The effects of male social environment on sperm phenotype and genome integrity

Sperm function and quality are primary determinants of male reproductive performance and hence fitness. The presence of rival males has been shown to affect ejaculate and sperm traits in a wide range of taxa. However, male physiological conditions may not only affect sperm phenotypic traits but also their genetic and epigenetic signatures, affecting the fitness of the resulting offspring. We investigated the effects of male-male competition on sperm quality using TUNEL assays and geometric morphometrics in the zebrafish, Danio rerio. We found that the sperm produced by males exposed to high male-male competition had smaller heads but larger midpiece and flagellum than sperm produced by males under low competition. Head and flagella also appeared less sensitive to the osmotic stress induced by activation with water. In addition, more sperm showed signals of DNA damage in ejaculates of males under high competition. These findings suggest that the presence of a rival male may have positive effects on phenotypic traits but negative effects on DNA integrity. Overall, males facing the presence of rival males may produce faster swimming and more competitive sperm but this may come at a cost for the next generation. This article is protected by copyright. All rights reserved

Yeast Mitochondrial Biogenesis: A Role for the PUF RNA-Binding Protein Puf3p in mRNA Localization

The asymmetric localization of mRNA plays an important role in coordinating posttranscriptional events in eukaryotic cells. We investigated the peripheral mitochondrial localization of nuclear-encoded mRNAs (MLR) in various conditions in which the mRNA binding protein context and the translation efficiency were altered. We identified Puf3p, a Pumilio family RNA-binding protein, as the first trans-acting factor controlling the MLR phenomenon. This allowed the characterization of two classes of genes whose mRNAs are translated to the vicinity of mitochondria. Class I mRNAs (256 genes) have a Puf3p binding motif in their 3'UTR region and many of them have their MLR properties deeply affected by PUF3 deletion. Conversely, mutations in the Puf3p binding motif alter the mitochondrial localization of BCS1 mRNA. Class II mRNAs (224 genes) have no Puf3p binding site and their asymmetric localization is not affected by the absence of PUF3. In agreement with a co-translational import process, we observed that the presence of puromycin loosens the interactions between most of the MLR-mRNAs and mitochondria. Unexpectedly, cycloheximide, supposed to solidify translational complexes, turned out to destabilize a class of mRNA-mitochondria interactions. Classes I and II mRNAs, which are therefore transported to the mitochondria through different pathways, correlated with different functional modules. Indeed, Class I genes code principally for the assembly factors of respiratory chain complexes and the mitochondrial translation machinery (ribosomes and translation regulators). Class II genes encode proteins of the respiratory chain or proteins involved in metabolic pathways. Thus, MLR, which is intimately linked to translation control, and the activity of mRNA-binding proteins like Puf3p, may provide the conditions for a fine spatiotemporal control of mitochondrial protein import and mitochondrial protein complex assembly. This work therefore provides new openings for the global study of mitochondria biogenesis

Bacterial production in the recently flooded Sep Reservoir : Diel changes in relation to dissolved carbohydrates and combined amino acids

International audienceThe spatial distribution of bacterial abundance and production were measured every 4 h in a recently flooded oligo-mesotrophic reservoir (the Sep Reservoir, Puy-De-Dôme, France), in relation to concentrations of dissolved carbohydrates and combined amino acids. The concentration of dissolved organic matter (DOM) components in the recently flooded Sep Reservoir were higher than those measured in other lakes of similar trophic status. Short-term variations in the bacterial production in this new reservoir appeared cyclical and endogenous to bacterial communities. These results highlight the need for the evaluation of diel changes in bacterial production, if estimation of the daily production rate of bacteria is to be done accurately for a reliable model of carbon flow through bacterioplankton and ultimately through aquatic microbial food webs. Bacterial growth, measured over time and space, did not appear exclusively governed by DOM components from phytoplankton primary production

Pericarp tissue microstructure and cell wall polysaccharide chemistry are differently affected in lines of tomato with contrasted firmness

International audienceThe contribution of tissue histology and cell wall polysaccharides chemistry to describing ripe tomato fruit texture was addressed in near isogenic lines of fruits harboring firmness QTL. These lines were constructed in Levovil (L), VilB (B), M82 (P) and Moneyberg (Mbg) genetic backgrounds and carried introgressed fragments from three origins on chromosomes 2, 3, 4, 5 or 9 (and two sub-regions a and b). The firmness of their pericarp tissue was measured by compression testing and related to cell size distribution and to published data on their cell wall polysaccharide chemistry. The pericarp tissue from all L9 lines, B9 and P3.4 was firmer than the respective parental line while that from Mbg9 and P9.2.5 was softer. The pericarp tissue from L4, L4a and Mbg5 fruit was made of larger cells while that from Mbg2 and Mbg9 had smaller cells than their parents. Correlations were found between firmness and cell size distribution for QTLs only in the Levovil group. Correlations between firmness, histological characteristics and cell wall polysaccharide chemistry indicate positive relations between glucose-containing polysaccharide (cellulose and hemicelluloses) contents and pericarp tissue thickness. Other positive relations were found between galactosylated pectins and hemicelluloses and firmness in QTL lines of the Levovil background. The results show that chromosomes 9, 5, 4 and 2 are associated with pericarp histology in these lines and that pericarp tissue firmness depends on histology and cell wall chemistry according to genetics. These tomato lines represent good models to study the complex contributions of turgor pressure, cell wall chemistry, tissue architecture and their mechanisms of modulation underpinning texture in ripening tomatoes

Actinomyces graevenitzii Pulmonary Abscess Mimicking Tuberculosis in a Healthy Young Man

Pulmonary actinomycosis is a rare disease that is often misdiag-nosed as tuberculosis or lung cancer. Actinomyces graevenitzii is a relatively new recognized Actinomyces species isolated from various clinical samples. The authors report a case of pulmonary actinomycosis caused by A graevenitzii. A computed tomography examination revealed an excavated consolidation in the middle right lobe of a previously healthy young man who presented with a long history of moderate cough. Cultures of the bronchoalveolar lavage fluid confirmed the diagnosis of pulmonary abscess caused by A gravenitzii. At the three-month follow-up consultation and, after six weeks of high-dose amoxicillin, the pulmonary lesion had completely disappeared

Pericarp histology and cell wall chemistry of tomato lines with altered fruit firmness

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Near isogenic lines of tomato for texture contrasted QTL showed altered pericarp histology and cell wall chemistry

International audienc

La gouvernance de la rénovation urbaine à l'épreuve des territoires

International audienceLa mission de l’Agence nationale pour la rénovation urbaine (ANRU) est de réaliser le programme national de rénovation urbaine en aidant les collectivités locales, porteuses de projets, à accompagner leur réalisation. Le Comité d’évaluation et de suivi de l’ANRU a souhaité analyser l’évolution de la gouvernance du programme national de rénovation urbaine, au niveau local et national, ainsi que leur articulation. A partir de l’analyse détaillée d’une douzaine de projets, l’équipe dresse le constat d’une multiplicité de gouvernances locales sur les territoires. Face à une gouvernance trop souvent mal interprétée et réduite à la « doctrine » de l’ANRU et au retour de l’État centralisateur, cette enquête pointe la prégnance des configurations locales et des marges de manœuvre très importantes qu’ont eu les acteurs locaux. Ce constat invite à repenser la prise en compte de la différenciation territoriale dans les politiques urbaines

The CCAAT-Binding Complex Controls Respiratory Gene Expression and Iron Homeostasis in Candida Glabrata

International audienceThe CCAAT-binding complex (CBC) is a heterotrimeric transcription factor which is widely conserved in eukaryotes. In the model yeast S. cerevisiae, CBC positively controls the expression of respiratory pathway genes. This role involves interactions with the regulatory subunit Hap4. In many pathogenic fungi, CBC interacts with the HapX regulatory subunit to control iron homeostasis. HapX is a bZIP protein which only shares with Hap4 the Hap4Like domain (Hap4L) required for its interaction with CBC. Here, we show that CBC has a dual role in the pathogenic yeast C. glabrata. It is required, along with Hap4, for the constitutive expression of respiratory genes and it is also essential for the iron stress response, which is mediated by the Yap5 bZIP transcription factor. Interestingly, Yap5 contains a vestigial Hap4L domain. The mutagenesis of this domain severely reduced Yap5 binding to its targets and compromised its interaction with Hap5. Hence, Yap5, like HapX in other species, acts as a CBC regulatory subunit in the regulation of iron stress response. This work reveals new aspects of iron homeostasis in C. glabrata and of the evolution of the role of CBC and Hap4L-bZIP proteins in this process

Physiological relationships among physical, sensory, and morphological attributes of texture in tomato fruits

International audienceTomato texture is one of the critical components for the consumer's perception of fruit quality. Texture is a complex character composed of several attributes that are difficult to evaluate and which change during fruit ripening. This study investigated the texture of tomato fruits at the rheological, sensory, morphological, and genetic levels, and attempted to correlate several parameters. Analyses were performed on tomato fruits from introgressed lines carrying quantitative trait loci (QTLs) associated with texture traits localized on different chromosomes, in two genetic backgrounds. Rheological measurements were used to determine resistance to deformation and fruit elasticity. Sensory analysis was used to assess flesh firmness, juiciness, mealiness, and skin toughness. Image analysis was used to study fruit morphology and to define the cellular structure and heterogeneity of the pericarp. A highly significant correlation was observed between instrumental and sensory firmness. Moreover, correlations were also established between some texture traits and parameters of the pericarp cellular structure. Compared with QTLs detected in a previous study, the phenotypic effects expected for mealiness were confirmed in all lines, whereas, for firmness, they were not confirmed. Significant interactions between QTL and genetic background were observed for several traits. In addition, kinetic analysis showed that differences in firmness occurred from the early stages of fruit development. These results provide both a broad description of texture components and preliminary information to understand their genetic control