LPS-Induced Genes in Intestinal Tissue of the Sea Cucumber Holothuria glaberrima

Metazoan immunity is mainly associated with specialized cells that are directly involved with the immune response. Nevertheless, both in vertebrates and invertebrates other organs might respond to immune activation and participate either directly or indirectly in the ongoing immune process. However, most of what is known about invertebrate immunity has been restricted to immune effector cells and little information is available on the immune responses of other tissues or organs. We now focus on the immune reactions of the intestinal tissue of an echinoderm. Our study employs a non-conventional model, the echinoderm Holothuria glaberrima, to identify intestinal molecules expressed after an immune challenge presented by an intra-coelomic injection of lipopolysaccharides (LPS). The expression profiles of intestinal genes expressed differentially between LPS-injected animals and control sea water-injected animals were determined using a custom-made Agilent microarray with 7209 sea cucumber intestinal ESTs. Fifty (50) unique sequences were found to be differentially expressed in the intestine of LPS-treated sea cucumbers. Seven (7) of these sequences represented homologues of known proteins, while the remaining (43) had no significant similarity with any protein, EST or RNA database. The known sequences corresponded to cytoskeletal proteins (Actin and alpha-actinin), metabolic enzymes (GAPDH, Ahcy and Gnmt), metal ion transport/metabolism (major yolk protein) and defense/recognition (fibrinogen-like protein). The expression pattern of 11 genes was validated using semi-quantitative RT-PCR. Nine of these corroborated the microarray results and the remaining two showed a similar trend but without statistical significance. Our results show some of the molecular events by which the holothurian intestine responds to an immune challenge and provide important information to the study of the evolution of the immune response.     

Diversification of Two Lineages of Symbiotic Photobacterium

Understanding of processes driving bacterial speciation requires examination of closely related, recently diversified lineages. To gain an insight into diversification of bacteria, we conducted comparative genomic analysis of two lineages of bioluminescent symbionts, Photobacterium leiognathi and ‘P. mandapamensis’. The two lineages are evolutionary and ecologically closely related. Based on the methods used in bacterial taxonomy for classification of new species (DNA-DNA hybridization and ANI), genetic relatedness of the two lineages is at a cut-off point for species delineation. In this study, we obtained the whole genome sequence of a representative P. leiognathi strain lrivu.4.1, and compared it to the whole genome sequence of ‘P. mandapamensis’ svers.1.1. Results of the comparative genomic analysis suggest that P. leiognathi has a more plastic genome and acquired genes horizontally more frequently than ‘P. mandapamensis’. We predict that different rates of recombination and gene acquisition contributed to diversification of the two lineages. Analysis of lineage-specific sequences in 25 strains of P. leiognathi and ‘P. mandapamensis’ found no evidence that bioluminescent symbioses with specific host animals have played a role in diversification of the two lineages.     

Vibrio Zinc-Metalloprotease Causes Photoinactivation of Coral Endosymbionts and Coral Tissue Lesions

Background

Coral diseases are emerging as a serious threat to coral reefs worldwide. Of nine coral infectious diseases, whose pathogens have been characterized, six are caused by agents from the family Vibrionacae, raising questions as to their origin and role in coral disease aetiology.

Methodology/Principal Findings

Here we report on a Vibrio zinc-metalloprotease causing rapid photoinactivation of susceptible Symbiodinium endosymbionts followed by lesions in coral tissue. Symbiodinium photosystem II inactivation was diagnosed by an imaging pulse amplitude modulation fluorometer in two bioassays, performed by exposing Symbiodinium cells and coral juveniles to non-inhibited and EDTA-inhibited supernatants derived from coral white syndrome pathogens.

Conclusion/Significance

These findings demonstrate a common virulence factor from four phylogenetically related coral pathogens, suggesting that zinc-metalloproteases may play an important role in Vibrio pathogenicity in scleractinian corals.     

Discovery Of Genetically Distinct Sympatric Lineages in the Freshwater Mussel Cyprogenia Aberti (Bivalvia: Unionidae)

The western fanshell, Cyprogenia aberti, occurs in the CentralHighlands region of North America and is the only congener ofthe federally endangered fanshell, C. stegaria. Due to a reductionin range size and local extirpations, extant populations ofC. aberti have become increasingly isolated. Consequently, C.aberti has been the focus of numerous conservation efforts,yet no work has examined the degree of genetic variation amongthe species' disjunct populations. Phylogenetic analyses ofnucleotide sequences from two mitochondrial gene portions (CO1and ND1) revealed results important to the conservation managementof C. aberti. First, phylogenetic analyses do not support amonophyletic C. aberti. Second, C. aberti is comprised of asmany as five independent lineages, one of which includes thefederally endangered C. stegaria. Third, analysis recoveredtwo genetically distinct sympatric lineages of C. aberti inthe Ouachita River Drainage. These phylogenetic results suggestthat the five distinct evolutionary lineages of C. aberti shouldbe managed as separate conservation units. This study illustrateswhy it is critical to evaluate genetic variability in endangeredand threatened ‘species’ prior to implementing arecovery program. These data also reveal the value of assessingbiological diversity of nonimperiled taxa before populationsare extirpated and valuable genetic data necessary for reconstructionof evolutionary relationships is lost. (Received 24 October 2005; accepted 8 June 2006)     

Phylogeny in Aid of the Present and Novel Microbial Lineages: Diversity in Bacillus

Bacillus represents microbes of high economic, medical and biodefense importance. Bacillus strain identification based on 16S rRNA sequence analyses is invariably limited to species level. Secondly, certain discrepancies exist in the segregation of Bacillus subtilis strains. In the RDP/NCBI databases, out of a total of 2611 individual 16S rDNA sequences belonging to the 175 different species of the genus Bacillus, only 1586 have been identified up to species level. 16S rRNA sequences of Bacillus anthracis (153 strains), B. cereus (211 strains), B. thuringiensis (108 strains), B. subtilis (271 strains), B. licheniformis (131 strains), B. pumilus (83 strains), B. megaterium (47 strains), B. sphaericus (42 strains), B. clausii (39 strains) and B. halodurans (36 strains) were considered for generating species-specific framework and probes as tools for their rapid identification. Phylogenetic segregation of 1121, 16S rDNA sequences of 10 different Bacillus species in to 89 clusters enabled us to develop a phylogenetic frame work of 34 representative sequences. Using this phylogenetic framework, 305 out of 1025, 16S rDNA sequences presently classified as Bacillus sp. could be identified up to species level. This identification was supported by 20 to 30 nucleotides long signature sequences and in silico restriction enzyme analysis specific to the 10 Bacillus species. This integrated approach resulted in identifying around 30% of Bacillus sp. up to species level and revealed that B. subtilis strains can be segregated into two phylogenetically distinct groups, such that one of them may be renamed.     

Ancient Divergence in the Trans-Oceanic Deep-Sea Shark Centroscymnus crepidater

Unravelling the genetic structure and phylogeographic patterns of deep-sea sharks is particularly challenging given the inherent difficulty in obtaining samples. The deep-sea shark Centroscymnus crepidater is a medium-sized benthopelagic species that exhibits a circumglobal distribution occurring both in the Atlantic and Indo-Pacific Oceans. Contrary to the wealth of phylogeographic studies focused on coastal sharks, the genetic structure of bathyal species remains largely unexplored. We used a fragment of the mitochondrial DNA control region, and microsatellite data, to examine genetic structure in C. crepidater collected from the Atlantic Ocean, Tasman Sea, and southern Pacific Ocean (Chatham Rise). Two deeply divergent (3.1%) mtDNA clades were recovered, with one clade including both Atlantic and Pacific specimens, and the other composed of Atlantic samples with a single specimen from the Pacific (Chatham Rise). Bayesian analyses estimated this splitting in the Miocene at about 15 million years ago. The ancestral C. crepidater lineage was probably widely distributed in the Atlantic and Indo-Pacific Oceans. The oceanic cooling observed during the Miocene due to an Antarctic glaciation and the Tethys closure caused changes in environmental conditions that presumably restricted gene flow between basins. Fluctuations in food resources in the Southern Ocean might have promoted the dispersal of C. crepidater throughout the northern Atlantic where habitat conditions were more suitable during the Miocene. The significant genetic structure revealed by microsatellite data suggests the existence of present-day barriers to gene flow between the Atlantic and Pacific populations most likely due to the influence of the Agulhas Current retroflection on prey movements.     

Embryogenesis and Larval Biology of the Cold-Water Coral Lophelia pertusa

Cold-water coral reefs form spectacular and highly diverse ecosystems in the deep sea but little is known about reproduction, and virtually nothing about the larval biology in these corals. This study is based on data from two locations of the North East Atlantic and documents the first observations of embryogenesis and larval development in Lophelia pertusa, the most common framework-building cold-water scleractinian. Embryos developed in a more or less organized radial cleavage pattern from ∼160 µm large neutral or negatively buoyant eggs, to 120–270 µm long ciliated planulae. Embryogenesis was slow with cleavage occurring at intervals of 6–8 hours up to the 64-cell stage. Genetically characterized larvae were sexually derived, with maternal and paternal alleles present. Larvae were active swimmers (0.5 mm s⁻¹) initially residing in the upper part of the water column, with bottom probing behavior starting 3–5 weeks after fertilization. Nematocysts had developed by day 30, coinciding with peak bottom-probing behavior, and possibly an indication that larvae are fully competent to settle at this time. Planulae survived for eight weeks under laboratory conditions, and preliminary results indicate that these planulae are planktotrophic. The late onset of competency and larval longevity suggests a high dispersal potential. Understanding larval biology and behavior is of paramount importance for biophysical modeling of larval dispersal, which forms the basis for predictions of connectivity among populations.     

Contrasting Activity Patterns of Sympatric and Allopatric Black and Grizzly Bears

ABSTRACT The distribution of grizzly (Ursus arctos) and American black bears (U. americanus) overlaps in western North America. Few studies have detailed activity patterns where the species are sympatric and no studies contrasted patterns where populations are both sympatric and allopatric. We contrasted activity patterns for sympatric black and grizzly bears and for black bears allopatric to grizzly bears, how human influences altered patterns, and rates of grizzly-black bear predation. Activity patterns differed between black bear populations, with those sympatric to grizzly bears more day-active. Activity patterns of black bears allopatric with grizzly bears were similar to those of female grizzly bears; both were crepuscular and day-active. Male grizzly bears were crepuscular and night-active. Both species were more night-active and less day-active when ≤1 km from roads or developments. In our sympatric study area, 2 of 4 black bear mortalities were due to grizzly bear predation. Our results suggested patterns of activity that allowed for intra- and inter-species avoidance. National park management often results in convergence of locally high human densities in quality bear habitat. Our data provide additional understanding into how bears alter their activity patterns in response to other bears and humans and should help park managers minimize undesirable bear-human encounters when considering needs for temporal and spatial management of humans and human developments in bear habitats.     

Oxygen and Heterotrophy Affect Calcification of the Scleractinian Coral Galaxea fascicularis

Heterotrophy is known to stimulate calcification of scleractinian corals, possibly through enhanced organic matrix synthesis and photosynthesis, and increased supply of metabolic DIC. In contrast to the positive long-term effects of heterotrophy, inhibition of calcification has been observed during feeding, which may be explained by a temporal oxygen limitation in coral tissue. To test this hypothesis, we measured the short-term effects of zooplankton feeding on light and dark calcification rates of the scleractinian coral Galaxea fascicularis (n = 4) at oxygen saturation levels ranging from 13 to 280%. Significant main and interactive effects of oxygen, heterotrophy and light on calcification rates were found (three-way factorial repeated measures ANOVA, p<0.05). Light and dark calcification rates of unfed corals were severely affected by hypoxia and hyperoxia, with optimal rates at 110% saturation. Light calcification rates of fed corals exhibited a similar trend, with highest rates at 150% saturation. In contrast, dark calcification rates of fed corals were close to zero under all oxygen saturations. We conclude that oxygen exerts a strong control over light and dark calcification rates of corals, and propose that in situ calcification rates are highly dynamic. Nevertheless, the inhibitory effect of heterotrophy on dark calcification appears to be oxygen-independent. We hypothesize that dark calcification is impaired during zooplankton feeding by a temporal decrease of the pH and aragonite saturation state of the calcifying medium, caused by increased respiration rates. This may invoke a transient reallocation of metabolic energy to soft tissue growth and organic matrix synthesis. These insights enhance our understanding of how oxygen and heterotrophy affect coral calcification, both in situ as well as in aquaculture.     

Deep-Sea Biodiversity in the Mediterranean Sea: The Known,the Unknown,and the Unknowable

Deep-sea ecosystems represent the largest biome of the global biosphere, but knowledge of their biodiversity is still scant. The Mediterranean basin has been proposed as a hot spot of terrestrial and coastal marine biodiversity but has been supposed to be impoverished of deep-sea species richness. We summarized all available information on benthic biodiversity (Prokaryotes, Foraminifera, Meiofauna, Macrofauna, and Megafauna) in different deep-sea ecosystems of the Mediterranean Sea (200 to more than 4,000 m depth), including open slopes, deep basins, canyons, cold seeps, seamounts, deep-water corals and deep-hypersaline anoxic basins and analyzed overall longitudinal and bathymetric patterns. We show that in contrast to what was expected from the sharp decrease in organic carbon fluxes and reduced faunal abundance, the deep-sea biodiversity of both the eastern and the western basins of the Mediterranean Sea is similarly high. All of the biodiversity components, except Bacteria and Archaea, displayed a decreasing pattern with increasing water depth, but to a different extent for each component. Unlike patterns observed for faunal abundance, highest negative values of the slopes of the biodiversity patterns were observed for Meiofauna, followed by Macrofauna and Megafauna. Comparison of the biodiversity associated with open slopes, deep basins, canyons, and deep-water corals showed that the deep basins were the least diverse. Rarefaction curves allowed us to estimate the expected number of species for each benthic component in different bathymetric ranges. A large fraction of exclusive species was associated with each specific habitat or ecosystem. Thus, each deep-sea ecosystem contributes significantly to overall biodiversity. From theoretical extrapolations we estimate that the overall deep-sea Mediterranean biodiversity (excluding prokaryotes) reaches approximately 2805 species of which about 66% is still undiscovered. Among the biotic components investigated (Prokaryotes excluded), most of the unknown species are within the phylum Nematoda, followed by Foraminifera, but an important fraction of macrofaunal and megafaunal species also remains unknown. Data reported here provide new insights into the patterns of biodiversity in the deep-sea Mediterranean and new clues for future investigations aimed at identifying the factors controlling and threatening deep-sea biodiversity.     

Promoter Variation and Transcript Divergence in Brassicaceae Lineages of FLOWERING LOCUS T

Brassica napus (AACC, 2n = 38), an oil crop of world-wide importance, originated from interspecific hybridization of B. rapa (AA, 2n = 20) and B. oleracea (CC, 2n = 18), and has six FLOWERING LOCUS T (FT) paralogues. Two located on the homeologous chromosomes A2 and C2 arose from a lineage distinct from four located on A7 and C6. A set of three conserved blocks A, B and C, which were found to be essential for FT activation by CONSTANS (CO) in Arabidopsis, was identified within the FT upstream region in B. napus and its progenitor diploids. However, on chromosome C2, insertion of a DNA transposable element (TE) and a retro-element in FT upstream blocks A and B contributed to significant structural divergence between the A and C genome orthologues. Phylogenetic analysis of upstream block A indicated the conserved evolutionary relationships of distinct FT genes within Brassicaceae. We conclude that the ancient At-α whole genome duplication contributed to distinct ancestral lineages for this key adaptive gene, which co-exist within the same genus. FT-A2 was found to be transcribed in all leaf samples from different developmental stages in both B. rapa and B. napus, whereas FT-C2 was not transcribed in either B. napus or B. oleracea. Silencing of FT-C2 appeared to result from TE insertion and consequent high levels of cytosine methylation in TE sequences within upstream block A. Interestingly, FT-A7/C6 paralogues were specifically silenced in winter type B. napus but abundantly expressed in spring type cultivars under vernalization-free conditions. Motif prediction indicated the presence of two CO protein binding sites within all Brassica block A and additional sites for FT activation in block C. We propose that the ancestral whole genome duplications have contributed to more complex mechanisms of floral regulation and niche adaptation in Brassica compared to Arabidopsis.     

In-situ Effects of Eutrophication and Overfishing on Physiology and Bacterial Diversity of the Red Sea Coral Acropora hemprichii

Coral reefs of the Central Red Sea display a high degree of endemism, and are increasingly threatened by anthropogenic effects due to intense local coastal development measures. Overfishing and eutrophication are among the most significant local pressures on these reefs, but there is no information available about their potential effects on the associated microbial community. Therefore, we compared holobiont physiology and 16S-based bacterial communities of tissue and mucus of the hard coral Acropora hemprichii after 1 and 16 weeks of in-situ inorganic nutrient enrichment (via fertilizer diffusion) and/or herbivore exclusion (via caging) in an offshore reef of the Central Red Sea. Simulated eutrophication and/or overfishing treatments did not affect coral physiology with respect to coral respiration rates, chlorophyll a content, zooxanthellae abundance, or δ ¹⁵N isotopic signatures. The bacterial community of A. hemprichii was rich and uneven, and diversity increased over time in all treatments. While distinct bacterial species were identified as a consequence of eutrophication, overfishing, or both, two bacterial species that could be classified to the genus Endozoicomonas were consistently abundant and constituted two thirds of bacteria in the coral. Several nitrogen-fixing and denitrifying bacteria were found in the coral specimens that were exposed to experimentally increased nutrients. However, no particular bacterial species was consistently associated with the coral under a given treatment and the single effects of manipulated eutrophication and overfishing could not predict the combined effect. Our data underlines the importance of conducting field studies in a holobiont framework, taking both, physiological and molecular measures into account.     

Sexual Reproduction and Seasonality of the Alaskan Red Tree Coral,Primnoa pacifica

The red tree coral Primnoa pacifica is an important habitat forming octocoral in North Pacific waters. Given the prominence of this species in shelf and upper slope areas of the Gulf of Alaska where fishing disturbance can be high, it may be able to sustain healthy populations through adaptive reproductive processes. This study was designed to test this hypothesis, examining reproductive mode, seasonality and fecundity in both undamaged and simulated damaged colonies over the course of 16 months using a deepwater-emerged population in Tracy Arm Fjord. Females within the population developed asynchronously, though males showed trends of synchronicity, with production of immature spermatocysts heightened in December/January and maturation of gametes in the fall months. Periodicity of individuals varied from a single year reproductive event to some individuals taking more than the 16 months sampled to produce viable gametes. Multiple stages of gametes occurred in polyps of the same colony during most sampling periods. Mean oocyte size ranged from 50 to 200 µm in any season, and maximum oocyte size (802 µm) suggests a lecithotrophic larva. No brooding larvae were found during this study, though unfertilized oocytes were found adhered to the outside of polyps, where they are presumably fertilized. This species demonstrated size-dependent reproduction, with gametes first forming in colonies over 42-cm length, and steady oocyte sizes being achieved after reaching 80-cm in length. The average fecundity was 86 (±12) total oocytes per polyp, and 17 (±12) potential per polyp fecundity. Sub-lethal injury by removing 21–40% of colony tissue had no significant reproductive response in males or females over the course of this study, except for a corresponding loss in overall colony fecundity. The reproductive patterns and long gamete generation times observed in this study indicate that recruitment events are likely to be highly sporadic in this species increasing its vulnerability to anthropogenic disturbances.     

Cellular Membrane Accommodation to Thermal Oscillations in the Coral Seriatopora caliendrum

In the present study, the membrane lipid composition of corals from a region with tidally induced upwelling was investigated. The coral community is subject to strong temperature oscillations yet flourishes as a result of adaptation. Glycerophosphocholine profiling of the dominant pocilloporid coral, Seriatopora caliendrum, was performed using a validated method. The coral inhabiting the upwelling region shows a definite shift in the ratio of lipid molecular species, covering several subclasses. Mainly, the coral possesses a higher percentage of saturated, monounsaturated and polyunsaturated plasmanylcholines and a lower percentage of polyunsaturated phosphatidylcholines. Higher levels of lyso–plasmanylcholines containing saturated or monounsaturated fatty acid chains were also revealed in coral tissue at the distal portion of the branch. Based on the physicochemical properties of these lipids, we proposed mechanisms for handling cellular membrane perturbations, such as tension, induced by thermal oscillation to determine how coral cells are able to spontaneously maintain their physiological functions, in both molecular and physical terms. Interestingly, the biochemical and biophysical properties of these lipids also have beneficial effects on the resistance, maintenance, and growth of the corals. The results of this study suggest that lipid metabolic adjustment is a major factor in the adaption of S. caliendrum in upwelling regions.     

Comparison of Biofilm Formation between Major Clonal Lineages of Methicillin Resistant Staphylococcus aureus

Objectives

Epidemic methicillin-resistant S. aureus (MRSA) clones cause infections in both hospital and community settings. As a biofilm phenotype further facilitates evasion of the host immune system and antibiotics, we compared the biofilm-forming capacities of various MRSA clones.

Methods

Seventy-six MRSA classified into 13 clones (USA300, EMRSA-15, Hungarian/Brazilian etc.), and isolated from infections or from carriers were studied for biofilm formation under static and dynamic conditions. Static biofilms in microtitre plates were quantified colorimetrically. Dynamic biofilms (Bioflux 200, Fluxion, USA) were studied by confocal laser-scanning and time-lapse microscopy, and the total volume occupied by live/dead bacteria quantified by Volocity 5.4.1 (Improvision, UK).

Results

MRSA harbouring SCCmec IV produced significantly more biomass under static conditions than SCCmec I–III (P = 0.003), and those harbouring SCCmec II significantly less than those harbouring SCCmec I or III (P<0.001). In the dynamic model, SCCmec I–III harbouring MRSA were significantly better biofilm formers than SCCmec IV (P = 0.036). Only 16 strains successfully formed biofilms under both conditions, of which 13 harboured SCCmec IV and included all tested USA300 strains (n = 3). However, USA300 demonstrated remarkably lower percentages of cell-occupied space (6.6%) compared to the other clones (EMRSA-15 = 19.0%) under dynamic conditions. Time-lapse microscopy of dynamic biofilms demonstrated that USA300 formed long viscoelastic tethers that stretched far from the point of attachment, while EMRSA-15 consisted of micro-colonies attached densely to the surface.

Conclusions

MRSA harbouring SCCmec types IV and I–III demonstrate distinct biofilm forming capacities, possibly owing to their adaptation to the community and hospital settings, respectively. USA300 demonstrated abundant biofilm formation under both conditions, which probably confers a competitive advantage, contributing to its remarkable success as a pathogen.     

Fast Growth May Impair Regeneration Capacity in the Branching Coral Acropora muricata

Regeneration of artificially induced lesions was monitored in nubbins of the branching coral Acropora muricata at two reef-flat sites representing contrasting environments at Réunion Island (21°07′S, 55°32′E). Growth of these injured nubbins was examined in parallel, and compared to controls. Biochemical compositions of the holobiont and the zooxanthellae density were determined at the onset of the experiment, and the photosynthetic efficiency (F_v/F_m) of zooxanthellae was monitored during the experiment. Acropora muricata rapidly regenerated small lesions, but regeneration rates significantly differed between sites. At the sheltered site characterized by high temperatures, temperature variations, and irradiance levels, regeneration took 192 days on average. At the exposed site, characterized by steadier temperatures and lower irradiation, nubbins demonstrated fast lesion repair (81 days), slower growth, lower zooxanthellae density, chlorophyll a concentration and lipid content than at the former site. A trade-off between growth and regeneration rates was evident here. High growth rates seem to impair regeneration capacity. We show that environmental conditions conducive to high zooxanthellae densities in corals are related to fast skeletal growth but also to reduced lesion regeneration rates. We hypothesize that a lowered regenerative capacity may be related to limited availability of energetic and cellular resources, consequences of coral holobionts operating at high levels of photosynthesis and associated growth.     

Vibrio owensii Induces the Tissue Loss Disease Montipora White Syndrome in the Hawaiian Reef Coral Montipora capitata

Incidences of coral disease in the Indo-Pacific are increasing at an alarming rate. In particular, Montipora white syndrome, a tissue-loss disease found on corals throughout the Hawaiian archipelago, has the potential to degrade Hawaii’s reefs. To identify the etiologic agent of Montipora white syndrome, bacteria were isolated from a diseased fragment of Montipora capitata and used in a screen for virulent strains. A single isolate, designated strain OCN002, recreated disease signs in 53% of coral fragments in laboratory infection trials when added to a final concentration of 10⁷ cells/ml of seawater. In addition to displaying similar signs of disease, diseased coral fragments from the field and those from infection trials both had a dramatic increase in the abundance of associated culturable bacteria, with those of the genus Vibiro well represented. Bacteria isolated from diseased fragments used in infection trails were shown to be descendants of the original OCN002 inocula based on both the presence of a plasmid introduced to genetically tag the strain and the sequence of a region of the OCN002 genome. In contrast, OCN002 was not re-isolated from fragments that were exposed to the strain but did not develop tissue loss. Sequencing of the rrsH gene, metabolic characterization, as well as multilocus sequence analysis indicated that OCN002 is a strain of the recently described species Vibrio owensii. This investigation of Montipora white syndrome recognizes V. owensii OCN002 as the first bacterial coral pathogen identified from Hawaii’s reefs and expands the range of bacteria known to cause disease in corals.