MOLECULAR ANATOMY OF LYMPHOCYSTIS DISEASE VIRUS

Lymphocystis disease (LD) has been reported to occur in over one hundr ed different species of fish worldwide. The disease is caused by lymph ocystis disease virus (LCDV), a member of the iridovirus family. Numer ous fish species that play an important role in fishery and fish farmi ng are highly susceptible to LCDV infection. The infected animals deve lop disseminated clusters of aberrant hypertrophied cells within their connective tissue, the so-called lymphocystis cells. In the cytoplasm of these cells a massive accumulation of virions can be observed. As a first step towards understanding the mechanisms of viral infection a nd pathogenesis the complete genomic nucleotide sequence of lymphocyst is disease virus type 1 (LCDV-1; flounder isolate) was determined. LCD V-1 is the type species of the genus Lymphocystivirus within the famil y Iridoviridae. The virions contain a single linear double-stranded DN A molecule that is circularly permuted, terminally redundant and heavi ly methylated. Since there is no convenient cell system for virus repl ication we determined the complete nucleotide sequence of the viral ge nome (102, 653 base pairs). Computer assisted analyses of 195 potentia l open reading frames resulted in the identification of a number of pu tative gene products with significant homology to functionally charact erized proteins of other species.