title: RNA-Seq in Mytilus galloprovincialis: comparative transcriptomics and expression profiles among different tissues.
abstract: BACKGROUND
  The Mediterranean mussel (Mytilus galloprovincialis) is a cosmopolitan, cultured bivalve with worldwide commercial and ecological importance. However, there is a qualitative and quantitative lack of knowledge of the molecular mechanisms involved in the physiology and immune response of this mollusc. In order to start filling this gap, we have studied the transcriptome of mantle, muscle and gills from naïve Mediterranean mussels and hemocytes exposed to distinct stimuli.
  
  
  RESULTS
  A total of 393,316 million raw RNA-Seq reads were obtained and assembled into 151,320 non-redundant transcripts with an average length of 570 bp. Only 55 % of the transcripts were shared across all tissues. Hemocyte and gill transcriptomes shared 60 % of the transcripts while mantle and muscle transcriptomes were most similar, with 77 % shared transcripts. Stimulated hemocytes showed abundant defense and immune-related proteins, in particular, an extremely high amount of antimicrobial peptides. Gills expressed many transcripts assigned to both structure and recognition of non-self patterns, while in mantle many transcripts were related to reproduction and shell formation. Moreover, this tissue presented additional and interesting hematopoietic, antifungal and sensorial functions. Finally, muscle expressed many myofibril and calcium-related proteins and was found to be unexpectedly associated with defense functions. In addition, many metabolic routes related to cancer were represented.
  
  
  CONCLUSIONS
  Our analyses indicate that whereas the transcriptomes of these four tissues have characteristic expression profiles in agreement with their biological structures and expected functions, tissue-specific transcriptomes reveal a complex and specialized functions.
authors.affiliation: Instituto de Investigaciones Marinas (IIM), Consejo Superior de Investigaciones Científicas (CSIC), Eduardo Cabello, 6, 36208, Vigo, Spain. rebecamoreira@iim.csic.es.
authors.forename: Rebeca
authors.initials: R
authors.lastname: Moreira
authors.affiliation: Instituto de Investigaciones Marinas (IIM), Consejo Superior de Investigaciones Científicas (CSIC), Eduardo Cabello, 6, 36208, Vigo, Spain. patriciapereiro@iim.csic.es.
authors.forename: Patricia
authors.initials: P
authors.lastname: Pereiro
authors.affiliation: Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Unidad Asociada CSIC, Universidade de Vigo, 36310, Vigo, Spain. canchaya@uvigo.es.
authors.forename: Carlos
authors.initials: C
authors.lastname: Canchaya
authors.affiliation: Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Unidad Asociada CSIC, Universidade de Vigo, 36310, Vigo, Spain. dposada@uvigo.es.
authors.forename: David
authors.initials: D
authors.lastname: Posada
authors.affiliation: Instituto de Investigaciones Marinas (IIM), Consejo Superior de Investigaciones Científicas (CSIC), Eduardo Cabello, 6, 36208, Vigo, Spain. antoniofigueras@iim.csic.es.
authors.forename: Antonio
authors.initials: A
authors.lastname: Figueras
authors.affiliation: Instituto de Investigaciones Marinas (IIM), Consejo Superior de Investigaciones Científicas (CSIC), Eduardo Cabello, 6, 36208, Vigo, Spain. beatriznovoa@iim.csic.es.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Novoa
mesh_terms: D000818:Animals; D005786:Gene Expression Regulation; D005880:Gills; D006434:Hemocytes; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods*; D049878:Mytilus / Q000235:genetics; D014018:Tissue Distribution / Q000235:genetics; D059467:Transcriptome / Q000235:genetics*