Epigenome-wide meta-analysis of blood DNA methylation in newborns and children identifies numerous loci related to gestational age

Background Preterm birth and shorter duration of pregnancy are associated with increased morbidity in neonatal and later life. As the epigenome is known to have an important role during fetal development, we investigated associations between gestational age and blood DNA methylation in children. Methods We performed meta-analysis of Illumina's HumanMethylation450-array associations between gestational age and cord blood DNA methylation in 3648 newborns from 17 cohorts without common pregnancy complications, induced delivery or caesarean section. We also explored associations of gestational age with DNA methylation measured at 4-18 years in additional pediatric cohorts. Follow-up analyses of DNA methylation and gene expression correlations were performed in cord blood. DNA methylation profiles were also explored in tissues relevant for gestational age health effects: fetal brain and lung. Results We identified 8899 CpGs in cord blood that were associated with gestational age (range 27-42 weeks), at Bonferroni significance, P <1.06 x 10(- 7), of which 3343 were novel. These were annotated to 4966 genes. After restricting findings to at least three significant adjacent CpGs, we identified 1276 CpGs annotated to 325 genes. Results were generally consistent when analyses were restricted to term births. Cord blood findings tended not to persist into childhood and adolescence. Pathway analyses identified enrichment for biological processes critical to embryonic development. Follow-up of identified genes showed correlations between gestational age and DNA methylation levels in fetal brain and lung tissue, as well as correlation with expression levels. Conclusions We identified numerous CpGs differentially methylated in relation to gestational age at birth that appear to reflect fetal developmental processes across tissues. These findings may contribute to understanding mechanisms linking gestational age to health effects.Peer reviewe

Data from The importance of wave exposure on the structural integrity of rhodoliths, Journal of Experimental Marine Biology and Ecology

The data here was used in the publication Melbourne et al, 2018, 'The importance of wave exposure on the structural integrity of rhodoliths', Journal of Experimental Marine Biology and Ecology, 503, Pages 109-119, doi.org/10.1016/j.jembe.2017.11.007 This paper focused on accurately quantifying the forced rhodoliths would experience under current and future wave velocities, as well as measuring accurate material properties. This dataset is part of a wider dataset for the PhD thesis of Leanne Melbourne titled 'The effect of environmental change on the structure, composition and subsequently the structural integrity of un-attached corallines'

Data from Potential and limitations of finite element modelling in assessing structural integrity of coralline algae under future global change, Biogeosciences

The data here was used in the publication Melbourne et al, 2015, 'Potential and limitations of finite element modelling in assessing structural integrity of coralline algae under future global change', Biogeosciences, 12, 5871–5883 doi:10.5194/bg-12-5871-2015 This paper focused on how finite element analysis can be used to assess structural integrity in rhodoliths (free-living forms of coralline algae). This dataset is part of a wider dataset for the PhD thesis of Leanne Melbourne titled 'The effect of environmental change on the structure, composition and subsequently the structural integrity of un-attached corallines'

Environmental impacts on the structural integrity of British rhodoliths

Abstract Coralline algae form complex habitats which are biodiversity hotspots. Experimental studies suggest that climate change will decrease coralline algal structural integrity. These experiments, however, lack information on local morphological variability and how much structural change would be needed to threaten habitat formation. Here, using finite element modelling, we assess variability in cellular structure and chemical composition of the carbonate skeleton of four coralline algal species from Britain in contemporary and historical specimens collected over the last 130 years. Cellular and mineral properties are highly variable within species, between sites and through time, with structurally weaker cells in the southern species and contemporary material compared to northern taxa and historical material. Yet, temporal differences in strength were smaller than spatial differences. Our work supports long term experiments which show the adaptation potential of this group. Our results suggest that future anthropogenic climate change may lead to loss of habitat complexity in the south and expansion of structurally weaker southern species into northern sites

Unexpected increase in structural integrity caused by thermally induced dwarfism in Large Benthic Foraminifera

Climate change is predicted to negatively impact calcification and change the structural integrity of biogenic carbonates, influencing their protective function. We assess impacts of warming on the morphology and crystallography of Amphistegina lobifera, an abundant benthic foraminifera species in shallow environments. Specimens from a thermally disturbed field area, mimicking future warming, are about 50% smaller compared to a control location. Differences in the position of the ν1 Raman mode of shells between the sites, which serves as a proxy for Mg content and calcification temperature, indicates that calcification is negatively impacted when temperatures are below the thermal range facilitating calcification. To test the impact of thermal stress on the Youngs modulus of calcite which contributes to structural integrity, we quantify elasticity changes in large benthic foraminifera by applying atomic force microscopy to a different genus, Operculina ammonoides, cultured under optimal and high temperatures. Building on these observations of size and the sensitivity analysis for temperature induced change in elasticity, we used finite element analysis to show that structural integrity is increased with reduced size and is largely insensitive to calcite elasticity. Our results indicate that warming-induced dwarfism creates shells that are more resistant to fracture because they are smaller