Mortality Caused by Bath Exposure of Zebrafish (Danio rerio) Larvae to Nervous Necrosis Virus Is Limited to the Fourth Day Postfertilization.
Nervous necrosis virus (NNV) is a member of the Betanodavirus genus that causes fatal diseases in over 40 species of fish worldwide. Mortality among NNV-infected fish larvae is almost 100%. In order to elucidate the mechanisms responsible for the susceptibility of fish larvae to NNV, we exposed zebrafish larvae to NNV by bath immersion at 2, 4, 6, and 8 days postfertilization (dpf). Here, we demonstrate that developing zebrafish embryos are resistant to NNV at 2 dpf due to the protection afforded by the egg chorion and, to a lesser extent, by the perivitelline fluid. The zebrafish larvae succumbed to NNV infection during a narrow time window around the 4th dpf, while 6- and 8-day-old larvae were much less sensitive, with mortalities of 24% and 28%, respectively.
Department of Pathology and the Lautenberg Center for General and Tumor Immunology, The Hebrew University Hadassah Medical School, Jerusalem, Israel.
Danny
D
Morick
Department of Pathology and the Lautenberg Center for General and Tumor Immunology, The Hebrew University Hadassah Medical School, Jerusalem, Israel.
Or
O
Faigenbaum
Department of Fisheries and Aquaculture, Ministry of Agriculture & Rural Development, Nir David, Israel.
Margarita
M
Smirnov
Department of Pathology and the Lautenberg Center for General and Tumor Immunology, The Hebrew University Hadassah Medical School, Jerusalem, Israel.
Yakov
Y
Fellig
Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel.
Adi
A
Inbal
Department of Pathology and the Lautenberg Center for General and Tumor Immunology, The Hebrew University Hadassah Medical School, Jerusalem, Israel moshek@ekmd.huji.ac.il.
Moshe
M
Kotler
D000818:Animals; D005260:Female; D005306:Fertilization; D005393:Fish Diseases / Q000401:mortality* / Q000503:physiopathology / Q000821:virology; D007814:Larva / Q000254:growth & development* / Q000821:virology; D008297:Male; D008969:Molecular Sequence Data; D030381:Nodaviridae / Q000502:physiology*; D012327:RNA Virus Infections / Q000401:mortality / Q000503:physiopathology / Q000662:veterinary* / Q000821:virology; D015027:Zebrafish / Q000254:growth & development / Q000502:physiology / Q000821:virology*