Genome-wide SNP data of Izumo and Makurazaki populations support inner-dual structure model for origin of Yamato people

The “Dual Structure” model on the formation of the modern Japanese population assumes that the indigenous huntergathering population (symbolized as Jomon people) admixed with rice-farming population (symbolized as Yayoi people) who migrated from the Asian continent after the Yayoi period started. The Jomon component remained high both in Ainu and Okinawa people who mainly reside in northern and southern Japan, respectively, while the Yayoi component is higher in the mainland Japanese (Yamato people). The model has been well supported by genetic data, but the Yamato population was mostly represented by people from Tokyo area. We generated new genome-wide SNP data using Japonica Array for 45 individuals in Izumo City of Shimane Prefecture and for 72 individuals in Makurazaki City of Kagoshima Prefecture in Southern Kyushu, and compared these data with those of other human populations in East Asia, including BioBank Japan data. Using principal component analysis, phylogenetic network, and f4 tests, we found that Izumo, Makurazaki, and Tohoku populations are slightly differentiated from Kanto (including Tokyo), Tokai, and Kinki regions. These results suggest the substructure within Mainland Japanese maybe caused by multiple migration events from the Asian continent following the Jomon period, and we propose a modified version of “Dual Structure” model called the “Inner-Dual Structure” model

Prevalência da infecção pelo papilomavirus humano nas aldeias rurais do Amazonas Boliviano

Cervical cancer constitutes a major health problem in developing countries like Bolivia. The roles of certain genotypes of human papillomaviruses (HPVs) in the pathogenesis of cervical cancer is well established. The prevalence of HPV infection among sexually active women varies greatly. Information regarding HPV infection in Bolivia is very much scarce, specially in regions like the Amazonian lowland. We studied 135 healthy women living in four rural localities of the Bolivian Amazon. Presence of HPV in DNA extracted from cervical swabs was analyzed using a reverse line hybridization assay. The estimated overall HPV infection prevalence among the studied rural localities was 5.9% (ranging from 0-16.6%). These values were unexpectedly low considering Bolivia has a high incidence of cervical cancer. The fact that Amazonian people seem to be less exposed to HPV, makes it likely that some other risk factors including host lifestyle behaviors and genetic background may be involved in the development of cervical cancer in this population.O câncer cervical constitui problema de saúde da maior importância nos países em desenvolvimento tais como a Bolívia. O papel de certos genótipos de papilomavirus humano (HPVs) na patologia do câncer cervical está bem estabelecido. A prevalência da infecção pelo HPV nas mulheres sexualmente ativas varia amplamente. Contudo, as informações existentes acerca da infecção pelo HPV na Bolivia são muito escassas, especialmente nas zonas rurais, nomeadamente na região amazônica do país. Foram estudadas 135 mulheres saudáveis, residentes em quatro localidades do Amazonas Boliviano. Foi detectada a presença de HPV no DNA extraído de esfregaços cervicais, utilizando o método de hibridização em linha reversa. A prevalência da infecção por HVP, encontrada nas localidades rurais, foi de 5,9% (variação entre 0-16,6%). Estes valores foram inesperadamente baixos, uma vez que a Bolívia é um país com alta incidência de câncer cervical. O fato da população do Amazonas parecer estar menos exposta ao HPV leva-nos a pensar que outros fatores de risco, inclusive estilos de vida e fatores genéticos, poderiam ter alguma relevância no desenvolvimento do câncer cervical nesta população