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Molecular identification and expression analysis of Toll‐like receptor 3 in common carp Cyprinus carpio
Author(s) -
Yang C.,
Su J.
Publication year - 2010
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/j.1095-8649.2010.02624.x
Subject(s) - biology , common carp , microbiology and biotechnology , innate immune system , grass carp , cyprinus , receptor , tlr3 , transmembrane domain , carp , mda5 , toll like receptor , gene , rna interference , genetics , rna , fishery , fish <actinopterygii>
The Toll‐like receptor (TLR) family is an evolutionarily conserved component of the innate immune system that responds to specific pathogen‐associated molecular patterns (PAMP) during infections. TLR3 is a putative pattern recognition receptor (PRR) for dsRNA, a common by‐product of viral replication. This study reports the identification and characterization of a full‐length orthologue of TLR3 (CcTLR3) in the common carp Cyprinus carpio . It is 2899 base pairs (bp) encoding 904 amino acid residues with a calculated molecular mass of 102 744 Da and an estimated isoelectric point of 6·89. The deduced amino acid sequence is characterized by a signal peptide, 14 leucine‐rich repeat (LRR) motifs, a transmembrane domain and a Toll–interleukin (IL)‐1 receptor (TIR) domain. Real‐time polymerase chain reaction (RT‐PCR) analysis indicated that CcTLR3 mRNA transcripts could be detected in a wide range of tissues. Although C. carpio is resistant to grass carp Ctenopharyngodon idella reovirus (GCRV), after injection with GCRV, CcTLR3 expression was downregulated from 24 h post‐injection ( P < 0·05) and returned to control levels at 72 h post‐injection ( P > 0·05). Antiviral effector Mx mRNA expression, however, was upregulated from 24 h post‐injection ( P < 0·05) and recovered to control levels at 96 h post‐injection ( P > 0·05). The results provide a better understanding of the anti‐GCRV mechanism and antiviral immune responses in fish, and help to develop suitable strategies to reduce viral diseases in fish.