Molecular Cloning， Sequences Analysis and Immune-related Expression Changes of aCCL4-like Gene from Ayu (Plecoglossus altivelis)

Abstract: CC chemokines are a kind of multi-functional cytokines and play vital roles in innate immune system of teleost fish. In this study， we obtained a cDNA sequence encoding CCL4-like from ayu. The predicted ayu CCL4-like (aCCL4-like) propeptide was 123 amino acids (aa) long with a 22 aa signal peptide in the N-terminus. The mature peptide contained four conserved cysteine residues and they could form two disulfide bonds. Phylogenetic tree analysis showed that Plecoglossus altivelis CCL4-like was closely to Salmo salar CCL4. The Real-time quantitative PCR(RT-qPCR) analysis displayed that aCCL4-like mRNAs were widely existed in kinds of tissues of healthy ayu， and that the highest expression was in the liver. After Listonella anguillarum (L.anguillarum) infection， aCCL4-like mRNAs were dramatically up-regulated in all detected ayu tissues， especially in the intestine. Followed by aCCL4-like prokaryotic expression and its preparation of antiserum. Western blot analysis revealed that the ayu serum aCCL4-like was no significant change after bacterial infection after 4 h， but increased suddenly at 8 h and since then continued to raise. In summary， our results suggested that aCCL4-like gene expression level was closely related to the progress of L.anguillarum infection， which predicts aCCL4-like’role in the immune response against microbial infections of ayu.

CSTR: 32200.14.cjcb.2013.05.0018