Identification and expression analysis of major histocompatibility complex IIB gene in orange-spotted grouper Epinephelus coioides

Authors

  • D. Q. Lu,

    1. State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and the Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, 135 Xingang West Street, Guangzhou 510275, PR China
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  • S. B. Yi,

    1. State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and the Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, 135 Xingang West Street, Guangzhou 510275, PR China
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  • M. Yao,

    1. State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and the Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, 135 Xingang West Street, Guangzhou 510275, PR China
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  • Y. W. Li,

    1. Key Laboratory for Aquatic Products Safety of Ministry of Education/State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, 135 Xingang West Street, Guangzhou 510275, PR China
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  • X. C. Liu,

    1. State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and the Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, 135 Xingang West Street, Guangzhou 510275, PR China
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  • Y. Zhang,

    Corresponding author
    1. State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and the Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, 135 Xingang West Street, Guangzhou 510275, PR China
      Tel.: +86 20 84113791; e-mail: lsszy@mail. sysu.edu.cn
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  • H. R. Lin

    1. State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and the Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, 135 Xingang West Street, Guangzhou 510275, PR China
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Tel.: +86 20 84113791; e-mail: lsszy@mail. sysu.edu.cn

Abstract

In this study, complementary DNA (cDNA) and DNA sequences of major histocompatibility complex (MHC) class IIB genes (mhcIIB) were cloned from orange-spotted grouper Epinephelus coioides. The gene structure of E. coioides mhcIIB consists of five exons and four introns, and its deduced amino acid sequence length is 249 amino acids, including a signal peptide, a peptide-binding region, an IGC1 domain, a transmembrane region and a cytoplasmic tail. A phylogenetic study showed that E. coioides mhcIIB shared 32·0–79·1% identity with those of other teleosts and mammals. Real-time reverse transcriptase (RT)-PCR was performed to detect the class IIB gene expression in eight different tissues. To characterize the relationship between E. coioides mhcIIB gene and pathogens, in vivo and in vitro studies were performed. Challenge of Cryptocaryon irritans revealed that class IIB genes were down-regulated after 24 and 48 h of challenge, and their expression was later restored at 72 h. Stimulation of isolated E. coioides leukocytes with lipopolysaccharide (LPS) and polyinosinic:polycytidylic acid (PolyI:C) significantly increased peripheral blood and spleen mhcIIB expression, while head kidney mhcIIB expression remained constant.

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