Lee, P.T.Bird, SteveZou, J.Martin, S.A.M.2017-05-1820172017-05-182017Lee, P. T., Bird, S., Zou, J., & Martin, S. A. M. (2017). Phylogeny and expression analysis of C-reactive protein (CRP) and serum amyloid-P (SAP) like genes reveal two distinct groups in fish. Fish and Shellfish Immunology, 65, 42–51. https://doi.org/10.1016/j.fsi.2017.03.0371050-4648https://hdl.handle.net/10289/11061The acute phase response (APR) is an early innate immune function that is initiated by inflammatory signals, leading to the release of acute phase proteins to the bloodstream to re-establish homeostasis following microbial infection. In this study we analysed the Atlantic salmon (Salmo salar) whole-genome database and identified five C-reactive protein (CRP)/serum amyloid P component (SAP) like molecules namely CRP/SAP-1a, CRP/SAP-1b, CRP/SAP-1c, CRP/SAP-2 and CRP/SAP-3. These CRP/SAP genes formed two distinct sub-families, a universal group (group I) present in all vertebrates and a fish/amphibian specific group (group II). Salmon CRP/SAP-1a, CRP/SAP-1b and CRP/SAP-1c and CRP/SAP-2 belong to the group I family whilst salmon CRP/SAP-3 is a member of group II. Gene expression analysis showed that the salmon CRP/SAP-1a as well as serum amyloid A-5 (SAA-5), one of the major acute phase proteins, were significantly up-regulated by recombinant cytokines (rIL-1β and rIFNγ) in primary head kidney cells whilst the other four CRP/SAPs remained refractory. Furthermore, SAA-5 was produced as the main acute phase protein (APP) in Atlantic salmon challenged with Aeromonas salmonicida (aroA(-) strain) whilst salmon CRP/SAPs remained unaltered. Overall, these data illustrate the potential different functions of expanded salmon CRP/SAPs to their mammalian homologues.application/pdfen© 2017 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).acute phase proteinC-reactive proteinserum amyloid-PAtlantic salmoninnate immunitygene expressionPhylogeny and expression analysis of C-reactive protein (CRP) and serum amyloid-P (SAP) like genes reveal two distinct groups in fishJournal Article10.1016/j.fsi.2017.03.0371095-9947