Molecular cloning and expression of PoIR2, a novel gene involved in immune response in Japanese flounder (Paralichthys olivaceus)

Abstract

A novel immune-related gene was expressed in Japanese flounder (Paralichthys olivaceus) injected with Vibrio anguillarum. The complete cDNA contained a 169 bp 5'UTR, a 336 bp open reading frame (ORF) encoding 111 amino acids and a 556bp 3'UTR. Six exons and five introns were identified in the PoIR2 gene. Blastp similarity comparison showed its encoding protein had 50% similarity to Danio rerio neuromedin S (NMS), but further alignment indicated they did not have NMS C-terminal conservational signature domain. So it was not defined as an NMS homologue. Protein structure analysis indicated it had a 26aa signal peptide and was a secretory pathway protein. RT-PCR demonstrated that the expression of PoIR2 was quickly induced and drastically increased in liver, kidney, spleen, gills, intestine, heart, and skeletal muscle after infected with V. anguillarum. These results indicated that the PoIR2 might play some important role in Japanese flounder immune response system. This gene was named PoIR2 (P.olivaceus immune-related gene 2, GenBank accession number: EU224372). The mature PoIR2 peptide was expressed in BL21(DE3) pLysS using pET-32a(+) vector and a great part of the recombinant mature peptide existed as soluble type.

Differential Effects of Dietary Supplementation of Krill Meal, Soybean Meal, Butyrate, and Bactocell® on the Gene Expression of Atlantic Salmon Head Kidney

“…This gene underwent a significant upregulation in the BU group, reaching 120-160 TPM (LogFC = 1.7, see Figure 1 and Table 1). TM4SF4 has been observed among the genes downregulated in response to acute infection with the viral hemorrhagic septicemia virus in the Pacific herring [78] and, in another study carried out in the Japanese flounder, it was modulated in various tissues (i.e., liver, head kidney, gill, and muscle) in response to Vibrio anguillarum challenges [79]. These two reports only provide indirect evidence of a possible involvement in the immune response and do not presently allow the formulation of a more comprehensive hypothesis concerning the functional link between TM4SF4 and the other genes involved in the molecular network of the DEGs activated by the BU-rich diet.…”