Endogenous viral sequences detected in an Ixodes scapularis-derived cell line

Tick cell lines are known to harbour several endogenous viruses. ISE6 cell line, which is derived from Ixodes scapularis, was subjected to deep sequencing analysis. The cell line has been maintained at Graduate School of Veterinary Medicine, Hokkaido University. The cells were maintained in L-15B medium supplemented with 10% FCS and 5% tryptose phosphate broth (SIGMA) at 32?C. The viral particles purified from the culture supernatant were used for RNA extraction, followed by illumina sequencing. The reads were de novo assembled and the resulting contigs were annotated by BLASTN and TBLASTX searches. The results indicated that ISE6 has at least three different viruses. These include viruses related to Iflavirus, Phasmavirus, and Ixodes scapularis associated virus-1.