Click
here to close Hello! We notice that
you are using Internet Explorer, which is not supported by Echinobase
and may cause the site to display incorrectly. We suggest using a
current version of Chrome,
FireFox,
or Safari.
PLoS One
2008 Mar 26;33:e1811. doi: 10.1371/journal.pone.0001811.
Show Gene links
Show Anatomy links
Cellular responses in sea fan corals: granular amoebocytes react to pathogen and climate stressors.
Mydlarz LD
,
Holthouse SF
,
Peters EC
,
Harvell CD
.
???displayArticle.abstract???
BACKGROUND: Climate warming is causing environmental change making both marine and terrestrial organisms, and even humans, more susceptible to emerging diseases. Coral reefs are among the most impacted ecosystems by climate stress, and immunity of corals, the most ancient of metazoans, is poorly known. Although coral mortality due to infectious diseases and temperature-related stress is on the rise, the immune effector mechanisms that contribute to the resistance of corals to such events remain elusive. In the Caribbean sea fan corals (Anthozoa, Alcyonacea: Gorgoniidae), the cell-based immune defenses are granular acidophilic amoebocytes, which are known to be involved in wound repair and histocompatibility.
METHODOLOGY/PRINCIPAL FINDINGS: We demonstrate for the first time in corals that these cells are involved in the organismal response to pathogenic and temperature stress. In sea fans with both naturally occurring infections and experimental inoculations with the fungal pathogen Aspergillus sydowii, an inflammatory response, characterized by a massive increase of amoebocytes, was evident near infections. Melanosomes were detected in amoebocytes adjacent to protective melanin bands in infected sea fans; neither was present in uninfected fans. In naturally infected sea fans a concurrent increase in prophenoloxidase activity was detected in infected tissues with dense amoebocytes. Sea fans sampled in the field during the 2005 Caribbean Bleaching Event (a once-in-hundred-year climate event) responded to heat stress with a systemic increase in amoebocytes and amoebocyte densities were also increased by elevated temperature stress in lab experiments.
CONCLUSIONS/SIGNIFICANCE: The observed amoebocyte responses indicate that sea fan corals use cellular defenses to combat fungal infection and temperature stress. The ability to mount an inflammatory response may be a contributing factor that allowed the survival of even infected sea fan corals during a stressful climate event.
???displayArticle.pubmedLink???
18364996
???displayArticle.pmcLink???PMC2267492 ???displayArticle.link???PLoS One
Figure 1. Picture of a sea fan coral (Gorgonia ventalina) infected with Aspergillus sydowii, multifocal purple annular lesions are indicative of infection (photo by Ernesto Weil).
Figure 2. Amoebocytes in mesoglea (connective tissue) of naturally diseased sea fan corals.A) Healthy coral with granular amoebocytes dispersed in mesoglea as indicated by arrows. B) Diseased coral with an increase in granular amoebocytes in the mesoglea. Scale bar = 25 µm.
Figure 3. Quantitative analysis of amoebocytes in mesoglea of sea fan corals showing a dramatic increase in amoebocytes in diseased coral tissue.% surface area covered by amoebocytes calculated from histological images of mesogleal tissue sampled from uninfected sea fans and mesogleal tissue adjacent to fungal infections in diseased sea fans. Data presented are mean±s.e.m, n = 8 , X
2 28.93, p<0.0001.
Figure 5. Prophenoloxidase activity in healthy and diseased sea fans as measured by the oxidation of L-dopa to dopachrome.Data presented are mean±s.e.m n = 12, F = 4.7, p = 0.040.
Figure 7. Amoebocytes are heterogeneously distributed within individual naturally infected sea fan colonies.Data presented are mean±s.e.m, n = 8, X
2 = 12.43, p = 0.0004.
Figure 9. Amoebocytes in mesoglea (connective tissue) of sea fan corals exposed to experimental heat stress.Images are of the same coral colony, with A) one fragment kept at 29°C and B) fragment kept at 31.5°C. Scale bar = 25 µm.
Blackstone,
Model systems for environmental signaling.
2005, Pubmed
Blackstone,
Model systems for environmental signaling.
2005,
Pubmed
Brakhage,
Systemic fungal infections caused by Aspergillus species: epidemiology, infection process and virulence determinants.
2005,
Pubmed
Bruno,
Thermal stress and coral cover as drivers of coral disease outbreaks.
2007,
Pubmed
Cerenius,
The prophenoloxidase-activating system in invertebrates.
2004,
Pubmed
Cheng,
Effects of intrinsic and extrinsic factors on the haemocyte profile of the prawn, Macrobrachium rosenbergii.
2001,
Pubmed
Cooper,
Digging for innate immunity since Darwin and Metchnikoff.
2002,
Pubmed
Ellner,
Within-host disease ecology in the sea fan Gorgonia ventalina: modeling the spatial immunodynamics of a coral-pathogen interaction.
2007,
Pubmed
,
Echinobase
Fine,
Scleractinian coral species survive and recover from decalcification.
2007,
Pubmed
Galloway,
Immunotoxicity in invertebrates: measurement and ecotoxicological relevance.
2001,
Pubmed
Griffin,
Evaluation of thermal acclimation capacity in corals with different thermal histories based on catalase concentrations and antioxidant potentials.
2006,
Pubmed
Grottoli,
Heterotrophic plasticity and resilience in bleached corals.
2006,
Pubmed
Harvell,
Climate warming and disease risks for terrestrial and marine biota.
2002,
Pubmed
Hoffmann,
Phylogenetic perspectives in innate immunity.
1999,
Pubmed
Hughes,
Climate change, human impacts, and the resilience of coral reefs.
2003,
Pubmed
Kim,
The rise and fall of a six-year coral-fungal epizootic.
2004,
Pubmed
,
Echinobase
Lesser,
Coral reef bleaching and global climate change: can corals survive the next century?
2007,
Pubmed
Little,
Flexibility in algal endosymbioses shapes growth in reef corals.
2004,
Pubmed
Meszaros,
Qualitative and quantitative study of wound healing processes in the coelenterate, Plexaurella fusifera: spatial, temporal, and environmental (light attenuation) influences.
1999,
Pubmed
Monari,
Effects of high temperatures on functional responses of haemocytes in the clam Chamelea gallina.
2007,
Pubmed
Nappi,
Melanogenesis and associated cytotoxic reactions: applications to insect innate immunity.
2005,
Pubmed
Olano,
Phagocytic activities of the gorgonian coral Swiftia exserta.
2000,
Pubmed
Ouedraogo,
Attenuation of fungal infection in thermoregulating Locusta migratoria is accompanied by changes in hemolymph proteins.
2002,
Pubmed
Ouedraogo,
Inhibition of fungal growth in thermoregulating locusts, Locusta migratoria, infected by the fungus Metarhizium anisopliae var acridum.
2003,
Pubmed
Porchet-Henneré,
Cellular immunity in an annelid (Nereis diversicolor, Polychaeta): production of melanin by a subpopulation of granulocytes.
1992,
Pubmed
Sadd,
Self-harm caused by an insect's innate immunity.
2006,
Pubmed
Vargas-Angel,
Cellular reactions to sedimentation and temperature stress in the Caribbean coral Montastraea cavernosa.
2007,
Pubmed