Characterization of herpes simplex virus type 1 DNA during latent infection in mice

Micrococcal nuclease digestion technique in combination with spot-blotting hybridization have been used for the characterization of latent Herpes simplex virus type 1 (HSV-1) DNA in mouse brainstems. Two kinds of samples were used i.e. undigested DNA from mouse brainstems and DNA after prolonged digestion (i.e. for 30 minutes) with micrococcal nuclease from the same source. Each sample contained 5 micrograms of DNA (concentration was measured after digestion with micrococcal nuclease and isolation of DNA). Two kinds of probes were used: -virus specific probe, -host cellular probe. In the performed experiments, we observed the increased susceptibility of latent HSV-1 DNA for micrococcal nuclease digestion, comparing it to host DNA, which may reflect differences in protection of latent viral DNA by nuclear proteins and also may be associated with existing limited transcription of HSV-1 genome during latency.