title: Ontogeny of anti-viral hemorrhagic septicemia virus (VHSV) immunity in developing Japanese flounder.
abstract: We examined the ability of developing Japanese flounder (Paralichthys olivaceus) to acquire protective immunity after exposure to viral hemorrhagic septicemia virus (VHSV). Juveniles measuring 9.8 cm average body length were not susceptible to infection with VHSV at 20 °C, while the smaller fish were susceptible. Mortality was not observed after secondary infection at 15 °C in the 9.8 cm cohort that had previously been exposed to the virus at 20 °C, while the smaller fish were susceptible to secondary infection. The expression of interferon (IFN)-related genes was shown to be better developed in larger fish upon virus infection and basal expression levels of the virus recognition proteins were higher in larger fish. Virus-specific antibody was detected in the larger fish, but not in smaller fish. These data indicate that the largest juvenile (9.8 cm) acquired immunity against VHSV infection at the first virus challenge, but smaller fish did not. The anti-viral immune system in the Japanese flounder matures when juveniles reach approximately 10 cm.
authors.affiliation: National Research Institute of Aquaculture, Fisheries Research Agency, Aquatic Animal Health Division, Minami-Ise, Mie 516-0193, Japan. matsuym@fra.affrc.go.jp
authors.forename: Tomomasa
authors.initials: T
authors.lastname: Matsuyama
authors.forename: Chihaya
authors.initials: C
authors.lastname: Nakayasu
authors.forename: Atsushi
authors.initials: A
authors.lastname: Fujiwara
authors.forename: Jun
authors.initials: J
authors.lastname: Kurita
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Takano
authors.forename: Takafumi
authors.initials: T
authors.lastname: Ito
authors.forename: Motohiko
authors.initials: M
authors.lastname: Sano
mesh_terms: D000818:Animals; D060467:Disease Resistance; D005393:Fish Diseases / Q000196:embryology* / Q000276:immunology* / Q000821:virology; D005432:Flounder; D006483:Hemorrhagic Septicemia / Q000196:embryology / Q000276:immunology / Q000662:veterinary* / Q000821:virology; D031941:Hemorrhagic Septicemia, Viral