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Lichens symbioses, commonly described as fungal partnerships with a photosynthetic partner (green algae and/or cyanobacteria) are associated with a diverse bacterial community. Whereas the microbiome diversity and function of terrestrial lichens has been well studied, knowledge about the non-photosynthetic bacteria associated with marine lichens is still scarce. Since there is a clear vertical zonation of lichens across the littoral belt we hypothesized that this correlates with significant variations of bacterial communities associated with these lichens. To test this hypothesis, 16S rRNA gene illumina sequencing was used to assess the culture-independent bacterial diversity in the strictly marine cyanolichen species Lichina pygmaea and Lichina confinis, and the maritime chlorolichen species Xanthoria sp. collected from the French Brittany coast. These species occupied the lower eulittoral, upper eulittoral and supralittoral zones respectively. Inland terrestrial cyanolichens from Austria were also analysed as for the marine lichens to examine further the impact of habitat/lichen species on the associated bacterial communities. The L. confinis and L. pygmaea communities were significantly different from those of the terrestrial lichens with the Bacteroidetes phylum accounting for 50% of the sequences, whereas Alphaproteobacteria, notably Sphingomonas, dominated the terrestrial lichens. Bacterial communities associated with the two Lichina species were significantly different sharing only 33 core OTUs, half of which were affiliated to the Bacteroidetes genera Rubricoccus, Tunicatimonas and Lewinella, suggesting an important role of these species in the marine lichen symbiosis. The presence of multiple OTUs of these genera that were differentially distributed between the two Lichina species, could be suggestive of ecological speciation driven by adaptation to the different conditions of the intertidal and supratidal zones. Marine cyanolichens showed a higher abundance of OTUs likely affiliated to moderately thermophilic and/or radiation resistant bacteria belonging to the Phyla Chloroflexi, Thermi, and the families Rhodothermaceae and Rubrobacteraceae when compared to those of terrestrial lichens. This most likely reflects the exposed and highly variable conditions to which marine lichens are subjected to daily.

International audience; The perinucleolar compartment (PNC) is a subnuclear stucture forming predominantly in cancer cells; its prevalence positively correlates with metastatic capacity. Although several RNA-binding proteins have been characterized in PNC, the molecular function of this compartment remains unclear. Here we demonstrate that the cyclin–dependent kinase 13 (CDK13) is a newly identified constituent of PNC. CDK13 is a kinase involved in the regulation of gene expression and whose overexpression was found to alter pre-mRNA processing. In this study we show that CDK13 is enriched in PNC and co-localizes all along the cell cycle with the PNC component PTB. In contrast, neither the cyclins K and L, known to associate with CDK13, nor the potential kinase substrates accumulate in PNC. We further show that CDK13 overexpres-sion increases PNC prevalence suggesting that CDK13 may be determinant for PNC formation. This result linked to the finding that CDK13 gene is amplified in different types of cancer indicate that this kinase can contribute to cancer development in human.

Summary A polyclonal antibody raised against allatostatin-3 of Blattella germanica (BLAST-3) has been used to immunolocalize allatostatin-like peptides in the brain-retrocerebral complex of Labidura riparia adult females. Strongly stained immunoreactive cells are observed in the pars intercerebralis (14 cells) and mainly in the pars lateralis (32 cells). Fibres leading to the corpus allatum are also stained. In the deutocerebrum, one cell is immunostained at the root of each antennal nerve. In the tritocerebmm two cells in each brain hemisphere are weakly immunostained. During the reproductive cycle, these cells and their axons show immunoreactivity at previtellogenic, ovulation and ovarian arrest periods. During vitellogenesis, immunoreactivity is restricted to only four perikarya in the pars intercerebralis. When young vitellogenic females are injected with 20-hydroxyecdysone (20E), which inhibits vitellogenesis, full immunoreactivity reappears, suggesting sensibility of these cells to 20E as is expecte...

The effect of NaCl on the thermal behaviour of wheat starch was investigated with particular focus on starch at low moisture contents (25-45 wt%). Increasing the level of NaCl reduced the starch peak viscosity (in 90% water) as measured by RVA and shifted all of the thermal peaks (up to 120°C) to higher temperatures as observed by DSC. Above a moisture content of 45%, the temperature difference of the first thermal transition of starch in the presence of 2% NaCl and in the absence of NaCl was found to be constant. In the absence of NaCl, the peak temperature of gelatinisation (Tp) increased by 12°C (from 62 to 74°C) as the water content was reduced from 35% to 25%. In the presence of 2% NaCl, the variation in Tp due to changes in water content was significantly reduced. At NaCl concentrations greater than 2% (w/w total), the Tp of the starch remained constant irrespective of water content. Evidence of this effect was observed in situ using confocal microscopy. In the presence of 2% NaCl, images taken at elevated temperatures show little difference in the extent of starch swelling at 25% compared to 45% water content. However, in the absence of NaCl, significantly more swelling was observed at 45% than at 25% water content. With increasing NaCl concentration, the interaction of starch and NaCl became dominate. Thus the on-set of the thermal transitions of starch granules is primarily controlled by the amount of NaCl present, and secondarily by the water content which becomes dominant when the NaCl concentration is low.

Fertilization relieves the oocyte from a cell cycle arrest, inducing progression towards mitotic cycles. While the signalling pathways involved in oocyte to embryo transition have been widely investigated, how they specifically trigger DNA replication is still unclear. We used sea urchin eggs whose oocytes are arrested in G1 to investigate in vivo the molecular mechanisms regulating initiation of replication after fertilization. Unexpectedly, we found that CDC6, Cdt1 and MCM3, components of the pre-replication complexes (pre-RC) which license origins for replication, were already loaded on female chromatin before fertilization. This is the first demonstration of a cell cycle arrest in metazoan in which chromatin is already licensed for replication. In contrast pre-RC assemble on chromatin post-fertilization as in other organisms. These differences in the timing of pre-RC assembly are accompanied by differences in Cdk2 requirement for DNA replication initiation between female and male chromatin post-fertilization. Finally, we demonstrated that a concomitant inhibition of MAP kinase and ATM/ATR pathways releases the block to DNA synthesis. Our findings provide new insight into the mechanisms contributing to the release of G1 arrest and the control of S-phase entry at fertilization.