Project description:Perkinsus marinus is an intracellular parasitic protozoan that is responsible for serious disease epizootics in marine bivalve molluscs worldwide and along with P. olseni belongs to the OIE list of notified diseases. Despite all available information on P. marinus genomics, more baseline data is required at the proteomic level for a better understanding of P. marinus biological processes, including virulence mechanisms. In the present study, we have established in vitro clonal cultures of P. marinus from infected gills and mantle tissues of C. rhizophorae to evaluate the parasite cellular proteomic profile. A high throughput label-free shotgun HDMS approach using nanoUPLC-MS was used. Our intention was to provide the first comprehensive proteome profile of P. marinus that might serve as a valuable resource for future investigations involving comparative analyses of P. marinus from different regions, as well as comparisons of different species of Perkinsus.
Project description:Parasites of the genus Perkinsus spp. cause high mortalities and economic losses to the most noticeable bivalves produced in the worldwide aquaculture. In this study, we analyze how P. olseni influences the gene expression profiles of hemocytes from Manila clam (Venerupis philippinarum) using experimental infections along a temporal series and a Manila clam immune-enriched DNA microarray. Healthy and Perkinsus-infected clams (V. philippinarum) were obtained from Carril and Pontevedra shellfish farms, respectively (Galicia, NW Spain). The presence-absence of P. olseni was confirmed using the Ray`s fluid thioglycollate medium assay (RFTM) (Ray, 1966). Healthy clams were maintained in an open circuit filtered sea water tanks at 15°C with aeration. Natural infected animals were maintained in the same conditions using closed circuit sea water. All animals were fed daily with a mixture of microalgae containing Phaeodactylum tricornutum, Isochrysis galbana and Rhodomonas lens. Clams were acclimatized to the aquarium conditions for one week before the experiments were conducted. Perkinsus trophozoites were isolated from naturally infected animals following the protocol established by Ford et al., (2002). The concentration was adjusted to 5x104 trophozoites /ml in filtered sea water (FSW). Healthy clams (P. olseni free animals) (n=100) with a weight of 2.25 ± 0.64 g soft tissue, were notched in the shell and intramuscularly injected with 100 µl of the trophozoites suspension. Control animals (n=100) were injected with 100 µl of FSW. After infection, clams were maintained in 50 l tanks with aeration.Twenty animals from each experimental group and time point were sampled at 5, 10, 14, and 31 days post infection (pi).Hemolymph were extracted to perform microarrays experiments. In each condition hemolymph from three five individuals was pooled. Total RNA isolation was conducted following the manufacturer’s specifications. Isolated RNAs were treated with DNase I and purified again using the RNeasy Mini kit (Qiagen). A 8x15K Agilent 60-mer oligo-microarray (GPL16450) was used to compare gene expression profiles of clams after P. olseni infection with uninfected animals. The Agilent Feature Extraction Software (version 9.5.1) was used for the data extraction and background subtraction following standard procedures. The GeneSpring software (Agilent) was used to normalize and analyze the microarray fluorescence data.
Project description:Oyster plasma contains various soluble factors secreted by hemocytes and other cells, which were separated from the haemolymph and collected for antibacterial activity as-says. Plasma was collected after V. parahaemolyticus injection, with PBS injection being set as a control. Plasma of the V. parahaemolyticus challenged group was markedly more bac-tericidal than that of the PBS treated control。Peptidomics was herein employed to identify new bioactive peptides with antibacterial activity from plasma based on liquid chromatography and tandem mass spectrometry. To apply large-scale peptidomics to oyster plasma proteins, oyster plasma was extracted from the V. parahaemolyticus challenged group (P4, P5, P6) and PBS treated control (P1, P2, P3).
2021-04-09 | PXD025247 | Pride
Project description:Variation in global transcriptomic response to Perkinsus marinus infection among Eastern oyster families highlights potential mechanisms of disease resistance