title: MgC1q, a novel C1q-domain-containing protein involved in the immune response of Mytilus galloprovincialis.
abstract: In this study, we present the characterization of a newly identified gene, MgC1q, revealed in suppression subtractive hybridization and cDNA libraries from immunostimulated mussels. Based on sequence homology, molecular architecture and domain similarity, this new C1q-domain-containing gene may be classified as a member of the C1q family and, therefore, part of the C1q-TNF superfamily. The expression of MgC1q was detected all along the mussel ontogeny, being detectable within 2h post-fertilization, with a notable increase after 1 month and continuing to increase until 3 months. Measurable transcript levels were also evident in all analyzed tissues of naïve adult mussels, and the hemocytes showed the highest expression levels. Experimental infection of adult mussels with Gram positive or Gram negative bacteria significantly modulated the MgC1q expression, and confirmed it as an immune-related gene. Intra- and inter-individual sequence analyses revealed extraordinary diversity of MgC1q at both the DNA and cDNA levels. While further research is needed to define its function, our data indicate that MgC1q is a pattern recognition molecule able to recognize pathogens during innate immune responses in Myitilus galloprovincialis. The high sequence variability suggests that somatic diversification of these nonself recognition molecules could have occurred.
authors.affiliation: Instituto de Investigaciones Marinas (CSIC), Eduardo Cabello 6, 36208 Vigo, Spain.
authors.forename: Camino
authors.initials: C
authors.lastname: Gestal
authors.forename: Alberto
authors.initials: A
authors.lastname: Pallavicini
authors.forename: Pallavicini
authors.initials: P
authors.lastname: Venier
authors.forename: Beatriz
authors.initials: B
authors.lastname: Novoa
authors.forename: Antonio
authors.initials: A
authors.lastname: Figueras
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001424:Bacterial Infections / Q000276:immunology*; D015922:Complement C1q / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D020869:Gene Expression Profiling; D014644:Genetic Variation; D006434:Hemocytes / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D007113:Immunity, Innate; D007155:Immunologic Factors / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D008969:Molecular Sequence Data; D049878:Mytilus / Q000276:immunology* / Q000382:microbiology; D010802:Phylogeny; D017434:Protein Structure, Tertiary / Q000235:genetics; D051192:Receptors, Pattern Recognition / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D017385:Sequence Homology
chemical_list: D007155:Immunologic Factors; D051192:Receptors, Pattern Recognition; D015922:Complement C1q