New cytokines and TLR pathway signaling molecules in Chinese rare minnow (Gobiocypris rarus): Molecular characterization, basal expression, and their response to chlorpyrifos

Abstract In this study, the cDNA fragments of cytokines ( il-8 ) and toll-like receptor (TLR) pathway signaling molecules ( myd88 , irak-1 , irf5 , and irf7 ) in the Chinese rare minnow were cloned and exhibited a high amino-acid sequence identity compared to other cyprinid fish orthologs. The mRNA expressions of these genes in the different tissues (liver, brain, spleen, kidney, and skin) were observed. The highest expression levels of myd88 , irak-1 , and irf5 were detected in the spleen, whereas il-8 and irf7 were detected in the kidney and liver respectively. The mRNA expression of irak-1 , irf5 , and irf7 in the liver from 0.1 μg/L and 0.5 μg/L CPF treatments were significantly increased on day 7 ( p irak-1 and irf7 were markedly increased on day 28 ( p il-8 in the spleen following 0.5 μg/L CPF treatments was significantly decreased on day 7 ( p irf7 in the spleen at 2.5 μg/L CPF on days 7 and 28 ( p irak-1 and myd88 in the spleen after 28 d exposure ( p