Ethnoepidemiology of Atl/htlv in Mongoloids With Special Reference To Mongoloid Dispersal

摘要

The origins of human T-cell leukemia virus type I and type II (HTLV-I/II) in the world are not weE understood, but are probably linked to a history of human dispersal with geographical clustering due to the natural transmission routes of HTLV. From the previous comprehensive research on genetic characteristics of Mongoloids in America, the Southern Japanese are similar to those of Andean highlanders with HTLV-I, but exclusively different from those of lowlanders with HTLV-II. To clarify the common origin of HTLV-I in Asia and Andes, we analyzed HTLV-I provirus DNA from Andean mummies about 1,500 years old. In 104 mummy bone marrow specimens, one out of two human beta-globin gene positives produced bands of 159 bp and 157 bp of HTLV-I-pX and -LTR (long terminal repeat) genes. Nucleotide sequences of ancient HTLV-I-LTR clones isolated from mummy bone marrow were similar to those in contemporary Andeans and Japanese. To explain the unique distribution of HTLV-I/II among Mongoloids, one hypothetical model pf migration history of HTLV-I and -II carriers in Pan-Pacific areas can be explored. Because of the similarity of genetic background between Southern Japanese and Andeans in South America, a paradoxical hypothesis which has not found general acceptance amongst anthropologists and archeologists seems plausible: HTLV-I-carrying people arrived in the Andes through a transpacific route after migration of HTLV-II-carrymg Asians to the South American continent.