# Evolution of an Extended Pathogenicity Motif in VP2 of Infectious Pancreatic Necrosis Virus Isolates from Farmed Rainbow Trout in Turkey

## TL;DR

This study tracks how a specific genetic change in a virus affecting rainbow trout evolved over 10 years in Turkey, linking it to trout farming practices.

## Contribution

The study reveals a time-dependent evolution of a pathogenicity motif in IPNV isolates from farmed rainbow trout in Turkey.

## Key findings

- A shift in the VP2 pathogenicity motif from P217T221A247 to P217T221E247 occurred over 10 years in Turkey.
- The PTE motif emerged between 2007 and 2017, causing significant fry morbidity by 2013.
- The evolution of the motif correlates with a peak in rainbow trout production in 2013.

## Abstract

Infectious pancreatic necrosis virus (IPNV) causes economic losses with a highly variable mortality rate worldwide, especially in rainbow trout. The virus has a double-stranded bi-partite RNA genome designated segment A and B. New complete genome sequences of nine rainbow trout isolates from Turkey were determined and subjected to phylogenetic analysis, identifying all as genotype 5 (serotype Sp). A time-dependent change in the extended pathogenicity motif of VP2 from P217T221A247 (PTA) to PTE P217T221E247 over a period of 10 years was identified. A wider analysis of 99 IPNV sequences from Turkey and Iran revealed the emergence of the motif PTE from 2007 to 2017, inducing significant morbidity in fry by 2013. In fact, displacement of the PTA motif, by the PTE motif in IPNV isolates appeared to be connected to a production peak of rainbow trout in 2013. An additional CAI analysis provided more evidence, indicating that rainbow trout culture in Turkey has an influence on the evolution of IPNV.