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Antimicrobial peptides (AMPs) are important components of the host innate immuneresponse against microbial invasion.
The cysteine-rich AMPs such as defensin and hepcidinhave been extensively studied from various organisms, but their role in disease defense in catfishis unknown. As a first step, here we sequenced the hepcidin cDNA from both channel catfishand blue catfish, and characterized the channel catfish hepcidin gene. The channel catfishhepcidin gene consists of two introns and three exons that encode a peptide of 96 amino acids.The amino acid sequences and gene organization were conserved between catfish and otherorganisms.In contrast to its almost exclusive expression in the liver in humans, the channelcatfish hepcidin gene was expressed in a wide range of tissues except brain.Its expression wasdetected early during embryonic and larval development.
The expression of hepcidin gene wasinduced after bacterial infection with Edwardsiella ictaluri, the causative agent of entericsepticemia of catfish (ESC) in a tissue-specific manner. Its expression was upregulated in thespleen and head kidney, but not in the liver.
The expression of hepcidin was upregulated 1-3days after challenge, but retumed to normal levels at 7 days after challenge. The expressionprofile of the catfish hepcidin gene during the course of bacterial infection mirrors those ofinflammatory proteins such as chemokines, suggesting an important role for hepcidin during inflammatory responses.
The cysteine-rich AMPs such as defensin and hepcidinhave been extensively studied from various organisms, but their role in disease defense in catfishis unknown. As a first step, here we sequenced the hepcidin cDNA from both channel catfishand blue catfish, and characterized the channel catfish hepcidin gene. The channel catfishhepcidin gene consists of two introns and three exons that encode a peptide of 96 amino acids.The amino acid sequences and gene organization were conserved between catfish and otherorganisms.In contrast to its almost exclusive expression in the liver in humans, the channelcatfish hepcidin gene was expressed in a wide range of tissues except brain.Its expression wasdetected early during embryonic and larval development.
The expression of hepcidin gene wasinduced after bacterial infection with Edwardsiella ictaluri, the causative agent of entericsepticemia of catfish (ESC) in a tissue-specific manner. Its expression was upregulated in thespleen and head kidney, but not in the liver.
The expression of hepcidin was upregulated 1-3days after challenge, but retumed to normal levels at 7 days after challenge. The expressionprofile of the catfish hepcidin gene during the course of bacterial infection mirrors those ofinflammatory proteins such as chemokines, suggesting an important role for hepcidin during inflammatory responses.