Major capsid protein gene sequence analysis of the Santee-Cooper ranaviruses DFV, GV6, and LMBV

The Santee-Cooper ranaviruses doctor fish virus (DFV), guppy virus 6 (GV6), and largemouth bass virus (LMBV) are members of the genus Ranavirus within the family Iridoviridae. The major capsid protein (MCP) is a main structural protein of iridoviruses and supports the differentiation and classification of ranaviruses. Presently the complete sequence of the MCP gene is known for most ranaviruses with the exception of the Santee-Cooper ranaviruses. In the present study, the complete nucleotide sequence of the MCP gene of DFV, GV6, and LMBV was determined. DFV and GV6 are identical within the MCP gene sequence. The identity compared to the corresponding sequence in LMBV amounts to 99.21%. The MCP gene of DFV, GV6, and LMBV exhibits only approximately 78% identity compared to the respective gene of other ranaviruses. Based on the sequence data obtained in the present study, a Rana MCP polymerase chain reaction (PCR) and subsequent restriction fragment length polymorphism (RFLP) analysis were developed to identify and differentiate ranaviruses, including DFV, GV6, and LMBV.