Effects of temperature on hard clam (Mercenaria mercenaria) immunity and QPX (Quahog Parasite Unknown) disease development: II. Defense parameters
| Autor: | Laura Gambino, Bassem Allam, Emmanuelle Pales Espinosa, Mickael Perrigault, Soren F. Dahl |
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| Rok vydání: | 2011 |
| Předmět: |
Hemocytes
animal structures Mercenaria biology Ecology Parasitic Diseases Animal Temperature Outbreak Zoology Broodstock biology.organism_classification Geographic distribution Massachusetts Phagocytosis Immunity Florida Prevalence Animals Enzootic Parasite hosting Seasons Hard clam Reactive Oxygen Species Ecology Evolution Behavior and Systematics |
| Zdroj: | Journal of Invertebrate Pathology. 106:322-332 |
| ISSN: | 0022-2011 |
| DOI: | 10.1016/j.jip.2010.11.004 |
| Popis: | Quahog Parasite Unknown (QPX) is a protistan parasite affecting hard clams Mercenaria mercenaria along the Northeastern coast of the United States. The geographic distribution and occurrence of disease epizootics suggests a primary role of temperature in disease development. This study was designed to investigate the effect of temperature on constitutive and QPX-induced defense factors in M. mercenaria. Control and QPX-challenged (both experimentally and naturally) clams were maintained at 13, 21 and 27°C for 4 months. Control and experimentally-infected clams originated from a southern broodstock (Florida, no prior reports of disease outbreak) while naturally-infected clams originated from a northern broodstock (Massachusetts, enzootic area). Standard and QPX-specific cellular and humoral defense parameters were assessed after 2 and 4 months. Measured parameters included total and differential hemocyte counts, reactive oxygen species production, phagocytic activity of hemocytes, lysozyme concentration in plasma, anti-QPX activity in plasma and resistance of hemocytes to cytotoxic QPX extracellular products. Results demonstrated a strong influence of temperature on constitutive clam defense factors with significant modulation of cellular and humoral parameters of control clams maintained at 13°C compared to 21 and 27°C. Similarly, clam response to QPX challenge was also affected by temperature. Challenged clams exhibited no difference from controls at 27°C whereas different responses were observed at 21°C and 13°C compared to controls. Despite differences in infection mode (experimentally or naturally infected) and clam origin (northern and southern broodstocks), similarities were observed at 13°C and 21°C between QPX infected clams from Florida and Massachusetts. Clam response to temperature and to QPX exhibited interesting relationship with QPX disease development highlighting major influence of temperature on disease development. |
| Databáze: | OpenAIRE |
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