Viral mutations and their implications for genetic diversity of the Infectious Myonecrosis Virus (IMNV)

Infectious Myonecrosis Virus (IMNV) is a main pathogen affecting global shrimp farming. It was first recorded in Brazil in 2002, but has spread to other Asian countries, especially Indonesia. Records of strains from different origins show different infection progress. Therefore, the present work aimed to evaluate the genetic differences between the IMMV strains, as well as their possible causes. Our results showed a great diversity of haplotypes, especially in Asia. We also observed that the majority of viral proteins present positive type selection, preserving their primary structure, although there are differences in SNPs among them. Our results reinforce the theory of the spread of IMNV from Brazil to Indonesia, where it appears to have spread to other Asian countries. Thus, the South American and Asian strains have a divergent evolutionary history, showing that virus mutations are influenced by the environment.