DNA methylation in adults and during development of the self-fertilizing mangrove rivulus, Kryptolebias marmoratus

In addition to genetic variation, epigenetic mechanisms such as DNA methylation might make important contributions to heritable phenotypic diversity in populations. However, it is often difficult to disentangle the contributions of genetic and epigenetic variation to phenotypic diversity. Here, we investigated global DNA methylation and mRNA expression of the methylation-associated enzymes during embryonic development and in adult tissues of one natural isogenic lineage of mangrove rivulus fish, Kryptolebias marmoratus. Being the best-known self-fertilizing hermaphroditic vertebrate affords the opportunity to work with genetically identical individuals to examine, explicitly, the phenotypic effects of epigenetic variance. Using the LUminometric Methylation Assay (LUMA), we described variable global DNA methylation at CpG sites in adult tissues, which differed significantly between hermaphrodite ovotestes and male testes (79.6% and 87.2%, respectively). After fertilization, an immediate decrease in DNA methylation occurred to 15.8% in gastrula followed by re-establishment to 70.0% by stage 26 (liver formation). Compared to zebrafish, at the same embryonic stages, this reprogramming event seems later, deeper, and longer. Furthermore, genes putatively encoding DNA methyltransferases (DNMTs), Ten-Eleven Translocation (TET), and MeCP2 proteins showed specific regulation in adult gonad and brain, and also during early embryogenesis. Their conserved domains and expression profiles suggest that these proteins play important roles during reproduction and development. This study raises questions about mangrove rivulus' peculiar reprogramming period in terms of epigenetic transmission and physiological adaptation of individuals to highly variable environments. In accordance with the general-purpose genotype model, epigenetic mechanisms might allow for the expression of diverse phenotypes among genetically identical individuals. Such phenotypes might help to overcome environmental challenges, making the mangrove rivulus a valuable vertebrate model for ecological epigenetic studies. The mangrove rivulus, Kryptolebias marmoratus, is the best-known self-fertilizing hermaphroditic vertebrate that allows to work with genetically identical individuals to examine, explicitly, the phenotypic effects of epigenetic variance. The reprogramming event is later, more dramatic and longer than in other described vertebrates. High evolutionary conservation and expression patterns of DNMT, TET, and MeCP2 proteins in K. marmoratus suggest biological roles for each member in gametogenesis and development

Absorption foliaire des métaux présents dans des particules atmosphériques issues d'une usine de recyclage de batteries : biotest laitue

National audienceLes flux de polluants émis dans l'environnement ont été considérablement réduits en particulier par la mise en place par les industriels de système de filtres performants. Cependant les particules très fines et particulièrement réactives sont toujours émises dans l'environnement. De nombreuses études décrivent le transfert sol-plante des métaux mais très peu concernent la voie de transfert atmosphère plante. Pourtant, selon le rapport parlementaire de Miquel (2001), l'enrichissement actuel des sols en plomb provient pour 68% des retombées atmosphériques qui sont aussi interceptées par les plantes. Le transfert foliaire direct via des aérosols particulaires a été démontré pour des radionucléides (137Cs, 85Sr, 133Ba et 123mTe) par Madoz-Escande et al. (2004). Or les voies de transport des radionucléides et métaux sont aussi celles des "oligoélements" (Zn, Co, Mo, Cu) dans les plantes. C'est pourquoi il paraît pertinent de s'intéresser au transfert foliaire des métaux. De nombreuses questions scientifiques se posent en effet concernant le transfert foliaire des métaux. Est-il possible? Si oui sous quelle forme sont les métaux? Quels sont les mécanismes physico chimiques et biologiques impliqués? Quelle est l'importance de cette voie vis-à-vis du transfert sol plante ? Pour répondre à ces questions, le transfert du plomb et du cadmium vers les parties aériennes des plantes via le dépôt atmosphérique de particules industrielles riches en métaux a été expérimenté et modélisé

Avaliando o papel da aprendizagem socioecológica em governança participativa: construindo resiliência em seis comitês de bacias hidrográficas brasileiras

Brazil has embedded the socio-ecological learning process in the participatory management of river basin councils through its “sister laws” on water and the environment. GTHIDRO or, Grupo Transdisciplinar de Pesquisas em Governança da Água e do Território/Tecnologias Sociais para a Gestão da Água (TSGA), a transdisciplinary group of researchers at the Federal University of Santa Catarina, took these laws and developed new interpretations of socio-ecological learning. They incorporated an ethical component and a dynamic and complex program of participatory “cycles of learning” that brought committees and communities to a common understanding of socio-ecological processes, laws, and potential for collective action. Using resilience theory as a framework for understanding how to sustain and enhance adaptive capacity (Folke et al., 2002), this paper analyzes the processes of socio-ecological learning, including focus groups, physical dynamics that blend the conceptual with the physical, visioning, socio-ecological mapping, project planning and community celebrations through interviews, meeting notes, and written documents of the six case studies. The potential for socio-ecological learning as a tool for building the capacity of basin committees (Turvo, Ermo, Nova Veneza, Orleans e Braço do Norte in the southern part of the state, Urubici in the mountainous region, and Concordia in the middle eastern part) to plan and implement projects is substantiated as an important tool for building the resilience of the combined systems. The case studies indicate that their greatest achievement is the Strategic Planning Model for Sustainable Development, entitled PEDS, which diagrams how to improve the management core group’s capacity to plan and implement projects of their own design, using strategies they have learned and networks they have established in their watershed and state. While the potential for conflict over water and energy between the various economic sectors is strong in Brazil and elsewhere, with the GTHIDRO model the potential for collaboration on resource issues becomes even stronger. Observação dos Editores: O artigo foi publicado online em 16 de julho de 2014. Em 30 de julho de 2014, o arquivo foi substituído para inclusão de nomes de coautores.O Brasil tem incorporado o processo de aprendizagem socioecológica na gestão participativa dos conselhos de bacias hidrográficas por meio de suas “leis-irmãs” sobre a água e o meio ambiente. GTHIDRO, ou Grupo Transdisciplinar de Pesquisas em Governança da Água e do Território/Tecnologias Sociais para a Gestão da Água (TSGA), um grupo transdisciplinar de pesquisadores da Universidade Federal de Santa Catarina, abordou essas leis e desenvolveu novas interpretações de aprendizagem socioecológica. Eles incorporaram um componente ético e um programa dinâmico e complexo dos “ciclos de aprendizagem” participativos que trouxeram as comissões e as comunidades a um entendimento comum sobre os processos socioecológicos, as leis e o potencial para a ação coletiva. Usando a teoria da resiliência como uma estrutura para a compreensão de como manter e melhorar a capacidade de adaptação (Folke et al., 2002), este artigo analisa os processos de aprendizagem socioecológica, incluindo grupos focais, a dinâmica física que mistura o conceitual com o físico, a visão de futuro, o mapeamento socioecológico, o planejamento de projetos e celebrações comunitárias por meio de entrevistas, notas de reuniões e documentos escritos dos seis estudos de caso. O potencial de aprendizagem socioecológica como ferramenta para a construção da capacidade dos comitês de bacias (Turvo, Ermo, Nova Veneza, Orleans e Braço do Norte, na parte sul do Estado, Urubici, na região montanhosa, e Concórdia, no centro-leste) para planejar e implementar projetos está fundamentado como uma ferramenta importante para a construção da resiliência dos sistemas combinados. Os estudos de caso indicam que a sua maior conquista é o Modelo de Planejamento Estratégico para o Desenvolvimento Sustentável, intitulado PEDS, que esquematiza a forma de melhorar a capacidade do núcleo do grupo de gestão para planejar e implementar projetos de sua própria concepção, o uso de estratégias que se aprenderam e as redes que se estabeleceram em sua bacia hidrográfica e em seu Estado. Enquanto o potencial de conflito sobre a água e energia entre os diversos setores econômicos é forte no Brasil e em outros lugares, com o modelo GTHIDRO o potencial para a colaboração em questões de recursos torna-se ainda mais forte. Observação dos Editores: O artigo foi publicado online em 16 de julho de 2014. Em 30 de julho de 2014, o arquivo foi substituído para inclusão de nomes de coautores

a PREVIEW intervention study

3706738). The Cambridge Weight Plan® (Northants, UK) kindly donated all low-energy diet products. This study was also supported by grants from the University of Helsinki, the Mary and Georg Ehnrooth Foundation and the Otto A. Malm Foundation.BACKGROUND: Low-energy diets (LEDs) comprise commercially formulated food products that provide between 800 and 1200 kcal/day (3.3-5 MJ/day) to aid body weight loss. Recent small-scale studies suggest that LEDs are associated with marked changes in the gut microbiota that may modify the effect of the LED on host metabolism and weight loss. We investigated how the gut microbiota changed during 8 weeks of total meal replacement LED and determined their associations with host response in a sub-analysis of 211 overweight adults with pre-diabetes participating in the large multicentre PREVIEW (PREVention of diabetes through lifestyle intervention and population studies In Europe and around the World) clinical trial. METHODS: Microbial community composition was analysed by Illumina sequencing of the hypervariable V3-V4 regions of the 16S ribosomal RNA (rRNA) gene. Butyrate production capacity was estimated by qPCR targeting the butyryl-CoA:acetate CoA-transferase gene. Bioinformatics and statistical analyses, such as comparison of alpha and beta diversity measures, correlative and differential abundances analysis, were undertaken on the 16S rRNA gene sequences of 211 paired (pre- and post-LED) samples as well as their integration with the clinical, biomedical and dietary datasets for predictive modelling. RESULTS: The overall composition of the gut microbiota changed markedly and consistently from pre- to post-LED (P = 0.001), along with increased richness and diversity (both P < 0.001). Following the intervention, the relative abundance of several genera previously associated with metabolic improvements (e.g., Akkermansia and Christensenellaceae R-7 group) was significantly increased (P < 0.001), while flagellated Pseudobutyrivibrio, acetogenic Blautia and Bifidobacterium spp. were decreased (all P < 0.001). Butyrate production capacity was reduced (P < 0.001). The changes in microbiota composition and predicted functions were significantly associated with body weight loss (P < 0.05). Baseline gut microbiota features were able to explain ~25% of variation in total body fat change (post-pre-LED). CONCLUSIONS: The gut microbiota and individual taxa were significantly influenced by the LED intervention and correlated with changes in total body fat and body weight in individuals with overweight and pre-diabetes. Despite inter-individual variation, the baseline gut microbiota was a strong predictor of total body fat change during the energy restriction period. TRIAL REGISTRATION: The PREVIEW trial was prospectively registered at ClinicalTrials.gov ( NCT01777893 ) on January 29, 2013.publishersversionpublishe

A PREVIEW-New Zealand Sub-Study

As obesity develops, metabolic changes increase the risk of non-communicable diseases such as type 2 diabetes (T2D). Weight loss is crucial for improving health in T2D and cardiometabolic conditions. However, weight loss rates vary between individuals, even with identical diets or energy restrictions, highlighting the need to identify markers or predictors of weight loss success to enhance intervention outcomes. Using nuclear magnetic resonance (NMR) spectroscopy-based metabolomics, we investigated the change in serum polar metabolites in 28 women with overweight or obesity and prediabetes who completed an 8-week low-energy diet (LED) as part of the PREVIEW (PREVention of diabetes through lifestyle intervention and population studies in Europe and around the World) clinical trial. We aimed to characterize the metabolic shift in substrate oxidation under fixed energy intake (~4 MJ/day) and its relation to weight loss success. Nine of the thirty-four serum metabolites identified significantly changed during the LED phase: 3-hydroxybutyrate, O-acetylcarnitine, 2-hydroxybutyrate, mannose, dimethyl sulfone and isobutyrate increased, whilst choline, creatine and tyrosine decreased. These results confirmed a shift towards lipid oxidation, but no metabolites predicted the response to the LED-induced weight loss. Further studies in larger populations are required to validate these metabolites as biomarkers of diet exposure.publishersversionpublishe

The PREVIEW_NZ cohort

Publisher Copyright: © 2024 The AuthorsAim: Accumulation of circulating branched-chain amino acids (BCAA) is a hallmark feature of impaired insulin sensitivity. As intracellular BCAA catabolism is dependent on glycine availability, we hypothesised that the concurrent measurement of circulating glycine and BCAA may yield a stronger association with markers of insulin sensitivity than either BCAA or glycine alone. This study therefore examined the correlative relationships of BCAA, BCAA and glycine together, plus glycine alone on insulin sensitivity-related markers before and after an 8-week low energy diet (LED) intervention. Methods: This is a secondary analysis of the PREVIEW (PREVention of diabetes through lifestyle Intervention and population studies in Europe and around the World) Study New Zealand sub-cohort. Eligible participants with pre-diabetes at baseline who achieved ≥8 % body weight loss following an LED intervention were included, of which 167 paired (Week 0 and Week 8) blood samples were available for amino acid analysis. Glycemic and other data were retrieved from the PREVIEW consortium database. Repeated measures linear mixed models were used to test the association between amino acids and insulin sensitivity-related markers (HOMA2-IR, glucose, insulin, and C-peptide). Results: Elevated BCAA was associated with impaired insulin sensitivity (p < 0.05), with strength of association (ηp2) almost doubled when glycine was added to the model. However, glycine in isolation was not associated with insulin sensitivity-related markers. The magnitude (β-estimates) of positive association between BCAA and HOMA2-IR, and inverse association between glycine and HOMA2-IR, increased when body weight was higher (Body weight∗BCAA, Body weight∗glycine, p < 0.05, both). Conclusion: Low serum glycine strengthened the association between BCAA and impaired insulin sensitivity. Given that glycine is necessary to facilitate intracellular BCAA catabolism, measurement of glycine is necessary to complement BCAA analysis to comprehensively understand the contribution of amino acid metabolism in insulin sensitivity. Clinical trial registration: This study was registered with ClinicalTrials.gov (NCT01777893).publishersversionpublishe

a Tū Ora/PREVIEW comparative study

3713851). Publisher Copyright: Copyright © 2023 Mathrani, Lu, Sequeira-Bisson, Silvestre, Hoggard, Barnett, Fogelholm, Raben, Poppitt and Taylor.Obesity-related metabolic diseases such as type 2 diabetes (T2D) are major global health issues, affecting hundreds of millions of people worldwide. The underlying factors are both diverse and complex, incorporating biological as well as cultural considerations. A role for ethnicity – a measure of self-perceived cultural affiliation which encompasses diet, lifestyle and genetic components – in susceptibility to metabolic diseases such as T2D is well established. For example, Asian populations may be disproportionally affected by the adverse ‘TOFI’ (Thin on the Outside, Fat on the Inside) profile, whereby outwardly lean individuals have increased susceptibility due to excess visceral and ectopic organ fat deposition. A potential link between the gut microbiota and metabolic disease has more recently come under consideration, yet our understanding of the interplay between ethnicity, the microbiota and T2D remains incomplete. We present here a 16S rRNA gene-based comparison of the fecal microbiota of European-ancestry and Chinese-ancestry cohorts with overweight and prediabetes, residing in New Zealand. The cohorts were matched for mean fasting plasma glucose (FPG: mean ± SD, European-ancestry: 6.1 ± 0.4; Chinese-ancestry: 6.0 ± 0.4 mmol/L), a consequence of which was a significantly higher mean body mass index in the European group (BMI: European-ancestry: 37.4 ± 6.8; Chinese-ancestry: 27.7 ± 4.0 kg/m2; p < 0.001). Our findings reveal significant microbiota differences between the two ethnicities, though we cannot determine the underpinning factors. In both cohorts Firmicutes was by far the dominant bacterial phylum (European-ancestry: 93.4 ± 5.5%; Chinese-ancestry: 79.6 ± 10.4% of 16S rRNA gene sequences), with Bacteroidetes and Actinobacteria the next most abundant. Among the more abundant (≥1% overall relative sequence abundance) genus-level taxa, four zero-radius operational taxonomic units (zOTUs) were significantly higher in the European-ancestry cohort, namely members of the Subdoligranulum, Blautia, Ruminoclostridium, and Dorea genera. Differential abundance analysis further identified a number of additional zOTUs to be disproportionately overrepresented across the two ethnicities, with the majority of taxa exhibiting a higher abundance in the Chinese-ancestry cohort. Our findings underscore a potential influence of ethnicity on gut microbiota composition in the context of individuals with overweight and prediabetes.publishersversionpublishe