| Summary: | Over the last years, there has been an increasing demand of shellfish for consumption. The ability of traditional capture fisheries to supply bivalves is unlikely to increase significantly because of the drops in natural recruitments of seed, which are mainly due to overexploitation of natural stocks. Production of bivalve seed in hatcheries is a relatively new industry for which empirical approaches were developed, adapting methods across species and measuring the resulting effect in terms of growth and survival. To date, only a few bivalve species of major aquacultural importance in Europe have benefited from newly developed genomic resources (e.g. microarrays and RNA sequencing) and gene silencing approaches, which are both expected to significantly improve the biological knowledge on these commercially important species in the coming years. The present PhD thesis aimed firstly at increasing, through Next Generation Sequencing, genomic information available for two emerging species, Venerupis decussata and Pecten maximus. The second aim was to investigate two main bottlenecks hampering the bivalve production in hatchery: efficiency of reproduction and susceptibility to pathogens. By means of microarray analysis, a gene expression study on V .decussata oocytes at different maturation stages was performed and the major biological processes involved in gamete maturation were identified. A RNA sequencing experiment was conducted on pathogen-challenged hemocytes and unchallenged controls to study the P. maximus immune transcriptome. mRNAs encoding proteins with a known immune function were detected and a global analysis of differential expression comparing gene-expression levels in stimulated hemocytes against controls provided evidence on a large set of transcripts involved in P. maximus immune response. Finally, reverse genetic and real-time PCR were implemented to investigate the role of IkB2 in the Crassostrea gigas immune response against Ostreid herpesvirus type 1. Following the injection of a dsRNA ...
|
|---|