119 research outputs found

    Identification of the master sex determining gene in Northern pike (Esox lucius) reveals restricted sex chromosome differentiation.

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    Teleost fishes, thanks to their rapid evolution of sex determination mechanisms, provide remarkable opportunities to study the formation of sex chromosomes and the mechanisms driving the birth of new master sex determining (MSD) genes. However, the evolutionary interplay between the sex chromosomes and the MSD genes they harbor is rather unexplored. We characterized a male-specific duplicate of the anti-MĂŒllerian hormone (amh) as the MSD gene in Northern Pike (Esox lucius), using genomic and expression evidence as well as by loss-of-function and gain-of-function experiments. Using RAD-Sequencing from a family panel, we identified Linkage Group (LG) 24 as the sex chromosome and positioned the sex locus in its sub-telomeric region. Furthermore, we demonstrated that this MSD originated from an ancient duplication of the autosomal amh gene, which was subsequently translocated to LG24. Using sex-specific pooled genome sequencing and a new male genome sequence assembled using Nanopore long reads, we also characterized the differentiation of the X and Y chromosomes, revealing a small male-specific insertion containing the MSD gene and a limited region with reduced recombination. Our study reveals an unexpectedly low level of differentiation between a pair of sex chromosomes harboring an old MSD gene in a wild teleost fish population, and highlights both the pivotal role of genes from the amh pathway in sex determination, as well as the importance of gene duplication as a mechanism driving the turnover of sex chromosomes in this clade

    A Trial of Early Antiretrovirals and Isoniazid Preventive Therapy in Africa

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    BACKGROUND: In sub-Saharan Africa, the burden of human immunodeficiency virus (HIV)-associated tuberculosis is high. We conducted a trial with a 2-by-2 factorial design to assess the benefits of early antiretroviral therapy (ART), 6-month isoniazid preventive therapy (IPT), or both among HIV-infected adults with high CD4+ cell counts in Ivory Coast. METHODS: We included participants who had HIV type 1 infection and a CD4+ count of less than 800 cells per cubic millimeter and who met no criteria for starting ART according to World Health Organization (WHO) guidelines. Participants were randomly assigned to one of four treatment groups: deferred ART (ART initiation according to WHO criteria), deferred ART plus IPT, early ART (immediate ART initiation), or early ART plus IPT. The primary end point was a composite of diseases included in the case definition of the acquired immunodeficiency syndrome (AIDS), non-AIDS-defining cancer, non-AIDS-defining invasive bacterial disease, or death from any cause at 30 months. We used Cox proportional models to compare outcomes between the deferred-ART and early-ART strategies and between the IPT and no-IPT strategies. RESULTS: A total of 2056 patients (41% with a baseline CD4+ count of ≄500 cells per cubic millimeter) were followed for 4757 patient-years. A total of 204 primary end-point events were observed (3.8 events per 100 person-years; 95% confidence interval [CI], 3.3 to 4.4), including 68 in patients with a baseline CD4+ count of at least 500 cells per cubic millimeter (3.2 events per 100 person-years; 95% CI, 2.4 to 4.0). Tuberculosis and invasive bacterial diseases accounted for 42% and 27% of primary end-point events, respectively. The risk of death or severe HIV-related illness was lower with early ART than with deferred ART (adjusted hazard ratio, 0.56; 95% CI, 0.41 to 0.76; adjusted hazard ratio among patients with a baseline CD4+ count of ≄500 cells per cubic millimeter, 0.56; 95% CI, 0.33 to 0.94) and lower with IPT than with no IPT (adjusted hazard ratio, 0.65; 95% CI, 0.48 to 0.88; adjusted hazard ratio among patients with a baseline CD4+ count of ≄500 cells per cubic millimeter, 0.61; 95% CI, 0.36 to 1.01). The 30-month probability of grade 3 or 4 adverse events did not differ significantly among the strategies. CONCLUSIONS: In this African country, immediate ART and 6 months of IPT independently led to lower rates of severe illness than did deferred ART and no IPT, both overall and among patients with CD4+ counts of at least 500 cells per cubic millimeter. (Funded by the French National Agency for Research on AIDS and Viral Hepatitis; TEMPRANO ANRS 12136 ClinicalTrials.gov number, NCT00495651.)

    The sterlet sturgeon genome sequence and the mechanisms of segmental rediploidization.

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    Sturgeons seem to be frozen in time. The archaic characteristics of this ancient fish lineage place it in a key phylogenetic position at the base of the ~30,000 modern teleost fish species. Moreover, sturgeons are notoriously polyploid, providing unique opportunities to investigate the evolution of polyploid genomes. We assembled a high-quality chromosome-level reference genome for the sterlet, Acipenser ruthenus. Our analysis revealed a very low protein evolution rate that is at least as slow as in other deep branches of the vertebrate tree, such as that of the coelacanth. We uncovered a whole-genome duplication that occurred in the Jurassic, early in the evolution of the entire sturgeon lineage. Following this polyploidization, the rediploidization of the genome included the loss of whole chromosomes in a segmental deduplication process. While known adaptive processes helped conserve a high degree of structural and functional tetraploidy over more than 180 million years, the reduction of redundancy of the polyploid genome seems to have been remarkably random

    OsWRKY IIa Transcription Factors Modulate Rice Innate Immunity

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    WRKY transcription factors regulate diverse plant processes including responses to biotic stresses. Our previous studies indicate that OsWRKY62, an OsWRKY IIa subfamily member, functions as a negative regulator of the rice defense against Xanthomonas oryzae pv. oryzae. Here, we report that a large inverted repeat construct designed to knock down the expression of the four OsWRKY IIa subfamily members (OsWRKY62, OsWRKY28, OsWRKY71, and OsWRKY76) leads to overexpression of all four genes and disease resistance in some transgenic plants. These phenotypes are stably inherited as reflected by progeny analysis. A pathogenesis-related gene, PR10, is up-regulated in plants overexpressing the OsWRKY IIa genes. These results suggest that OsWRKY IIa proteins interact functionally to modulate plant innate immunity

    Genome-wide profiling of G protein-coupled receptors in cerebellar granule neurons using high-throughput, real-time PCR

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    <p>Abstract</p> <p>Background</p> <p>G protein-coupled receptors (GPCRs) are major players in cell communication, regulate a whole range of physiological functions during development and throughout adult life, are affected in numerous pathological situations, and constitute so far the largest class of drugable targets for human diseases. The corresponding genes are usually expressed at low levels, making accurate, genome-wide quantification of their expression levels a challenging task using microarrays.</p> <p>Results</p> <p>We first draw an inventory of all endo-GPCRs encoded in the murine genome. To profile GPCRs genome-wide accurately, sensitively, comprehensively, and cost-effectively, we designed and validated a collection of primers that we used in quantitative RT-PCR experiments. We experimentally validated a statistical approach to analyze genome-wide, real-time PCR data. To illustrate the usefulness of this approach, we determined the repertoire of GPCRs expressed in cerebellar granule neurons and neuroblasts during postnatal development.</p> <p>Conclusions</p> <p>We identified tens of GPCRs that were not detected previously in this cell type; these GPCRs represent novel candidate players in the development and survival of cerebellar granule neurons. The sequences of primers used in this study are freely available to those interested in quantifying GPCR expression comprehensively.</p

    The rise and fall of the ancient northern pike master sex determining gene

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    The understanding of the evolution of variable sex determination mechanisms across taxa requires comparative studies among closely related species. Following the fate of a known master sex-determining gene, we traced the evolution of sex determination in an entire teleost order (Esociformes). We discovered that the northern pike (Esox lucius) master sex-determining gene originated from a 65 to 90 million-year-old gene duplication event and that it remained sex-linked on undifferentiated sex chromosomes for at least 56 million years in multiple species. We identified several independent species- or population-specific sex determination transitions, including a recent loss of a Y-chromosome. These findings highlight the diversity of evolutionary fates of master sex-determining genes and the importance of population demographic history in sex determination studies. We hypothesize that occasional sex reversals and genetic bottlenecks provide a non-adaptive explanation for sex determination transitions

    Modulation of defense signal transduction by flagellin-induced WRKY41 transcription factor in Arabidopsis thaliana

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    Flagellin, a component of the flagellar filament of Pseudomonas syringae pv. tabaci 6605 (Pta), induces hypersensitive reaction in its non-host Arabidopsis thaliana. We identified the WRKY41 gene, which belongs to a multigene family encoding WRKY plant-specific transcription factors, as one of the flagellin-inducible genes in A. thaliana. Expression of WRKY41 is induced by inoculation with the incompatible pathogen P. syringae pv. tomato DC3000 (Pto) possessing AvrRpt2 and the non-host pathogens Pta within 6-h after inoculation, but not by inoculation with the compatible Pto. Expression of WRKY41 was also induced by inoculation of A. thaliana with an hrp-type three secretion system (T3SS)-defective mutant of Pto, indicating that effectors produced by T3SS in the Pto wild-type suppress the activation of WRKY41. Arabidopsis overexpressing WRKY41 showed enhanced resistance to the Pto wild-type but increased susceptibility to Erwinia carotovora EC1. WRKY41-overexpressing Arabidopsis constitutively expresses the PR5 gene, but suppresses the methyl jasmonate-induced PDF1.2 gene expression. These results demonstrate that WRKY41 may be a key regulator in the cross talk of salicylic acid and jasmonic acid pathways.</p

    Effect of isoniazid preventive therapy on risk of death in west African, HIV-infected adults with high CD4 cell counts: long-term follow-up of the Temprano ANRS 12136 trial.

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    BACKGROUND: Temprano ANRS 12136 was a factorial 2 × 2 trial that assessed the benefits of early antiretroviral therapy (ART; ie, in patients who had not reached the CD4 cell count threshold used to recommend starting ART, as per the WHO guidelines that were the standard during the study period) and 6-month isoniazid preventive therapy (IPT) in HIV-infected adults in CĂŽte d'Ivoire. Early ART and IPT were shown to independently reduce the risk of severe morbidity at 30 months. Here, we present the efficacy of IPT in reducing mortality from the long-term follow-up of Temprano. METHODS: For Temprano, participants were randomly assigned to four groups (deferred ART, deferred ART plus IPT, early ART, or early ART plus IPT). Participants who completed the trial follow-up were invited to participate in a post-trial phase. The primary post-trial phase endpoint was death, as analysed by the intention-to-treat principle. We used Cox proportional models to compare all-cause mortality between the IPT and no IPT strategies from inclusion in Temprano to the end of the follow-up period. FINDINGS: Between March 18, 2008, and Jan 5, 2015, 2056 patients (mean baseline CD4 count 477 cells per ÎŒL) were followed up for 9404 patient-years (Temprano 4757; post-trial phase 4647). The median follow-up time was 4·9 years (IQR 3·3-5·8). 86 deaths were recorded (Temprano 47 deaths; post-trial phase 39 deaths), of which 34 were in patients randomly assigned IPT (6-year probability 4·1%, 95% CI 2·9-5·7) and 52 were in those randomly assigned no IPT (6·9%, 5·1-9·2). The hazard ratio of death in patients who had IPT compared with those who did not have IPT was 0·63 (95% CI, 0·41 to 0·97) after adjusting for the ART strategy (early vs deferred), and 0·61 (0·39-0·94) after adjustment for the ART strategy, baseline CD4 cell count, and other key characteristics. There was no evidence for statistical interaction between IPT and ART (pinteraction=0·77) or between IPT and time (pinteraction=0·94) on mortality. INTERPRETATION: In CĂŽte d'Ivoire, where the incidence of tuberculosis was last reported as 159 per 100 000 people, 6 months of IPT has a durable protective effect in reducing mortality in HIV-infected people, even in people with high CD4 cell counts and who have started ART. FUNDING: National Research Agency on AIDS and Viral Hepatitis (ANRS)

    The 'PUCE CAFE' Project: the First 15K Coffee Microarray, a New Tool for Discovering Candidate Genes correlated to Agronomic and Quality Traits

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    Background: Understanding the genetic elements that contribute to key aspects of coffee biology will have an impact on future agronomical improvements for this economically important tree. During the past years, EST collections were generated in Coffee, opening the possibility to create new tools for functional genomics. Results: The "PUCE CAFE" Project, organized by the scientific consortium NESTLE/IRD/CIRAD, has developed an oligo-based microarray using 15,721 unigenes derived from published coffee EST sequences mostly obtained from different stages of fruit development and leaves in Coffea Canephora (Robusta). Hybridizations for two independent experiments served to compare global gene expression profiles in three types of tissue matter (mature beans, leaves and flowers) in C. canephora as well as in the leaves of three different coffee species (C. canephora, C. eugenoides and C. arabica). Microarray construction, statistical analyses and validation by Q-PCR analysis are presented in this study. Conclusion: We have generated the first 15 K coffee array during this PUCE CAFE project, granted by Genoplante (the French consortium for plant genomics). This new tool will help study functional genomics in a wide range of experiments on various plant tissues, such as analyzing bean maturation or resistance to pathogens or drought. Furthermore, the use of this array has proven to be valid in different coffee species (diploid or tetraploid), drastically enlarging its impact for high-throughput gene expression in the community of coffee research

    Trials

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    OBJECTIVES: To assess the efficacy of several repurposed drugs to prevent hospitalisation or death in patients aged 65 or more with recent symptomatic SARS-CoV-2 infection (COVID-19) and no criteria for hospitalisation. TRIAL DESIGN: Phase III, multi-arm (5) and multi-stage (MAMS), randomized, open-label controlled superiority trial. Participants will be randomly allocated 1:1:1:1:1 to the following strategies: Arm 1: Control arm Arms 2 to 5: Experimental treatment arms Planned interim analyses will be conducted at regular intervals. Their results will be reviewed by an Independent Data and Safety Monitoring Board. Experimental arms may be terminated for futility, efficacy or toxicity before the end of the trial. New experimental arms may be added if new evidence suggests that other treatments should be tested. A feasibility and acceptability substudy as well as an immunological substudy will be conducted alongside the trial. PARTICIPANTS: Inclusion criteria are: 65-year-old or more; Positive test for SARS-CoV-2 on a nasopharyngeal swab; Symptoms onset within 3 days before diagnosis; No hospitalisation criteria; Signed informed consent; Health insurance. Exclusion criteria are: Inability to make an informed decision to participate (e.g.: dementia, guardianship); Rockwood Clinical Frailty Scale ≄7; Long QT syndrome; QTc interval > 500 ms; Heart rate 5.5 mmol/L or <3.5 mmol/L; Ongoing treatment with piperaquine, halofantrine, dasatinib, nilotinib, hydroxyzine, domperidone, citalopram, escitalopram, potent inhibitors or inducers of cytochrome P450 CYP3A4 isoenzyme, repaglinide, azathioprine, 6-mercaptopurine, theophylline, pyrazinamide, warfarin; Known hypersensitivity to any of the trial drugs or to chloroquine and other 4-aminoquinolines, amodiaquine, mefloquine, glafenine, floctafenine, antrafenine, ARB; Hepatic porphyria; Liver failure (Child-Pugh stage ≄B); Stage 4 or 5 chronic kidney disease (GFR <30 mL/min/1.73 mÂČ); Dialysis; Hypersentivity to lactose; Lactase deficiency; Abnormalities in galactose metabolism; Malabsorption syndrome; Glucose-6-phosphate dehydrogenase deficiency; Symptomatic hyperuricemia; Ileus; Colitis; Enterocolitis; Chronic hepatitis B virus disease. The trial is being conducted in France in the Bordeaux, Corse, Dijon, Nancy, Paris and Toulouse areas as well as in the Grand Duchy of Luxembourg. Participants are recruited either at home, nursing homes, general practices, primary care centres or hospital outpatient consultations. INTERVENTION AND COMPARATOR: The four experimental treatments planned in protocol version 1.2 (April 8(th), 2020) are: (1) Hydroxychloroquine 200 mg, 2 tablets BID on day 0, 2 tablets QD from day 1 to 9; (2) Imatinib 400 mg, 1 tablet QD from day 0 to 9; (3) Favipiravir 200 mg, 12 tablets BID on day 0, 6 tablets BID from day 1 to 9; (4) Telmisartan 20 mg, 1 tablet QD from day 0 to 9. The comparator is a complex of vitamins and trace elements (AZINC Forme et VitalitĂ©Âź), 1 capsule BID for 10 days, for which there is no reason to believe that they are active on the virus. In protocol version 1.2 (April 8th, 2020): People in the control arm will receive a combination of vitamins and trace elements; people in the experimental arms will receive hydroxychloroquine, or favipiravir, or imatinib, or telmisartan. MAIN OUTCOME: The primary outcome is the proportion of participants with an incidence of hospitalisation and/or death between inclusion and day 14 in each arm. RANDOMISATION: Participants are randomized in a 1:1:1:1:1 ratio to each arm using a web-based randomisation tool. Participants not treated with an ARB or ACEI prior to enrolment are randomized to receive the comparator or one of the four experimental drugs. Participants already treated with an ARB or ACEI are randomized to receive the comparator or one of the experimental drugs except telmisartan (i.e.: hydroxychloroquine, imatinib, or favipiravir). Randomisation is stratified on ACEI or ARBs treatment at inclusion and on the type of residence (personal home vs. nursing home). BLINDING (MASKING): This is an open-label trial. Participants, caregivers, investigators and statisticians are not blinded to group assignment. NUMBERS TO BE RANDOMISED (SAMPLE SIZE): A total of 1057 participants will be enrolled if all arms are maintained until the final analysis and no additional arm is added. Three successive futility interim analyses are planned, when the number of participants reaches 30, 60 and 102 in the control arm. Two efficacy analyses (interim n°3 and final) will be performed successively. TRIAL STATUS: This describes the Version 1.2 (April 8(th), 2020) of the COVERAGE protocol that was approved by the French regulatory authority and ethics committee. The trial was opened for enrolment on April 15(th), 2020 in the Nouvelle Aquitaine region (South-West France). Given the current decline of the COVID-19 pandemic in France and its unforeseeable dynamic in the coming months, new trial sites in 5 other French regions and in Luxembourg are currently being opened. A revised version of the protocol was submitted to the regulatory authority and ethics committee on June 15(th), 2020. It contains the following amendments: (i) Inclusion criteria: age ≄65 replaced by age ≄60; time since first symptoms <3 days replaced by time since first symptoms <5 days; (ii) Withdrawal of the hydroxychloroquine arm (due to external data); (iii) increase in the number of trial sites. TRIAL REGISTRATION: The trial was registered on Clinical Trials.gov on April 22(nd), 2020 (Identifier: NCT04356495): and on EudraCT on April 10(th), 2020 (Identifier: 2020-001435-27). FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest of expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol. The study protocol has been reported in accordance with the Standard Protocol Items: Recommendations for Clinical Interventional Trials (SPIRIT) guidelines (Additional file 2)
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