이리도바이러스에 인위 감염된 쏘가리(Siniperca scherzeri)의 면역유전자 발현 특성

Abstract

Infectious spleen and kidney necrosis virus(ISKNV), family Iridoviridae, genus megalocytivirus is causative agent of provoking high mortality of mandarin fish in China and have attracted more attention because of their ecological and economic impacts on wild and cultured fishes. In this study korean mandarin fish Siniperca scherzeri which is same Percichthyidae family with chinese mandarin fish Siniperca chuatsi is used to investigate the pathogenicity of ISKNV-like megalocytivirus, named PGIV-1, isolated from pearl gourami in Korea after intraperitoneal challenge with analysis of the changed immune genes expression. Cumulative mortalities of S.scherzeri challenged with three different density of PGIV-1 infected kidney of homogenates, 100㎍ fish-1, 10㎍ fish-1, 1㎍ fish-1 were calculated. No mortality is observed in challenged group with the lowest PGIV-1 density, 1㎍ fish-1 over 30 days as the control group injected with PBS. However, other two challenged groups, density of PGIV-1 100㎍ fish-1 and 10㎍ fish-1 showed 100% mortality. For cloning of immune genes, degenerated primer sets were designed after alignment with the corresponding genes of chinese mandarin fish for PCR amplification. After cloning of the target genes, amino acid sequences were also deduced and compared with those in S.chuatsi from china to determine the identity with each other. Real-time PCR is performed to measure the expression level of the immune genes in S.scherzeri after various times of PGIV-1 challenge. Expression of interleukin 8, IRF1, viperin and Mx genes were up-regulated significantly, which is contrast to the expression of IRF2 and IRF7 genes showing consistent expression.