Author(s): Thirunavukkarasu Periyasamy and Ming-Wei Lu

Abstract: The interferon regulatory factor (IRF8) is considered to play essential roles in innate and adaptive immune responses. In this present study, the full-length cDNA sequences characterization, tissue distribution and expression in response to immune stimulation and nervous necrosis (NNV) challenges were in Malabar grouper (Epinephelus malabaricus). The full-length cDNA of MgIRF8 was of 2537 bp, including 5’-terminal untranslated region (UTR) of 483 bp and 3’-terminal untranslated region (UTR) 785 bp. It contains an open reading frame (ORF) of 1269 bp including encoding 422 amino acid, molecular weight 47.8 KDa and 5.74 isoelectric points. The putative protein sequence possesses a DNA-binding domain (DBD), IRF-association domain (IAD) and a nuclear localization signal (NLS). Phylogenetic tree analysis classified MgIRF8 into the cluster of fish IRF8 with in vertebrate IRF8 group with IRF4 family. Quantitative real-time PCR analysis revealed a brad expression of IRF8 transcript with the highest expression of IRF8 in developmental stage at 120 h post fertilization and the tissue specific expression resulted showed that spleen, skin, muscle and head kidney were highly expressed. The expression levels of IRF8 after challenged with immuno-stimulation and NNV challenge were examined in brain, spleen and head kidney tissues. These finding contribute to an understanding of host antiviral responses and function of IRF8 in teleost fish.

Pages: 213-221  |  1023 Views  119 Downloads

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