THE TAT AND C2-V3 ENVELOPE GENES IN THE MOLECULAR EPIDEMIOLOGY OF HUMAN IMMUNODEFICIENCY VIRUS-1

in this study HIV-1 proviral DNA sequences derived from 201 clones of the C2-V3 env region and the first exon of tat were obtained from six HIV-1-infected heterosexual couples. These molecular data were used to confirm the epidemiological relationships. The ability of the molecul ar data to draw such conclusions was also tested. A bootstrap parsimon y analysis of the C2-V3 sequences showed one couple failed to cluster and only two couples clustered in more than 70% of the replicates. The rapid diversification of the C2-V3 region and the length of time that elapsed since the infection event may have limited the certainty of t he conclusions that can he reached to infer epidemiological relatednes s from this region, Using data from the tat region, all couples cluste red, four of them in more than 80% of bootstrap replicates. A single c lone from the tat region did not cluster with others from that patient or with those from that patient's partner, indicating that multiple c lones are necessary to firmly establish phylogenetic linkage. Neverthe less, the tat region was much more useful in establishing epidemiologi cal relationships among this group than the commonly used C2-V3. (C) 1 996 Academic Press, Inc.