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STICS ability to simulate long-term soil organic matter dynamics in crop-grassland rotations
No full textPopulation and evolutionary genetics of the PAH locus to uncover overdominance and adaptive mechanisms in phenylketonuria: Results from a multiethnic study.
No full textBackground
Phenylketonuria (PKU) is the most common inborn error of amino acid metabolism in Europe. The reasons underlying the high prevalence of heterozygous carriers are not clearly understood. We aimed to look for pathogenic PAH variant enrichment according to geographical areas and patients’ ethnicity using a multiethnic nationwide cohort of patients with PKU in France. We subsequently appraised the population differentiation, balancing selection and the molecular evolutionary history of the PAH locus.
Methods
The French nationwide PKU study included patients who have been referred at the national level to the University Hospital of Nancy, and for whom a molecular diagnosis of phenylketonuria was made by Sanger sequencing. We performed enrichment analyses by comparing alternative allele frequencies using Fisher's exact test with Bonferroni adjustment. We estimated the amount of genetic differentiation among populations using Wright's fixation index (Fst). To estimate the molecular evolutionary history of the PAH gene, we performed phylogenetic and evolutionary analyses using whole-genome and exome-sequencing data from healthy individuals and non-PKU patients, respectively. Finally, we used exome-wide association study to decipher potential genetic loci associated with population divergence on PAH.
Findings
The study included 696 patients and revealed 132 pathogenic PAH variants. Three geographical areas showed significant enrichment for a pathogenic PAH variant: North of France (p.Arg243Leu), North-West of France (p.Leu348Val), and Mediterranean coast (p.Ala403Val). One PAH variant (p.Glu280Gln) was significantly enriched among North-Africans (OR = 23·23; 95% CI: 9·75–55·38). PAH variants exhibiting a strong genetic differentiation were significantly enriched in the ‘Biopterin_H’ domain (OR = 6·45; 95% CI: 1·99–20·84), suggesting a balancing selection pressure on the biopterin function of PAH. Phylogenetic and timetree analyses were consistent with population differentiation events on European-, African-, and Asian-ancestry populations. The five PAH variants most strongly associated with a high selection pressure were phylogenetically close and were located within the biopterin domain coding region of PAH or in its vicinity. Among the non-PAH loci potentially associated with population divergence, two reached exome-wide significance: SSPO (SCO-spondin) and DBH (dopamine beta-hydroxylase), involved in neuroprotection and metabolic adaptation, respectively.
Interpretation
Our data provide evidence on the combination of evolutionary and adaptive events in populations with distinct ancestries, which may explain the overdominance of some genetic variants on PAH.
Funding
French National Institute of Health and Medical Research (INSERM) UMR_S 1256
GASP-2 overexpressing mice exhibit a hypermuscular phenotype with contrasting molecular effects compared to GASP-1 transgenics
No full textMuscle atrophy is associated with many diseases including genetic disorders, sarcopenia, or cachexia syndromes. Myostatin (Mstn), a transforming growth factor-beta (TGF-beta) member, plays a key role in skeletal muscle homeostasis as a powerful negative regulator. Over the last decade, about 15 clinical trials aimed at inhibiting the Mstn pathway, failed to produce conclusive results. In this context, we investigated whether growth and differentiation factor-associated serum protein-1 (GASP-1) or GASP-2, two natural inhibitors of Mstn, might represent a potential therapeutic. As we previously reported, mice overexpressing Gasp-1 (Tg(Gasp-1)) present an increase of muscle mass but develop metabolic disorders with aging. Here, we showed that overexpression of Gasp-2 increases the muscular mass without metabolic defects. We also found that Tg(Gasp-2) mice displayed, like Mstn(-/-) mice, a switch from slow- to fast-twitch myofibers whereas Tg(Gasp-1) mice exhibit a reverse switch. Our studies supported the fact that GASP-2 has less affinity than GASP-1 for Mstn, leading to a constitutive Mstn upregulation only in Tg(Gasp-1) mice, responsible for the observed phenotypic differences. Altogether, our findings highlighted a gene expression regulatory network of TGF-beta members and their inhibitors in muscle
High-Rate Anaerobic Digestion of Waste Activated Sludge by Integration of Electro-Fenton Process
No full textAnaerobic digestion (AD), being the most effective treatment method of waste activated sludge (WAS), allows for safe disposal. The present study deals with the electro-Fenton (EF) pretreatment for enhancing the WAS biogas potential with low-cost iron electrodes. The effect of pretreatment on the physicochemical characteristics of sludge was assessed. Following EF pretreatment, the pH, conductivity, soluble chemical oxygen demand (SCOD), and volatile fatty acids (VFA) increased to 7.5, 13.72 mS/cm, 4.1 g/L, and 925 mg/L, respectively. Capillary suction time (CST) analysis highlighted the dewaterability effect of EF on WAS, as demonstrated by the decrease in CST from 429 to 180 s following 30 min of pretreatment. Batch digestion assays presented an increase in the biogas yield to 0.135 L/g volatile solids (VS) after 60 min of EF pretreatment in comparison to raw sludge (0.08 L/g VS). Production of biogas was also found to improve during semi-continuous fermentation of EF-pretreated sludge conducted in a lab-scale reactor. In comparison to raw sludge, EF-pretreated sludge produced the highest biogas yield (0.81 L biogas/g VS) with a high COD removal rate, reaching 96.6% at an organic loading rate (OLR) of 2.5 g VS/L. d. Results revealed that the EF process could be an effective WAS disintegration method with maximum recovery of bioenergy during A
Genomic characterization of three novel Pseudomonas phages within the subfamily of Autographivirinae isolated from organic waste
No full textThree phages targeting Pseudomonas syringae GAW0113 have been isolated from organic waste samples: Pseudomonas phage Bertil, Misse and Strit. The phages have double-stranded DNA genomes ranging from 41342 to 41374 bp in size comprising 50 to 51 open reading frames. The three phages genomes are highly similar and genomic comparison analyses shows that they all belong to the Autographivirinae subfamily of the family Podoviridae. The phages are however only distantly related to other members of this family, and have limited gene synteny with type-phages of other genera within Autographivirinae, suggesting that the newly isolated phages could represent a new genus
Connaître, conserver et promouvoir les arbres-habitats
No full textLa biodiversité joue un rôle important dans le fonctionnement des écosystèmes forestiers. Les arbres-habitats
(fig. 1) sont des éléments clés pour les espèces vivant en forêt. Des spécialistes européens ont élaboré une typologie détaillée des dendromicrohabitats, petits milieux de vie portés par les arbres et qui sont indispensables à
des milliers d’organismes spécialisés. La présentation homogène des formes, groupes et types de dendromicrohabitats ainsi définis facilite la mise en œuvre des recommandations dans la pratique forestière. En outre, les données homogénéisées qui résultent de l’emploi de cette typologie sont utiles pour le monitoring de la biodiversité forestière ou pour l’évaluation des résultats de mesures destinées à promouvoir cette diversité
Évaluation du risque simplifiée du tomato brown rugose fruit virus pour la France métropolitaine : Avis de l'Anses. Rapport d'expertise collective
No full textHow Big is the “Lemons” Problem? Historical Evidence from FrenchWines
No full textThis paper provides empirical evidence of large welfare losses associated with asymmetric in-
formation about product quality in a competitive market. When consumers cannot observe
product characteristics at the time of purchase, atomistic producers have no incentive to supply
costly quality. We compare wine prices across administrative districts around the enactment of
historic regulations aimed at certifying the quality of more than 250 French appellation wines
to identify welfare losses from asymmetric information. We estimate that these losses represent
up to 13% of total market value, suggesting an important role for credible certification schemes.Cet article donne des preuves empiriques de pertes importantes de bien-être causées par l’asymétrie
d’information sur la qualité des produits dans un marché concurrentiel. Lorsque les conso-
mateurs ne peuvent pas observer les caractéristiques du produit au moment de l’achat, les pro-
ducteurs atomistiques n’ont aucune incitation à fournir de biens de meilleure qualité s’ils sont
plus coûteux à produire. Nous comparons les prix du vin dans les différentes circonscriptions
administratives autour de la mise en place d’une réglementation historique visant à certifier la
qualité de plus de 250 vins français d’appellation d’origine, de manière à identifier les pertes
de bien-être dues à l’asymétrie d’information avant la réforme. Nous estimons que ces pertes
représentent jusqu’à 13% de la valeur totale du marché, ce qui suggère un rôle important pour
des systèmes de certification crédibles
