@article {10514, title = {Enrichment of low-frequency functional variants revealed by whole-genome sequencing of multiple isolated European populations.}, journal = {Nat Commun}, volume = {8}, year = {2017}, month = {2017 06 23}, pages = {15927}, abstract = {

The genetic features of isolated populations can boost power in complex-trait association studies, and an in-depth understanding of how their genetic variation has been shaped by their demographic history can help leverage these advantageous characteristics. Here, we perform a comprehensive investigation using 3,059 newly generated low-depth whole-genome sequences from eight European isolates and two matched general populations, together with published data from the 1000 Genomes Project and UK10K. Sequencing data give deeper and richer insights into population demography and genetic characteristics than genotype-chip data, distinguishing related populations more effectively and allowing their functional variants to be studied more fully. We demonstrate relaxation of purifying selection in the isolates, leading to enrichment of rare and low-frequency functional variants, using novel statistics, DVxy and SVxy. We also develop an isolation-index (Isx) that predicts the overall level of such key genetic characteristics and can thus help guide population choice in future complex-trait association studies.

}, keywords = {European Continental Ancestry Group, Gene Frequency, Genetic Variation, Genetics, Population, Genome, Human, Humans, Polymorphism, Single Nucleotide, Whole Genome Sequencing}, issn = {2041-1723}, doi = {10.1038/ncomms15927}, author = {Xue, Yali and Mezzavilla, Massimo and Haber, Marc and McCarthy, Shane and Chen, Yuan and Narasimhan, Vagheesh and Gilly, Arthur and Ayub, Qasim and Colonna, Vincenza and Southam, Lorraine and Finan, Christopher and Massaia, Andrea and Chheda, Himanshu and Palta, Priit and Ritchie, Graham and Asimit, Jennifer and Dedoussis, George and Gasparini, Paolo and Palotie, Aarno and Ripatti, Samuli and Soranzo, Nicole and Toniolo, Daniela and Wilson, James F and Durbin, Richard and Tyler-Smith, Chris and Zeggini, Eleftheria} } @article {3622, title = {Genetic landscape of populations along the Silk Road: admixture and migration patterns.}, journal = {BMC Genet}, volume = {15}, year = {2014}, month = {2014}, pages = {131}, abstract = {

BACKGROUND: The ancient Silk Road has been a trading route between Europe and Central Asia from the 2(nd) century BCE to the 15(th) century CE. While most populations on this route have been characterized, the genetic background of others remains poorly understood, and little is known about past migration patterns. The scientific expedition "Marco Polo" has recently collected genetic and phenotypic data in six regions (Georgia, Armenia, Azerbaijan, Uzbekistan, Kazakhstan, Tajikistan) along the Silk Road to study the genetics of a number of phenotypes.

RESULTS: We characterized the genetic structure of these populations within a worldwide context. We observed a West-East subdivision albeit the existence of a genetic component shared within Central Asia and nearby populations from Europe and Near East. We observed a contribution of up to 50\% from Europe and Asia to most of the populations that have been analyzed. The contribution from Asia dates back to ~25 generations and is limited to the Eastern Silk Road. Time and direction of this contribution are consistent with the Mongolian expansion era.

CONCLUSIONS: We clarified the genetic structure of six populations from Central Asia and suggested a complex pattern of gene flow among them. We provided a map of migration events in time and space and we quantified exchanges among populations. Altogether these novel findings will support the future studies aimed at understanding the genetics of the phenotypes that have been collected during the Marco Polo campaign, they will provide insights into the history of these populations, and they will be useful to reconstruct the developments and events that have shaped modern Eurasians genomes.

}, keywords = {Asian Continental Ancestry Group, Commonwealth of Independent States, European Continental Ancestry Group, Gene Flow, Homozygote, Human Migration, Humans, Phenotype, Polymorphism, Single Nucleotide, Principal Component Analysis, Sequence Analysis, DNA}, issn = {1471-2156}, doi = {10.1186/s12863-014-0131-6}, author = {Mezzavilla, Massimo and Vozzi, Diego and Pirastu, Nicola and Girotto, Giorgia and d{\textquoteright}Adamo, Pio and Gasparini, Paolo and Colonna, Vincenza} }