In conclusion, a CD59 gene (On-CD59) was cloned from Nile tilapia successfully. On-CD59 contained main structural features
required for complementeinhibitory activity, which were highly
conserved in known CD59 genes. Quantitative RT-PCR analysis
revealed that On-CD59 was expressed strongly in the brain and
responded to S. agalactiae stimulus. The assays for the complementeinhibitory
activity suggest that On-CD59 may have a
species-selective inhibition of complement. Moreover, On-CD59
may play complement-independent roles via showing it possesses
both binding activities to PGN and LTA and inhibiting activity
of S. agalactiae. Our findings will provide some reference for further
exploration of complement system in teleost.