Genomic organization and tissue-specific expression analysis of hepcidin-like genes from black porgy (Acanthopagrus schlegelii B).
Hepcidin is an antimicrobial peptide and putative iron regulatory hormone previously described in mice and humans. Dozens of fish hepcidins have been isolated and characterized so far. Here we present seven hepcidin-like cDNA sequences named AS-hepc1-7, amplified from the normal commercially cultured fish (black porgy) by RACE-PCR. Sequence analysis reveals that these seven potential hepcidin peptides have highly conserved sequences with other known hepcidins, but they are different from each other in constitution and characteristics of predicted mature amino acids. Based on the study, it is deduced that AS-hepc1-7 represent different variants of a family of hepcidin genes in black porgy. To understand the organization of these hepcidin-like genes, we sequenced AS-hepc2 DNA, AS-hepc3 DNA, AS-hepc4 DNA, AS-hepc7 DNA and AS-hepc2 upstream region; and all of the four genomic DNAs consisted of two introns and three exons, the same organization as other reported hepcidins. The tissue-specific gene expression of hepcidins in normal black porgy was evaluated using RT-PCR and dot blot approaches. RT-PCR showed that transcripts of hepcidin-like mRNAs were present in each tested tissue of normal juvenile black porgy, including liver, spleen, kidney, heart, brain, stomach, intestine, gill, skin and blood, but abundant hepcidin-like mRNA transcripts were only detected in the liver, kidney, spleen, intestine and stomach by dot blot assay. In addition, using dot blot and Northern blot approach, a significant increase of hepcidin mRNA transcription was observed in the liver within 48 h after immersion in a suspension of live bacteria, which suggested that the expression pattern of hepcidin-like genes in black porgy might be different in the liver from the other tissues as previously reported in several hepcidin studies.
Yang
Ming
M
State Key Laboratory of Marine Environmental Science, College of Oceanography and Environmental Science, Xiamen University, Xiamen, Fujian 361005, China.
Wang
Ke-Jian
KJ
Chen
Jun-Hui
JH
Qu
Hai-Dong
HD
Li
Shao-Jing
SJ
D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000235:genetics*; D001424:Bacterial Infections / Q000378:metabolism / Q000662:veterinary; D018407:Bacterial Physiological Phenomena; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D005393:Fish Diseases / Q000378:metabolism / Q000382:microbiology; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D023061:Gene Order / Q000235:genetics*; D064451:Hepcidins; D008969:Molecular Sequence Data; D010473:Perciformes / Q000235:genetics* / Q000378:metabolism*; D010802:Phylogeny; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013997:Time Factors
D023181:Antimicrobial Cationic Peptides; D018076:DNA, Complementary; C578702:HAMP protein, human; C579599:Hamp protein, mouse; D064451:Hepcidins