Role of the endocytic recycling pathway in lysosome exocytosis

Until recently, lysosomes were considered as the end-point of the endocytic pathway, to where cargo is delivered to be degraded. However, several studies showed that conventional lysosomes can undergo regulated exocytosis in response to an increase in intracellular calcium concentration, an important process for plasma membrane repair and secretion of lysosomal contents. Nevertheless, the molecular machinery involved in lysosome transport and fusion with the plasma membrane is not fully understood. Our group found recently that the small GTPases Rab11a and Rab11b are essential for calcium-triggered lysosome exocytosis in HeLa cells. Therefore, we aim to find the Rab11a/b effectors that mediate lysosome exocytosis process. To this end, we silenced several known effectors such as Rab11 family of interacting proteins (FIPs), Myosin Va/b or subunits of the exocyst tethering complex (Sec8, Sec15 and Exo70). After stimulation with the calcium ionophore ionomycin, we investigated the cell surface expression levels of the late endosome/lysosome marker LAMP1, as well as the release of the lysosomal enzyme β-hexosaminidase. We found that the silencing of Sec15 impairs lysosome exocytosis, while in the absence of FIP1-C or FIP2 there is an increase in LAMP1 cell surface levels and β-hexosaminidase release. Moreover, we confirmed the interaction and co-localization of Rab11a/b with the effector proteins studied using co-immunoprecipitation assays and confocal immunofluorescence microscopy, respectively. Finally, using live cell imaging, we found that Rab11-positive vesicles interact transiently with late endosomes/lysosomes near the plasma membrane, upon ionomycin stimulation. Thus, our results provide new insights into the role of Rab11 and its effectors in the regulation of conventional lysosome exocytosis

Size matters in Triticeae polyploids: larger genomes have higher remodeling

ReviewPolyploidization is one of the major driving forces in plant evolution and is extremely relevant to speciation and diversity creation. Polyploidization leads to a myriad of genetic and epigenetic alterations that ultimately generate plants and species with increased genome plasticity. Polyploids are the result of the fusion of two or more genomes into the same nucleus and can be classified as allopolyploids (different genomes) or autopolyploids (same genome). Triticeae synthetic allopolyploid species are excellent models to study polyploids evolution, particularly the wheat–rye hybrid triticale, which includes various ploidy levels and genome combinations. In this review, we reanalyze data concerning genomic analysis of octoploid and hexaploid triticale and different synthetic wheat hybrids, in comparison with other polyploid species. This analysis reveals high levels of genomic restructuring events in triticale and wheat hybrids, namely major parental band disappearance and the appearance of novel bands. Furthermore, the data shows that restructuring depends on parental genomes, ploidy level, and sequence type (repetitive, low copy, and (or) coding); is markedly different after wide hybridization or genome doubling; and affects preferentially the larger parental genome. The shared role of genetic and epigenetic modifications in parental genome size homogenization, diploidization establishment, and stabilization of polyploid species is discussed

Involvement of disperse repetitive sequences in wheat/rye genome adjustment

The union of different genomes in the same nucleus frequently results in hybrid genotypes with improved genome plasticity related to both genome remodeling events and changes in gene expression. Most modern cereal crops are polyploid species. Triticale, synthesized by the cross between wheat and rye, constitutes an excellent model to study polyploidization functional implications. We intend to attain a deeper knowledge of dispersed repetitive sequence involvement in parental genome reshuffle in triticale and in wheat-rye addition lines that have the entire wheat genome plus each rye chromosome pair. Through Random Amplified Polymorphic DNA (RAPD) analysis with OPH20 10-mer primer we unraveled clear alterations corresponding to the loss of specific bands from both parental genomes. Moreover, the sequential nature of those events was revealed by the increased absence of rye-origin bands in wheat-rye addition lines in comparison with triticale. Remodeled band sequencing revealed that both repetitive and coding genome domains are affected in wheat-rye hybrid genotypes. Additionally, the amplification and sequencing of pSc20H internal segments showed that the disappearance of parental bands may result from restricted sequence alterations and unraveled the involvement of wheat/rye related repetitive sequences in genome adjustment needed for hybrid plant stabilizatio

Enterprise resource planning adoption and satisfaction determinants

Enterprise Resource Planning (ERP) systems are at the core of every firm. Making people use this costly and time-consuming investment is one of the most important issues to deal with. The main objective of the present study is to find the key determinants that open the door to user satisfaction and adoption. A theoretical model was set and an online survey was conducted to understand ERP users' perspective on such matters.The outcome was the model validation an dthe understanding that top management support, training, and the system quality are important constructs to assess adoption user satisfaction. Infact,thelatter (systemquality) has a significant influence on the behaviour a lintention to use and also in the overall user satisfaction. As management support is a very relevant determinant to ERP usage. Accordingly, this study enlightens theory, by contributing to a new model of ERP adoption and satisfaction. It also provides relevant evidence to companies involved in the ERP implementation process.info:eu-repo/semantics/publishedVersio

Genome merger: from sequence rearrangements in triticale to their elimination in wheat-rye addition lines

Abstract Genetic and epigenetic modifications resulting from different genomes adjusting to a common nuclear environment have been observed in polyploids. Sequence restructuring within genomes involving retrotransposon/ microsatellite-rich regions has been reported in triticale. The present study uses inter-retrotransposon amplified polymorphisms (IRAP) and retrotransposon microsatellite amplified polymorphisms (REMAP) to assess genome rearrangements in wheat–rye addition lines obtained by the controlled backcrossing of octoploid triticale to hexaploid wheat followed by self-fertilization. The comparative analysis of IRAP and REMAP banding profiles, involving a complete set of wheat–rye addition lines, and their parental species revealed in those lines the presence of wheat-origin bands absent in triticale, and the absence of rye-origin and triticale-specific bands. The presence in triticale x wheat backcrosses (BC) of rye-origin bands that were absent in the addition lines demonstrated that genomic rearrangement events were not a direct consequence of backcrossing, but resulted from further genome structural rearrangements in the BC plant progeny. PCR experiments using primers designed from different rye-origin sequences showed that the absence of a rye-origin band in wheat–rye addition lines results from sequence elimination rather than restrict changes on primer annealing sites, as noted in triticale. The level of genome restructuring events evaluated in all seven wheat–rye addition lines, compared to triticale, indicated that the unbalanced genome merger situation observed in the addition lines induced a new round of genome rearrangement, suggesting that the lesser the amount of rye chromatin introgressed into wheat the larger the outcome of genome reshuffling

Durum wheat diversity for heat stress tolerance during inflorescence emergence is correlated to TdHSP101C expression in early developmental stages

Research articleThe predicted world population increase along with climate changes threatens sustainable agricultural supply in the coming decades. It is therefore vital to understand crops diversity associated to abiotic stress response. Heat stress is considered one of the major constrains on crops productivity thus it is essential to develop new approaches for a precocious and rigorous evaluation of varietal diversity regarding heat tolerance. Plant cell membrane thermostability (CMS) is a widely used method for wheat thermotolerance assessment although its limitations require complementary solutions. In this work we used CMS assay and explored TdHSP101C genes as an additional tool for durum wheat screening. Genomic and transcriptomic analyses of TdHSP101C genes were performed in varieties with contrasting CMS results and further correlated with heat stress tolerance during fertilization and seed development. Although the durum wheat varieties studied presented a very high homology on TdHSP101C genes (>99%) the transcriptomic assessment allowed the discrimination between varieties with good CMS results and its correlation with differential impacts of heat treatment during inflorescence emergence and seed development on grain yield. The evidences here reported indicate that TdHSP101C transcription levels induced by heat stress in fully expanded leaves may be a promising complementary screening tool to discriminate between durum wheat varieties identified as thermotolerant through CMSinfo:eu-repo/semantics/publishedVersio

Motivação de atletas federados para a prática de atletismo

Foi estudado o que motiva atletas federados para a prática de atletismo, de forma a compreender se os atletas procuram a conquista de estatuto ou o simples prazer de estar na companhia de quem mais gostam. Para isso foi usado o QmAD (Questionário de Motivação para as Actividades Desportivas), aplicado a uma amostra de 50 atletas de vários clubes da região norte: 40 atletas do género masculino e 10 atletas do género feminino, com idades compreendidas entre os 18 e 45 anos. tratou-se de uma amostra acidental não probabilística. o método utilizado foi a abordagem quantitativa, configurando-se com um estudo observacional descritivo. os 3 principais motivos para a prática federada de atletismo foram: Afiliação geral, competência técnica e Forma Física. The main purpose of this study was to identify what motivates federated athletes for the practice of athletics, to understand if the athletes search the conquer of status or the simple pleasure of being in the company of those they like the best. it was used the pmQ (Participation Motivation Questionnaire), applied to a sample of 50 athletes from various clubs from the north region: 40 male athletes and 10 female athletes, with ages between 18 and 45 years old. This sample was accidental and not probabilistic. the method used for the development of the empirical phase was the quantitative approach, configuring with an observational descriptive study. The 3 principle motives for the practice of athletics were: Affiliation, skills and Fitness

Educação, trabalho e família : trajectórias de diplomados universitários

O trabalho que agora se apresenta constituiu uma análise articulada das relações entre a universidade, o trabalho e a família, com incidência nos processos que determinam e permitem compreender a inserção social dos diplomados universitários. Assim definida, esta problemática foi estruturada em dois eixos principais, correspondentes às vias de organização da vida dos indivíduos na sua passagem para a condição adulta. O primeiro eixo, relativo à transição da escola para o trabalho, diz respeito aos processos de inserção profissional vividos pelos diplomados; o segundo eixo, referente à passagem da família de orientação para a família de procriação, remete para os processos de inserção familiar experimentados pelos indivíduos. De forma específica, foi nosso objectivo conhecer, descrever e compreender as configurações da inserção social dos diplomados universitários, equacionando os factores sociais, económicos e culturais que a moldam e, igualmente, a importância, o papel e o lugar nela desempenhado pela educação universitária. Com a finalidade de tornar mais clara a multidimensionalidade subjacente aos processos de inserção social, construímos as trajectórias sócio-profissionais dos diplomados, que permitiram objectivar as formas individuais e colectivas que eles assumem, dado consistirem na descrição e análise dos tempos e das formas dos diferentes acontecimentos, da interacção entre os diversos papéis sociais assumidos e do impacto que de cada etapa sobre as seguintes. A pesquisa realizada com base neste objecto de estudo foi conduzida através de uma perspectiva sociológica, com o contributo de outras áreas do saber com relevância para o aprofundamento das diversas temáticas que dele se desprendem, e com base no método hipotético-dedutivo.The following work has been an articulate analysis of the relations between university, work and family, focussing on the processes that determine and help to understand the social insertion of the graduated students. The problematic issue is structured in two main axes, corresponding to the ways the individuals’ life were organized on their transition to adulthood. The first axis, relating to the passage from school to work, is about the professional insertion experienced by the graduates; the second axis, referring to the passage from guiding family to the breeding family, is about family insertion processes experienced by individuals. In a specific way, it has been our purpose to know, describe and understand the features of the social insertion of the graduates, taking into account the social, economical and cultural factors that shape it and also the the importance, role and place of university education. Aiming at clarify the underlying multi-dimensionality to the processes of the social insertion, we have put up the socio-professional trajectory of the graduates. This has made it possible to objectify the individual and collective shapes that have been assumed, consisting in the description and analysis of the times and forms of the different events, of the interaction between the different social roles assumed and the impact that each stage has had on the following one. The research done on this study object basis has been led in a sociological perspective, with the contribution of other knowledge areas relevant to the deepening of the diverse themes that can derive from it, and based on the hypothetic-deductive method

Unravelling the hidden inter and intra-varietal diversity of durum wheat commercial varieties used in Portugal

Short CommunicationAssessing durum wheat genomic diversity is crucial in a changing environmental particularly in the Mediterranean region where it is largely used to produce pasta. Durum wheat varieties cultivated in Portugal and previously assessed regarding thermotolerance ability were screened for the variability of coding sequences associated with technological traits and repetitive sequences. As expected, reduced variability was observed regarding low molecular weight glutenin subunits (LMW-GS) but a specific LMW-GS allelic form associated with improved pasta-making characteristics was absent in one variety. Contrastingly, molecular markers targeting repetitive elements like microsatellites and retrotransposons – Inter Simple Sequence Repeat (ISSR) and Inter Retrotransposons Amplified Polymorphism (IRAP) – disclosed significant inter and intra-varietal diversity. This high level of polymorphism was revealed by the 20 distinct ISSR/IRAP concatenated profiles observed among the 23 individuals analysed. Interestingly, median joining networks and PCoA analysis grouped individuals of the same variety and clustered varieties accordingly with geographical origin. Globally, this work demonstrates that durum wheat breeding strategies induced selection pressure for some relevant coding sequences while maintaining high levels of genomic variability in non-coding regions enriched in repetitive sequencesinfo:eu-repo/semantics/publishedVersio