Repligen Corporation, Cambridge, Massachusetts 02139.
The DNA sequence of the envelope gene of the HTLV-1 proviral clone MT-2 was determined and compared with envelope sequences of other HTLV-1 isolates. The comparison of this sequence with another of Japanese origin and two of Caribbean origin does not support the proposal by K.T.A. Malik, J. Even, and A. Karpas (J. Gen. Virol. 69, 1695-1710, 1988) that isolates of similar geographic origins are more homologous than isolates of different origins. No significant differences in the degree of homology could be found among the HTLV-1 envelope gene sequences from Japanese and Caribbean isolates. The comparison confirms the high degree of homology previously found between various HTLV-1 isolates (greater than 97%).