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nucleotide sequence of ub52 from the cnidarian acropora millepora reveals high evolutionary conservation.we report the cdna sequence encoding ub52 from the cnidarian acropora millepora. as in other eukaryotes, the n-terminal region of the deduced amino-acid sequence is a ubiquitin moiety and the c-terminal region cep52, a protein component of the large ribosomal subunit. a millepora ub52 is highly homologous (> 95% identical) with the corresponding drosophila and vertebrate sequences, the cnidarian sequence having higher identity with these 'higher' metazoan homologs than does the corresponding cae ...19968921914
pax-6 origins--implications from the structure of two coral pax genes.vertebrate pax-6 and its drosophila homolog eyeless play central roles in eye specification, although it is not clear if this represents the ancestral role of this gene class. as the most "primitive" animals with true nervous systems, the cnidaria may be informative in terms of the evolution of the pax gene family. for this reason we surveyed the pax gene complement of a representative of the basal cnidarian class (the anthozoa), the coral acropora millepora. cdnas encoding two coral pax protein ...19989716726
pax gene diversity in the basal cnidarian acropora millepora (cnidaria, anthozoa): implications for the evolution of the pax gene family.pax genes encode a family of transcription factors, many of which play key roles in animal embryonic development but whose evolutionary relationships and ancestral functions are unclear. to address these issues, we are characterizing the pax gene complement of the coral acropora millepora, an anthozoan cnidarian. as the simplest animals at the tissue level of organization, cnidarians occupy a key position in animal evolution, and the anthozoa are the basal class within this diverse phylum. we ha ...200010781047
inhibition of coral fertilisation and larval metamorphosis by tributyltin and copper.fertilisation and larval metamorphosis of reef-building corals are important life history events leading to recruitment of juvenile corals to reef populations. little is known of the sensitivity of these early life phases to pollution, or their relative susceptibility to certain toxicants compared with established coral colonies. inhibition of fertilisation and larval metamorphosis of the coral acropora millepora (ehrenberg, 1834) was assessed in response to solutions of the antifoulants tributy ...200111125701
gene structure and larval expression of cnox-2am from the coral acropora millepora.we have cloned a hox-like gene, cnox-2am, from a staghorn coral, acropora millepora, an anthozoan cnidarian, and characterised its embryonic and larval expression. cnox-2am and its orthologs in other cnidarians and trichoplax most closely resemble the gsx and, to a lesser extent, hox 3/4 proteins. developmental northern blots and in situ hybridisation are consistent in showing that cnox-2am message appears in the planula larva shortly after the oral/aboral axis is formed following gastrulation. ...200111277400
conservation of a dpp/bmp signaling pathway in the nonbilateral cnidarian acropora millepora.members of the tgf-beta superfamily of signaling molecules are widespread in metazoans, but the evolutionary origin of particular subclasses of signaling mechanisms is poorly defined. the dpp/bmp class, for example, is implicated in dorsal-ventral patterning, neural patterning, and limb development. here we report the presence of several components of a dpp/bmp-specific signal transduction cascade in a nonbilateral animal, the coral acropora millepora. the discovery of these components, a putati ...201011478521
the evolution of nuclear receptors: evidence from the coral acropora.we have amplified and sequenced pcr products derived from 10 nuclear receptor (nr) genes from the anthozoan cnidarian acropora millepora, including five products corresponding to genes not previously reported from the phylum cnidaria. cdnas corresponding to seven of these products were sequenced and at least three encode full-length proteins, increasing the number of complete cnidarian nr coding sequences from one to four. all clear orthologs of acropora nrs either lack an activation domain or l ...200111603940
intron dynamics and the evolution of integrin beta-subunit genes: maintenance of an ancestral gene structure in the coral, acropora millepora.we have determined the genomic structure of an integrin beta-subunit gene from the coral, acropora millepora. the coding region of the gene contains 26 introns, spaced relatively uniformly, and this is significantly more than have been found in any integrin beta-subunit genes from higher animals. twenty-five of the 26 coral introns are also found in a beta-subunit gene from at least one other phylum, indicating that the coral introns are ancestral. while there are some suggestions of intron gain ...200111677630
localized expression of a dpp/bmp2/4 ortholog in a coral embryo.as the closest outgroup to the bilateria, the phylum cnidaria is likely to be critical to understanding the origins and evolution of body axes. proteins of the decapentaplegic (dpp)/bone morphogenetic protein (bmp) 2/4 subfamily are central to the specification of the dorsoventral (d/v) axis in bilateral animals, albeit with an axis inversion between arthropods and chordates. we show that a dpp/bmp2/4 ortholog (bmp2/4-am) is present in the reef-building scleractinian coral, acropora millepora (c ...200212048233
coral development: from classical embryology to molecular control.the phylum cnidaria is the closest outgroup to the triploblastic metazoans and as such offers unique insights into evolutionary questions at several levels. in the post-genomic era, a knowledge of the gene complement of representative cnidarians will be important for understanding the relationship between the expansion of gene families and the evolution of morphological complexity among more highly evolved metazoans. studies of cnidarian development and its molecular control will provide informa ...200212141456
changes in zooxanthellae density, morphology, and mitotic index in hermatypic corals and anemones exposed to cyanide.sodium cyanide (nacn) is widely used for the capture of reef fish throughout southeast asia and causes extensive fish mortality, but the effect of nacn on reef corals remains debated. to document the impact of cyanide exposure on corals, the species acropora millepora, goniopora sp., favites abdita, trachyphyllia geoffrio, plerogyra sp., heliofungia actinformis, euphyllia divisa, and scarophyton sp., and the sea anemone aiptasia pallida were exposed to varying concentrations of cyanide for varyi ...200312735955
a dm domain protein from a coral, acropora millepora, homologous to proteins important for sex determination.the identification and functional studies of dm domain-containing proteins doublesex, mab-3, and dmrt1 indicated that flies, nematodes, and humans share at least some of the molecular mechanisms of sex determination. we identified a gene, amdm1, from the coral acropora millepora that encodes a homologous dm domain-containing protein. molecular analyses show that the amdm1 primary transcript is processed to generate four different messenger rnas. alternative use of two polyadenylation sites produ ...201612752764
mutational analysis of the acropora millepora paxd paired domain highlights the importance of the linker region for dna binding.pax transcription factors are found in animals, from simple sponges to insects and vertebrates. the defining feature of pax proteins is the dna-binding paired domain (pd), which consists of two helix-turn-helix subdomains, joined with a linker region. despite high specificity in vivo, the paired domains of different pax proteins bind similar consensus dna sequences in vitro. using bandshift techniques, we show here that the paired domain of the acropora millepora paxd protein, which unambiguousl ...200314597391
est analysis of the cnidarian acropora millepora reveals extensive gene loss and rapid sequence divergence in the model invertebrates.a significant proportion of mammalian genes are not represented in the genomes of drosophila, caenorhabditis or saccharomyces, and many of these are assumed to have been vertebrate innovations. to test this assumption, we conducted a preliminary est project on the anthozoan cnidarian, acropora millepora, a basal metazoan. more than 10% of the acropora ests with strong metazoan matches to the databases had clear human homologs but were not represented in the drosophila or caenorhabditis genomes; ...200314680636
snail expression during embryonic development of the coral acropora: blurring the diploblast/triploblast divide?although corals are nominally diploblastic, the early development of acropora millepora involves a process that clearly resembles gastrulation in higher metazoans. this similarity at the morphological level led us to search for the acropora equivalents of genes whose key roles in gastrulation are conserved across the higher metazoa. we here report the characterisation of one such gene, snail, which in both drosophila and the mouse is expressed in cells undergoing an epithelial-mesenchyme transit ...200415029498
tandem organization of independently duplicated homeobox genes in the basal cnidarian acropora millepora.a number of examples of independently duplicated regulatory genes have been identified in cnidarians, but the extent of this phenomenon and organization of these duplicated genes are unknown. here we describe the identification of three pairs of independently duplicated homeobox genes in the anthozoan cnidarian, acropora millepora. in each case, the pairs of paralogous genes are tightly linked, but the extent of sequence divergence implies that these do not reflect recent duplication events. the ...200515702325
effects of the herbicide diuron on the early life history stages of coral.the effects of the herbicide diuron on the early life history stages of broadcast spawning and brooding corals were examined in laboratory experiments. fertilisation of acropora millepora and montipora aequituberculata oocytes were not inhibited at diuron concentrations of up to 1000 microg l(-1). metamorphosis of symbiont-free a. millepora larvae was only significantly inhibited at 300 microg l(-1) diuron. pocillopora damicornis larvae, which contain symbiotic dinoflagellates, were able to unde ...200515757736
effects of algal turfs and sediment on coral settlement.successful settlement and recruitment of corals is critical to the resilience of coral reefs. given that many degraded reefs are dominated by benthic algae, recovery of coral populations after bleaching and other disturbances requires successful settlement amidst benthic algae. algal turfs often accumulate sediments, sediments are known to inhibit coral settlement, and reefs with high inputs of terrestrial sediments are often dominated by turfs. we investigated the impacts of two algal turf asse ...200515757739
the role of zooxanthellae in the thermal tolerance of corals: a 'nugget of hope' for coral reefs in an era of climate change.the ability of coral reefs to survive the projected increases in temperature due to global warming will depend largely on the ability of corals to adapt or acclimatize to increased temperature extremes over the next few decades. many coral species are highly sensitive to temperature stress and the number of stress (bleaching) episodes has increased in recent decades. we investigated the acclimatization potential of acropora millepora, a common and widespread indo-pacific hard coral species, thro ...200616928632
components of both major axial patterning systems of the bilateria are differentially expressed along the primary axis of a 'radiate' animal, the anthozoan cnidarian acropora millepora.cnidarians are animals with a single (oral/aboral) overt body axis and with origins that nominally predate bilaterality. to better understand the evolution of axial patterning mechanisms, we characterized genes from the coral, acropora millepora (class anthozoa) that are considered to be unambiguous markers of the bilaterian anterior/posterior and dorsal/ventral axes. homologs of otx/otd and emx/ems, definitive anterior markers across the bilateria, are expressed at opposite ends of the acropora ...200616952346
sequence and expression of four coral g protein-coupled receptors distinct from all classifiable members of the rhodopsin family.a measure of the functional importance of g protein-coupled receptors (gpcrs) as signalling molecules is that over seven hundred have been cloned and identified in the human genome alone. yet few have been characterized in the lower metazoan phyla, especially in the phylum cnidaria which is well positioned phylogenetically for tracing the early evolution of gpcrs owing to their possession of the first-evolved nervous systems. we report here the cloning and characterization of four novel rhodopsi ...200717196770
expression of pax gene family members in the anthozoan cnidarian, nematostella vectensis.pax genes are a family of homeodomain transcription factors that have been isolated from protostomes (e.g., eight in drosophilia) and deuterostomes (e.g., nine in vertebrates) as well as outside the bilateria, from sponges, a placozoan, and several classes of cnidarians. the genome of an anthozoan cnidarian, the starlet sea anemone, nematostella vectensis, has been surveyed by both degenerate polymerase chain reaction and in silico for the presence of pax genes. n. vectensis possesses seven pax ...200717227364
fluorescence lifetime imaging of coral fluorescent proteins.corals, like many other coelenterates, contain fluorescent pigments that show considerable homology with the well known green fluorescent protein of the jellyfish aequoria. in corals, unlike jellyfish, multiple proteins are present and the range of excitations and emissions suggest the possibility of energy transfer. the occurrence of förster resonant energy transfer (fret) between fluorescent proteins in corals has already been reported and time-resolved spectra have shown the effect on fluores ...200717279514
immunohistochemical localization of a retinoic acid-like receptor in nerve cells of two colonial anthozoans (cnidaria).retinoic acid is known to induce vertebrate stem cells to differentiate into a variety of cell types, including neurons. although retinoic acid was reported to affect morphogenetic pattern specification in the hydrozoan hydractinia (müller, w.a., 1984. retinoids and pattern formation in a hydroid. j. embryol. exp. morph. 81, 253-271) and a retinoid rxr receptor was cloned in the jellyfish tripedalia (kostrouch, z., kostrouchova, m., love, w., jannini, e., piatigorsky, j., rall, j.e., 1998. retin ...200717376496
the innate immune repertoire in cnidaria--ancestral complexity and stochastic gene loss.characterization of the innate immune repertoire of extant cnidarians is of both fundamental and applied interest--it not only provides insights into the basic immunological 'tool kit' of the common ancestor of all animals, but is also likely to be important in understanding the global decline of coral reefs that is presently occurring. recently, whole genome sequences became available for two cnidarians, hydra magnipapillata and nematostella vectensis, and large expressed sequence tag (est) dat ...200717437634
apparent involvement of a beta1 type integrin in coral fertilization.integrins are involved in a wide variety of cell adhesion processes, and have roles in gamete binding and fusion in mammals. integrins have been also discovered in the scleractinian coral acropora millepora (cnidaria: anthozoa). as a first step toward understanding the molecular basis of fertilization in corals, we examined the effect of polyclonal antisera raised against recombinant coral integrins on gamete interactions in a. millepora. antiserum raised against integrin betacn1 dramatically de ...200717694414
light-responsive cryptochromes from a simple multicellular animal, the coral acropora millepora.hundreds of species of reef-building corals spawn synchronously over a few nights each year, and moonlight regulates this spawning event. however, the molecular elements underpinning the detection of moonlight remain unknown. here we report the presence of an ancient family of blue-light-sensing photoreceptors, cryptochromes, in the reef-building coral acropora millepora. in addition to being cryptochrome genes from one of the earliest-diverging eumetazoan phyla, cry1 and cry2 were expressed pre ...200717947585
gene expression of a green fluorescent protein homolog as a host-specific biomarker of heat stress within a reef-building coral.recent incidences of mass coral bleaching indicate that major reef building corals are increasingly suffering thermal stress associated with climate-related temperature increases. the development of pulse amplitude modulated (pam) fluorometry has enabled rapid detection of the onset of thermal stress within coral algal symbionts, but sensitive biomarkers of thermal stress specific to the host coral have been slower to emerge. differential display reverse transcription polymerase chain reaction ( ...200817994304
changes in coral-associated microbial communities during a bleaching event.environmental stressors such as increased sea surface temperatures are well-known for contributing to coral bleaching; however, the effect of increased temperatures and subsequent bleaching on coral-associated microbial communities is poorly understood. colonies of the hard coral acropora millepora were tagged on a reef flat off magnetic island (great barrier reef) and surveyed over 2.5 years, which included a severe bleaching event in january/february 2002. daily average water temperatures exce ...200818059490
a community change in the algal endosymbionts of a scleractinian coral following a natural bleaching event: field evidence of acclimatization.the symbiosis between reef-building corals and their algal endosymbionts (zooxanthellae of the genus symbiodinium) is highly sensitive to temperature stress, which makes coral reefs vulnerable to climate change. thermal tolerance in corals is known to be substantially linked to the type of zooxanthellae they harbour and, when multiple types are present, the relative abundance of types can be experimentally manipulated to increase the thermal limits of individual corals. although the potential ex ...200818348962
unexpected diversity of cnidarian integrins: expression during coral gastrulation.adhesion mediated through the integrin family of cell surface receptors is central to early development throughout the metazoa, playing key roles in cell-extra cellular matrix adhesion and modulation of cadherin activity during the convergence and extension movements of gastrulation. it has been suggested that caenorhabditis elegans, which has a single beta and two alpha integrins, might reflect the ancestral integrin complement. investigation of the integrin repertoire of anthozoan cnidarians s ...200818466626
species-specific interactions between algal endosymbionts and coral hosts define their bleaching response to heat and light stress.the impacts of warming seas on the frequency and severity of bleaching events are well documented, but the potential for different symbiodinium types to enhance the physiological tolerance of reef corals is not well understood. here we compare the functionality and physiological properties of juvenile corals when experimentally infected with one of two homologous symbiodinium types and exposed to combined heat and light stress. a suite of physiological indicators including chlorophyll a fluoresc ...200818577506
an ancient and variable mannose-binding lectin from the coral acropora millepora binds both pathogens and symbionts.corals form the framework of the world's coral reefs and are under threat from increases in disease and bleaching (symbiotic dysfunction), yet the mechanisms of pathogen and symbiont recognition remain largely unknown. here we describe the isolation and characterisation of an ancient mannose-binding lectin in the coral acropora millepora, which is likely to be involved in both processes. the lectin ('millectin') was isolated by affinity chromatography and was shown to bind to bacterial pathogens ...200818599120
diversity and evolution of coral fluorescent proteins.gfp-like fluorescent proteins (fps) are the key color determinants in reef-building corals (class anthozoa, order scleractinia) and are of considerable interest as potential genetically encoded fluorescent labels. here we report 40 additional members of the gfp family from corals. there are three major paralogous lineages of coral fps. one of them is retained in all sampled coral families and is responsible for the non-fluorescent purple-blue color, while each of the other two evolved a full com ...200818648549
evidence of an inflammatory-like response in non-normally pigmented tissues of two scleractinian corals.increasing evidence of links between climate change, anthropogenic stress and coral disease underscores the importance of understanding the mechanisms by which reef-building corals resist infection and recover from injury. cellular inflammation and melanin-producing signalling pathway are two mechanisms employed by invertebrates to remove foreign organisms such as pathogens, but they have not been recorded previously in scleractinian corals. this study demonstrates the presence of the phenoloxid ...200818700208
sox genes in the coral acropora millepora: divergent expression patterns reflect differences in developmental mechanisms within the anthozoa.sox genes encode transcription factors that function in a wide range of developmental processes across the animal kingdom. to better understand both the evolution of the sox family and the roles of these genes in cnidarians, we are studying the sox gene complement of the coral, acropora millepora (class anthozoa).200819014479
microsatellite characterization and marker development from public est and wgs databases in the reef-building coral acropora millepora (cnidaria, anthozoa, scleractinia).mining for microsatellites (also called simple sequence repeats [ssrs]) in public sequence databases of a common indo-pacific coral acropora millepora identified 191 ssrs from 10 258 expressed sequence tag (est) and 618 ssrs from 14 625 whole-genome shotgun (wgs) sequences. in contrast to other animals, trinucleotide repeats, rather than dinucleotide repeats, are dominant in the wgs-ssrs, and aat is the most frequent trinucleotide motif in est-ssrs. we successfully developed 40 polymorphic marke ...200919043068
identification and gene expression analysis of a taxonomically restricted cysteine-rich protein family in reef-building corals.the amount of genomic sequence information continues to grow at an exponential rate, while the identification and characterization of genes without known homologs remains a major challenge. for non-model organisms with limited resources for manipulative studies, high-throughput transcriptomic data combined with bioinformatics methods provide a powerful approach to obtain initial insights into the function of unknown genes. in this study, we report the identification and characterization of a nov ...200919283069
diversities of coral-associated bacteria differ with location, but not species, for three acroporid corals on the great barrier reef.patterns in the diversity of bacterial communities associated with three species of acropora (acropora millepora, acropora tenuis and acropora valida) were compared at two locations (magnetic island and orpheus island) on the great barrier reef to better understand the nature and specificity of coral-microbial symbioses. three culture-independent techniques demonstrated consistent bacterial communities among replicate samples of each coral species, confirming that corals associate with specific ...200919302548
coral-associated bacteria and their role in the biogeochemical cycling of sulfur.marine bacteria play a central role in the degradation of dimethylsulfoniopropionate (dmsp) to dimethyl sulfide (dms) and acrylic acid, dms being critical to cloud formation and thereby cooling effects on the climate. high concentrations of dmsp and dms have been reported in scleractinian coral tissues although, to date, there have been no investigations into the influence of these organic sulfur compounds on coral-associated bacteria. two coral species, montipora aequituberculata and acropora m ...200919346350
transcriptome analysis of the circadian regulatory network in the coral acropora millepora.entrained circadian rhythms control many biological processes. these cyclical systems are synchronized by environmental signals but continue to free run for a considerable time when the synchronizing stimuli are removed. in scleractinian corals that reproduce by broadcast spawning, timing processes are essential in ensuring successful fertilization. it is not known whether spawn timing is regulated directly by environmental signals or if it is entrained and regulated by circadian or circalunar r ...200919366924
sequencing and de novo analysis of a coral larval transcriptome using 454 gsflx.new methods are needed for genomic-scale analysis of emerging model organisms that exemplify important biological questions but lack fully sequenced genomes. for example, there is an urgent need to understand the potential for corals to adapt to climate change, but few molecular resources are available for studying these processes in reef-building corals. to facilitate genomics studies in corals and other non-model systems, we describe methods for transcriptome sequencing using 454, as well as s ...200919435504
microarray analysis reveals transcriptional plasticity in the reef building coral acropora millepora.we investigated variation in transcript abundance in the scleractinian coral, acropora millepora, within and between populations characteristically exposed to different turbidity regimes and hence different levels of light and suspended particulate matter. we examined phenotypic plasticity by comparing levels of gene expression between source populations and following 10 days of acclimatization to a laboratory environment. analyses of variance revealed that 0.05% of genes were differentially exp ...200919538339
onset of algal endosymbiont specificity varies among closely related species of acropora corals during early ontogeny.juveniles of a number of corals with horizontal transmission of dinoflagellate endosymbionts naturally acquire and maintain symbiodinium types that differ from those found in adult populations. however, the duration of this early period of symbiont flexibility and successional changes leading to dominance by the characteristic adult (homologous) type are unknown. to document natural succession of symbiodinium types within juvenile corals, we monitored symbiodinium communities in juveniles of acr ...200919627494
highly infectious symbiont dominates initial uptake in coral juveniles.the majority of reef-building corals acquire their obligate algal symbionts (symbiodinium) from the environment. however, factors shaping the initial establishment of coral-algal symbioses, including parental effects, local environmental conditions and local availability of symbionts, are not well understood. this study monitored the uptake and maintenance of symbiodinium in juveniles of two common corals, acropora tenuis and acropora millepora, that were reciprocally explanted between sites whe ...200919627495
the roles and interactions of symbiont, host and environment in defining coral fitness.reef-building corals live in symbiosis with a diverse range of dinoflagellate algae (genus symbiodinium) that differentially influence the fitness of the coral holobiont. the comparative role of symbiont type in holobiont fitness in relation to host genotype or the environment, however, is largely unknown. we addressed this knowledge gap by manipulating host-symbiont combinations and comparing growth, survival and thermal tolerance among the resultant holobionts in different environments.200919629182
differential expression of three galaxin-related genes during settlement and metamorphosis in the scleractinian coral acropora millepora.the coral skeleton consists of caco3 deposited upon an organic matrix primarily as aragonite. currently galaxin, from galaxea fascicularis, is the only soluble protein component of the organic matrix that has been characterized from a coral. three genes related to galaxin were identified in the coral acropora millepora.200919638240
predicting water toxicity: pairing passive sampling with bioassays on the great barrier reef.many coral reefs worldwide occur adjacent to urban or agricultural land which places these ecosystems at threat of exposure to complex mixtures of pollutants. in this study, the pairing of passive sampler extracts with bioassays is proposed as a tool for predicting effects of organic pollutant mixtures on key biota within coral reef ecosystems. passive samplers, sdb-rps empore disks, which sequester a mixture of the contaminants present in the environment, were deployed at three sites in the gre ...200919819564
chimerism in wild adult populations of the broadcast spawning coral acropora millepora on the great barrier reef.chimeras are organisms containing tissues or cells of two or more genetically distinct individuals, and are known to exist in at least nine phyla of protists, plants, and animals. although widespread and common in marine invertebrates, the extent of chimerism in wild populations of reef corals is unknown.200919888471
early molecular responses of coral larvae to hyperthermal stress.most of the work on the impact of elevated temperature and light on symbiodinium-invertebrate symbioses have focused primarily on how the photosynthetic (algal) partner is impacted. understanding how the same stresses affect the invertebrate host, however, is in its infancy. in this study, we re-examined the direct effect of elevated temperatures on the invertebrate host exploring the early transcriptional response of aposymbiotic (without algal symbionts) coral larvae. the temperatures tested i ...200919900172
construction of a high-resolution genetic linkage map and comparative genome analysis for the reef-building coral acropora millepora.worldwide, coral reefs are in decline due to a range of anthropogenic disturbances, and are now also under threat from global climate change. virtually nothing is currently known about the genetic factors that might determine whether corals adapt to the changing climate or continue to decline. quantitative genetics studies aiming to identify the adaptively important genomic loci will require a high-resolution genetic linkage map. the phylogenetic position of corals also suggests important applic ...200919900279
patterns of gene expression in a scleractinian coral undergoing natural bleaching.coral bleaching is a major threat to coral reefs worldwide and is predicted to intensify with increasing global temperature. this study represents the first investigation of gene expression in an indo-pacific coral species undergoing natural bleaching which involved the loss of algal symbionts. quantitative real-time polymerase chain reaction experiments were conducted to select and evaluate coral internal control genes (icgs), and to investigate selected coral genes of interest (gois) for chang ...201020041338
differential regulation by heat stress of novel cytochrome p450 genes from the dinoflagellate symbionts of reef-building corals.exposure to heat stress has been recognized as one of the major factors leading to the breakdown of the coral-alga symbiosis and coral bleaching. here, we describe the presence of three new cytochrome p450 (cyp) genes from the reef-building coral endosymbiont symbiodinium (type c3) and changes in their expression during exposure to severe and moderate heat stress conditions. sequence analysis of the cyp c-terminal region and two conserved domains, the "perf" and "heme-binding" domains, confirmed ...201020228102
estimating the potential for adaptation of corals to climate warming.the persistence of tropical coral reefs is threatened by rapidly increasing climate warming, causing a functional breakdown of the obligate symbiosis between corals and their algal photosymbionts (symbiodinium) through a process known as coral bleaching. yet the potential of the coral-algal symbiosis to genetically adapt in an evolutionary sense to warming oceans is unknown. using a quantitative genetics approach, we estimated the proportion of the variance in thermal tolerance traits that has a ...201020305781
characterisation of nitric oxide synthase in three cnidarian-dinoflagellate symbioses.nitric oxide synthase (nos) is an enzyme catalysing the conversion of l-arginine to l-citrulline and nitric oxide (no), the latter being an essential messenger molecule for a range of biological processes. whilst its role in higher vertebrates is well understood little is known about the role of this enzyme in early metazoan groups. for instance, nos-mediated signalling has been associated with cnidaria-algal symbioses, however controversy remains about the contribution of enzyme activities by t ...201020442851
potential costs of acclimatization to a warmer climate: growth of a reef coral with heat tolerant vs. sensitive symbiont types.one of the principle ways in which reef building corals are likely to cope with a warmer climate is by changing to more thermally tolerant endosymbiotic algae (zooxanthellae) genotypes. it is highly likely that hosting a more heat-tolerant algal genotype will be accompanied by tradeoffs in the physiology of the coral. to better understand one of these tradeoffs, growth was investigated in the indo-pacific reef-building coral acropora millepora in both the laboratory and the field. in the keppel ...201020454653
characterization of a group of mites with unusual features from two coral genomes.miniature inverted-repeat transposable elements (mites), which are common in eukaryotic genomes, are small non-coding elements that transpose by utilizing transposases encoded by autonomous transposons. recent genome-wide analyses and cross-mobilization assays have greatly improved our knowledge on mite proliferation, however, specific mechanisms for the origin and evolution of mites are still unclear.201020502527
analysis of evolutionarily conserved innate immune components in coral links immunity and symbiosis.reef-building corals are representatives of one of the earliest diverging metazoan lineages and are experiencing increases in bleaching events (breakdown of the coral-symbiodinium symbiosis) and disease outbreaks. the present study investigates the roles of two pattern recognition proteins, the mannose binding lectin millectin and a complement factor c3-like protein (c3-am), in the coral acropora millepora. the results indicate that the innate immune functions of these molecules are conserved an ...201020600272
validation of housekeeping genes for gene expression studies in symbiodinium exposed to thermal and light stress.unicellular photosynthetic algae (dinoflagellate) from the genus symbiodinium live in mutualistic symbiosis with reef-building corals. cultured symbiodinium sp. (clade c) were exposed to a range of environmental stresses that included elevated temperatures (29°c and 32°c) under high (100 μmol quanta m(-2) s(-1) photosynthetic active radiation) and low (10 μmol quanta m(-2) s(-1)) irradiances. using real-time rt-pcr the stability of expression for the nine selected putative housekeeping genes (hk ...201020668900
gene expression profiles of cytosolic heat shock proteins hsp70 and hsp90 from symbiotic dinoflagellates in response to thermal stress: possible implications for coral bleaching.unicellular photosynthetic dinoflagellates of the genus symbiodinium are the most common endosymbionts of reef-building scleractinian corals, living in a symbiotic partnership known to be highly susceptible to environmental changes such as hyperthermic stress. in this study, we identified members of two major heat shock proteins (hsps) families, hsp70 and hsp90, in symbiodinium sp. (clade c) with full-length sequences that showed the highest similarity and evolutionary relationship with other kn ...201120821176
chemical and physical environmental conditions underneath mat- and canopy-forming macroalgae, and their effects on understorey corals.disturbed coral reefs are often dominated by dense mat- or canopy-forming assemblages of macroalgae. this study investigated how such dense macroalgal assemblages change the chemical and physical microenvironment for understorey corals, and how the altered environmental conditions affect the physiological performance of corals. field measurements were conducted on macroalgal-dominated inshore reefs in the great barrier reef in quadrats with macroalgal biomass ranging from 235 to 1029 g dw m(-2) ...201020856882
fluorescence of coral larvae predicts their settlement response to crustose coralline algae and reflects stress.multi-coloured homologues of the green fluorescent protein generate some of the most striking visual phenomena in the ocean. despite their natural prominence in reef-building corals and widespread use in biotechnology, their biological role remains obscure. here, we experimented with larvae of acropora millepora to determine what can be learned about a coral larva or recruit from its fluorescent colour. we performed 12 crosses between seven a. millepora colonies representing differing fluorescen ...201121270034
regulation of apoptotic mediators reveals dynamic responses to thermal stress in the reef building coral acropora millepora.mass coral bleaching is increasing in scale and frequency across the world's coral reefs and is being driven primarily by increased levels of thermal stress arising from global warming. in order to understand the impacts of projected climate change upon corals reefs, it is important to elucidate the underlying cellular mechanisms that operate during coral bleaching and subsequent mortality. in this respect, increased apoptotic cell death activity is an important cellular process that is associat ...201121283671
a multilocus, temperature stress-related gene expression profile assay in acropora millepora, a dominant reef-building coral.we report an accurate multiplex reverse transcription quantitative polymerase chain reaction (rt-qpcr) assay, capable of reproducing gene expression profiles from 16 target genes [12 genes of interest (gois) and four reference genes (rgs)] in acropora millepora, a common reef-building model coral species. the 12 gois have known or putative roles in the coral bleaching response, yet the method is not restricted to this particular assay and gene set. the procedure is based on the beckman coulter ( ...201121429140
unexpected complexity of the reef-building coral acropora millepora transcription factor network.abstract:201121526989
a comparative study of phenoloxidase activity in diseased and bleached colonies of the coral acropora millepora.in scleractinian (hard) corals, immune responses involving phenoloxidase (po) activity are known to play a role in coral wound healing, but there have been no studies investigating their roles in mitigating either disease or bleaching in an indo-pacific coral. po activity induces the release of reactive oxygen species leading to a cytotoxic cellular environment, which enhances resistance against pathogens, but is also likely to compound oxidative stress induced during bleaching. antioxidants suc ...201121527282
induction of larval metamorphosis of the coral acropora millepora by tetrabromopyrrole isolated from a pseudoalteromonas bacterium.the induction of larval attachment and metamorphosis of benthic marine invertebrates is widely considered to rely on habitat specific cues. while microbial biofilms on marine hard substrates have received considerable attention as specific signals for a wide and phylogenetically diverse array of marine invertebrates, the presumed chemical settlement signals produced by the bacteria have to date not been characterized. here we isolated and fully characterized the first chemical signal from bacter ...201121559509
quantification of algal endosymbionts (symbiodinium) in coral tissue using real-time pcr.understanding the flexibility of the endosymbioses between scleractinian corals and single-cell algae of the genus symbiodinium will provide valuable insights into the future of coral reefs. here, a real-time polymerase chain reaction (pcr) assay is presented to accurately determine the cell densities of symbiodinium clades c and d in the scleractinian coral acropora millepora, which can be extended to other coral-symbiont associations in the future. the assay targets single- to low-copy genes o ...200921564569
microsatellite loci isolated from the scleractinian coral, acropora nobilis.we report the isolation and characterization of eight microsatellite loci from the scleractinian coral, acropora nobilis. the microsatellite loci were obtained using compound ssr primers or an enrichment protocol. all the loci were polymorphic with four to eight alleles per locus and observed heterozygosities ranging from 0.22 to 0.76. some of the primers developed for the two congeners, acropora palmata and acropora millepora were applicable to a. nobilis. these loci are useful for studying the ...200821585840
rapid evolution of coral proteins responsible for interaction with the environment.corals worldwide are in decline due to climate change effects (e.g., rising seawater temperatures), pollution, and exploitation. the ability of corals to cope with these stressors in the long run depends on the evolvability of the underlying genetic networks and proteins, which remain largely unknown. a genome-wide scan for positively selected genes between related coral species can help to narrow down the search space considerably.201121633702
high potential for formation and persistence of chimeras following aggregated larval settlement in the broadcast spawning coral, acropora millepora.in sessile modular marine invertebrates, chimeras can originate from fusions of closely settling larvae or of colonies that come into contact through growth or movement. while it has been shown that juveniles of brooding corals fuse under experimental conditions, chimera formation in broadcast spawning corals, the most abundant group of reef corals, has not been examined. this study explores the capacity of the broadcast spawning coral acropora millepora to form chimeras under experimental condi ...201221752820
transcriptomic variation in a coral reveals pathways of clonal organisation.a microarray study was undertaken to examine the potential for clonal gene expression variation in a branching reef building coral, acropora millepora. the role of small-scale gradients in light and water flow was examined by comparing gene expression levels between branch elevation (tip and base) and position (centre and edge) of replicate coral colonies (n=3). analyses of variance revealed that almost 60% of variation in gene expression was present between colonies and 34 genes were considered ...200921798180
profiling gene expression responses of coral larvae (acropora millepora) to elevated temperature and settlement inducers using a novel rna-seq procedure.elevated temperatures resulting from climate change pose a clear threat to reef-building corals; however, the traits that might influence corals' survival and dispersal during climate change remain poorly understood. global gene expression profiling is a powerful hypothesis-forming tool that can help elucidate these traits. here, we applied a novel rna-seq protocol to study molecular responses to heat and settlement inducers in aposymbiotic larvae of the reef-building coral acropora millepora. t ...201121801258
circadian cycles of gene expression in the coral, acropora millepora.circadian rhythms regulate many physiological, behavioral and reproductive processes. these rhythms are often controlled by light, and daily cycles of solar illumination entrain many clock regulated processes. in scleractinian corals a number of different processes and behaviors are associated with specific periods of solar illumination or non-illumination--for example, skeletal deposition, feeding and both brooding and broadcast spawning.201121949855
resistance to thermal stress in corals without changes in symbiont composition.discovering how corals can adjust their thermal sensitivity in the context of global climate change is important in understanding the long-term persistence of coral reefs. in this study, we showed that short-term preconditioning to higher temperatures, 3°c below the experimentally determined bleaching threshold, for a period of 10 days provides thermal tolerance for the symbiosis stability between the scleractinian coral, acropora millepora and symbiodinium. based on genotypic analysis, our resu ...201221976690
Regulation of Bacterial Communities Through Antimicrobial Activity by the Coral Holobiont.Interactions between corals and associated bacteria and amongst these bacterial groups are likely to play a key role in coral health. However, the complexity of these interactions is poorly understood. We investigated the functional role of specific coral-associated bacteria in maintaining microbial communities on the coral Acropora millepora (Ehrenberg 1834) and the ability of coral mucus to support or inhibit bacterial growth. Culture-independent techniques were used to assess bacterial commun ...201121984347
historical and contemporary factors shape the population genetic structure of the broadcast spawning coral, acropora millepora, on the great barrier reef.effective management of reef corals requires knowledge of the extent to which populations are open or closed and the scales over which genetic exchange occurs, information which is commonly derived from population genetic data. such data are sparse for great barrier reef (gbr) corals and other organisms, with the studies that are available being mostly based on a small number of sampling locations spanning only part of the gbr. using 11 microsatellite loci, we genotyped 947 colonies of the reef- ...201122026459
effects of herbivory, nutrients, and reef protection on algal proliferation and coral growth on a tropical reef.maintaining coral reef resilience against increasing anthropogenic disturbance is critical for effective reef management. resilience is partially determined by how processes, such as herbivory and nutrient supply, affect coral recovery versus macroalgal proliferation following disturbances. however, the relative effects of herbivory versus nutrient enrichment on algal proliferation remain debated. here, we manipulated herbivory and nutrients on a coral-dominated reef protected from fishing, and ...201122038059
environmental factors controlling the distribution of symbiodinium harboured by the coral acropora millepora on the great barrier reef.the symbiodinium community associated with scleractinian corals is widely considered to be shaped by seawater temperature, as the coral's upper temperature tolerance is largely contingent on the symbiodinium types harboured. few studies have challenged this paradigm as knowledge of other environmental drivers on the distribution of symbiodinium is limited. here, we examine the influence of a range of environmental variables on the distribution of symbiodinium associated with acropora millepora c ...201122065989
differential gene expression at coral settlement and metamorphosis--a subtractive hybridization study.a successful metamorphosis from a planktonic larva to a settled polyp, which under favorable conditions will establish a future colony, is critical for the survival of corals. however, in contrast to the situation in other animals, e.g., frogs and insects, little is known about the molecular basis of coral metamorphosis. we have begun to redress this situation with previous microarray studies, but there is still a great deal to learn. in the present paper we have utilized a different technology, ...201122065994
ocean acidification reduces coral recruitment by disrupting intimate larval-algal settlement interactions.ecology letters (2012) 15: 338-346 abstract: successful recruitment in shallow reef ecosystems often involves specific cues that connect planktonic invertebrate larvae with particular crustose coralline algae (cca) during settlement. while ocean acidification (oa) can reduce larval settlement and the abundance of cca, the impact of oa on the interactions between planktonic larvae and their preferred settlement substrate are unknown. here, we demonstrate that co2 concentrations (800 and 1300 μatm ...201222321314
corals form characteristic associations with symbiotic nitrogen-fixing bacteria.the complex symbiotic relationship between corals and their dinoflagellate partner symbiodinium is believed to be sustained through close associations with mutualistic bacterial communities, though little is known about coral associations with bacterial groups able to fix nitrogen (diazotrophs). in this study, we investigated the diversity of diazotrophic bacterial communities associated with three common coral species (acropora millepora, acropora muricata, and pocillopora damicormis) from thre ...201222344646
whole transcriptome analysis of the coral acropora millepora reveals complex responses to co₂-driven acidification during the initiation of calcification.the impact of ocean acidification (oa) on coral calcification, a subject of intense current interest, is poorly understood in part because of the presence of symbionts in adult corals. early life history stages of acropora spp. provide an opportunity to study the effects of elevated co(2) on coral calcification without the complication of symbiont metabolism. therefore, we used the illumina rnaseq approach to study the effects of acute exposure to elevated co(2) on gene expression in primary pol ...201222490231
a "neural" enzyme in nonbilaterian animals and algae: preneural origins for peptidylglycine α-amidating monooxygenase.secreted peptides, produced by enzymatic processing of larger precursor molecules, are found throughout the animal kingdom and play important regulatory roles as neurotransmitters and hormones. many require a carboxy-terminal modification, involving the conversion of a glycine residue into an α-amide, for their biological activity. two sequential enzymatic activities catalyze this conversion: a monooxygenase (peptidylglycine α-hydroxylating monooxygenase or phm) and an amidating lyase (peptidyl- ...201222496439
major cellular and physiological impacts of ocean acidification on a reef building coral.as atmospheric levels of co(2) increase, reef-building corals are under greater stress from both increased sea surface temperatures and declining sea water ph. to date, most studies have focused on either coral bleaching due to warming oceans or declining calcification due to decreasing oceanic carbonate ion concentrations. here, through the use of physiology measurements and cdna microarrays, we show that changes in ph and ocean chemistry consistent with two scenarios put forward by the intergo ...201222509341
using bacterial extract along with differential gene expression in acropora millepora larvae to decouple the processes of attachment and metamorphosis.biofilms of the bacterium pseudoalteromonas induce metamorphosis of acroporid coral larvae. the bacterial metabolite tetrabromopyrrole (tbp), isolated from an extract of pseudoalteromonas sp. associated with the crustose coralline alga (cca) neogoniolithon fosliei, induced coral larval metamorphosis (100%) with little or no attachment (0-2%). to better understand the molecular events and mechanisms underpinning the induction of acropora millepora larval metamorphosis, including cell proliferatio ...201222655067
first frozen repository for the great barrier reef coral created.to build new tools for the continued protection and propagation of coral from the great barrier reef (gbr), an international group of coral and cryopreservation scientists known as the reef recovery initiative joined forces during the november 2011 mass-spawning event. the outcome was the creation of the first frozen bank for australian coral from two important gbr reef-building species, acropora tenuis and acropora millepora. approximately 190 frozen samples each with billions of cells were pla ...201222659104
chronic exposure of corals to fine sediments: lethal and sub-lethal impacts.understanding the sedimentation and turbidity thresholds for corals is critical in assessing the potential impacts of dredging projects in tropical marine systems. in this study, we exposed two species of coral sampled from offshore locations to six levels of total suspended solids (tss) for 16 weeks in the laboratory, including a 4 week recovery period. dose-response relationships were developed to quantify the lethal and sub-lethal thresholds of sedimentation and turbidity for the corals. the ...201222662225
expression of putative immune response genes during early ontogeny in the coral acropora millepora.corals, like many other marine invertebrates, lack a mature allorecognition system in early life history stages. indeed, in early ontogeny, when corals acquire and establish associations with various surface microbiota and dinoflagellate endosymbionts, they do not efficiently distinguish between closely and distantly related individuals from the same population. however, very little is known about the molecular components that underpin allorecognition and immunity responses or how they change th ...201222792163
a lipidomic approach to understanding free fatty acid lipogenesis derived from dissolved inorganic carbon within cnidarian-dinoflagellate symbiosis.the cnidarian-dinoflagellate symbiosis is arguably one of the most important within the marine environment in that it is integral to the formation of coral reefs. however, the regulatory processes that perpetuate this symbiosis remain unresolved. it is essential to understand these processes, if we are to elucidate the mechanisms that support growth and resource accumulation by coral host, and conversely, recently observed reduction and/or mortality of corals in response to rapid environmental c ...201223115631
interactions among chronic and acute impacts on coral recruits: the importance of size-escape thresholds.newly settled recruits typically suffer high mortality from disturbances, but rapid growth reduces their mortality once size-escape thresholds are attained. ocean acidification (oa) reduces the growth of recruiting benthic invertebrates, yet no direct effects on survivorship have been demonstrated. we tested whether the reduced growth of coral recruits caused by oa would increase their mortality by prolonging their vulnerability to an acute disturbance: fish herbivory on surrounding algal turf. ...201223185875
coral thermal tolerance: tuning gene expression to resist thermal stress.the acclimatization capacity of corals is a critical consideration in the persistence of coral reefs under stresses imposed by global climate change. the stress history of corals plays a role in subsequent response to heat stress, but the transcriptomic changes associated with these plastic changes have not been previously explored. in order to identify host transcriptomic changes associated with acquired thermal tolerance in the scleractinian coral acropora millepora, corals preconditioned to a ...201223226355
photoreception and signal transduction in corals: proteomic and behavioral evidence for cytoplasmic calcium as a mediator of light responsivity.little is known about how corals sense and respond to light. in this report the proteome of coral is explored using 2d protein electrophoresis in two species, montastraea cavernosa and acropora millepora. multiple protein species have major shifts in abundance in both species when sampled in daylight compared to corals sampled late in the night. these changes were observed both in larvae lacking zooxanthellae and in adult tissue containing zooxanthellae, including both pacific and caribbean cora ...201223264475
the neuronal calcium sensor protein acrocalcin: a potential target of calmodulin regulation during development in the coral acropora millepora.to understand the calcium-mediated signalling pathways underlying settlement and metamorphosis in the scleractinian coral acropora millepora, a predicted protein set derived from larval cdnas was scanned for the presence of ef-hand domains (pfam id: pf00036). this approach led to the identification of a canonical calmodulin (amcam) protein and an uncharacterised member of the neuronal calcium sensor (ncs) family of proteins known here as acrocalcin (amac). while amcam transcripts were present th ...201223284743
does trophic status enhance or reduce the thermal tolerance of scleractinian corals? a review, experiment and conceptual framework.global warming, and nutrient and sediment runoff from coastal development, both exert increasing pressures on coastal coral reefs. the objective of this study was to resolve the question of whether coastal eutrophication may protect corals from thermal stress by improving their nutritional status, or rather diminish their thermal tolerance through the synergy of dual stressors. a review of previous studies on the topic of combined trophic status and heat exposure on the thermal tolerance of cora ...201323349876
the n-terminal intrinsically disordered domain of mgm101p is localized to the mitochondrial nucleoid.the mitochondrial genome maintenance gene, mgm101, is essential for yeasts that depend on mitochondrial dna replication. previously, in saccharomyces cerevisiae, it has been found that the carboxy-terminal two-thirds of mgm101p has a functional core. furthermore, there is a high level of amino acid sequence conservation in this region from widely diverse species. by contrast, the amino-terminal region, that is also essential for function, does not have recognizable conservation. using a bioinfor ...201323418572
genotype - environment correlations in corals from the great barrier reef.knowledge of genetic markers that are correlated to stress tolerance may improve spatial mapping of reef vulnerability and can inform restoration efforts, including the choice of genotypes for breeding and reseeding. in this manuscript we present two methods for screening transcriptome data for candidate genetic markers in two reef building corals, acropora millepora and pocillopora damicornis (types α and β). in a. millepora, single nucleotide polymorphisms (snps) were pre-selected by targeting ...201323433436
high natural gene expression variation in the reef-building coral acropora millepora: potential for acclimative and adaptive plasticity.ecosystems worldwide are suffering the consequences of anthropogenic impact. the diverse ecosystem of coral reefs, for example, are globally threatened by increases in sea surface temperatures due to global warming. studies to date have focused on determining genetic diversity, the sequence variability of genes in a species, as a proxy to estimate and predict the potential adaptive response of coral populations to environmental changes linked to climate changes. however, the examination of natur ...201323565725
gene expression signatures of energetic acclimatisation in the reef building coral acropora millepora.understanding the mechanisms by which natural populations cope with environmental stress is paramount to predict their persistence in the face of escalating anthropogenic impacts. reef-building corals are increasingly exposed to local and global stressors that alter nutritional status causing reduced fitness and mortality, however, these responses can vary considerably across species and populations.201323671571
spatial and temporal genetic structure of symbiodinium populations within a common reef-building coral on the great barrier reef.the dinoflagellate photosymbiont symbiodinium plays a fundamental role in defining the physiological tolerances of coral holobionts, but little is known about the dynamics of these endosymbiotic populations on coral reefs. sparse data indicate that symbiodinium populations show limited spatial connectivity; however, no studies have investigated temporal dynamics for in hospite symbiodinium populations following significant mortality and recruitment events in coral populations. we investigated th ...201323730715
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