Project description:The Manila clam (Ruditapes philippinarum) is a cultured bivalve species with high worldwide commercial importance. Nevertheless, diseases can cause high economical losses. For this reason, the study of immune genes in bivalve mollusks has increased in the last years. The present work describes the construction of the first R. philippinarum microarray containing immune-related hemocyte sequences and its application for the study of the gene transcription profiles of hemocytes from clams challenged with Vibrio alginolyticus through a time course. A comparative analysis of gene expression was conducted between R. philippinarum infected and non-infected by V. alginolyticus clam hemocytes. Clams (n=100) were notched in the shell next to the adductor muscles and injected with 100 Âµl of Vibrio alginolyticus, strain TA15, (10^8 UFC/ml in PBS) to mimic an intramuscular infection. Controls (n=100) were injected with 100 Âµl of PBS. After stimulation, clams were returned to the tanks and maintained at 15ÂºC until sampling at 3, 8, 24, and 72 hours after challenge Hemolymph (1 ml) was withdrawn from the adductor muscle of the clams with a 0.5mm diameter (25G) disposable needle. Hemolymph from four individuals was pooled and biological replicates were taken at each sampling point. Hemolymph was centrifuged at 4Â°C at 3000 g for 10 minutes. The pellet was resuspended in 250 Âµl of Trizol (Invitrogen). Total RNA isolation was conducted following the manufacturer's specifications in combination with the RNeasy mini kit (Qiagen) for RNA purification after DNase I treatment. Gene expression profiling was performed using an R. philippinarum oligo-DNA microarray of 13,671 probes based on single-colour detection (Cyanine-3 only). Microarrays were scanned with Agilent scanner G2565BA at a resolution of 5 microns; all slides were scanned twice at two different sensitivity settings (XDRHi 100% and XDRLo 10%); the scanner software created a unique ID for each pair of XDR scans and saved it to both scan image files. Feature Extraction (FE) 9.5 used XDR ID to link the pairs of scans together automatically when extracting data. The signal left after all the FE processing steps have been completed is ProcessedSignal that contains the Multiplicatively Detrended, Background-Subtracted Signal.

Project description:Transcriptional profiling of different clam tissues (hemolymph, extrapallial fluid and mantle) in response to brown ring disease; Brown ring disease (BRD) is a bacterial infection affecting the economically-important clam Ruditapes philippinarum. The disease is caused by a bacterium, Vibrio tapetis, that colonizes the edge of the mantle, altering the biomineralization process and normal shell growth. Altered organic shell matrices accumulate on the inner face of the shell leading to the formation of the typical brown ring in the extrapallial space (between the mantle and the shell). Even though structural and functional changes have been described in solid (mantle) and fluid (hemolymph and extrapallial fluids) tissues from infected clams, the underlying molecular alterations and responses remain largely unknown. This study was designed to gather information on clam molecular responses to the disease and to compare focal responses at the site of the infection (mantle and extrapallial fluid) with systemic (hemolymph) responses. To do so, we designed and produced a Manila clam expression oligoarray (15K Agilent) using transcriptomic data available in public databases and used this platform to comparatively assess transcriptomic changes in mantle, hemolymph and extrapallial fluid of infected clams. Results showed significant regulation in diseased clams of molecules involved in pathogen recognition (e.g. lectins, C1q domain-containing proteins) and killing (defensin), apoptosis regulation (death-associated protein, bcl-2) and in biomineralization (shell matrix proteins, perlucin, galaxin, chitin- and calcium-binding proteins). While most changes in response to the disease were tissue-specific, systemic alterations included co-regulation in all 3 tested tissues of molecules involved in microbe recognition and killing (complement-related factors, defensin). These results provide a first glance at molecular alterations and responses caused by BRD and identify targets for future functional investigations.

Project description:Transcriptional profiling of different clam tissues (hemolymph, extrapallial fluid and mantle) in response to brown ring disease; Brown ring disease (BRD) is a bacterial infection affecting the economically-important clam Ruditapes philippinarum. The disease is caused by a bacterium, Vibrio tapetis, that colonizes the edge of the mantle, altering the biomineralization process and normal shell growth. Altered organic shell matrices accumulate on the inner face of the shell leading to the formation of the typical brown ring in the extrapallial space (between the mantle and the shell). Even though structural and functional changes have been described in solid (mantle) and fluid (hemolymph and extrapallial fluids) tissues from infected clams, the underlying molecular alterations and responses remain largely unknown. This study was designed to gather information on clam molecular responses to the disease and to compare focal responses at the site of the infection (mantle and extrapallial fluid) with systemic (hemolymph) responses. To do so, we designed and produced a Manila clam expression oligoarray (15K Agilent) using transcriptomic data available in public databases and used this platform to comparatively assess transcriptomic changes in mantle, hemolymph and extrapallial fluid of infected clams. Results showed significant regulation in diseased clams of molecules involved in pathogen recognition (e.g. lectins, C1q domain-containing proteins) and killing (defensin), apoptosis regulation (death-associated protein, bcl-2) and in biomineralization (shell matrix proteins, perlucin, galaxin, chitin- and calcium-binding proteins). While most changes in response to the disease were tissue-specific, systemic alterations included co-regulation in all 3 tested tissues of molecules involved in microbe recognition and killing (complement-related factors, defensin). These results provide a first glance at molecular alterations and responses caused by BRD and identify targets for future functional investigations. Two-condition experiment (healthy/diseased), 3 tissues, 6 biological replicates/tissue/condition Please note that mantle tissues from this study were labelled with Cy3 and hybridized against a set of reference samples that are not part of this study. Thus, the Cy5 data from the associated raw data files were excluded in the analysis. Please note that hemocytes are collected from hemolymph or extrapallial fluid and hybridized on the same array (i.e. technically as dual channel) but the results were processed as though they are single channel (Cy3 and Cy5 signals are calculated). The hemocytes from extrapallial fluid were labelled with Cy3, while hemocytes from hemolymph were labelled with Cy5. The raw data files that are associated with two sample records are linked as series supplementary files and are indicated in the sample description field.

Project description:Digestive Gland Samples: A manila clam oligo microarray platform (GPL10900) was used to profile gene expression in digestive gland of R. philippinarum. Total RNA was extracted from three (3) independent biological replicates of digestive gland for each sampling site, each consisting of tissue pools of five (5) animals. Statistical analysis with SAM (Significance Analysis of Microarray) identified1,127 probes differentially expressed. Gills Samples: A manila clam oligo microarray platform (GPL10900) was used to profile gene expression in gills of R. philippinarum. Total RNA was extracted from three (3) independent biological replicates of gills for each sampling site, each consisting of tissue pools of five (5) animals. Statistical analysis with SAM (Significance Analysis of Microarray) identified1,127 probes differentially expressed. Digestive Gland Samples: In this study, we analyzed six (6) samples, three (3) pools of digestive gland of Manila clam sampled in Marghera and three(3) pools of digestive gland of Manila clam sampled in Alberoni. Gene expression profiling was performed using the Agilent-019810 Ruditapes philippinarum Oligo Microarray platform (GPL10900) based on single-colour detection (Cyanine-3 only). Microarrays were scanned with Agilent scanner G2565BA (barcode on the left, DNA on the back surface, scanned through the glass) at a resolution of 5 microns; all slides were scanned twice at two different sensitivity settings (XDRHi 100% and XDRLo 10%); the scanner software created a unique ID for each pair of XDR scans and saved it to both scan image files. Feature Extraction (FE) 9.5 used XDR ID to link the pairs of scans together automatically when extracting data. The signal left after all the FE processing steps have been completed is ProcessedSignal that contains the Multiplicatively Detrended, Background-Subtracted Signal. Gills Samples: In this study, we analyzed six (6) samples, three (3) pools of gills of Manila clam sampled in Marghera and three(3) pools of gills of Manila clam sampled in Alberoni. Gene expression profiling was performed using the Agilent-019810 Ruditapes philippinarum Oligo Microarray platform (GPL10900) based on single-colour detection (Cyanine-3 only). Microarrays were scanned with Agilent scanner G2565BA (barcode on the left, DNA on the back surface, scanned through the glass) at a resolution of 5 microns; all slides were scanned twice at two different sensitivity settings (XDRHi 100% and XDRLo 10%); the scanner software created a unique ID for each pair of XDR scans and saved it to both scan image files. Feature Extraction (FE) 9.5 used XDR ID to link the pairs of scans together automatically when extracting data. The signal left after all the FE processing steps have been completed is ProcessedSignal that contains the Multiplicatively Detrended, Background-Subtracted Signal.

Dataset Information

Gene expression profile of hemocytes from Manila clam (Venerupis philippinarum) after a Perkinsus olseni challenge using an immune-enriched oligo-microarray

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