RESUMO
Northwest China is closely adjacent to Central Asia, an intermediate region of the Eurasian continent. Moreover, the Silk Road through the northwest of China once had a vital role in the east-west intercommunications. Nevertheless, little has been known about the genetic makeup of populations in this region. We collected 503 male samples from 14 ethnic groups in the northwest of China, and surveyed 29 Y-chromosomal biallelic markers and 8 short tandem repeats (STRs) loci to reconstruct the paternal architecture. Our results illustrated obvious genetic difference among these ethnic groups, and in general their genetic background is more similar with Central Asians than with East Asians. The ancestors of present northwestern populations were the admixture of early East Asians peopling northwestward and later Central Asians immigrating eastward. This population mixture was dated to occur within the past 10 000 years. The J2-M172 lineages likely entered China during the eastward migration of Central Asians. The influence from West Eurasia through gene flows on the extant ethnic groups in Northwest China was relatively weak.
Assuntos
Cromossomos Humanos Y/genética , Genética Populacional , Repetições de Microssatélites/genética , Polimorfismo de Nucleotídeo Único , Análise de Variância , Ásia/etnologia , Povo Asiático/genética , China , Análise por Conglomerados , Etnicidade/genética , Frequência do Gene , Variação Genética , Genótipo , Geografia , Haplótipos , Humanos , Masculino , FilogeniaRESUMO
OBJECTIVE: To analyze the geographical distribution and risk factors of HIV-1 subtypes in Yunnan province. METHODS: Blood samples from 1319 HIV positives were collected in Yunnan Province from 2001 to 2006. The nested polymerase chain reaction was used to amplify the gag (p24)-protease fragments from RNA extracted from plasma or sera. The sequences were used for subtype determination by phylogenetic tree analysis. RESULTS: Among 1319 samples studied, the subtypes has been successfully obtained from 644 samples that were constituted of seven subtypes: CRF08_BC, CRF07_BC, CRF07/08_BC, CRF01_AE, C, B' and URFB/C. C/CRF07_BC/CRF08_BC were distributed in the whole province, but CRF01_AE were mainly distributed in the boarding areas with Myanmar such as Dehong, Baoshan, Xishuangbanna and Puer. Moreover, injecting drugs users accounted for 61.6% (270/438) among C/CRF07_BC/CRF08_BC infections, while only 8.5% (15/177) among CRF01_AE infections. CONCLUSION: Our data indicated that at least seven subtypes were identified in Yunnan province, the relationship between subtypes and transmission routes were analyzed, and the geographic difference of subtypes was also observed.