Author
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Yeh, Hung-Yueh |
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Klesius, Phillip |
Submitted to: Veterinary Immunology and Immunopathology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/17/2007 Publication Date: 2/1/2008 Citation: Yeh, H., Klesius, P.H. 2008. Channel catfish, Ictalurus punctatus, cyclophilin A and B cDNA characterization and expression analysis. Veterinary Immunology and Immunopathology. 121: 370-377. Interpretive Summary: Channel catfish production is the largest aquacultural industry in the southeastern United States. Its annual output reaches 410 million dollars. In the course of studying Edwardsiella ictaluri pathogenesis, we cloned and sequenced the cyclophilin genes (CyPA and CyPB) of channel catfish. The deduced amino acid sequence was compared with CyPA and CyPB of other species deposited in the GenBank database. The sequence of the channel catfish CyPA and CyPB consists of 1170 and 996 base pairs, respectively. Analyses of the nucleotide sequences reveal one open reading frame and 5’- as well as 3’-untranslated regions. The open reading frame potentially encodes 164 and 216 amino acids for CyPA and CyPB, respectively. The degrees of conservation of channel catfish cyclophilin A and cyclophilin B amino acid sequences to counterparts of other species were ranging from 74 to 84% and 80 to 92%, respectively. Both cyclophilin A and cyclophilin B transcripts were found in all tissues of four fish examined. These results not only provide information for further exploring the role of cyclophilins in fish pathophysiology, but also fill the gap of evolutionary tree. Technical Abstract: Our preliminary observation of up-regulation of cyclophilin transcripts during Edwardsiella ictaluri infection prompted us to speculate the roles of cyclophilins in the early stage of infection. To provide a framework for answering these questions, we first identified, cloned and characterized two cyclophilin genes of channel catfish, Ictalurus punctatus, in this study. The complete nucleotide sequences of cyclophilin A and cyclophilin B cDNA consisted of 1170 and 996 bases, respectively. Analyses of the sequences revealed each had one open reading frame potentially encoding 164 amino acids with calculated molecular mass of 17,450 daltons and 216 amino acids with calculated molecular mass of 23,852 daltons for cyclophilin A and cyclophilin B, respectively. The degrees of conservation of channel catfish cyclophilin A and cyclophilin B amino acid sequences to counterparts of other species were ranging from 74 to 84% and 80 to 92%, respectively. Both cyclophilin A and cyclophilin B transcripts were constitutively expressed in all tissues of four fish examined. Further, both cyclophilins were cloned and expressed in E. coli. The recombinant cyclophilin B protein was purified and confirmed by matrix assisted laser desorption ionization – time of flight mass spectrometry. These results not only provide information for further exploring the role of cyclophilins in fish pathophysiology, but also fill the gap of evolutionary tree. |