In situ gynogenetic haploid plants of chicory (Cichorium intybus L.) after intergeneric hybridization with Cicerbita alpina Walbr.

The possibility of obtaining haploid plants of chicory (Cichorium intybus L.) was investigated through intergeneric hybridization. Chicory plants (industrial chicory and Chioggia) were pollinated with pollen of Lactuca tatarica L. and Cicerbita alpina Walbr. Many achenes contained embryos which were rescued in vitro. Only a few embryos developed into plants which were then acclimatized in soil. Among them, three expressed a chicory phenorype and were haploidAbbreviations DAPI 4,6-diamidinophenylindole - DH doubled haploid - DNA deoxyribonucleic acid - GUS ß glucuronidase - RFLP Restriction Fragment Length Polymorphism - X-Gluc 5-bromo-4-chloro-3-indolyl-glucuronide - mtDNA mitochondrial DNA     

Palynoflores dans la coupe de l'Albien de Foz do Folcao (Portugal)

In the area of Lisbon (Portugal) near Foz do Folcao and along the sea-shore, the transgressive facies of the marly 0611 Albian may be seen sesting on the “Upper continental sandstones of Almargem”. On the basis of the variety and of the relative frequencies of reticulate pollen grains in particular, the following age assessment can be made. The topmost part of the “Upper sandstones of Almargem” as well as the lowermost transgressive facies, just underlaying the albian levels with associated faunas, are suggested to be middle Albian.     

Myomaker mediates fusion of fast myocytes in zebrafish embryos

Myomaker (also called Tmem8c), a new membrane activator of myocyte fusion was recently discovered in mice. Using whole mount in situ hybridization on zebrafish embryos at different stages of embryonic development, we show that myomaker is transiently expressed in fast myocytes forming the bulk of zebrafish myotome. Zebrafish embryos injected with morpholino targeted against myomaker were alive after yolk resorption and appeared morphologically normal, but they were unable to swim, even under effect of a tactile stimulation. Confocal observations showed a marked phenotype characterized by the persistence of mononucleated muscle cells in the fast myotome at developmental stages where these cells normally fuse to form multinucleated myotubes. This indicates that myomaker is essential for myocyte fusion in zebrafish. Thus, there is an evolutionary conservation of myomaker expression and function among Teleostomi.     

Central modulation in cluster headache patients treated with occipital nerve stimulation: an FDG-PET study

Background  

Occipital nerve stimulation (ONS) has raised new hope for drug-resistant chronic cluster headache (drCCH), a devastating condition. However its mode of action remains elusive. Since the long delay to meaningful effect suggests that ONS induces slow neuromodulation, we have searched for changes in central pain-control areas using metabolic neuroimaging.     

Recurrence of COVID-19 after recovery ? A case series in health care workers,France

We describe 3 cases of coronavirus disease 2019 in health care workers in France involving presumed clinical and microbiological recurrence after recovery. All patients were immunocompetent with clinical mild form. These cases highlight the possibility of coronavirus disease–recurrence.     

Hypericin Site Specific Interactions Within Polynucleotides Used as DNA Model Compounds

Summary

Interactions of the antiretroviral hypericin molecule with polynucleotides, i.e. poly(dG-dC), poly(dA-dT), poly(rG) and poly(rC), have been studied in aqueous solutions by resonance Raman spectroscopy, using an UV excitation wavelength which induces a specific resonance enhancement of spectral band intensities corresponding to proper nucleic base modes of vibration. It is shown that : i) hypericin selectively interacts with the N7 sites of purines, ii) the strength of interaction depends on the polymer structure, and : iii) interaction with guanine is stronger than with adenine molecules.     

Phosphorylation of the Deubiquitinase USP20 by Protein Kinase A Regulates Post-endocytic Trafficking of β2 Adrenergic Receptors to Autophagosomes during Physiological Stress

Ubiquitination by the E3 ligase Nedd4 and deubiquitination by the deubiquitinases USP20 and USP33 have been shown to regulate the lysosomal trafficking and recycling of agonist-activated β₂ adrenergic receptors (β₂ARs). In this work, we demonstrate that, in cells subjected to physiological stress by nutrient starvation, agonist-activated ubiquitinated β₂ARs traffic to autophagosomes to colocalize with the autophagy marker protein LC3-II. Furthermore, this trafficking is synchronized by dynamic posttranslational modifications of USP20 that, in turn, are induced in a β₂AR-dependent manner. Upon β₂AR activation, a specific isoform of the second messenger cAMP-dependent protein kinase A (PKAα) rapidly phosphorylates USP20 on serine 333 located in its unique insertion domain. This phosphorylation of USP20 correlates with a characteristic SDS-PAGE mobility shift of the protein, blocks its deubiquitinase activity, promotes its dissociation from the activated β₂AR complex, and facilitates trafficking of the ubiquitinated β₂AR to autophagosomes, which fuse with lysosomes to form autolysosomes where receptors are degraded. Dephosphorylation of USP20 has reciprocal effects and blocks trafficking of the β₂AR to autophagosomes while promoting plasma membrane recycling of internalized β₂ARs. Our findings reveal a dynamic regulation of USP20 by site-specific phosphorylation as well as the interdependence of signal transduction and trafficking pathways in balancing adrenergic stimulation and maintaining cellular homeostasis.