Iridoviruses are a family of viruses (130--300
nanometers in size) that contain DNA as their genetic
material and have an icosahedral (20-sided) capsid.
Iridoviruses have been found in a wide variety of
fish, including both freshwater and saltwater species.
Some iridoviruses have been associated with serious
diseases (e.g., viral erythrocytic necrosis of
salmonids) while others have only been found in
apparently healthy animals (e.g., goldfish iridovirus).
One iridovirus causes a disease called lymphocystis
which causes unsightly skin lesions on infected fish,
but otherwise is of little consequence.
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).