The complement system, a critical component of innate immunity in fish, plays a pivotal role in the defense against Grass Carp Reovirus (GCRV) infection in grass carp. This study explores the structural characteristics of C1S , a crucial molecule in the classical pathway of the complement system, and its involvement in the response to GCRV infection. We found that the grass carp C1S gene comprises six domains similar to those in mammals: two CUB (Complement C1r/C1s, Uegf, Bmp1) domains, two CCP (Complement control protein) domains, one EGFCA (C...
