Molecular characterization of SIV in tissues from experimentally infected macaques.

Tissues from SIV-infected, immunodeficient macaques were analyzed by southern blot and polymerase chain reaction (PCR) amplification of env sequences. Provirus was readily detected in both lymphoid and non-lymphoid tissues by southern blot analysis. The majority of virus was in an unintegrated state. Analysis of envelope sequences by PCR revealed that tissues contain many distinct, but closely related genotypes; however, only a subset of these proviral genomes are recovered after tissue culture passage in human cell lines. Thus, tissue culture isolates of SIV do not represent the complete spectrum of genotypes in an infected macaque.