scholarly journals Coral mucus rapidly induces chemokinesis and genome-wide transcriptional shifts toward early pathogenesis in a bacterial coral pathogen

2021 ◽  
Author(s):  
Cherry Gao ◽  
Melissa Garren ◽  
Kevin Penn ◽  
Vicente I. Fernandez ◽  
Justin R. Seymour ◽  
...  
Keyword(s):  
Coral Disease ◽  
Fold Increase ◽  
Transcript Abundance ◽  
Coral Tissue ◽  
Coral Host ◽  
Secretion Systems ◽  
Nutrient Metabolism ◽  
Transcriptional Responses ◽  
Coral Mucus ◽  
Algal Symbiont

AbstractElevated seawater temperatures have contributed to the rise of coral disease mediated by bacterial pathogens, such as the globally distributed Vibrio coralliilyticus, which utilizes coral mucus as a chemical cue to locate stressed corals. However, the physiological events in the pathogens that follow their entry into the coral host environment remain unknown. Here, we present simultaneous measurements of the behavioral and transcriptional responses of V. coralliilyticus BAA-450 incubated in coral mucus. Video microscopy revealed a strong and rapid chemokinetic behavioral response by the pathogen, characterized by a two-fold increase in average swimming speed within 6 min of coral mucus exposure. RNA sequencing showed that this bacterial behavior was accompanied by an equally rapid differential expression of 53% of the genes in the V. coralliilyticus genome. Specifically, transcript abundance 10 min after mucus exposure showed upregulation of genes involved in quorum sensing, biofilm formation, and nutrient metabolism, and downregulation of flagella synthesis and chemotaxis genes. After 60 min, we observed upregulation of genes associated with virulence, including zinc metalloproteases responsible for causing coral tissue damage and algal symbiont photoinactivation, and secretion systems that may export toxins. Together, our results suggest that V. coralliilyticus employs a suite of behavioral and transcriptional responses to rapidly shift into a distinct infection mode within minutes of exposure to the coral microenvironment.

Analysis of wound-induced gene expression in Nicotiana species with contrasting alkaloid profiles

2004 ◽  
Vol 31 (7) ◽  
pp. 721 ◽  
Author(s):  
Steven J. Sinclair ◽  
Richard Johnson ◽  
John D. Hamill
Keyword(s):  
Fold Increase ◽  
Transcript Abundance ◽  
Nicotiana Sylvestris ◽  
Nicotiana Glauca ◽  
Transcriptional Responses ◽  
Transcript Levels ◽  
Solanaceae Species ◽  
Genes Encoding ◽  
Root Tissues ◽  
Alkaloid Profiles

We determined the capacity of three Nicotiana (Solanaceae) species with very different alkaloid profiles (Nicotiana sylvestris Speg & Comes, Nicotiana alata Link & Otto and Nicotiana glauca Grah.) to increase their alkaloid contents in both leaf and root tissues following foliage damage. We also investigated the transcriptional responses of genes encoding enzymes important for alkaloid biosynthesis, namely quinolinate phosphoribosyltransferase (QPT), putrescine N-methyltransferase (PMT), ornithine decarboxylase (ODC) and the putative alkaloid biosynthetic gene A622. In response to wounding of foliage in the well studied ‘model’ species N. sylvestris, a rise, approximately 2-fold, in leaf nicotine levels was observed several days after a 4–5-fold increase in the transcript levels of all genes in the roots. In contrast, leaf tissues of the ornamental tobacco N. alata showed very low levels of any pyridine alkaloid, even when analysed 1 week after wounding, correlating with a general lack of transcript abundance representing any of these genes in leaves or roots following foliage damage. However, addition of methyl jasmonate to cultured roots of N. alata did produce elevated levels of nicotine and anatabine raising the possibility that components of the leaf–root wound signalling system in N. alata are different from those in N. sylvestris. Wounding of the tree tobacco N. glauca, was followed by a 2-fold increase in anabasine levels several days later. This increase followed a large rise in transcript levels of ODC, QPT and A622, though not PMT, in wounded leaves, but not in non-wounded leaves or roots. These data support the hypothesis that N. glauca is able to produce increased anabasine levels following wounding in its foliage, setting it apart from N. sylvestris where induced alkaloid production takes place in roots. We discuss the possibility that increased transcript levels detected by ODC and A622 probes play important roles in anabasine synthesis in N. glauca.

scholarly journals Coupled Epidemio-Hydrodynamic Modeling to Understand the Spread of a Deadly Coral Disease in Florida

2020 ◽  
Vol 7 ◽  
Author(s):  
Thomas Dobbelaere ◽  
Erinn M. Muller ◽  
Lewis J. Gramer ◽  
Daniel M. Holstein ◽  
Emmanuel Hanert
Keyword(s):  
Causative Agent ◽  
Coral Disease ◽  
Propagation Speed ◽  
Tissue Loss ◽  
Coral Tissue ◽  
Model Parameters ◽  
Dade County ◽  
Coral Mucus ◽  
Disease Threshold ◽  
Neutrally Buoyant

For the last six years, the Florida Reef Tract (FRT) has been experiencing an outbreak of the Stony Coral Tissue Loss Disease (SCTLD). First reported off the coast of Miami-Dade County in 2014, the SCTLD has since spread throughout the entire FRT with the exception of the Dry Tortugas. However, the causative agent for this outbreak is currently unknown. Here we show how a high-resolution bio-physical model coupled with a modified patch Susceptible-Infectious-Removed epidemic model can characterize the potential causative agent(s) of the disease and its vector. In the present study, the agent is assumed to be transported within composite material (e.g., coral mucus, dying tissues, and/or resuspended sediments) driven by currents and potentially persisting in the water column for extended periods of time. In this framework, our simulations suggest that the SCTLD is likely to be propagated within neutrally buoyant material driven by mean barotropic currents. Calibration of our model parameters with field data shows that corals are diseased within a mean transmission time of 6.45 days, with a basic reproduction number slightly above 1. Furthermore, the propagation speed of the disease through the FRT is shown to occur for a well-defined range of values of a disease threshold, defined as the fraction of diseased corals that causes an exponential growth of the disease in the reef site. Our results present a new connectivity-based approach to understand the spread of the SCTLD through the FRT. Such a method can provide a valuable complement to field observations and lab experiments to support the management of the epidemic as well as the identification of its causative agent.

scholarly journals The coral symbiont Candidatus Aquarickettsia is variably abundant in threatened Caribbean acroporids and transmitted horizontally

2021 ◽  
Author(s):  
Lydia J. Baker ◽  
Hannah G. Reich ◽  
Sheila A. Kitchen ◽  
J. Grace Klinges ◽  
Hanna R. Koch ◽  
...  
Keyword(s):  
Positive Selection ◽  
Coral Disease ◽  
Horizontal Transmission ◽  
Geographic Location ◽  
Geographic Region ◽  
Pcr Analysis ◽  
Coral Host ◽  
Acropora Cervicornis ◽  
Coral Colony ◽  
Algal Symbiont

AbstractThe symbiont “Candidatus Aquarickettsia rohweri” infects a diversity of aquatic hosts. In the threatened Caribbean coral, Acropora cervicornis, Aquarickettsia proliferates in response to increased nutrient exposure, resulting in suppressed growth and increased disease susceptibility and mortality of coral. This study evaluated the extent, as well as the ecology and evolution of Aquarickettsia infecting threatened corals, Ac. cervicornis, and Ac. palmata and their hybrid (“Ac. prolifera”). Aquarickettsia was found in all acroporids, with coral host and geographic location impacting the infection magnitude. Phylogenomic and genome-wide single-nucleotide variant analysis of Aquarickettsia found phylogenetic clustering by geographic region, not by coral taxon. Analysis of Aquarickettsia fixation indices suggests multiple sequential infections of the same coral colony are unlikely. Furthermore, relative to other Rickettsiales species, Aquarickettsia is undergoing positive selection, with Florida populations experiencing greater positive selection relative to other Caribbean locations. This may be due in part to Aquarickettsia proliferating in response to greater nutrient stress in Florida, as indicated by greater in situ replication rates in these corals. Aquarickettsia was not found to significantly codiversify with either the coral animal or the coral’s algal symbiont (Symbiodinium “fitti”). Quantitative PCR analysis showed that gametes, larvae, recruits, and juveniles from susceptible, captive-reared coral genets were not infected with Aquarickettsia. Thus, horizontal transmission of Aquarickettsia via coral mucocytes or an unidentified host is more likely. The prevalence of Aquarickettsia in Ac. cervicornis and its high abundance in the Florida coral population suggests that coral disease mitigation efforts focus on preventing early infection via horizontal transmission.

scholarly journals Microscale tracking of coral disease reveals timeline of infection and heterogeneity of polyp fate

2018 ◽  
Author(s):  
Assaf R. Gavish ◽  
Orr H. Shapiro ◽  
Esti Kramarsky-Winter ◽  
Assaf Vardi
Keyword(s):  
Disease Progression ◽  
Defense Mechanism ◽  
Coral Disease ◽  
Coral Host ◽  
Pocillopora Damicornis ◽  
Spatial And Temporal Scales ◽  
Infection Dynamics ◽  
Key Steps ◽  
Coral Pathogen ◽  
Gastrovascular System

AbstractCoral disease is often studied at scales ranging from single colonies to the entire reef. This is particularly true for studies following disease progression through time. To gain a mechanistic understanding of key steps underlying infection dynamics, it is necessary to study disease progression, and host-pathogen interactions, at relevant microbial scales. Here we provide a dynamic view of the interaction between the model coral pathogen Vibrio coralliilyticus and its coral host Pocillopora damicornis at unprecedented spatial and temporal scales. This view is achieved using a novel microfluidics-based system specifically designed to allow microscopic study of coral infection in-vivo under controlled environmental conditions. Analysis of exudates continuously collected at the system’s outflow, allows a detailed biochemical and microbial analyses coupled to the microscopic observations of the disease progression. The resulting multilayered dataset provides the most detailed description of a coral infection to-date, revealing distinct pathogenic processes as well as the defensive behavior of the coral host. We provide evidence that infection in this system occurs following ingestion of the pathogen, and may then progress through the gastrovascular system. We further show infection may spread when pathogens colonize lesions in the host tissue. Copious spewing of pathogen-laden mucus from the polyp mouths results in effective expulsion of the pathogen from the gastrovascular system, possibly serving as a first line of defense. A secondary defense mechanism entails the severing of calicoblastic connective tissues resulting in the controlled isolation of diseased polyps, or the survival of individual polyps within infected colonies. Further investigations of coral-pathogen interactions at these scales will help to elucidate the complex interactions underlying coral disease, as we as the versatile adaptive response of the coral ecosystems to fluctuating environments.

scholarly journals Pengamatan Laju Penyakit White Syndrome Pada Montipora sp. Di Pulau Pramuka, Taman Nasional Laut Kepulauan Seribu, DKI Jakarta

2018 ◽  
Vol 5 (1) ◽  
pp. 22
Author(s):  
Abdur Rosyid ◽  
Oktiyas Muzaky Luthfi
Keyword(s):  
National Park ◽  
Coral Disease ◽  
Tissue Loss ◽  
Coral Tissue ◽  
Progression Rate ◽  
White Syndrome ◽  
Coral Surface ◽  
Pathogenic Vibrio ◽  
Imagej Software ◽  
Main Factor

Coral disease now became main factor of coral degradation in the world. There is still a few report about coral disease in Kepulauan Seribu Marine National Park (TNKPS) include of white syndrome (WS) in Montipora sp. WS was characterized by white area on coral surface at several stages. WS had caused coral tissue loss and leaved bare CaCO3 skeleton that was caused by pathogenic Vibrio coralliitycus associated with other microorganisms. In this study the progress of WS calculated by measurement of the distances of WS that moved from diseased to healty coral surface. All calculations was performed used ImageJ Software. Our result showed that WS progression rate in first week was 9.06 cm2 and the second week was 2.37 cm2. Total coral tissue mortality was 12.03% for 2 weeks.

scholarly journals Next-Generation Sequencing Identifies Polyunsaturated Fatty Acid Responsive Genes in the Juvenile Rat Cerebellum

Nutrients ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 407 ◽  
Author(s):  
Aaron Mehus ◽  
Aaron Dickey ◽  
Timothy Smith ◽  
Kathleen Yeater ◽  
Matthew Picklo
Keyword(s):  
Fatty Acids ◽  
Corn Oil ◽  
Docosapentaenoic Acid ◽  
Fold Increase ◽  
Transcript Abundance ◽  
Male Rats ◽  
Rat Cerebellum ◽  
Normalization Methods ◽  
Docosatetraenoic Acid ◽  
Generation Sequencing

Dietary n-3 polyunsaturated fatty acids (PUFA) influence postnatal brain growth and development. However, little data exist regarding the impacts of dietary n-3 PUFA in juvenile animals post weaning, which is a time of rapid growth. We tested the hypothesis that depleting dietary n-3 PUFA would result in modifications to the cerebellar transcriptome of juvenile rats. To test this hypothesis, three week old male rats (an age that roughly corresponds to an 11 month old child in brain development) were fed diets containing either soybean oil (SO) providing 1.1% energy from α-linolenic acid (ALA; 18:3n-3; ALA-sufficient) or corn oil (CO) providing 0.13% energy from ALA (ALA-deficient) for four weeks. Fatty acids (FAs) in the cerebellum were analyzed and revealed a 4-fold increase in n-6 docosapentaenoic acid (DPA; 22:5n-6), increases in arachidonic acid (AA; 20:4n-6) and docosatetraenoic acid (DTA; 22:4n-6), but no decrease in docosahexaenoic acid (DHA; 22:6n-3), in animals fed CO versus SO. Transcript abundance was then characterized to identify differentially expressed genes (DEGs) between the two diets. Upper quartile (UQ) scaling and transcripts per million (TPM) data normalization identified 100 and 107 DEGs, respectively. Comparison of DEGs from the two normalization methods identified 70 genes that overlapped, with 90% having abundance differences less than 2-fold. Nr4a3, a transcriptional activator that plays roles in neuroprotection and learning, was elevated over 2-fold from the CO diet. These data indicate that expression of Nr4a3 in the juvenile rat cerebellum is responsive to dietary n-3 PUFA, but additional studies are needed clarify the neurodevelopmental relationships between n-3 PUFA and Nr4a3 and the resulting impacts.

scholarly journals Measuring light scattering and absorption in corals with Inverse Spectroscopic Optical Coherence Tomography (ISOCT): a new tool for non-invasive monitoring

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
G. L. C. Spicer ◽  
A. Eid ◽  
D. Wangpraseurt ◽  
T. D. Swain ◽  
J. A. Winkelmann ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Properties ◽  
Light Scattering ◽  
Light Propagation ◽  
Coral Tissue ◽  
Coral Host ◽  
Invasive Monitoring ◽  
Optical Coherence ◽  
Invasive Approach ◽  
Non Invasive

Abstract The success of reef-building corals for >200 million years has been dependent on the mutualistic interaction between the coral host and its photosynthetic endosymbiont dinoflagellates (family Symbiodiniaceae) that supply the coral host with nutrients and energy for growth and calcification. While multiple light scattering in coral tissue and skeleton significantly enhance the light microenvironment for Symbiodiniaceae, the mechanisms of light propagation in tissue and skeleton remain largely unknown due to a lack of technologies to measure the intrinsic optical properties of both compartments in live corals. Here we introduce ISOCT (inverse spectroscopic optical coherence tomography), a non-invasive approach to measure optical properties and three-dimensional morphology of living corals at micron- and nano-length scales, respectively, which are involved in the control of light propagation. ISOCT enables measurements of optical properties in the visible range and thus allows for characterization of the density of light harvesting pigments in coral. We used ISOCT to characterize the optical scattering coefficient (μs) of the coral skeleton and chlorophyll a concentration of live coral tissue. ISOCT further characterized the overall micro- and nano-morphology of live tissue by measuring differences in the sub-micron spatial mass density distribution (D) that vary throughout the tissue and skeleton and give rise to light scattering, and this enabled estimates of the spatial directionality of light scattering, i.e., the anisotropy coefficient, g. Thus, ISOCT enables imaging of coral nanoscale structures and allows for quantifying light scattering and pigment absorption in live corals. ISOCT could thus be developed into an important tool for rapid, non-invasive monitoring of coral health, growth and photophysiology with unprecedented spatial resolution.

scholarly journals Differential Responses of the Coral Host and Their Algal Symbiont to Thermal Stress

PLoS ONE ◽  
2011 ◽  
Vol 6 (10) ◽  
pp. e26687 ◽  
Author(s):  
William Leggat ◽  
Francois Seneca ◽  
Kenneth Wasmund ◽  
Lubna Ukani ◽  
David Yellowlees ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Coral Host ◽  
Algal Symbiont ◽  
Differential Responses

scholarly journals Quantitative proteomic analysis of auxin signaling during seedling development

2017 ◽  
Author(s):  
Dior R. Kelley ◽  
Zhouxin Shen ◽  
Justin W. Walley ◽  
Elisabeth J. Chapman ◽  
Steven P. Briggs ◽  
...  
Keyword(s):  
Transcript Abundance ◽  
Absolute Quantification ◽  
Auxin Signaling ◽  
Data Sets ◽  
Transcriptional Responses ◽  
Downstream Signaling ◽  
Regulation Mechanisms ◽  
Isobaric Tags ◽  
Hypocotyl Tissue ◽  
Spatial Specificity

AbstractAuxin induces rapid gene expression changes throughout plant development. How these transcriptional responses relate to changes in protein abundance is not well characterized. We have identified auxin regulated proteins in whole seedlings, roots and hypocotyls and at three different time points (30 min, 120 min and 3 hours) using an iTRAQ (isobaric tags for relative and absolute quantification) based quantitative proteomics approach. These profiling experiments detected 4,701 proteins from seedling tissue, 6,740 proteins from root tissue and 3,925 proteins from hypocotyl tissue. Comparisons between the differentially expressed proteins data sets showed little overlap, suggesting that auxin proteomes exhibit both temporal and spatial specificity. Numerous proteins showed significant changes in abundance following auxin treatment independent of changes in cognate transcript abundance. This includes several well characterized proteins with various roles in auxin pathways, suggesting that complex gene regulation mechanisms follow auxin signaling events. Specifically, regulation of translation may play a role as inferred from MapMan categorization analyses and protein interaction networks comprised of auxin regulated proteins. Additionally, functional categorization of auxin regulated proteins indicates rapid and complex metabolic changes occur in both roots and hypocotyls in response to auxin which are not apparent from transcriptome analyses. Altogether these data describe novel auxin-regulated proteomes and are an excellent resource for identifying new downstream signaling components related to auxin-mediated plant growth and development.

Sign in / Sign up

Export Citation Format

Share Document