A Plant-Specific Transcription Factor IIB-Related Protein, pBRP2, Is Involved in Endosperm Growth Control

General transcription factor IIB (TFIIB) and TFIIB-related factor (BRF), are conserved RNA polymerase II/III (RNAPII/III) selectivity factors that are involved in polymerase recruitment and transcription initiation in eukaryotes. Recent findings have shown that plants have evolved a third type of B-factor, plant-specific TFIIB-related protein 1 (pBRP1), which seems to be involved in RNAPI transcription. Here, we extend the repertoire of B-factors in plants by reporting the characterization of a novel TFIIB-related protein, plant-specific TFIIB-related protein 2 (pBRP2), which is found to date only in the Brassicacea family. Unlike other B-factors that are ubiquitously expressed, PBRP2 expression is restricted to reproductive organs and seeds as shown by RT-PCR, immunofluorescence labelling and GUS staining experiments. Interestingly, pbrp2 loss-of-function specifically affects the development of the syncytial endosperm, with both parental contributions required for wild-type development. pBRP2, is the first B-factor to exhibit cell-specific expression and regulation in eukaryotes, and might play a role in enforcing bi-parental reproduction in angiosperms

Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

A role for CHROMOMETHYLASE3 in mediating transposon and euchromatin silencing during egg cell reprogramming in Arabidopsis

During embryogenesis there is a major switch from dependence upon maternally-deposited products to reliance on products of the zygotic genome. In animals, this so-called maternal-to-zygotic transition occurs following a period of transcriptional quiescence. Recently, we have shown that the early embryo in Arabidopsis is also quiescent, a state inherited from the female gamete and linked to specific patterns of H3K9 dimethylation and TERMINAL FLOWER2 (TFL2) localization. We also demonstrated that CHROMOMETHYLASE 3 (CMT3) is required for H3K9 dimethylation in the egg cell and for normal embryogenesis during the first few divisions of the zygote. Subsequent analysis of CMT3 mutants points to a key role in egg cell reprogramming by controlling silencing in both transposon and euchromatic regions. A speculative model of the CMT3-induced egg cell silencing is presented here, based on these results and current data from the literature suggesting the potential involvement of small RNAs targeted to the egg cell, a process conceptually similar to the division of labor described in the male gametophyte for which we show that H3K9 modifications and TFL2 localization are reminiscent of the female gametophyte

Clinical characteristics of singers attending a phoniatric outpatient clinic

International audiencePurpose: Studies suggest that singers are over-represented in voice clinics and present a high risk ofdeveloping voice disorders. This retrospective study aims to describe the characteristics of 78 singersconsulting a phoniatrician.Methods: In their medical files, data related to age, gender, occupational status, singing training,musical style, voice complaint, diagnosis, voice-quality grading (GRBAS) and treatment were gathered.Results: The patients were mostly female singers (87%). Non-professional singers (semi-professionalincluded) represented 64%, professional singers 25% and students of singing 11%. The majority ofsingers were choristers (27%) and 22% were classical-style/oratorio-style singers. Two-thirds of thepopulation had intensive vocal activity in speech or singing. Vocal endurance, somatosensory signsand difficulties with high pitches were the most frequent symptoms. Among the patients, 79% presentedwith singing-voice disorders with 85% of these having vocal fold lesions. Generally, their speakingvoices were preserved. Vocal-folds nodules were the most prevalent pathology (37%) followed bysulcus (26%) and voice therapy was the main treatment.Conclusions: This study emphasizes the fact that singers have specific voice complaints related totheir voice usage. The high occurrence of sulcus and other congenital-lesion suspicions, unusual in thegeneral population consulting an ENT phoniatrician, seems to be rather specific for singers in agreementwith the literature

Prevalence of voice disorders in singers

International audienc

Clinical characteristics of singers attending a phoniatric outpatient clinic in France

International audienceStudies suggest that singers are over-represented in voice clinics and present a high risk of developing voice disorders. This retrospective study aims to describe the characteristics of 78 singers consulting a phoniatrician. In their medical files, data related to age, gender, occupational status, singing training, musical style, voice complaint, diagnosis, voice-quality grading (GRBAS) and treatment were gathered. The patients were mostly female singers (87%). Non-professional singers (semi-professional included) represented 64%, professional singers 25% and students of singing 11%. The majority of singers were choristers (27%) and 22% were classical-style /oratorio-style singers. Two-thirds of the population had intensive vocal activity in speech or singing. Vocal endurance, somatosensory signs and difficulties with high pitches were the most frequent symptoms. Among the patients, 79% presented with singing-voice disorders with 85% of these having vocal fold lesions. Generally, their speaking voices were preserved. Vocal-folds nodules were the most prevalent pathology (37 %) followed by sulcus (26%) and voice therapy was the main treatment. This study emphasizes the fact that singers have specific voice complaints related to their voice usage. The high occurrence of sulcus and other congenital-lesion suspicions, unusual in the general population consulting an ENT phoniatrician, seems to be rather specific for singers in agreement with the literature

Profils aérodynamiques de patients dysodiques : une étude de cas

International audienceLa voix chantée sollicite parfois de façon extrême l’appareil vocal selon le style de chant, les différentes pratiques et le niveau d’entraînement (Aronson et Bless, 2009). Lorsqu’elle est altérée, on parle de dysodie (perte des habiletés vocales chantées, associée ou non à une laryngopathie), se traduisant par des signes acoustiques (anomalies tonales, dynamiques ou de timbre) et/ou physiques. Elle peut avoir un retentissement psychologique (Amy de la Bretèque, 2012). Les patients consultant pour dysodie sont des chanteurs amateurs, professionnels ou étudiants. Les chanteurs sont plus enclins à développer des troubles vocaux (Miller et Verdolini, 1995). La grande majorité des dysodiques sont des femmes (Hunter et al., 2011). Le nodule reste la lésion la plus retrouvée mais les lésions congénitales arrivent en second chez les chanteurs (Bouchayer et Cornut, 1992).L’intérêt des paramètres aérodynamiques pour le diagnostic des pathologies vocales est aujourd’hui largement démontré (Holmberg et al., 2003). Parmi eux, les mesures de pression sous-glottique estimée (PSGE) et de débit d’air oral (DAO) dépendent du niveau d’entraînement des chanteurs et du type de dysfonction vocale. Ces paramètres sont plus élevés chez les chanteurs lyriques que chez les non chanteurs (Dargin et Searl, 2015). En clinique, la PSGE est plus élevée lors du forçage vocal (Morsomme et al., 2015). Concernant le DAO, les résultats sont controversés : augmentation avec l’effort vocal chez des non chanteurs euphoniques (Rosenthal et al. 2014) ; diminution lors de l’augmentation d’intensité chez un non chanteur euphonique (Pillot-Loiseau, 2011).Nous avons étudié le comportement aérodynamique de 6 chanteuses et 4 chanteurs venus consulter en phoniatrie, puis les avons comparés à une population euphonique (13 chanteuses et 6 chanteurs) recrutée lors d’une précédente étude (Beaud, 2015). Les profils de PSGE et de DAO selon la fréquence montrent une très grande variabilité interindividuelle (Figures 1 à 4). Chez les patients dysodiques (Figures 1 et 4), ils corroborent les observations cliniques. L’exemple d’une patiente (P4), chanteuse d’opéra professionnelle avec sulcus, montre une corrélation entre sa plainte (difficultés d’aigus depuis le début de son activité), les données cliniques (difficulté d’initialisation du son au-delà du ré4) et les données aérodynamiques : le contrôle des débits et pressions est correct jusqu’au do4 (554Hz) environ. Au-delà, ces valeurs diminuent soudainement. Chez une autre chanteuse (P8), choriste amateur et enseignante avec nodules, le bilan vocal décrit une dysphonie modérée et une désonorisation lors de la transition entre mécanismes laryngés M1 et M2. Les données aérodynamiques reflètent le dysfonctionnement : le débit est anormalement bas, les valeurs de pression sont augmentées et leur évolution avec la hauteur n’est pas régulière. On retrouve une zone d’instabilité autour de 300Hz (zone de passage) : la pression et le débit diminuent puis ré-augmentent. Ces comportements s’éloignent de ceux des chanteurs euphoniques chez qui la pression augmente régulièrement avec la hauteur et l’intensité (Figures 2 et 3). Ces difficultés reflétées dans la gestion aérodynamique des notes chantées appellent à une rééducation ciblée sur le comportement pneumophonique dans le chant, pour laquelle la méthode de rééducation à la paille pourrait être prometteuse

Embryo and Endosperm Inherit Distinct Chromatin and Transcriptional States from the Female Gametes in Arabidopsis[C][W]

This work provides a description of the transcriptional and epigenetic state of the female gametes and the early embryo in Arabidopsis. It shows that while the endosperm is transcriptionally active, the embryo is relatively quiescent, a difference that is established prefertilization in the female gametes, maintained postfertilization, and which may play a role in the reprogramming of the young plant embryo