Detection of antimicrobial peptides related to piscidin 4 in important aquacultured fish

• Published in: Developmental and comparative immunology 2010-03, Vol.34 (3), p.331-343
• Main Authors: Corrales, Jone, Mulero, Ivan, Mulero, Victoriano, Noga, Edward J.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Antimicrobial Cationic Peptides - biosynthesis; Antimicrobial Cationic Peptides - immunology; Antimicrobial Cationic Peptides - metabolism; Antimicrobial peptides; Aquaculture; Barramundi; Bass - immunology; Bass - metabolism; Basses; Blotting, Western; Chrysops; Dicentrarchus labrax; Enzyme-Linked Immunosorbent Assay; Fish Proteins - immunology; Fish Proteins - metabolism; Gilthead seabream; Immunohistochemistry; Lates calcarifer; Marine; Mast Cells - immunology; Mast Cells - metabolism; Molecular Sequence Data; Morone saxatilis; Piscidin; Protein Isoforms - biosynthesis; Protein Isoforms - immunology; Red drum; Sciaenops ocellatus; Sea Bream - immunology; Sea Bream - metabolism; Sequence Alignment; Sparus aurata
• ISSN: 0145-305X; 1879-0089
• DOI: 10.1016/j.dci.2009.11.004

Epithelial surfaces of fish, such as the gut, skin and gills, comprise a large surface area for possible pathogen invasion. Antimicrobial peptides (AMPs), innate immunity components, play a significant role in protecting fish. Piscidins are a family of AMPs. In this study, we detected the presence of the recently discovered piscidin 4 via bug blot, Western blot, ELISA and/or immunohistochemistry in striped bass ( Morone saxatilis), white bass ( M. chrysops), European seabass ( Dicentrarchus labrax), gilthead seabream ( Sparus aurata), red drum ( Sciaenops ocellatus), and barramundi ( Lates calcarifer). Via bug blot, gill extracts from all species had antibacterial activity corresponding to the migration rate of piscidin 4. Western blotting showed that piscidin 4 immunoreactivity was greatest in striped bass gill extract. The concentrations of piscidin 4 detected by the ELISA in striped bass gill (∼20 μg/ml) were well within the levels that are inhibitory to important fish bacterial pathogens. Piscidin 4 was also detected via immunohistochemistry in all fish except barramundi. Piscidin 4-positive cells were identified as mast cells (MC), but not all MC were piscidin 4-positive. Species, age, size and physiological condition at sampling were some factors that might affect piscidin expression in different species. Our data provide strong evidence that piscidin 4 isoforms are present in all these commercially important species.