Frontiers in Marine Science (Jun 2014)
Genomic characterization of the aquaculture resource <i>Mytilus galloprovincialis</i>
Abstract
In the autonomous community of Galicia (NW Spain), M. galloprovincialis is a natural resource of high economic importance to the economy of this region. More than 250,000 MTs of mussels are produced per year, representing 40% of the European production of this bivalve and 80% of the marine aquacultural production of the country. Besides its aquaculture interest, study of the biology M. galloprovincialis may also help to understand better fundamental aspects of molluscan biology. On the other hand, some fascinating features of mediterranean mussels are unique to this species such as its extraordinary resistance to diseases. In fact, in comparison with other bivalves, no records of massive mortality of this organism caused by pathogens has been reported so far. Although some of the molecular components of the innate immune system, responsible of this resistance, have been previously identified and characterized, the genetic mechanisms underlying their diversity are poorly understood. In order to understand better this organism at genome level and search for the genetic basis of its disease resistance, we sequenced its genome at high depth using Illumina technology. After assembling the resulting reads and assisted with transcriptomic data, we annotated its genome sequence. First, we analysed the content of repetitive elements, finding those that are common among molluscs as well as identifying new repeat families unique to M. galloprovincialis. Second, we predicted and annotated its gene repertoire, defining the total number of genes and their density in its genome. Finally, the resulting in silico predicted genes were functionally annotated. Altogether, this information will allow the identification of genes of interest, such as those participating in the innate immunity and will allow us to delve into the possibility of whether their variability has a genetic basis or relies on post-transcriptional events. In addition to this annotation, some comparative analysis with the genome of other molluscs was done. Study of the genomic similarities and differences within this group will finally lead us to identify evolutionary patterns that are particular of molluscs. Genomic data obtained from this study will provide the the starting point for future programs of conservation, breeding and exploitation of this marine resource.
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