n Fig. 3).
It has been suggested that SSN-1 cells are persistently
infected with snakehead retrovirus (SnRV), and SSN-1 cells
carry productive SnRVs (Iwamoto et al., 2000). However,
unlike SSN-1 cells, the SnRVs were not found in E-11 cell
although pol gene of SnRV was found in genomic DNA of
E-11 cell (Iwamoto et al., 2000). A report suggested that the
SnRVs have important role in propagation and infection of