Abstract
BackgroundThe European seabass (Dicentrarchus labrax), one of the most extensively cultured species in European aquaculture productions, is, along with the gilthead sea bream (Sparus aurata), a prospective model species for the Perciformes which includes several other commercially important species. Massive mortalities may be caused by bacterial or viral infections in intensive aquaculture production. Revealing transcripts involved in immune response and studying their relative expression enhances the understanding of the immune response mechanism and consequently also the creation of vaccines. The analysis of expressed sequence tags (EST) is an efficient and easy approach for gene discovery, comparative genomics and for examining gene expression in specific tissues in a qualitative and quantitative way.ResultsHere we describe the construction, analysis and comparison of a total of ten cDNA libraries, six from different tissues infected with V. anguillarum (liver, spleen, head kidney, gill, peritoneal exudates and intestine) and four cDNA libraries from different tissues infected with Nodavirus (liver, spleen, head kidney and brain). In total 9605 sequences representing 3075 (32%) unique sequences (set of sequences obtained after clustering) were obtained and analysed. Among the sequences several immune-related proteins were identified for the first time in the order of Perciformes as well as in Teleostei.ConclusionThe present study provides new information to the Gene Index of seabass. It gives a unigene set that will make a significant contribution to functional genomic studies and to studies of differential gene expression in relation to the immune system. In addition some of the potentially interesting genes identified by in silico analysis and confirmed by real-time PCR are putative biomarkers for bacterial and viral infections in fish.
Highlights
The European seabass (Dicentrarchus labrax), one of the most extensively cultured species in European aquaculture productions, is, along with the gilthead sea bream (Sparus aurata), a prospective model species for the Perciformes which includes several other commercially important species
Summary of expressed sequence tags (EST) from the cDNA libraries infected with Nodavirus and V. anguillarum The amplified libraries contained insert size from approximately 0.5 to 2.0 kb
Cluster analyses performed for each library separately (Table 1a and Table 1b) revealed redundancy rates which varied from 72% (28% unique sequences) in intestine cDNA library infected with V. anguillarum to 37% (63% unique sequences) in spleen cDNA library infected with V. anguillarum (Table 1a)
Summary
The European seabass (Dicentrarchus labrax), one of the most extensively cultured species in European aquaculture productions, is, along with the gilthead sea bream (Sparus aurata), a prospective model species for the Perciformes which includes several other commercially important species. In the present study we have generated a collection of EST sequences from tissues of European seabass infected with V. anguillarum and Nodavirus. Within this collection we were able to isolate immune relevant genes, and have gone on to compare gene expression in different tissues after viral and pathogenic bacteria infection. Genes showing in silico differential expression between Nodavirus infection and V. anguillarum infection were further analysed by real-time PCR
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
