| Infectious Myonecrosis Virus (IMNV) is a virus that commonly infects Litopenaeus vannamei. In 2004, there were first outbreaks due to IMNV in Brazil, then followed by Situbondo in 2006. The clinical symptom of IMNV was muscle necrosis (white-muscle) in the abdominal segments and the tail. The objectives of this study were to identify and characterize IMNV at L.vannamei farming in Indonesia. Gene target of this research was RNA-dependent RNA polymerase (RdRp), 2211 bp long and conserved. RNA was extracted from gill tissue section that collected by PT Centra Proteinaprima. RNA was reverse-transcribed into cDNA and amplified using PCR technique. Then, continued by cloning and sequencing. Sequences from SumUt-10-2, Babel-10-1, Lampung-10-4, JaTim-10-2a, JaTim-10-2b, and NTB-10-1 were compared to Brazilian IMNV (GenBank accession no. AY570982.1) and Situbondo IMNV (GenBank accession no. EF061744.1) to describe the similiarity of the sequences. The result was 6 isolates had 99 % sequence identity with Brazilian and Situbondo IMNV. Those sequences with 13 other IMNV isolates (unpublished data) were aligned to construct a phylogenetic tree used for describing the relationships between the isolates. Based on the phylogenetic tree, we knew that there were 2 clusters that classify all Indonesian IMNV isolates. Isolate from -10-2a, SumUt-10-2a, and NTB-10-1 were grouped in one cluster. Besides that, isolate from JaTim-10-2b, Babel-10-1, and Lampung-10-4 were classified in another cluster. However, in general, all Indonesian IMNV isolates have close relationship between each other. |