultural Biotechnology Programme (ABP) to increase the sustainability of groups of poor rural workers from the Colombian Atlantic Coast by providing them with plants having good organoleptic characteristics and increased tuber yield. This work's main objective was the molecular characterisation of those varieties of yam from the Colombian Atlantic Coast used in the ABP, through Amplified Fragment Length Polymorphism (AFLP) molecular markers. This aimed at determining if there is conformity between that morphological taxonomy established for the classification of ABP programme species and varieties with the discrimination and grouping of individuals by their molecular band profiles provided by AFLP Seven varieties of D. alata specie and the sole variety of the D. rotundata specie were characterised. Gibco-BRL, New York Analysis System I and Analysis System II kits were used to obtain AFLP patterns, following handbook instructions. Presence/absence matrices were constructed for the statistical analysis; similarity was determined from the Dice similarity index by using the Gel Stats statistical package. Later matrices became distance matrices and dendograms were constructed from these by using UPGMA (Unweighted Pair Group Method Average) for grouping strategy. Comparison was then made between matrices by using Mantel permutation analysis. The results show that only three of all the seven Dioscorea alata varieties analysed presented polymorphism allowing them to be differentiated. The other four varieties were grouped as a sole variety or belonged to a single variety. These results have great importance for widening information concerning yam in Colombia, particularly for the Colombian ABR since it makes it possible to reduce collection and maintenance costs, leading to information regarding each accession to Colombia's germplasm banks to be increased. This is the first molecular characterisation work carried out in Colombia on yam species (Dioscorea spp.)

Multi-ancestry GWAS reveals excitotoxicity associated with outcome after ischaemic stroke

During the first hours after stroke onset, neurological deficits can be highly unstable: some patients rapidly improve, while others deteriorate. This early neurological instability has a major impact on long-term outcome. Here, we aimed to determine the genetic architecture of early neurological instability measured by the difference between the National Institutes of Health Stroke Scale (NIHSS) within 6 h of stroke onset and NIHSS at 24 h. A total of 5876 individuals from seven countries (Spain, Finland, Poland, USA, Costa Rica, Mexico and Korea) were studied using a multi-ancestry meta-analyses. We found that 8.7% of NIHSS at 24 h of variance was explained by common genetic variations, and also that early neurological instability has a different genetic architecture from that of stroke risk. Eight loci (1p21.1, 1q42.2, 2p25.1, 2q31.2, 2q33.3, 5q33.2, 7p21.2 and 13q31.1) were genome-wide significant and explained 1.8% of the variability suggesting that additional variants influence early change in neurological deficits. We used functional genomics and bioinformatic annotation to identify the genes driving the association from each locus. Expression quantitative trait loci mapping and summary data-based Mendelian randomization indicate that ADAM23 (log Bayes factor = 5.41) was driving the association for 2q33.3. Gene-based analyses suggested that GRIA1 (log Bayes factor = 5.19), which is predominantly expressed in the brain, is the gene driving the association for the 5q33.2 locus. These analyses also nominated GNPAT (log Bayes factor = 7.64) ABCB5 (log Bayes factor = 5.97) for the 1p21.1 and 7p21.1 loci. Human brain single-nuclei RNA-sequencing indicates that the gene expression of ADAM23 and GRIA1 is enriched in neurons. ADAM23, a presynaptic protein and GRIA1, a protein subunit of the AMPA receptor, are part of a synaptic protein complex that modulates neuronal excitability. These data provide the first genetic evidence in humans that excitotoxicity may contribute to early neurological instability after acute ischaemic stroke. Ibanez et al. perform a multi-ancestry meta-analysis to investigate the genetic architecture of early stroke outcomes. Two of the eight genome-wide significant loci identified-ADAM23 and GRIA1-are involved in synaptic excitability, suggesting that excitotoxicity contributes to neurological instability after ischaemic stroke.Peer reviewe

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

Peer reviewe

Caracterización molecular de algunas especies y variedades de ñame presentes en la Costa Atlántica colombiana

En Colombia el ñame (Dioscorea data y Dioscorea rotundata) es un cultivo de importancia para los pequeños productores de la Costa Atlántica. El Programa Colombiano de Biotecnología Agrícola (PBA) de Ñame tiene el objetivo de incrementar la sostenibilidad de grupos de campesinos de la región, adelantando investigaciones participativas en diferentes aspectos relacionados con el cultivo. En el presente trabajo, el objetivo principal fue caracterizar molecularmente las ocho variedades de ñame utilizadas en el PBA, a través de marcadores moleculares tipo AFLP para determinar si existe concordancia entre la taxonomía morfológica establecida para la clasificación de las especies y variedades con la discriminación y agrupación de los individuos por sus perfiles de bandas moleculares aportados por los AFLP Para la obtención de los patrones de AFLP se utilizaron los kits de Gibco-BRL, New York Analysis System I y Analysis System II, siguiendo los manuales de instrucción. Para el análisis estadístico se realizaron matrices de presencia ausencia, se determinaron las similitudes a partir del índice de similaridad de Dice con el paquete estadístico Gel Stats. Posteriormente, las matrices se transformaron en matrices de distancia, y a partir de éstas se construyeron los dendogramas utilizando como estrategia de agrupamientos UPGMA (Unweighted Pare Group Method Averange). Finalmente se realizó una comparación entre matrices utilizando el análisis de permutaciones de Mantel. Los resultados muestran que de las siete variedades de Dioscorea alata analizadas solamente tres de ellas presentan polimorfismos que permiten diferenciarlas. Las otras cuatro se agruparon como una sola variedad.

Paternidade contemporânea: levantamento da produção acadêmica no período de 2000 a 2007

Este estudo teve como objetivo verificar a incidência de artigos internacionais e nacionais sobre o tema paternidade no período de 2000 a 2007 indexados nas bases de dados: LILACS, SciELO, Web of Science, MEDLINE, Redalyc. Um total de 2.205 trabalhos foi identificado, sendo analisados 353 artigos em relação ao ano de publicação, país, método e temática. Os resultados apontam para significativa produção internacional e nacional, destacando-se EUA, Inglaterra e Brasil. Verificou-se que o tema paternidade é foco importante para a compreensão das relações familiares, questão fundamental para a implantação de políticas públicas de apoio às famílias em diferentes contextos

Circulating miRNAs, isomiRs and small RNA clusters in human plasma and breast milk

Circulating small RNAs, including miRNAs but also isomiRs and other RNA species, have the potential to be used as non-invasive biomarkers for communicable and non-communicable diseases. This study aims to characterize and compare small RNA profiles in human biofluids. For this purpose, RNA was extracted from plasma and breast milk samples from 15 healthy postpartum mothers. Small RNA libraries were prepared with the NEBNext® small RNA library preparation kit and sequenced in an Illumina HiSeq2000 platform. miRNAs, isomiRs and clusters of small RNAs were annotated using seqBuster/seqCluster framework in 5 plasma and 10 milk samples that passed the initial quality control. The RNA yield was 81 ng/mL [standard deviation (SD): 41] and 3985 ng/mL (SD: 3767) for plasma and breast milk, respectively. Mean number of good quality reads was 4.04 million (M) (40.01% of the reads) in plasma and 12.5M (89.6%) in breast milk. One thousand one hundred eighty two miRNAs, 12,084 isomiRs and 1,053 small RNA clusters that included piwi-interfering RNAs (piRNAs), tRNAs, small nucleolar RNAs (snoRNA) and small nuclear RNAs (snRNAs) were detected. Samples grouped by biofluid, with 308 miRNAs, 1,790 isomiRs and 778 small RNA clusters differentially detected. In summary, plasma and milk showed a different small RNA profile. In both, miRNAs, piRNAs, tRNAs, snRNAs, and snoRNAs were identified, confirming the presence of non-miRNA species in plasma, and describing them for the first time in milk