142 research outputs found

    Chromatin Evolution-Key Innovations Underpinning Morphological Complexity

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    The history of life consists of a series of major evolutionary transitions, including emergence and radiation of complex multicellular eukaryotes from unicellular ancestors. The cells of multicellular organisms, with few exceptions, contain the same genome, however, their organs are composed of a variety of cell types that differ in both structure and function. This variation is largely due to the transcriptional activity of different sets of genes in different cell types. This indicates that complex transcriptional regulation played a key role in the evolution of complexity in eukaryotes. In this review, we summarize how gene duplication and subsequent evolutionary innovations, including the structural evolution of nucleosomes and chromatin-related factors, contributed to the complexity of the transcriptional system and provided a basis for morphological diversity

    Chromatin Evolution-Key Innovations Underpinning Morphological Complexity

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    The history of life consists of a series of major evolutionary transitions, including emergence and radiation of complex multicellular eukaryotes from unicellular ancestors. The cells of multicellular organisms, with few exceptions, contain the same genome, however, their organs are composed of a variety of cell types that differ in both structure and function. This variation is largely due to the transcriptional activity of different sets of genes in different cell types. This indicates that complex transcriptional regulation played a key role in the evolution of complexity in eukaryotes. In this review, we summarize how gene duplication and subsequent evolutionary innovations, including the structural evolution of nucleosomes and chromatin-related factors, contributed to the complexity of the transcriptional system and provided a basis for morphological diversity

    Adaptation of maize source leaf metabolism to stress related disturbances in carbon, nitrogen and phosphorus balance

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    Schlueter U, Colmsee C, Scholz U, et al. Adaptation of maize source leaf metabolism to stress related disturbances in carbon, nitrogen and phosphorus balance. BMC Genomics. 2013;14(1): 442.Background: Abiotic stress causes disturbances in the cellular homeostasis. Re-adjustment of balance in carbon, nitrogen and phosphorus metabolism therefore plays a central role in stress adaptation. However, it is currently unknown which parts of the primary cell metabolism follow common patterns under different stress conditions and which represent specific responses. Results: To address these questions, changes in transcriptome, metabolome and ionome were analyzed in maize source leaves from plants suffering low temperature, low nitrogen (N) and low phosphorus (P) stress. The selection of maize as study object provided data directly from an important crop species and the so far underexplored C-4 metabolism. Growth retardation was comparable under all tested stress conditions. The only primary metabolic pathway responding similar to all stresses was nitrate assimilation, which was down-regulated. The largest group of commonly regulated transcripts followed the expression pattern: down under low temperature and low N, but up under low P. Several members of this transcript cluster could be connected to P metabolism and correlated negatively to different phosphate concentration in the leaf tissue. Accumulation of starch under low temperature and low N stress, but decrease in starch levels under low P conditions indicated that only low P treated leaves suffered carbon starvation. Conclusions: Maize employs very different strategies to manage N and P metabolism under stress. While nitrate assimilation was regulated depending on demand by growth processes, phosphate concentrations changed depending on availability, thus building up reserves under excess conditions. Carbon and energy metabolism of the C-4 maize leaves were particularly sensitive to P starvation

    Developing and testing a Corona VaccinE tRiAL pLatform (COVERALL) to study Covid-19 vaccine response in immunocompromised patients

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    BACKGROUND The rapid course of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic calls for fast implementation of clinical trials to assess the effects of new treatment and prophylactic interventions. Building trial platforms embedded in existing data infrastructures is an ideal way to address such questions within well-defined subpopulations. METHODS We developed a trial platform building on the infrastructure of two established national cohort studies: the Swiss human immunodeficiency virus (HIV) Cohort Study (SHCS) and Swiss Transplant Cohort Study (STCS). In a pilot trial, termed Corona VaccinE tRiAL pLatform (COVERALL), we assessed the vaccine efficacy of the first two licensed SARS-CoV-2 vaccines in Switzerland and the functionality of the trial platform. RESULTS Using Research Electronic Data Capture (REDCap), we developed a trial platform integrating the infrastructure of the SHCS and STCS. An algorithm identifying eligible patients, as well as baseline data transfer ensured a fast inclusion procedure for eligible patients. We implemented convenient re-directions between the different data entry systems to ensure intuitive data entry for the participating study personnel. The trial platform, including a randomization algorithm ensuring balance among different subgroups, was continuously adapted to changing guidelines concerning vaccination policies. We were able to randomize and vaccinate the first trial participant the same day we received ethics approval. Time to enroll and randomize our target sample size of 380 patients was 22 days. CONCLUSION Taking the best of each system, we were able to flag eligible patients, transfer patient information automatically, randomize and enroll the patients in an easy workflow, decreasing the administrative burden usually associated with a trial of this size

    The cis-acting CTTC-P1BS module is indicative for gene function of LjVTI12, a Qb-SNARE protein gene that is required for arbuscule formation in Lotus japonicus

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    Lota F, Wegmueller S, Buer B, et al. The cis-acting CTTC-P1BS module is indicative for gene function of LjVTI12, a Qb-SNARE protein gene that is required for arbuscule formation in Lotus japonicus. The Plant Journal. 2013;74(2):280-293.The majority of land plants live in symbiosis with arbuscular mycorrhizal fungi from the phylum Glomeromycota. This symbiosis improves acquisition of phosphorus (P) by the host plant in exchange for carbohydrates, especially under low-P availability. The symbiosome, constituted by root cortex cells accommodating arbuscular mycorrhizal fungal hyphae, is the site at which bi-directional exchange of nutrients and metabolites takes place. Uptake of orthophosphate (Pi) in the symbiosome is facilitated by mycorrhiza-specific plant Pi transporters. Modifications of the potato Pi transporter 3 (StPT3) promoter were analysed in transgenic mycorrhizal roots, and it was found that the CTTC cis-regulatory element is necessary and sufficient for a transcriptional response to fungal colonization under low-Pi conditions. Phylogenetic foot-printing also revealed binary combination of the CTTC element with the Pi starvation response-associated PHR1-binding site (P1BS) in the promoters of several mycorrhiza-specific Pi transporter genes. Scanning of the Lotus japonicus genome for gene promoters containing both cis-regulatory elements revealed a strong over-representation of genes involved in transport processes. One of these, LjVTI12, encoding a member of the SNARE family of proteins involved in membrane transport, exhibited enhanced transcript levels in Lotus roots colonized with the arbuscular mycorrhizal fungus Glomus intraradices. Down-regulation of LjVTI12 by RNA interference resulted in a mycorrhiza-specific phenotype characterized by distorted arbuscule morphology. The results highlight cooperative cis-regulation which integrates mycorrhiza and Pi starvation signaling with vesicle trafficking in symbiosome development

    Antibody Response in Immunocompromised Patients After the Administration of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Vaccine BNT162b2 or mRNA-1273: A Randomized Controlled Trial

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    BACKGROUND BNT162b2 by Pfizer-BioNTech and mRNA-1273 by Moderna are the most commonly used vaccines to prevent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Head-to-head comparison of the efficacy of these vaccines in immunocompromised patients is lacking. METHODS Parallel, 2-arm (allocation 1:1), open-label, noninferiority randomized clinical trial nested into the Swiss HIV Cohort Study and the Swiss Transplant Cohort Study. People living with human immunodeficiency virus (PLWH) or solid organ transplant recipients (SOTR; ie, lung and kidney) from these cohorts were randomized to mRNA-1273 or BNT162b2. The primary endpoint was antibody response to SARS-CoV-2 spike (S1) protein receptor binding domain (Elecsys Anti-SARS-CoV-2 immunoassay, Roche; cutoff ≥0.8 units/mL) 12 weeks after first vaccination (ie, 8 weeks after second vaccination). In addition, antibody response was measured with the Antibody Coronavirus Assay 2 (ABCORA 2). RESULTS A total of 430 patients were randomized and 412 were included in the intention-to-treat analysis (341 PLWH and 71 SOTR). The percentage of patients showing an immune response was 92.1% (95% confidence interval [CI]: 88.4-95.8; 186/202) for mRNA-1273 and 94.3% (95% CI: 91.2-97.4; 198/210) for BNT162b2 (difference: -2.2%; 95% CI: -7.1 to 2.7), fulfilling noninferiority of mRNA-1273. With the ABCORA 2 test, 89.1% had an immune response to mRNA-1273 (95% CI: 84.8-93.4; 180/202) and 89.5% to BNT162b2 (95% CI: 85.4-93.7; 188/210). Based on the Elecsys test, all PLWH had an antibody response (100.0%; 341/341), whereas for SOTR, only 60.6% (95% CI: 49.2-71.9; 43/71) had titers above the cutoff level. CONCLUSIONS In immunocompromised patients, the antibody response of mRNA-1273 was noninferior to BNT162b2. PLWH had in general an antibody response, whereas a high proportion of SOTR had no antibody response

    Determinants of antibody response to severe acute respiratory syndrome coronavirus 2 mRNA vaccines in people with HIV.

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    We identified determinants of SARS-CoV-2 mRNA vaccine antibody response in people with HIV (PWH). Antibody response was higher among PWH less than 60 years, with CD4+ cell count superior to 350 cells/μl and vaccinated with mRNA-1273 by Moderna compared with BNT162b2 by Pfizer-BioNTech. Preinfection with SARS-CoV-2 boosted the antibody response and smokers had an overall lower antibody response. Elderly PWH and those with low CD4+ cell count should be prioritized for booster vaccinations

    Antibody response in immunocompromised patients after the administration of SARS-CoV-2 vaccine BNT162b2 or mRNA-1273: A randomised controlled trial.

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    BACKGROUND BNT162b2 by Pfizer-BioNTech and mRNA-1273 by Moderna are the most commonly used vaccines to prevent SARS-CoV-2 infections. Head-to-head comparison of the efficacy of these vaccines in immunocompromised patients is lacking. METHODS Parallel, two-arm (allocation 1:1), open-label, non-inferiority randomised clinical trial nested into the Swiss HIV Cohort Study and the Swiss Transplant Cohort Study. Patients living with HIV (PLWH) or solid organ transplant recipients (SOTR; i.e. lung and kidney) from these cohorts were randomised to mRNA-1273 or BNT162b2. The primary endpoint was antibody response to SARS-CoV-2 spike (S1) protein receptor binding domain (Elecsys Anti-SARS-CoV-2 immunoassay, Roche; cut-off ≥0.8 units/ml) 8 weeks after second vaccination. In addition, antibody response was measured with the Antibody CORonavirus Assay 2 (ABCORA 2). RESULTS 430 patients were randomised and 412 were included in the intention-to-treat analysis (341 PLWH and 71 SOTR). The percentage of patients showing an immune response was 92.1% (95% confidence interval [CI] 88.4-95.8%; 186/202) for mRNA-1273 and 94.3% (95% CI 91.2-97.4; 198/210) for BNT162b2 (difference: 2.2%; 95% CI -7.1 to 2.7), fulfilling non-inferiority of mRNA-1273. With the ABCORA 2 test 89.1% had an immune response to mRNA-1273 (95% CI 84.8-93.4%; 180/202) and 89.5% to BNT162b2 (95% CI 85.4-93.7%; 188/210). Based on the Elecsys test, all PLWH had an antibody response (100.0%; 341/341), while for SOTR only 60.6% (95% CI 49.2-71.9%; 43/71) had titres above the cut-off. CONCLUSIONS In immunocompromised patients the antibody response of mRNA-1273 was non-inferior to BNT162b2. PLWH had in general an antibody response, while a high proportion of SOTR had no antibody response

    Antibody Response After Third Vaccination With mRNA-1273 or BNT162b2: Extension of a Randomized Controlled SARS-CoV-2 Noninferiority Vaccine Trial in Patients With Different Levels of Immunosuppression (COVERALL-2).

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    Extension of the COVERALL (COrona VaccinE tRiAL pLatform) randomized trial showed noninferiority in antibody response of the third dose of Moderna mRNA-1273 vaccine (95.3% [95% confidence interval {CI}, 91.9%-98.7%]) compared to Pfizer-BioNTech BNT162b2 vaccine (98.1% [95% CI, 95.9%-100.0%]) in individuals with different levels of immunosuppression (difference, -2.8% [95% CI, -6.8% to 1.3%])
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