Browsing by Author "Saw, W.Y."

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Characterising private and shared signatures of positive selection in 37 Asian populations
    (Nature Publishing Group, 2017) Liu, X.; Lu, D.; Saw, W.Y.; Wangkumhang, P.; Ngamphiw, C.; Fucharoen, S.; Lert-Itthiporn, W.; Chin-Inmanu, K.; Chau, T.N.; Anders, K.; Kasturiratne, A.; de Silva, H.J.; Katsuya, T.; Kimura, R.; Nabika, T.; Ohkubo, T.; Tabara, Y.; Takeuchi, F.; Yamamoto, K.; Yokota, M.; Mamatyusupu, D.; Yang, W.; Chung, Y.J.; Jin, L.; Hoh, B.P.; Wickremasinghe, A.R.; Ong, R.H.; Khor, C.C.; Dunstan, S.J.; Simmons, C.; Tongsima, S.; Suriyaphol, P.; Kato, N.; Xu, S.; Teo, Y.Y.
    The Asian Diversity Project (ADP) assembled 37 cosmopolitan and ethnic minority populations in Asia that have been densely genotyped across over half a million markers to study patterns of genetic diversity and positive natural selection. We performed population structure analyses of the ADP populations and divided these populations into four major groups based on their genographic information. By applying a highly sensitive algorithm haploPS to locate genomic signatures of positive selection, 140 distinct genomic regions exhibiting evidence of positive selection in at least one population were identified. We examined the extent of signal sharing for regions that were selected in multiple populations and observed that populations clustered in a similar fashion to that of how the ancestry clades were phylogenetically defined. In particular, populations predominantly located in South Asia underwent considerably different adaptation as compared with populations from the other geographical regions. Signatures of positive selection present in multiple geographical regions were predicted to be older and have emerged prior to the separation of the populations in the different regions. In contrast, selection signals present in a single population group tended to be of lower frequencies and thus can be attributed to recent evolutionary events
  • Thumbnail Image
    Item
    Dissecting the genetic structure and admixture of four geographical Malay populations
    (Nature Publishing Group, 2015) Deng, L.; Hoh, B.P.; Lu, D.; Saw, W.Y.; Twee-Hee Ong, R.; Kasturiratne, A.; de Silva, H.J.; Zilfalil, B.A.; Kato, N.; Wickremasinghe, A.R.; Teo, Y.Y.; Xu, S.
    The Malay people are an important ethnic composition in Southeast Asia, but their genetic make-up and population structure remain poorly studied. Here we conducted a genome-wide study of four geographical Malay populations: Peninsular Malaysian Malay (PMM), Singaporean Malay (SGM), Indonesian Malay (IDM) and Sri Lankan Malay (SLM). All the four Malay populations showed substantial admixture with multiple ancestries. We identified four major ancestral components in Malay populations: Austronesian (17%-62%), Proto-Malay (15%-31%), East Asian (4%-16%) and South Asian (3%-34%). Approximately 34% of the genetic makeup of SLM is of South Asian ancestry, resulting in its distinct genetic pattern compared with the other three Malay populations. Besides, substantial differentiation was observed between the Malay populations from the north and the south, and between those from the west and the east. In summary, this study revealed that the genetic identity of the Malays comprises a mixed entity of multiple ancestries represented by Austronesian, Proto-Malay, East Asian and South Asian, with most of the admixture events estimated to have occurred 175 to 1,500 years ago, which in turn suggests that geographical isolation and independent admixture have significantly shaped thegenetic architectures and the diversity of the Malay populations.