Submitted to: Keystone Symposia on Molecular and Cellular Biology
Publication Type: Abstract Only
Publication Acceptance Date: 3/27/1998
Publication Date: N/A
Citation: N/A Interpretive Summary:
Technical Abstract: Pseudorabies virus (PrV) causes a neuropathologic disease in swine, with high mortality among young piglets. Animals that recover from the acute disease develop a latent infection with the viral genome residing in the trigeminal ganglia. Pigs that are latently infected with the virus can have periods of reactivation, where they become intermittent shedders of infectious virus. It is not yet known how the establishment of latency is initiated, but it may be related to gene expression during various stages of the cell cycle. MDBK cells and mouse fibroblasts (3T3) were subjected to various treatments to arrest them in the G1/S, G0, or G2/M phases of the cell cycle. To halt cells in G1/S, cells were treated with aphidicolin for 24 hr. For the G0 phase, cells were incubated in medium deficient of serum for 48 hr. To halt cells in the G2/M phase, cells were incubated in nocodazole for 24 hr to inhibit spindle formation. All cells were then infected with the InFh strain of PrV. RNA was harvested at various times after infection and analyzed by Northern blot, using probes specific for the immediate early, early, and late genes. Samples were also taken at various times to determine the rate of virus replication. Our results showed that in MDBK cells, PrV gene expression and infectious progeny virus production are similar in all stages of the cell cycle. There was a slight delay in replication seen in the aphidicolin treated cells. Preliminary results with the 3T3 cells showed extreme variation in PrV gene expression among the various cell cycles. Gene expression during an asynchronous infection showed results similar to those seen in the MDBK cells. However, the cells arrested in the G1/S, G0, and G2/M phases of the cell cycle had markedly different gene expression patterns.