Biology subjects

Quigley, K.

Publications and source records attributed to Quigley, K..

13 recordsLinked to original sources

bioRxiv2025

Past thermal history and heat stress shape patterns of coral-algal symbioses in massive Porites

Massive corals, like some Porites species, are key reef-builders and provide critical habitat on coral reefs. Porites often exhibit high tolerance to stressors, like warming from climate change, although the drivers of these patterns are unclear. Using high-throughput sequencing, we examined whether associations with Symbiodiniaceae underpin this tolerance. Symbiodiniaceae diversity and community composition within two massive species (Porites lutea and P. lobata), whose identities were verified through morphometric examinations, were examined across 200 km of Ningaloo World Heritage Reef, Australia. Contrary to previous studies showing low diversity of high-fidelity symbionts, we found significant variability within Cladocopium, which differed significantly across host species, reef sites, and temperature metrics. Locations with broader temperature ranges and a greater number of extreme accumulated heat stress events (measured as [≥] 8 Degree Heating Weeks) exhibited significantly higher prevalence and abundance of thermotolerant Cladocopium C116. Community structure also varied significantly by the number of DHW events per location, where a low level of disturbance (1-3 events) resulted in a relatively lower community diversity compared to sites with 3-6 and 6-9 events. The southernmost and coolest site (in terms of Maximum Monthly Mean) harboured the greatest Symbiodiniaceae community diversity, whereas the northernmost and warmest site harboured the greatest Symbiodiniaceae sequence diversity. These lines of evidence suggest that Porites may hold greater capacity to vary, and by extension modify, their symbiont community diversity than previously thought. This flexibility could contribute to the genus Porites long-term evolutionary success and relative resilience to global marine heatwaves.

ecology↗

bioRxiv2025

Selective breeding enhances coral heat tolerance even over small spatial scales

Coral reefs globally are experiencing escalating mass bleaching and mortality. Reefs along the western Indian Ocean have been relatively unimpacted. We assessed heat tolerance baselines in two widespread reef-building Acropora species and used selective breeding from two thermally distinct (present day and stress histories) northern (Mean Monthly Maximum 27.9 {degrees}C) and southern (26.6 {degrees}C) reefs along the Ningaloo World Heritage Reef. Fitness responses were measured in control and heat stress temperatures (adults = 31.0 {degrees}C, larvae = 35.5 {degrees}C), including survival, tissue necrosis, bleaching, and photosynthesis. Larvae with one parent from the warmer population exhibited >2.2-fold higher survival under heat stress, while those with both parents from the warmer population survived 1.6-fold better (compared to control larvae with two parents from the cooler population). Photosynthesis was maintained in both species and both populations, suggesting heat responses were host driven. Adults from both populations from one species (A. tenuis) exhibited similar responses to heat, while the other (A. millepora) was more variable. These findings are the first to demonstrate that selective breeding can provide heat tolerance enhancement for corals in the Indian Ocean and will be critical to preparing for future marine heatwaves.

ecology↗

bioRxiv2023

HES1 and ID3 temporally regulate p27 levels and endothelial cell flow-mediated quiescence depth

BackgroundEndothelial cells regulate their cell cycle as blood vessels remodel and transition to quiescence downstream of blood flow-induced mechanotransduction. Laminar blood flow leads to quiescence, but how flow-mediated quiescence is established and maintained is poorly understood. MethodsPrimary human endothelial cells were exposed to laminar flow regimens and gene expression manipulations, and quiescence depth was analyzed via time to cell cycle re-entry after flow cessation. Mouse and zebrafish endothelial expression patterns were examined via scRNA seq analysis, and mutant or morphant fish lacking p27 were analyzed for endothelial cell cycle regulation and in vivo cellular behaviors. ResultsArterial flow-exposed endothelial cells had a distinct transcriptome, and they first entered a deep quiescence, then transitioned to shallow quiescence under homeostatic maintenance conditions. In contrast, venous-flow exposed endothelial cells entered deep quiescence early that did not change with homeostasis. The cell cycle inhibitor p27 (CDKN1B) was required to establish endothelial flow-mediated quiescence, and expression levels positively correlated with quiescence depth. p27 loss in vivo led to endothelial cell cycle upregulation and ectopic sprouting, consistent with loss of quiescence. HES1 and ID3, transcriptional repressors of p27 upregulated by arterial flow, were required for quiescence depth changes and the reduced p27 levels associated with shallow quiescence. ConclusionsEndothelial cell flow-mediated quiescence has unique properties and temporal regulation of quiescence depth that depends on the flow stimulus. These findings are consistent with a model whereby flow-mediated endothelial cell quiescence depth is temporally regulated downstream of p27 transcriptional regulation by HES1 and ID3. The findings are important in understanding endothelial cell quiescence mis-regulation that leads to vascular dysfunction and disease. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=197 SRC="FIGDIR/small/544403v2_ufig1.gif" ALT="Figure 1"> View larger version (43K): org.highwire.dtl.DTLVardef@1137a1forg.highwire.dtl.DTLVardef@1b6bf1dorg.highwire.dtl.DTLVardef@bd4965org.highwire.dtl.DTLVardef@11dbb9b_HPS_FORMAT_FIGEXP M_FIG C_FIG HIGHLIGHTSO_LIDifferent quiescence stimuli lead to distinct transcriptional and functional quiescence profiles in endothelial cells C_LIO_LIp27 is required for endothelial cell quiescence and depth is temporally regulated in a flow stimulus-dependent manner that correlates with p27 levels and flow-regulated repressors HES1 and ID3 C_LIO_LIp27 is expressed in endothelial cells according to flow magnitude in vivo and is functionally required for cell cycle regulation and sprouting in vivo C_LI

cell biology↗

bioRxiv2023

A defined clathrin-mediated trafficking pathway regulates sFLT1/VEGFR1 secretion from endothelial cells

FLT1/VEGFR1 negatively regulates VEGF-A signaling and is required for proper vessel morphogenesis during vascular development and vessel homeostasis. Although a soluble isoform, sFLT1, is often mis-regulated in disease and aging, how sFLT1 is trafficked and secreted from endothelial cells is not well understood. Here we define requirements for constitutive sFLT1 trafficking and secretion in endothelial cells from the Golgi to the plasma membrane, and we show that sFLT1 secretion requires clathrin at or near the Golgi. Perturbations that affect sFLT1 trafficking blunted endothelial cell secretion and promoted intracellular mis-localization in cells and zebrafish embryos. siRNA-mediated depletion of specific trafficking components revealed requirements for RAB27A, VAMP3, and STX3 for post-Golgi vesicle trafficking and sFLT1 secretion, while STX6, ARF1, and AP1 were required at the Golgi. Depletion of STX6 altered vessel sprouting in a 3D angiogenesis model, indicating that endothelial cell sFLT1 secretion is important for proper vessel sprouting. Thus, specific trafficking components provide a secretory path from the Golgi to the plasma membrane for sFLT1 in endothelial cells that utilizes a specialized clathrin-dependent intermediate, suggesting novel therapeutic targets.

cell biology↗

bioRxiv2021

Selecting species for restoration in foundational assemblages

O_LIHumans have long sought to restore species, but little attention has been directed at how to best select a subset of foundation species for maintaining rich assemblages that support ecosystems, like coral reefs and rainforests that are increasingly threatened by environmental change. C_LIO_LIWe propose a two-part hedging approach that selects optimized sets of species for restoration. The first part acknowledges that biodiversity supports ecosystem functions and services, and so it takes precaution against loss by ensuring an even spread of phenotypic traits. The second part maximizes species and ecosystem persistence by weighting species based on characteristics that are known to improve ecological persistence--e.g., abundance, species range and tolerance to environmental change. C_LIO_LIUsing existing phenotypic trait and ecological characteristic data for reef building corals, we identified sets of ecologically persistent species by examining marginal returns in occupancy of phenotypic trait space. We compared optimal sets of species with those from the worlds southern-most coral reef which naturally harbors low coral diversity to show these occupy much of the trait space. Comparison with an existing coral restoration program indicated that current corals used for restoration only cover part of the desired trait space and may be improved by including species with different traits. C_LIO_LISynthesis and applications. While there are many possible criteria for selecting species for restoration, the approach proposed here addresses the need to insure against unpredictable losses of ecosystem services by focusing on a wide range of phenotypic traits and ecological characteristics. Furthermore, the flexibility of the approach enables the functional goals of restoration to vary depending on environmental context, stakeholder values, and the spatial and temporal scales at which meaningful impacts can be achieved. C_LI

ecology↗

bioRxiv2021

Drivers of adaptive capacity in wild populations: implications for genetic interventions

The unprecedented rate of environmental change in the Anthropocene poses evolutionary challenges for wild populations globally. Active human interventions are being increasingly considered to accelerate natural adaptive processes. Evolutionary models can evaluate how species may fare under future climate, elucidate which evolutionary processes are critical to rapid adaptation, and how active interventions may influence fitness trajectories of organisms. Here we use polygenic metapopulation adaptation models to quantify the relative importance (effect sizes) of different eco-evolutionary parameters on the rates of adaptation in wild populations i) without active interventions, and ii) under a subset of active interventions. We demonstrate that genetic diversity (heterozygosity, He), population connectivity and the effect size of additive genetic variance are the primary drivers of natural adaptation rates. We quantify the effect sizes of these parameters on population fitness across three proposed assisted evolution scenarios and identify critical thresholds for intervention effectiveness and implementation. Specifically, the interventions tested here were most effective at low levels of genetic diversity in target populations (He < 0.2) and when timed during a cold-to-warm phase of an ENSO-like oscillation. Beneficial levels of connectivity were highly dependent on desired outcomes for the meta-population. We also present a global meta-analysis of genetic diversity in tropical reef-building corals as a case study of how thresholds derived from evolutionary models can be used to guide decision making by managers. We find genetic diversity to be highly variable by coral taxon and region, highlighting how thresholds from evolutionary models can be used in conjunction with empirical data to assess intervention needs and priorities. Finally, we highlight the critical knowledge and data gaps to produce the next suite of applied models for conservation management decision-support.

evolutionary biology↗

bioRxiv2020

Single-Cell RNA Sequencing Reveals Endothelial Cell Transcriptome Heterogeneity under Homeostatic Laminar Flow

ObjectiveEndothelial cells that form the innermost layer of all vessels exhibit heterogeneous cell behaviors and responses to pro-angiogenic signals that are critical for vascular sprouting and angiogenesis. Once vessels form, remodeling and blood flow lead to endothelial cell quiescence, and homogeneity in cell behaviors and signaling responses. These changes are important for the function of mature vessels, but whether and at what level endothelial cells regulate overall expression heterogeneity during this transition is poorly understood. Here we profiled endothelial cell transcriptomic heterogeneity, and expression heterogeneity of selected proteins, under homeostatic laminar flow. Approach and ResultsSingle-cell RNA sequencing and fluorescence microscopy were used to characterize heterogeneity in RNA and protein gene expression levels of human endothelial cells under homeostatic laminar flow compared to non-flow conditions. Analysis of transcriptome variance, Gini coefficient, and coefficient of variation showed that more genes increased RNA heterogeneity under laminar flow relative to genes whose expression became more homogeneous. Analysis of a subset of genes for relative protein expression revealed that most protein profiles showed decreased heterogeneity under flow. In contrast, the magnitude of expression level changes in RNA and protein was coordinated among endothelial cells in flow vs. non-flow conditions. ConclusionsEndothelial cells exposed to homeostatic laminar flow showed increased cohort heterogeneity in RNA expression levels, while cohort expression heterogeneity of selected cognate proteins decreased under laminar flow. These findings suggest that EC homeostasis is imposed at the level of protein translation and/or stability rather than transcriptionally.

cell biology↗

bioRxiv2018

Relationship between Acropora millepora juvenile fluorescence and composition of newly established Symbiodinium assemblage

Coral-dinoflagellate symbiosis is the key biological interaction enabling existence of modern-type coral reefs, but the mechanisms regulating initial host-symbiont attraction, recognition and symbiont proliferation thus far remain largely unclear. A common reef-building coral, Acropora millepora, displays conspicuous fluorescent polymorphism during all phases of its life cycle, due to the differential expression of fluorescent proteins (FPs) of the green fluorescent protein family. In this study, we examine whether fluorescent variation in young coral juveniles exposed to natural sediments is associated with the uptake of disparate Symbiodinium assemblages determined using ITS-2 deep sequencing. We found that Symbiodinium assemblages varied significantly when redness values varied, specifically in regards to abundances of clades A and C. Whether fluorescence was quantified as a categorical or continuous trait, clade A was found at higher abundances in redder juveniles. These preliminary results suggest juvenile fluorescence may be associated with Symbiodinium uptake, potentially acting as either as an attractant to ecologically specific types or as a mechanism to modulate the internal light environment to control Symbiodinium physiology within the host.

ecology↗

bioRxiv2018

Transgenerational inheritance of shuffled symbiont communities in the coral Montipora digitata

Adult organisms may \"prime\" their offspring for environmental change through a number of genetic and non-genetic mechanisms, termed parental effects. Some coral species can alter their thermal tolerance by shuffling the proportions of Symbiodinium types within their endosymbiotic communities, but it is unclear if this plasticity can be transferred to offspring in corals that have maternal symbiont transmission. We evaluated symbiont community composition in tagged colonies of Montipora digitata from Orpheus Island, Australia, over two successive annual spawning seasons, the second of which overlapped with the 2016 mass coral bleaching event on the Great Barrier Reef. We applied amplicon sequencing of the ITS2 locus to samples of four families (parent colonies and 10-12 eggs per family) to characterize their potential for symbiont shuffling and to determine if shuffled abundances were preserved in gametes. Symbiont cell densities and photochemical efficiencies of the symbionts photosystem II differed significantly among adults in 2016, suggesting differential responses to increased temperatures. Although abundances of the dominant symbiont haplotype, a representative of clade C15, did not differ among families or over time, low-abundance (\"background\") ITS2 types differed more among years (2015 vs. 2016) than between life stages (parent vs. offspring). Results indicate that background symbiont shuffling can occur in a canonically stable symbiosis, and that such plastic changes to the symbiont community are heritable. To our knowledge, this is the first evidence that shuffled Symbiodinium communities can be inherited by early life-history stages and supports the hypothesis that plastic changes in microbial communities may serve as a mechanism of rapid coral acclimation to changing environmental conditions.

microbiology↗

bioRxiv2017

Temperature and Water Quality-Related Patterns in Sediment-Associated Symbiodinium Communities Impact Symbiont Uptake and Fitness of Juvenile Acroporid Corals

The majority of corals acquire their photo-endosymbiont Symbiodinium from environmental sources anew each generation. Despite the critical role that environmental availability of Symbiodinium plays in the potential for corals to acclimate and adapt to changing environments, little is known about the diversity of free-living Symbiodinium communities and how variation in these communities influences uptake and in hospite communities in juvenile corals. Here we characterize Symbiodinium community diversity in sediment samples collected from eight reefs representing latitudinal and cross-shelf variation in water quality and temperature regimes. Sediment-associated Symbiodinium communities were then compared to in hospite communities acquired by A. tenuis and A. millepora juveniles following 11 - 145 days of experimental exposure to sediments from each of the reefs. Communities associated with juveniles and sediments differed substantially, with sediments harbouring four times more unique OTUs than juveniles (1125 OTUs vs. 271). Moreover, only 10.6% of these OTUs were shared between juveniles and sediments, indicating selective uptake by acroporid juveniles. The diversity and abundance of Symbiodinium types differed among sediment samples from different temperature and water quality environments. Symbiodinium communities acquired by juveniles also differed among the sediment treatments, despite juveniles having similar parentage. Moreover, Symbiodinium communities displayed different rates of infection, mortality, and photochemical efficiencies. This study demonstrates that the biogeography of free-living Symbiodinium types found within sediment reservoirs follows patterns along latitudinal and water quality environmental gradients on the Great Barrier Reef. We also demonstrate a bipartite strategy for Symbiodinium uptake by juvenile corals of two horizontally-transmitting acroporid species, whereby uptake is selective within the constraints of environmental availability.

ecology↗

bioRxiv2017

Unexpected mixed-mode transmission and moderate genetic regulation of Symbiodinium communities in a brooding coral

Determining the extent to which Symbiodinium communities in corals are inherited versus environmentally-acquired is fundamental to understanding coral resilience and to predicting coral responses to stressors like warming oceans that disrupt this critical endosymbiosis. We examined the fidelity with which Symbiodinium communities in the brooding coral Seriatopora hystrix are vertically transmitted and the extent to which communities are genetically regulated, by genotyping 60 larvae and their parents (9 maternal and 45 paternal colonies) using high throughput sequencing of the ITS-2 locus. Unexpectedly, Symbiodinium communities associated with brooded larvae were distinct from those within parent colonies, including the presence of types not detected in adults. Bayesian heritability (h2) analysis revealed that 33% of variability in larval Symbiodinium communities was genetically controlled. Results highlight flexibility in the establishment of larval communities and overturn the paradigm that symbiont transmission is exclusively vertical in brooding corals. Instead, we show that Symbiodinium transmission in S. hystrix involves a mixed-mode strategy, similar to many terrestrial invertebrate symbioses. Also, variation in the abundances of common Symbiodinium types among adult communities suggests that microhabitat differences influence the structure of in hospite Symbiodinium communities. Partial genetic regulation coupled with flexibility in the environmentally-acquired component of larval Symbiodinium communities implies that corals with vertical transmission, like S. hystrix, may be more resilient to environmental change than previously thought.

microbiology↗

bioRxiv2017

Heritability of the Symbiodinium community in vertically- and horizontally-transmitting broadcast spawning corals

The dinoflagellate-coral partnership influences the coral holobionts tolerance to thermal stress and bleaching. However, the comparative roles of host genetic versus environmental factors in determining the composition of this symbiosis are largely unknown. Here we quantify the heritability of the initial Symbiodinium communities for two broadcast-spawning corals with different symbiont transmission modes: Acropora tenuis has environmental acquisition, whereas Montipora digitata has maternal transmission. Using high throughput sequencing of the ITS-2 region to characterize communities in parents, juveniles and eggs, we describe previously undocumented Symbiodinium diversity and dynamics in both corals. After one month of uptake in the field, Symbiodinium communities associated with A. tenuis juveniles were dominated by A3, C1, D1, A-type CCMP828, and D1a in proportional abundances conserved between experiments in two years. M. digitata eggs were predominantly characterized by C15, D1, and A3. In contrast to current paradigms, host genetic influences accounted for a surprising 29% of phenotypic variation in Symbiodinium communities in the horizontally-transmitting A. tenuis, but only 62% in the vertically-transmitting M. digitata. Our results reveal hitherto unknown flexibility in the acquisition of Symbiodinium communities and substantial heritability in both species, providing material for selection to produce partnerships that are locally adapted to changing environmental conditions.

molecular biology↗

bioRxiv2017

Evidence for a Large-Scale Brain System Supporting Allostasis and Interoception in Humans

AbstractLarge-scale intrinsic brain systems have been identified for exteroceptive senses (e.g., sight, hearing, touch). We introduce an analogous system for representing sensations from within the body, called interoception, and demonstrate its relation to regulating peripheral systems in the body, called allostasis. Employing the recently introduced Embodied Predictive Interoception Coding (EPIC) model, we used tract-tracing studies of macaque monkeys, followed by two intrinsic functional magnetic resonance imaging samples (N = 280 and N = 270) to evaluate the existence of an intrinsic allostatic/interoceptive system in the human brain. Another sample (N = 41) allowed us to evaluate the convergent validity of the hypothesized allostatic/interoceptive system by showing that individuals with stronger connectivity between system hubs performed better on an implicit index of interoceptive ability related to autonomic fluctuations. Implications include novel insights for the brains functional architecture, dissolving the artificial boundary between mind and body, and unifying mental and physical illness.

neuroscience↗