There is more to maerl than meets the eye:DNA barcoding reveals a new species in Britain, <i>Lithothamnion erinaceum</i> sp. nov. (Hapalidiales, Rhodophyta)

<p>Due to the high plasticity of coralline algae, identification based on morphology alone can be extremely difficult, so studies increasingly use a combination of morphology and genetics in species delimitation. A DNA barcoding study was carried out on maerl-forming coralline algae using the mitochondrial cytochrome oxidase 1 gene, CO1, and the plastid gene, <i>psb</i>A, on field specimens from Falmouth and Oban together with herbarium specimens from the Natural History Museum, UK, and the Smithsonian Institution, Washington, USA. Results revealed the presence in the north of Britain of a new species, <i>Lithothamnion erinaceum</i> Melbourne & J. Brodie, sp. nov., which was previously misidentified as <i>Lithothamnion glaciale</i>. The results also indicated that <i>Lithothamnion lemoineae</i>, which had earlier been recorded from Britain, was not present. One of the biggest concerns at present is how organisms will respond to climate change and ocean acidification, and it is imperative that investigations are put on a firm taxonomic basis. Our study has highlighted the importance of using molecular techniques to aid in the elucidation of cryptic diversity.</p

Insoluble prokaryotic membrane lipids in continental shelf sediments offshore Cape Town:implications for organic matter preservation

The largest organic carbon (OC) reservoir on Earth is in the geosphere, mainly comprising insoluble organic matter (IOM). IOM formation, therefore, plays an important role in the short and long-term carbon cycle, carbon bioavailability and formation of source rocks. To explore the mechanism of insolubilization of organic matter (OM), we have analysed soluble and IOM fractions of continental shelf marine sediments. We have applied sequential solvent-extractions followed by a selective chemical degradation of the post-extraction residue, specifically targeting prokaryotic membrane lipids (branched fatty acids – FAs, hopanoids, archaeol and glycerol dialkyl glycerol tetraethers – GDGTs). Up to 80% of prokaryotic membrane lipids are not solvent-extractable, and we observe compound-specific differences in partitioning between soluble and IOM fractions. Based on these observations, we propose a variety of mechanisms for the incorporation of prokaryotic lipids into IOM in marine sediments: First, OM association with authigenic carbonates; second, cross-linking via esterification reactions with time, which could be particularly relevant for FAs; third, competition between reactivity and loss of polar head groups, the latter rendering the OM less susceptible to incorporation; and finally, inherent solvent-insolubility of some lipids associated with prokaryotic cells

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 Importance of the local environment on skeletal structural integrity of coralline algae (Rhodophyta) around the UK_Marine Ecological Progress Series

The data here was used in the publication Melbourne et al, 2021, 'Importance of the local environment on skeletal structural integrity of coralline algae (Rhodophyta) around the UK ', Marine Ecological Progress Series (submitted). This paper focused on the spatial and temporal variability of the structural integrity of rhodoliths (free-living forms of coralline algae) from around the UK. 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 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'

Historical records of plasticity in coralline algae

In the shallow marine environment, a small number of habitat-forming skeletal organisms provide shelter and nursery grounds for other species. Free-living coralline algae (rhodoliths) build a complex three-dimensional skeleton and in large numbers form maerl beds which are biodiversity hotspots. Experiments suggest that coralline algae will be impacted by climate change. Here we assess phenotypic plasticity within cellular structure, growth rate and elemental composition of four species of coralline algae from the north and south of Britain. We compare contemporary specimens with historical material collected over the last century and determine how potential changes in growth affect structural integrity. Variation in cellular and mineral properties within a specimen and species is large. The cold temperate species L. glaciale and L. erinaceum have rounder, smaller cells compared to the more rectangular, larger cells of the warm temperate species P. calcareum and L. corallioides. Contemporary specimens form weaker skeletons than their historical counterparts, but the difference over time is not as large as the difference between cold adapted and warm adapted species. We predict that warm temperate species will still be structurally weaker as they will form more fragile skeletons compared to their cold temperate counterparts