Characterization of rock bream (Oplegnathus fasciatus) complement components C1r and C1s in terms of molecular aspects, genomic modulation, and immune responsive transcriptional profiles following bacterial and viral pathogen exposure. Issue 2 (October 2015)

• Record Type: Journal Article
• Authors: Godahewa, G.I.; Bathige, S.D.N.K.; Herath, H.M.L.P.B.; Noh, Jae Koo; Lee, Jehee
• Is Part Of: Fish & shellfish immunology. Volume 46:Issue 2(2015:Oct.)
• Page Start: 656
• Page End: 668
• Publication Date: 2015-10
• Subjects: Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2015.07.026
• Languages: English
• ISSNs: 1050-4648

Abstract

<abstract xml:lang="en" abstract-type="author" id="abs0010"> <title id="sectitle0010">Abstract</title> <sec> <p id="abspara0010">The complement components C1r and C1s play a crucial role in innate immunity <italic>via</italic> activation of the classical complement cascade system. As initiators of the pathogen-induced signaling cascade, C1r and C1s modulate innate immunity. In order to understand the immune responses of teleost C1r and C1s, <italic>Oplegnathus fasciatus</italic> C1r and C1s genes (<italic>OfC1r</italic> and <italic>OfC1s</italic>) were identified and characterized. The genomic sequence of <italic>OfC1r</italic> was enclosed with thirteen exons that represented a putative peptide with 704 amino acids (aa), whereas eleven exons of <italic>OfC1s</italic> represented a 691 aa polypeptide. In addition, genomic analysis revealed that both <italic>OfC1r</italic> and <italic>OfC1s</italic> were located on a single chromosome. These putative polypeptides were composed of two CUB domains, an EGF domain, two CCP domains, and a catalytically active serine protease domain. Phylogenetic analysis of C1r and C1s showed that <italic>OfC1r</italic> and <italic>OfC1s</italic> were evolutionary close to the orthologs of <italic>Pundamilia nyererei</italic> (identity = 73.4%) and <italic>Oryzias latipes</italic> (identity = 58.0%), respectively. Based on the results of quantitative real-time qPCR analysis, <italic>OfC1r</italic> and <italic>OfC1s</italic> transcripts were detected in all the eleven different tissues, with higher levels of <italic>OfC1r</italic> in blood and <italic>OfC1s</italic> in liver. The putative roles of <italic>OfC1r</italic> and <italic>OfC1s</italic> in response to pathogenic bacteria (<italic>Edwardsiella tarda</italic> and <italic>Streptococcus iniae</italic>) and virus (rock bream iridovirus, RBIV) were investigated in liver and head kidney tissues. The transcription of <italic>OfC1r</italic> and <italic>OfC1s</italic> was found to be significantly upregulated in response to pathogenic bacterial and viral infections. Overall findings of the present study demonstrate the potential immune responses of <italic>OfC1r</italic> and <italic>OfC1s</italic> against invading microbial pathogens and the activation of classical signaling cascade in rock bream.</p> </sec> </abstract>