Modulation of Brain β-Endorphin Concentration by the Specific Part of the Y Chromosome in Mice

International audienceBackground: Several studies in animal models suggest a possible effect of the specific part of the Y-chromosome (Y NPAR) on brain opioid, and more specifically on brain b-endorphin (BE). In humans, male prevalence is found in autistic disorder in which observation of abnormal peripheral or central BE levels are also reported. This suggests gender differences in BE associated with genetic factors and more precisely with Y NPAR. Methodology/Principal Findings: Brain BE levels and plasma testosterone concentrations were measured in two highly inbred strains of mice, NZB/BlNJ (N) and CBA/HGnc (H), and their consomic strains for the Y NPAR. An indirect effect of the Y NPAR on brain BE level via plasma testosterone was also tested by studying the correlation between brain BE concentration and plasma testosterone concentration in eleven highly inbred strains. There was a significant and major effect (P,0.0001) of the Y NPAR in interaction with the genetic background on brain BE levels. Effect size calculated using Cohen's procedure was large (56% of the total variance). The variations of BE levels were not correlated with plasma testosterone which was also dependent of the Y NPAR. Conclusions/Significance: The contribution of Y NPAR on brain BE concentration in interaction with the genetic background is the first demonstration of Y-chromosome mediated control of brain opioid. Given that none of the genes encompassed by the Y NPAR encodes for BE or its precursor, our results suggest a contribution of the sex-determining region (Sry, carried by Y NPAR) to brain BE concentration. Indeed, the transcription of the Melanocortin 2 receptor gene (Mc2R gene, identified as the proopiomelanocortin receptor gene) depends on the presence of Sry and BE is derived directly from proopiomelanocortin. The results shed light on the sex dependent differences in brain functioning and the role of Sry in the BE system might be related to the higher frequency of autistic disorder in males

Suicide risk and prevention during the COVID-19 pandemic

No abstract available

Vigour control of the olive tree in a high density planting system: two experimental approaches

International audienceIn France, high density planting of olive orchards is progressively increasing. With this new training system tree vigour needs to be controlled. Both research and experimental organizations aim to help growers optimize the use of this system, by improving the management of existing orchards (better tree management, optimiza-tion of pruning, reduction of inputs) and searching for low vigour plant material adapted to high-density training system (identification of low vigour genotypes, use of dwarfing rootstocks). This work relies on a network of growers who are involved in the definition of experimental protocols and in orchard measurements. A first trial began in 2004 at Ctifl to study tree management in palmette in comparison to central axis. Three cultivars (‘Picholine du Languedoc’, ‘Aglandau’ and ‘Arbequina’) were planted in hedgerows, on the basis of 30 trees per cultivar and management system. First results show a non-significant difference in vigour between palmette and axis, but shape obtained in palmette is more suited to mechanical harvesting. A second trial conducted by AFIDOL-CTO began in 2005 on the adaptability to high-density training systems of new French genotypes. Eight genotypes, noticed for their low vigour, were planted in hedgerow on the basis of 20 trees per genotype. Five genotypes were also planted in four other locations in 2009 to evaluate the genotype × environment interaction. The first results obtained in the orchard planted in 2005 show that two genotypes are less vigorous than the others. These results are discussed in comparison with those obtained in other coun-tries where similar trials have been carried out and in terms of technical solutions they can offer to French growers

La pollinisation de l'olivier ; conditions à respecter et choix des pollinisateurs

National audienc