Hunan locates in the south-central part of China, to the south of the middle reaches of the Yangtze River and south of Lake Dongting. According to the historical records, the peopling of Hunan by modern human ancestors can ascend to 40 thousand years ago. Thus, to trace the ancient maternal components can offer further insight into the origin of south-central China. In this study, we investigated the mitochondrial DNA of 114 individuals from Hunan Province (including 34 Han, 40 Tujia and 40 Miao).
In spite of the remarkable diversity of HIV-1 env genes, several amino acids are extremely conserved, probably due to functional constraints. One example is the proline found at the second position of the GPGR motif. Several viruses, however, bear substitutions at this site, for instance, GWGR subtype B variant. GWGR viruses are described in Brazil since the beginning of the epidemics, but the extent of their dispersion or the geographical origin of the variant remains unknown.