(ii) The essence of iridovirus. The recent advances in genome
sequencing technology have made it possible to scan the
whole genome to define the genes that are homologous between
iridoviruses. Comparison of different iridovirus genomes
has revealed that many genes have been conserved during
evolution, and this comparison would enable understanding of
relationship between the phenotype and genotype. Besides, the
genomic comparison would also allow the identification of
genes which define iridoviruses and their host range.
Recently, five iridovirus genomes have been completely sequenced,
including those of Lymphocystis disease virus 1
(LCDV-1; genus Lymphocystivirus) (51), Chilo iridescent virus
(CIV; genus Iridovirus) (29), Tiger frog virus (TFV; genus Ranavirus)
(24), Infectious spleen and kidney necrosis virus (ISKNV;
unclassified genus) (23) and Ambystoma tigrinum virus (ATV;
genus Ranavirus) (30). Considering the disease problems
caused by viruses in fish aquaculture and their impact on fish
farming economy and to facilitate the understanding of the
molecular mechanism of infection, we describe here another
complete genome sequencing and analyses of an iridovirus, the
grouper iridovirus (GIV), which was isolated from diseased
yellow grouper, Epinephelus awoara (34, 37).