Molecular cloning, characterization and gene expression analysis of twelve interleukins in obscure puffer .

Interleukins (ILs) are a subgroup of secreted cytokines, which are molecules involved in the intercellular regulation of the immune system. In this study, 12 IL homologs were cloned and functionally identified from obscure puffer , and they were termed as , and . Multiple alignment results showed that except for ToIL-24 and ToIL-27, other deduced ToIL proteins shared typical characteristics and structure with other known fish ILs. Phylogenetic analysis revealed that 12 ToILs were evolutionarily closely related to their counterparts in other selected vertebrates. Tissue distribution assay demonstrated that the mRNA transcripts of most genes were constitutively expressed in all tissues examined, with relatively high expression in immune tissues. Following and infection, the expression levels of 12 in the spleen and liver were significantly upregulated, and their response over time varied. Taken together, these data were discussed accordingly with the expression and the immune response under the different situations tested. The results suggest that the 12 genes are involved in the antibacterial immune response in .