FIG. 7.

ΔTfi establishes latent infections efficiently but does not reactivate in vivo. Groups of mice were infected with the indicated titers of ΔTfi and ΔTfiR on both scarified corneas and snouts as described in Materials and Methods. The mice were maintained for at least 40 days postinfection. Top: Purified neurons derived from six trigeminal ganglia were analyzed by CXA for the presence of viral genomes as described in Materials and Methods. The gray bars indicate the percentages of neurons that were latently infected with ΔTfiR, and the black bars indicate the percentages latently infected with ΔTfi. The numbers of neurons positive for the viral genome/number of neurons tested are shown for the bars. Bottom: groups of animals were subjected to hyperthermic stress to induce reactivation as described in Materials and Methods. At 22 h postinduction, TG were removed, homogenized, and assayed for the presence of infectious virus. The gray bars indicate the percentages of ΔTfiR-infected animals positive for virus. The black bars indicate the percentages of ΔTfi-infected mice positive for virus. The numbers of animals positive/tested are shown for the bars.