Phylogenetic relationships on
gene (1302 nt) of the HIV-1
gene between the HIV-1 putative recombinant forms circulating in Italy (shown in bold and underlined) and the reference sequences of the CRFs of the HIV-1 M group from the Los Alamos HIV Sequence Database. Bootstrap values <90% are not shown. The scale bar indicates 3% nucleotide sequence divergence.* indicates the P value < 0.001 (zero length branch test) and the bootstrap values more than 70%.