Herpesvirus gene expression is co-ordinately regulated and sequentially ordered
during productive infection. The viral genes can be classified into three distinct
kinetic groups: immediate-early, early, and late classes. In this study, a
massively parallel sequencing technique that is based on PacBio Single
Molecule Real-time sequencing platform, was used for quantifying the poly(A)
fraction of the lytic transcriptome of pseudorabies virus (PRV) throughout a 12-
hour interval of productive infection on PK-15 cells. Other approaches, including
microarray, real-time RT-PCR and Illumina sequencing are capable of detecting
only the aggregate transcriptional activity of particular genomic regions, but not
individual herpesvirus transcripts. However, SMRT sequencing allows for a
distinction between transcript isoforms, including length- and splice variants, as
well as between overlapping polycistronic RNA molecules. The non-amplified
Isoform Sequencing (Iso-Seq) method was used to analyse the kinetic
properties of the lytic PRV transcripts and to then classify them accordingly.
Additionally, the present study demonstrates the general utility of long-read
sequencing for the time-course analysis of global gene expression in practically
any organism.
