Fig. 2.

(A) ML phylogenetic tree of the envelope gene of the virus inoculum. (B) ML trees of envelope sequences derived from proviral DNA, plasma viral RNA, and the inoculum. Envelope genes were amplified using SGA and were sequenced directly from animals Ri112 and Ri102 at 2 weeks postchallenge. Filled squares, sequences derived from proviral DNA; open squares, viral RNA sequences derived from plasma; circles, sequences derived from the challenge stock. Bars, 1 nucleotide substitution. Asterisks indicate hypermutated sequences.