Thumbnail Image

Theses (PG)

Browse

20211
Reset filters
Subject: Fish Health × Author: DHEERAJ, S. B., × End date: 2021 ×
Reset filters

Search Results

Now showing 1 - 1 of 1
  • Thumbnail Image
    ThesisItemOpen Access
    IMMUNE GENES EXPRESSION IN ORNAMENTAL FISH AGAINST INFECTIOUS SPLEEN AND KIDNEY NECROSIS VIRUS (ISKNV) INFECTION
    (KARNATAKA VETERINARY, ANIMAL & FISHERIES SCIENCES UNIVERSITY, BIDAR, 2021) DHEERAJ, S. B.,; S.K.GIRISHA
    Ornamental sector in fisheries is one of the important growing sectors in the world. Movement of innumerable exotic ornamental fishes paved the spread of various potent infectious viral diseases. Among these viral diseases, recent incidence of Infectious spleen and kidney necrosis virus (ISKNV) belonging to the genus Megalocytivirus has imposed a major threat to many ornamental fishes in India. In the present study, screening of ornamental fishes for ISKNV infection aided to identify the incidence of the virus in various species of ornamental fishes. The obtained ISKNV isolates showed 98.40%-98.76% nucleotide similarity with the MCP gene of ISKNV reference strains (NCBI genbank). Further, the phylogenetic tree constructed by using the sequences of the MCP gene clustered together with the same clade of ISKNV from the NCBI reference strains indicating that the positive samples belong to ISKNV. To understand the host pathogen interaction of ISKNV and ornamental fishes, different immune genes expression profile against ISKNV infection was performed in zebrafish as a model. This is the first kind of the study from India. A total of 14 immune related genes were selected and their relative expression was compared with the PBS control. Major immune related genes like type I interferons (T1-IFN), interferon regulatory factor 3 (IRF3) and tumour necrosis factor (TNFα) were highly expressed during the initial hours of the experiment. Interferon induced antiviral genes like myxovirus A (MxA) and viperin 1 (Vig1) genes were slowly upregulated and reached a maximum during 24-72hpi. Other genes related to adaptive immunity viz., CD4, CD8a, MHC I and IgM were lately expressed when compared with the innate immune genes. The major expression levels were observed in spleen, kidney and liver of ISKNV infected zebrafish. This study indicates, the ISKNV infection imparts a severe damage to organs like spleen, kidney and liver and considered as the target organs for ISKNV infection