title: Tissue localization of piscidin host-defense peptides during striped bass (Morone saxatilis) development.
abstract: Infectious diseases are a major cause of larval mortality in finfish aquaculture. Understanding ontogeny of the fish immune system and thus developmental timing of protective immune tissues and cells, may help to decrease serious losses of larval fishes when they are particularly vulnerable to infection. One component of the innate immune system of fishes is the host-defense peptides, which include the piscidins. Piscidins are small, amphipathic, α-helical peptides with a broad-spectrum of action against viral, bacterial, fungal, and protozoan pathogens. We describe for the first time the cellular and tissue localization of three different piscidins (1, 3, and 4) during striped bass (Morone saxatilis) larval ontogeny using immunofluorescent histochemistry. From 16 days post hatch to 12 months of age, piscidin staining was observed in cells of the epithelial tissues of gill, digestive tract, and skin, mainly in mast cells. Staining was also seen in presumptive hematopoietic cells in the head kidney. The three piscidins showed variable cellular and tissue staining patterns, possibly relating to differences in tissue susceptibility or pathogen specificity. This furthers our observation that the piscidins are not a monolithic family of antimicrobials, but that different AMPs have different (more specialized) functions. Furthermore, no immunofluorescent staining of piscidins was observed in post-vitellogenic oocytes, embryos, or larvae from hatch to 14 days post hatch, indicating that this critical component of the innate immune system is inactive in pre-hatch and young larval striped bass.
authors.affiliation: Department of Applied Ecology, North Carolina State University, Raleigh, NC, United States. Electronic address: sasalger@ncsu.edu.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Salger
authors.affiliation: Department of Applied Ecology, North Carolina State University, Raleigh, NC, United States.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Reading
authors.affiliation: Department of Clinical Sciences, North Carolina State University, College of Veterinary Medicine, Raleigh, NC, United States.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Noga
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000235:genetics* / Q000378:metabolism; D001492:Bass / Q000196:embryology / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D007150:Immunohistochemistry / Q000662:veterinary; D009928:Organ Specificity
chemical_list: D023181:Antimicrobial Cationic Peptides; D029941:Fish Proteins; C449802:moronecidin protein, Morone saxatilis; C541375:piscidin 4, striped bass
keywords: Host-defense peptides; Innate immunity; Ontogeny; Piscidin; Striped bass