Cloning of the full-length cDNA of Cctlr19. A A schematic diagram showing the domain architecture of common carp Tlr19. The gray box represents the signal peptide. The leucine-rich-repeat (LRR) regions are shown with green rectangles. The transmembrane (TM) domains are shown with red rectangles, and Toll/interleukin-1 receptor (TIR) domains are shown as yellow ovals. B Modeled three-dimensional structure of common carp Tlr19 shown as a cartoon. C Phylogenetic analysis of Tlr19 amino acid sequences. The phylogenetic tree was constructed using multiple alignment of amino acids generated by the neighbor-joining method in the MEGA 6.0. program. Green, black, purple, blue, red and orange color represents the TLR1, 3, 4, 5, 7 and 11 subfamilies, respectively, while the black box indicated the CcTlr19. The GenBank accession numbers of TLR sequences are shown in Additional file 1.