FIG. 1.
Analysis of Us9-EGFP mediated anterograde spread in the rat visual system. (A) Schematic representation of the genome of PRV 164. A CMV Us9-GFP expression cassette was inserted into the gG locus (striped box upstream of gD), and the endogenous Us9 open reading frame was deleted (black box between gE and Us2). IR, inverted repeat. (B) Approximately 2.5 × 105 PFU of either PRV Becker or PRV 164 was injected into the vitreous humor of Sprague-Dawley male rats. At the time of imminent death, the animals were sacrificed and the brains were fixed and sliced into 35-μm-thick coronal sections with a freezing microtome. Infected tissue was stained for PRV antigen or Us9-EGFP (with Rb133 or Us9 rabbit polyvalent antiserum, respectively). Areas reached by anterograde, transneuronal spread are highlighted in red. D, dorsal; V, ventral.