Phylogenetic study of p24-p7 gene sequences of 51 HIV-1 seropositive strains from Calcutta, the eastern region of India, with 44 other C strains from different regions of India. The symbols used with the isolate names denote the origins of the strains as defined in the figure. Samples from Calcutta are designated “cal.” GenBank accession numbers of the Calcutta sequences are given in the text. The different isolates used for the study are as follows: NARI_GAG_1, NARI_GAG_2, NARI_GAG_3, NARI_GAG_4, NARI_GAG_5, NARI_GAG_6, 01IN565_10, 01IN565_11, 01IN565_13, 01IN565_14, 95IN21068, 93IN904, 94IN11246, 93IN101, 93IN905, 93IN9999, 98IN022, 94IN476, 98IN012, 50437, 60161, 60080, 60133, 60615, 50813, 50322, 49670, 50581, 33840, 33842, 49587, 80496, 50542, 70177, 50823, 50950, 50561, MYA1, IMP1, IMP3, IMP4, IMP5, IMP6, and C_GAG_221.