Tissue tropism of Tilapia Lake Virus infection by experimental route in Tilapines (Oreochromis niloticus)

Aquaculture production sectors are often vulnerable to various aquatic diseases which could be specific to species or climate. Tilapia Lake Virus (TiLV), a virus that only affects Tilapia, has been responsible for recent years' widespread fish death. Understanding both horizontal and vertical routes of viral transmission is crucial in preventing this disease. Since there are studies on TiLV mostly focussed on In Vitro methodology for the experimental infection. However, we demonstrated the horizontal route of transmission by In Vivo method through intraperitoneal injection. The immune genes are highly responsible to evade the viral infection, in the case of TiLV infection, three different immune genes of Tilapia (MYD88, MCP, TNFα) were upregulated along with the viral load. To understand the aetiology of this disease, the viral load at different organs of the infected fish were estimated by Real Time PCR at regular intervals of time till the moribund stage. The immune genes endured a sharp decline in the middle of pathogenesis with the sudden increase of Viral load which made the fishes to attain the moribund stage.