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  • Journal article
    Budzak J, Goodwin I, Tiengwe C, Rudenko Get al., 2023,

    Imaging of genomic loci in Trypanosoma brucei using an optimised LacO-LacI system

    , Molecular and Biochemical Parasitology, Vol: 256, ISSN: 0166-6851

    Visualisation of genomic loci by microscopy is essential for understanding nuclear organisation, particularly at the single cell level. One powerful technique for studying the positioning of genomic loci is through the Lac Operator-Lac Repressor (LacO-LacI) system, in which LacO repeats introduced into a specific genomic locus can be visualised through expression of a LacI-protein fused to a fluorescent tag. First utilised in Trypanosoma brucei over 20 years ago, we have now optimised this system with short, stabilised LacO repeats of less than 2 kb paired with a constitutively expressed mNeongreen::LacI fusion protein to facilitate visualisation of genomic loci. We demonstrate the compatibility of this system with super-resolution microscopy and propose its suitability for multiplexing with inducible RNAi or protein over expression which will allow analysis of nuclear organisation after perturbation of gene expression.

  • Journal article
    Gonzalez A, Vihervaara P, Balvanera P, Bates AE, Bayraktarov E, Bellingham PJ, Bruder A, Campbell J, Catchen MD, Cavender-Bares J, Chase J, Coops N, Costello MJ, Czúcz B, Delavaud A, Dornelas M, Dubois G, Duffy EJ, Eggermont H, Fernandez M, Fernandez N, Ferrier S, Geller GN, Gill M, Gravel D, Guerra CA, Guralnick R, Harfoot M, Hirsch T, Hoban S, Hughes AC, Hugo W, Hunter ME, Isbell F, Jetz W, Juergens N, Kissling WD, Krug CB, Kullberg P, Le Bras Y, Leung B, Londoño-Murcia MC, Lord J-M, Loreau M, Luers A, Ma K, MacDonald AJ, Maes J, McGeoch M, Mihoub JB, Millette KL, Molnar Z, Montes E, Mori AS, Muller-Karger FE, Muraoka H, Nakaoka M, Navarro L, Newbold T, Niamir A, Obura D, O'Connor M, Paganini M, Pelletier D, Pereira H, Poisot T, Pollock LJ, Purvis A, Radulovici A, Rocchini D, Roeoesli C, Schaepman M, Schaepman-Strub G, Schmeller DS, Schmiedel U, Schneider FD, Shakya MM, Skidmore A, Skowno AL, Takeuchi Y, Tuanmu M-N, Turak E, Turner W, Urban MC, Urbina-Cardona N, Valbuena R, Van de Putte A, van Havre B, Wingate VR, Wright E, Torrelio CZet al., 2023,

    Author Correction: A global biodiversity observing system to unite monitoring and guide action.

    , Nat Ecol Evol, Vol: 7
  • Journal article
    Beattie JW, Rowland-Jones RC, Farys M, Bettany H, Hilton D, Kazarian SG, Byrne Bet al., 2023,

    Application of Raman spectroscopy to dynamic binding capacity analysis

    , Applied Spectroscopy, Vol: 77, Pages: 1393-1400, ISSN: 0003-7028

    Protein A affinity chromatography is a key step in isolation of biotherapeutics (BTs) containing fragment crystallizable regions, including monoclonal and bispecific antibodies. Dynamic binding capacity (DBC) analysis assesses how much BT will bind to a protein A column. DBC reduces with column usage, effectively reducing the amount of recovered product over time. Drug regulatory bodies mandate chromatography resin lifetime for BT isolation, through measurement of parameters including DBC, so this feature is carefully monitored in industrial purification pipelines. High-performance affinity chromatography (HPAC) is typically used to assess the concentration of BT, which when loaded to the column results in significant breakthrough of BT in the flowthrough. HPAC gives an accurate assessment of DBC and how this changes over time but only reports on protein concentration, requires calibration for each new BT analyzed, and can only be used offline. Here we utilized Raman spectroscopy and revealed that this approach is at least as effective as both HPAC and ultraviolet chromatogram methods at monitoring DBC of protein A resins. In addition to reporting on protein concentration, the chemical information in the Raman spectra provides information on aggregation status and protein structure, providing extra quality controls to industrial bioprocessing pipelines. In combination with partial least square (PLS) analysis, Raman spectroscopy can be used to determine the DBC of a BT without prior calibration. Here we performed Raman analysis offline in a 96-well plate format, however, it is feasible to perform this inline. This study demonstrates the power of Raman spectroscopy as a significantly improved approach to DBC monitoring in industrial pipelines.

  • Journal article
    Peng Y, Prentice IC, Bloomfield KJ, Campioli M, Guo Z, Sun Y, Tian D, Wang X, Vicca S, Stocker BDet al., 2023,

    Global terrestrial nitrogen uptake and nitrogen use efficiency

    , Journal of Ecology, Vol: 111, Pages: 2676-2693, ISSN: 0022-0477

    1. Plant biomass production (BP), nitrogen uptake (Nup) and their ratio, nitrogen use efficiency (NUE), must be quantified to understand how nitrogen (N) cycling constrains terrestrial carbon (C) uptake. But the controls of key plant processes determining Nup and NUE, including BP, C and N allocation, tissue C:N ratios and N resorption efficiency (NRE), remain poorly known. 2. We compiled measurements from 804 forest and grassland sites and derived regression models for each of these processes with growth temperature, vapour pressure deficit, stand age, soil C:N ratio, fAPAR (remotely sensed fraction of photosynthetically active radiation absorbed by green vegetation) and growing-season average daily incident photosynthetic photon flux density (gPPFD) (effectively the seasonal concentration of light availability, which increases polewards) as predictors. An empirical model for leaf N was based on optimal photosynthetic capacity (a function of gPPFD and climate) and observed leaf mass-per-area. The models were used to produce global maps of Nup and NUE. 3. Global BP was estimated as 72 Pg C/yr; Nup as 950 Tg N/yr; and NUE as 76 gC/gN. Forest BP was found to increase with growth temperature and fAPAR and to decrease with stand age, soil C:N ratio and gPPFD. Forest NUE is controlled primarily by climate through its effect on C allocation – especially to leaves, being richer in N than other tissues. NUE is greater in colder climates, where N is less readily available, because belowground allocation is increased. NUE is also greater in drier climates because leaf allocation is reduced. NRE is enhanced (further promoting NUE) in both cold and dry climates. 4. These findings can provide observationally based benchmarks for model representations of C–N cycle coupling. State-of-the-art vegetation models in the TRENDY ensemble showed variable performance against these benchmarks, and models including coupled C–N cycling produced relatively poor simulations o

  • Journal article
    Delabre I, Lyons-White J, Melot C, Veggeberg EI, Alexander A, Schleper MCC, Ewers RMM, Knight ATTet al., 2023,

    Should I stay or should I go? Understanding stakeholder dis/engagement for deforestation-free palm oil

    , Business Strategy and the Environment, Vol: 32, Pages: 5128-5145, ISSN: 0964-4733

    Addressing tropical deforestation in the palm oil sector involves a diverse range of stakeholders who engage or disengage with each other. Palm oil global value chain (GVC) firms (plantation companies, traders and processors, and consumer goods manufacturers and retailers), as well as nongovernmental organisations, financial institutions, consultancies and certification bodies, pursue their respective organisations' agendas through engagement practices, including through coalitions, in a palm oil sustainability network (POSN). Building on interviews with different stakeholder groups, this qualitative study characterises and critically analyses ‘stakeholder engagement’ by examining (1) the priority targets for engagement among different POSN stakeholders, (2) how mechanisms and tools are used in POSN stakeholder engagement or disengagement for addressing deforestation, and (3) the implications of stakeholder engagement or disengagement for addressing deforestation. Engagement and disengagement practices are shaped by and reshape GVC governance, with powerful stakeholders emerging as knowledge brokers and norm setters, raising important challenges for how deforestation is addressed.

  • Journal article
    Chawda MM, Ross S, Lau C-I, Yánez DC, Rowell J, Kilbride P, Crompton Tet al., 2023,

    Cryopreservation of mouse thymus depletes thymocytes but supports immune reconstitution on transplantation.

    , Eur J Immunol, Vol: 53

    Cryopreservation of mouse thymus depletes donor thymocytes but preserves thymus function when transplanted after thawing into athymic mice. No differences in immune reconstitution were observed between fresh and frozen/thawed transplants suggesting that donor thymocyte depletion does not affect outcome. Thus, cryopreservation of thymus may improve outcomes in thymus transplant patients.

  • Journal article
    Keenan TF, Luo X, Stocker BD, De Kauwe MG, Medlyn BE, Prentice IC, Smith NG, Terrer C, Wang H, Zhang Y, Zhou Set al., 2023,

    A constraint on historic growth in global photosynthesis due to rising CO2

    , Nature Climate Change, Vol: 13, Pages: 1376-1381, ISSN: 1758-678X

    Theory predicts that rising CO2 increases global photosynthesis, a process known as CO2 fertilization, and that this is responsible for a large proportion of the current terrestrial carbon sink. The estimated magnitude of the historic CO2 fertilization, however, differs by an order ofmagnitude between long-term proxies, remote sensing-based estimates and terrestrial biosphere models. Here we constrain the likely historic effect of CO2 on global photosynthesis by combining terrestrial biosphere models, ecological optimality theory, remote sensing approaches and an emergent constraint based on global carbon budget estimates. Our analysis suggests that CO2 fertilization increased global annual terrestrial photosynthesis by 13.5 ± 3.5%, or 15.9 ± 2.9 Pg C u(mean ± standard deviation) between 1981 and 2020. Our results help resolve conflicting estimates of the historic sensitivity of global terrestrial photosynthesis to CO2 and highlight the large impact anthropogenic emissions have had on ecosystems worldwide.

  • Journal article
    Matanza XM, Clements A, 2023,

    Pathogenicity and virulence of Shigella sonnei: A highly drug-resistant pathogen of increasing prevalence.

    , Virulence, Vol: 14

    Shigella spp. are the causative agent of shigellosis (or bacillary dysentery), a diarrhoeal disease characterized for the bacterial invasion of gut epithelial cells. Among the 4 species included in the genus, Shigella flexneri is principally responsible for the disease in the developing world while Shigella sonnei is the main causative agent in high-income countries. Remarkably, as more countries improve their socioeconomic conditions, we observe an increase in the relative prevalence of S. sonnei. To date, the reasons behind this change in aetiology depending on economic growth are not understood. S. flexneri has been widely used as a model to study the pathogenesis of the genus, but as more research data are collected, important discrepancies with S. sonnei have come to light. In comparison to S. flexneri, S. sonnei can be differentiated in numerous aspects; it presents a characteristic O-antigen identical to that of one serogroup of the environmental bacterium Plesiomonas shigelloides, a group 4 capsule, antibacterial mechanisms to outcompete and displace gut commensal bacteria, and a poorer adaptation to an intracellular lifestyle. In addition, the World Health Organization (WHO) have recognized the significant threat posed by antibiotic-resistant strains of S. sonnei, demanding new approaches. This review gathers knowledge on what is known about S. sonnei within the context of other Shigella spp. and aims to open the door for future research on understanding the increasing spread of this pathogen.

  • Journal article
    Maretvadakethope S, Hazel AL, Vasiev B, Bearon RNet al., 2023,

    The interplay between bulk flow and boundary conditions on the distribution of microswimmers in channel flow

    , Journal of Fluid Mechanics, Vol: 976, ISSN: 0022-1120

    While previous experimental and numerical studies of dilute microswimmer suspensions have focused on the behaviours of swimmers in the bulk flow and near boundaries, models typically do not account for the interplay between bulk flow and the choice of boundary conditions imposed in continuum models. In our work, we highlight the effect of boundary conditions on the bulk flow distributions, such as through the development of boundary layers or secondary peaks of cell accumulation in bulk-flow swimmer dynamics. For the case of a dilute swimmer suspension in Poiseuille flow, we compare the distribution (in physical and orientation space) obtained from individual-based stochastic models with those from continuum models, and identify under what conditions it is mathematically sensible to use specific continuum boundary conditions to capture different physical scenarios (i.e. specular reflection, uniform random reflection and absorbing boundaries). We identify that the spread of preferred cell orientations is dependent on the interplay between rotation driven by the shear flow (Jeffery orbits) and rotational diffusion. We find that in the absence of hydrodynamic wall interactions, swimmers preferentially approach the walls perpendicular to the surface in the presence of high rotational diffusion, and that the preferential approach of swimmers to the walls is shape-dependent at low rotational diffusion (when suspensions tend towards a fully deterministic case). In the latter case, the preferred orientations are nearly parallel to the surface for elongated swimmers and nearly perpendicular to the surface for near-spherical swimmers. Furthermore, we highlight the effects of swimmer geometries and shear throughout the bulk-flow on swimmer trajectories and show how the full history of bulk-flow dynamics affects the orientation distributions of microswimmer wall incidence.

  • Journal article
    Merali N, Chouari T, Terroire J, Jessel M-D, Liu DSK, Smith J-H, Wooldridge T, Dhillon T, Jiménez JI, Krell J, Roberts KJ, Rockall TA, Velliou E, Sivakumar S, Giovannetti E, Demirkan A, Annels NE, Frampton AEet al., 2023,

    Bile microbiome signatures associated with pancreatic ductal adenocarcinoma compared to benign disease: a UK pilot study

    , International Journal of Molecular Sciences, Vol: 24, ISSN: 1422-0067

    Pancreatic ductal adenocarcinoma (PDAC) has a very poor survival. The intra-tumoural microbiome can influence pancreatic tumourigenesis and chemoresistance and, therefore, patient survival. The role played by bile microbiota in PDAC is unknown. We aimed to define bile microbiome signatures that can effectively distinguish malignant from benign tumours in patients presenting with obstructive jaundice caused by benign and malignant pancreaticobiliary disease. Prospective bile samples were obtained from 31 patients who underwent either Endoscopic Retrograde Cholangiopancreatography (ERCP) or Percutaneous Transhepatic Cholangiogram (PTC). Variable regions (V3-V4) of the 16S rRNA genes of microorganisms present in the samples were amplified by Polymerase Chain Reaction (PCR) and sequenced. The cohort consisted of 12 PDAC, 10 choledocholithiasis, seven gallstone pancreatitis and two primary sclerosing cholangitis patients. Using the 16S rRNA method, we identified a total of 135 genera from 29 individuals (12 PDAC and 17 benign). The bile microbial beta diversity significantly differed between patients with PDAC vs. benign disease (Permanova p = 0.0173). The separation of PDAC from benign samples is clearly seen through unsupervised clustering of Aitchison distance. We found three genera to be of significantly lower abundance among PDAC samples vs. benign, adjusting for false discovery rate (FDR). These were Escherichia (FDR = 0.002) and two unclassified genera, one from Proteobacteria (FDR = 0.002) and one from Enterobacteriaceae (FDR = 0.011). In the same samples, the genus Streptococcus (FDR = 0.033) was found to be of increased abundance in the PDAC group. We show that patients with obstructive jaundice caused by PDAC have an altered microbiome composition in the bile compared to those with benign disease. These bile-based microbes could be developed into potential diagnostic and prognostic biomarkers for PDAC and warrant further investigation.

  • Journal article
    Stępień P, Świątek S, Robles MYY, Markiewicz-Mizera J, Balakrishnan D, Inaba-Inoue S, De Vries AH, Beis K, Marrink SJ, Heddle JGet al., 2023,

    CRAFTing Delivery of Membrane Proteins into Protocells using Nanodiscs.

    , ACS Appl Mater Interfaces, Vol: 15, Pages: 56689-56701

    For the successful generative engineering of functional artificial cells, a convenient and controllable means of delivering membrane proteins into membrane lipid bilayers is necessary. Here we report a delivery system that achieves this by employing membrane protein-carrying nanodiscs and the calcium-dependent fusion of phosphatidylserine lipid membranes. We show that lipid nanodiscs can fuse a transported lipid bilayer with the lipid bilayers of small unilamellar vesicles (SUVs) or giant unilamellar vesicles (GUVs) while avoiding recipient vesicles aggregation. This is triggered by a simple, transient increase in calcium concentration, which results in efficient and rapid fusion in a one-pot reaction. Furthermore, nanodiscs can be loaded with membrane proteins that can be delivered into target SUV or GUV membranes in a detergent-independent fashion while retaining their functionality. Nanodiscs have a proven ability to carry a wide range of membrane proteins, control their oligomeric state, and are highly adaptable. Given this, our approach may be the basis for the development of useful tools that will allow bespoke delivery of membrane proteins to protocells, equipping them with the cell-like ability to exchange material across outer/subcellular membranes.

  • Journal article
    Dimitrov D, Xu X, Su X, Shrestha N, Liu Y, Kennedy JD, Lyu L, Nogués-Bravo D, Rosindell J, Yang Y, Fjeldså J, Liu J, Schmid B, Fang J, Rahbek C, Wang Zet al., 2023,

    Diversification of flowering plants in space and time.

    , Nat Commun, Vol: 14

    The rapid diversification and high species richness of flowering plants is regarded as 'Darwin's second abominable mystery'. Today the global spatiotemporal pattern of plant diversification remains elusive. Using a newly generated genus-level phylogeny and global distribution data for 14,244 flowering plant genera, we describe the diversification dynamics of angiosperms through space and time. Our analyses show that diversification rates increased throughout the early Cretaceous and then slightly decreased or remained mostly stable until the end of the Cretaceous-Paleogene mass extinction event 66 million years ago. After that, diversification rates increased again towards the present. Younger genera with high diversification rates dominate temperate and dryland regions, whereas old genera with low diversification dominate the tropics. This leads to a negative correlation between spatial patterns of diversification and genus diversity. Our findings suggest that global changes since the Cenozoic shaped the patterns of flowering plant diversity and support an emerging consensus that diversification rates are higher outside the tropics.

  • Journal article
    Xu H, Wang H, Prentice IC, Harrison SPet al., 2023,

    Leaf carbon and nitrogen stoichiometric variation alongenvironmental gradients

    , Biogeosciences, Vol: 20, Pages: 4511-4525, ISSN: 1726-4170

    Leaf stoichiometric traits are central to ecosystem function and biogeochemical cycling, yet no accepted theory predicts their variation along environmental gradients. Using data in the China Plant Trait Database version 2, we aimed to characterize variation in leaf carbon and nitrogen per unit mass (Cmass, Nmass) and their ratio, and to test an eco-evolutionary optimality model for Nmass. Community-mean trait values were related to climate variables by multiple linear regression. Climatic optima and tolerances of major genera were estimated; Pagel’s λ was used to quantify phylogenetic controls, and Bayesian phylogenetic linear mixed models to assess the contributions of climate, species identity and phylogeny. Optimality-based predictions of community-mean Nmass were compared to observed values. All traits showed strong phylogenetic signals. Climate explained only 18 % of C : N ratio variation among species but 45 % among communities, highlighting the role of taxonomic replacement in mediating community-level responses. Geographic distributions of deciduous taxa separated primarily by moisture, evergreens by temperature. Cmass increased with irradiance, but decreased with moisture and temperature. Nmass declined with all three variables. C : N ratio variations were dominated by Nmass. The coefficients relating Nmass to the ratio of maximum carboxylation capacity at 25 °C (Vcmax25) and leaf mass per area (Ma) were influenced by leaf area index. The optimality model captured 68 % and 53 % of variation between communities for Vcmax25 and Ma respectively, and 30 % for Nmass. We conclude that stoichiometric variations along climate gradients are achieved largely by environmental selection among species and clades with different characteristic trait values. Variations in leaf C : N ratio are mainly determined by Nmass, and optimality-based modelling shows useful predictive ability for community-mean Nmass. These findings should help to improve the repres

  • Journal article
    Brazeau M, Castiello M, El Fassi El Fehri A, Hamilton L, Ivanov AO, Johanson Z, Friedman Met al., 2023,

    Fossil evidence for a pharyngeal origin of the vertebrate pectoral girdle

    , Nature, Vol: 623, Pages: 550-554, ISSN: 0028-0836

    The origin of vertebrate paired appendages is one of the most investigated and debated examples of evolutionary novelty. Paired appendages are widely considered key innovations that allowed new opportunities for controlled swimming and gill ventilation and were prerequisites for the eventual transition from water to land. The last 150 years of debate has been shaped by two contentious theories: the ventrolateral fin-fold hypothesis and the archipterygium hypothesis. The latter proposes that fins and girdles evolved from an ancestral gill arch. Although tantalizing developmental evidence has revived interest in this idea, it is apparently unsupported by fossil evidence. Here we present fossil evidence of a pharyngeal basis for the vertebrate shoulder girdle. We use CT scanning to reveal details of the braincase of Kolymaspis sibirica, a placoderm fish from the Early Devonian of Siberia that suggests a pharyngeal component of the shoulder. We combine these findings with refreshed comparative anatomy of placoderms and jawless outgroups to place the origin of the shoulder girdle on the sixth branchial arch. These findings provide a novel framework for understanding the origin of the pectoral girdle. Our new evidence clarifies the location of the presumptive head-trunk interface in jawless fishes and explains the constraint on branchial arch number in gnathostomes. The results revive a key aspect of the archipterygium hypothesis, but also reconciles it with the ventrolateral fin fold model.

  • Journal article
    Davydova S, Liu J, Kandul NP, Braswell WE, Akbari OS, Meccariello Aet al., 2023,

    Next-generation genetic sexing strain establishment in the agricultural pest Ceratitis capitata.

    , Sci Rep, Vol: 13

    Tephritid fruit fly pests pose an increasing threat to the agricultural industry due to their global dispersion and a highly invasive nature. Here we showcase the feasibility of an early-detection SEPARATOR sex sorting approach through using the non-model Tephritid pest, Ceratitis capitata. This system relies on female-only fluorescent marker expression, accomplished through the use of a sex-specific intron of the highly-conserved transformer gene from C. capitata and Anastrepha ludens. The herein characterized strains have 100% desired phenotype outcomes, allowing accurate male-female separation during early development. Overall, we describe an antibiotic and temperature-independent sex-sorting system in C. capitata, which, moving forward, may be implemented in other non-model Tephritid pest species. This strategy can facilitate the establishment of genetic sexing systems with endogenous elements exclusively, which, on a wider scale, can improve pest population control strategies like sterile insect technique.

  • Other
    Blackford KR, Kasoar M, Burton C, Burke E, Prentice IC, Voulgarakis Aet al., 2023,

    Supplementary material to "INFERNO-peat v1.0.0: A representation of northern high latitude peat fires in the JULES-INFERNO global fire model"

  • Journal article
    Jones H, Willis J, Firth L, Giachello C, Gilestro Get al., 2023,

    A reductionist paradigm for high-throughput behavioural fingerprinting in Drosophila melanogaster

    , eLife, ISSN: 2050-084X
  • Journal article
    Mwima R, Hui T-YJ, Nanteza A, Burt A, Kayondo JKet al., 2023,

    Potential persistence mechanisms of the major Anopheles gambiae species complex malaria vectors in sub-Saharan Africa: a narrative review

    , Malaria Journal, Vol: 22, ISSN: 1475-2875

    The source of malaria vector populations that re-establish at the beginning of the rainy season is still unclear yet knowledge of mosquito behaviour is required to effectively institute control measures. Alternative hypotheses like aestivation, local refugia, migration between neighbouring sites, and long-distance migration (LDM) are stipulated to support mosquito persistence. This work assessed the malaria vector persistence dynamics and examined various studies done on vector survival  via these hypotheses; aestivation, local refugia, local or long-distance migration across sub-Saharan Africa, explored a range of methods used, ecological parameters and highlighted the knowledge trends and gaps. The results about a particular persistence mechanism that supports the re-establishment of Anopheles gambiae, Anopheles coluzzii or Anopheles arabiensis in sub-Saharan Africa were not conclusive given that each method used had its limitations. For example, the Mark-Release-Recapture (MRR) method whose challenge is a low recapture rate that affects its accuracy, and the use of time series analysis through field collections whose challenge is the uncertainty about whether not finding mosquitoes during the dry season is a weakness of the conventional sampling methods used or because of hidden shelters. This, therefore, calls for further investigations emphasizing the use of ecological experiments under controlled conditions in the laboratory or semi-field, and genetic approaches, as they are known to complement each other. This review, therefore, unveils and assesses the uncertainties that influence the different malaria vector persistence mechanisms and provides recommendations for future studies.

  • Journal article
    Cruz-Silva E, Harrison SP, Colin Prentice I, Marinova E, Bartlein PJ, Renssen H, Zhang Yet al., 2023,

    Pollen-based reconstructions of Holocene climate trends in the eastern Mediterranean region

    , Climate of the Past, Vol: 19, Pages: 2093-2108, ISSN: 1814-9324

    There has been considerable debate about the degree to which climate has driven societal changes in the eastern Mediterranean region, partly through reliance on a limited number of qualitative records of climate changes and partly reflecting the need to disentangle the joint impact of changes in different aspects of climate. Here, we use tolerance-weighted, weighted-averaging partial least squares to derive reconstructions of the mean temperature of the coldest month (MTCO), mean temperature of the warmest month (MTWA), growing degree days above a threshold of 0 C (GDD0), and plant-available moisture, which is represented by the ratio of modelled actual to equilibrium evapotranspiration (α) and corrected for past CO2 changes. This is done for 71 individual pollen records from the eastern Mediterranean region covering part or all of the interval from 12.3 ka to the present. We use these reconstructions to create regional composites that illustrate the long-term trends in each variable. We compare these composites with transient climate model simulations to explore potential causes of the observed trends. We show that the glacial-Holocene transition and the early part of the Holocene was characterised by conditions colder than the present. Rapid increases in temperature occurred between ca. 10.3 and 9.3 ka, considerably after the end of the Younger Dryas. Although the time series are characterised by centennial to millennial oscillations, the MTCO showed a gradual increase from 9 ka to the present, consistent with the expectation that winter temperatures were forced by orbitally induced increases in insolation during the Holocene. The MTWA also showed an increasing trend from 9 ka and reached a maximum of ca. 1.5 C greater than the present at ca. 4.5 and 5 ka, followed by a gradual decline towards present-day conditions. A delayed response to summer insolation changes is likely a reflection of the persistence of the Laurentide and Fennoscandian ice sheets; subse

  • Journal article
    Burton VJ, Baselga A, De Palma A, Phillips HRP, Mulder C, Eggleton P, Purvis Aet al., 2023,

    Effects of land use and soil properties on taxon richness and abundance of soil assemblages

    , European Journal of Soil Science, Vol: 74, ISSN: 1351-0754

    Land-use change and habitat degradation are among the biggest drivers of aboveground biodiversity worldwide but their effects on soil biodiversity are less well known, despite the importance of soil organisms in developing soil structure, nutrient cycling and water drainage. Combining a global compilation of biodiversity data from soil assemblages collated as part of the PREDICTS project with global data on soil characteristics, we modelled how taxon richness and total abundance of soil organisms have responded to land use. We also estimated the global Biodiversity Intactness Index (BII)—the average abundance and compositional similarity of taxa that remain in an area, compared to a minimally impacted baseline, for soil biodiversity. This is the first time the BII has been calculated for soil biodiversity. Relative to undisturbed vegetation, soil organism total abundance and taxon richness were reduced in all land uses except pasture. Soil properties mediated the response of soil biota, but not in a consistent way across land uses. The global soil BII in cropland is, on average, a third of that originally present. However, in grazed sites the decline is less severe. The BII of secondary vegetation depends on age, with sites with younger growth showing a lower BII than mature vegetation. We conclude that land-use change has reduced local soil biodiversity worldwide, and this further supports the proposition that soil biota should be considered explicitly when using global models to estimate the state of biodiversity.

  • Journal article
    Mayfield MM, Lau JA, Tobias JA, Ives AR, Strauss SYet al., 2023,

    What Can Evolutionary History Tell Us about the Functioning of Ecological Communities? The ASN Presidential Debate

    , AMERICAN NATURALIST, ISSN: 0003-0147
  • Journal article
    Stewart K, Carmona CP, Clements C, Venditti C, Tobias JA, González-Suárez Met al., 2023,

    Functional diversity metrics can perform well with highly incomplete data sets

    , Methods in Ecology and Evolution, Vol: 14, Pages: 2856-2872

    Characterising changes in functional diversity at large spatial scales provides insight into the impact of human activity on ecosystem structure and function. However, the approach is often based on trait data sets that are incomplete and unrepresentative, with uncertain impacts on functional diversity estimates. To address this knowledge gap, we simulated random and biased removal of data from three empirical trait data sets: an avian data set (9579 species), a plant data set (2185 species) and a crocodilian data set (25 species). For these data sets, we assessed whether functional diversity metrics were robust to data incompleteness with and without using imputation to fill data gaps. We compared two metrics each calculated with two methods: functional richness (calculated with convex hulls and trait probabilities densities) and functional divergence (calculated with distance-based Rao and trait probability densities). Without imputation, estimates of functional diversity (richness and divergence) for birds and plants were robust when 20%–70% of species had missing data for four out of 11 and two out of six continuous traits, respectively, depending on the severity of bias and method used. However, when missing traits were imputed, functional diversity metrics consistently remained representative of the true value when 70% of bird species were missing data for four out of 11 traits and when 50% of plant species were missing data for two out of six traits. Trait probability densities and distance-based Rao were particularly robust to missingness and bias when combined with imputation. Convex hull-based estimations of functional richness were less reliable. When applied to a smaller data set (crocodilians, 25 species), all functional diversity metrics were much more sensitive to missing data. Expanding global morphometric data sets to represent more taxa and traits, and to quantify intraspecific variation, remains a priority. In the meantime, our results show

  • Journal article
    Saunders T, Adkins J, Beard KH, Atwood TB, Waring BGet al., 2023,

    Herbivores influence biogeochemical processes by altering litter quality and quantity in a subarctic wetland

    , Biogeochemistry, Vol: 166, Pages: 67-85, ISSN: 0168-2563

    Global change drivers that modify the quality and quantity of litter inputs to soil affect greenhouse gas fluxes, and thereby constitute a feedback to climate change. Carbon cycling in the Yukon–Kuskokwim (Y–K) River Delta, a subarctic wetland system, is influenced by landscape variations in litter quality and quantity generated by herbivores (migratory birds) that create ‘grazing lawns’ of short stature, nitrogen-rich vegetation. To identify the mechanisms by which these changes in litter inputs affect soil carbon balance, we independently manipulated qualities and quantities of litter representative of levels found in the Y–K Delta in a fully factorial microcosm experiment. We measured CO2 fluxes from these microcosms weekly. To help us identify how litter inputs influenced greenhouse gas fluxes, we sequenced soil fungal and bacterial communities, and measured soil microbial biomass carbon, dissolved carbon, inorganic nitrogen, and enzyme activity. We found that positive correlations between litter input quantity and CO2 flux were dependent upon litter type, due to differences in litter stoichiometry and changes to the structure of decomposer communities, especially the soil fungi. These community shifts were particularly pronounced when litter was added in the form of herbivore feces, and in litter input treatments that induced nitrogen limitation (i.e., senesced litter). The sensitivity of carbon cycling to litter quality and quantity in this system demonstrates that herbivores can strongly impact greenhouse gas fluxes through their influence on plant growth and tissue chemistry. Graphical abstract: [Figure not available: see fulltext.]

  • Journal article
    McKenna S, Aylward F, Miliara X, Lau RJ, Huemer CB, Giblin SP, Huse KK, Liang M, Reeves L, Pearson M, Xu Y, Rouse SL, Pease JE, Sriskandan S, Kagawa TF, Cooney J, Matthews Set al., 2023,

    The protease associated (PA) domain in ScpA from Streptococcus pyogenes plays a role in substrate recruitment

    , BBA: Proteins and Proteomics, Vol: 1871, Pages: 1-11, ISSN: 1570-9639

    Annually, over 18 million disease cases and half a million deaths worldwide are estimated to be caused by Group A Streptococcus. ScpA (or C5a peptidase) is a well characterised member of the cell enveleope protease family, which possess a S8 subtilisin-like catalytic domain and a shared multi-domain architecture. ScpA cleaves complement factors C5a and C3a, impairing the function of these critical anaphylatoxins and disrupts complement-mediated innate immunity. Although the high resolution structure of ScpA is known, the details of how it recognises its substrate are only just emerging. Previous studies have identified a distant exosite on the 2nd fibronectin domain that plays an important role in recruitment via an interaction with the substrate core. Here, using a combination of solution NMR spectroscopy, mutagenesis with functional assays and computational approaches we identify a second exosite within the protease-associated (PA) domain. We propose a model in which the PA domain assists optimal delivery of the substrate's C terminus to the active site for cleavage.

  • Journal article
    Basu S, Shukron O, Hall D, Parutto P, Ponjavic A, Shah D, Boucher W, Lando D, Zhang W, Reynolds N, Sober LH, Jartseva A, Ragheb R, Ma X, Cramard J, Floyd R, Balmer J, Drury TA, Carr AR, Needham L-M, Aubert A, Communie G, Gor K, Steindel M, Morey L, Blanco E, Bartke T, Di Croce L, Berger I, Schaffitzel C, Lee SF, Stevens TJ, Klenerman D, Hendrich BD, Holcman D, Laue EDet al., 2023,

    Live-cell three-dimensional single-molecule tracking reveals modulation of enhancer dynamics by NuRD.

    , Nat Struct Mol Biol, Vol: 30, Pages: 1628-1639

    To understand how the nucleosome remodeling and deacetylase (NuRD) complex regulates enhancers and enhancer-promoter interactions, we have developed an approach to segment and extract key biophysical parameters from live-cell three-dimensional single-molecule trajectories. Unexpectedly, this has revealed that NuRD binds to chromatin for minutes, decompacts chromatin structure and increases enhancer dynamics. We also uncovered a rare fast-diffusing state of enhancers and found that NuRD restricts the time spent in this state. Hi-C and Cut&Run experiments revealed that NuRD modulates enhancer-promoter interactions in active chromatin, allowing them to contact each other over longer distances. Furthermore, NuRD leads to a marked redistribution of CTCF and, in particular, cohesin. We propose that NuRD promotes a decondensed chromatin environment, where enhancers and promoters can contact each other over longer distances, and where the resetting of enhancer-promoter interactions brought about by the fast decondensed chromatin motions is reduced, leading to more stable, long-lived enhancer-promoter relationships.

  • Journal article
    Bailey AJ, Ukegbu CV, Giorgalli M, Besson TRB, Christophides GK, Vlachou Det al., 2023,

    Intracellular Plasmodium aquaporin 2 is important for sporozoite production in the mosquito vector and malaria transmission.

    , Proc Natl Acad Sci U S A, Vol: 120

    Malaria remains a devastating disease and, with current measures failing to control its transmission, there is a need for novel interventions. A family of proteins that have long been pursued as potential intervention targets are aquaporins, which are channels facilitating the movement of water and other solutes across membranes. We identify an aquaporin in malaria parasites and demonstrate that it is important for completion of Plasmodium development in the mosquito vector. Disruption of AQP2 in the human parasite Plasmodium falciparum and the rodent parasite Plasmodium berghei blocks sporozoite production inside oocysts established on mosquito midguts, greatly limiting parasite infection of salivary glands and transmission to a new host. In vivo epitope tagging of AQP2 in P. berghei, combined with immunofluorescence assays, reveals that the protein is localized in vesicle-like organelles found in the cytoplasm of gametocytes, ookinetes, and sporozoites. The number of these organelles varies between individual parasites and lifecycle stages suggesting that they are likely part of a dynamic endomembrane system. Phylogenetic analysis confirms that AQP2 is unique to malaria and closely related parasites and most closely resembles intracellular aquaporins. Structure prediction analyses identify several unusual features, including a large accessory extracellular loop and an arginine-to-phenylalanine substitution in the selectivity filter principally determining pore function, a unique feature among known aquaporins. This in conjunction with the importance of AQP2 for malaria transmission suggests that AQP2 may be a fruitful target of antimalarial interventions.

  • Journal article
    Sammon D, Krueger A, Busse-Wicher M, Morgan RM, Haslam S, Schumann B, Briggs D, Hohenester Eet al., 2023,

    Molecular mechanism of decision-making in glycosaminoglycan biosynthesis

    , Nature Communications, Vol: 14, ISSN: 2041-1723

    Two major glycosaminoglycan types, heparan sulfate (HS) and chondroitin sulfate (CS), control many aspects of development and physiology in a type-specific manner. HS and CS are attached to core proteins via a common linker tetrasaccharide, but differ in their polymer backbones. How core proteins are specifically modified with HS or CS has been an enduring mystery. By reconstituting glycosaminoglycan biosynthesis in vitro, we establish that the CS-initiating N-acetylgalactosaminyltransferase CSGALNACT2 modifies all glycopeptide substrates equally, whereas the HS-initiating N-acetylglucosaminyltransferase EXTL3 is selective. Structure-function analysis reveals that acidic residues in the glycopeptide substrate and a basic exosite in EXTL3 are critical for specifying HS biosynthesis. Linker phosphorylation by the xylose kinase FAM20B accelerates linker synthesis and initiation of both HS and CS, but has no effect on the subsequent polymerisation of the backbone. Our results demonstrate that modification with CS occurs by default and must be overridden by EXTL3 to produce HS.

  • Journal article
    Liang G, Reed SC, Stark JM, Waring BGet al., 2023,

    Unraveling mechanisms underlying effects of wetting-drying cycles on soil respiration in a dryland

    , BIOGEOCHEMISTRY, ISSN: 0168-2563
  • Journal article
    El Omari K, Duman R, Mykhaylyk V, Orr CM, Latimer-Smith M, Winter G, Grama V, Qu F, Bountra K, Kwong HS, Romano M, Reis RI, Vogeley L, Vecchia L, Owen CD, Wittmann S, Renner M, Senda M, Matsugaki N, Kawano Y, Bowden TA, Moraes I, Grimes JM, Mancini EJ, Walsh MA, Guzzo CR, Owens RJ, Jones EY, Brown DG, Stuart DI, Beis K, Wagner Aet al., 2023,

    Experimental phasing opportunities for macromolecular crystallography at very long wavelengths.

    , Commun Chem, Vol: 6

    Despite recent advances in cryo-electron microscopy and artificial intelligence-based model predictions, a significant fraction of structure determinations by macromolecular crystallography still requires experimental phasing, usually by means of single-wavelength anomalous diffraction (SAD) techniques. Most synchrotron beamlines provide highly brilliant beams of X-rays of between 0.7 and 2 Å wavelength. Use of longer wavelengths to access the absorption edges of biologically important lighter atoms such as calcium, potassium, chlorine, sulfur and phosphorus for native-SAD phasing is attractive but technically highly challenging. The long-wavelength beamline I23 at Diamond Light Source overcomes these limitations and extends the accessible wavelength range to λ = 5.9 Å. Here we report 22 macromolecular structures solved in this extended wavelength range, using anomalous scattering from a range of elements which demonstrate the routine feasibility of lighter atom phasing. We suggest that, in light of its advantages, long-wavelength crystallography is a compelling option for experimental phasing.

  • Journal article
    Blackhurst L, Gilestro G, 2023,

    Ethoscopy and ethoscope-lab: a framework for behavioural analysis to lower entrance barrier and aid reproducibility behavioural analysis to lower entrance barrier and aidreproducibility

    , Bioinformatics Advances, Vol: 3, ISSN: 2635-0041

    High-throughput analysis of behaviour is a pivotal instrument in modern neuroscience, allowing researchers to combine modern genetics breakthrough to unbiased, objective, reproducible experimental approaches. To this extent, we recently created an open-source hardware platform (ethoscope (Geissmann et al., 2017)) that allows for inexpensive, accessible, high-throughput analysis of behaviour in Drosophila or other animal models. Here we equip ethoscopes with a Python framework for data analysis, ethoscopy, designed to be a user-friendly yet powerful platform, meeting the requirements of researchers with limited coding expertise as well as experienced data scientists. Ethoscopy is best consumed in a prebakedJupyter-based docker container, ethoscope-lab, to improve accessibility and to encourage the use of notebooks as anatural platform to share post-publication data analysis. Ethoscopy is a Python package available on GitHub and PyPi. Ethoscope-lab is a docker container available on DockerHub. A landing page aggregating all the code and documentation is available at https://lab.gilest.ro/ethoscopy.

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