scholarly journals Population-specific sequence and expression differentiation in Europeans

2019 ◽  
Author(s):  
Xueyuan Jiang ◽  
Raquel Assis

AbstractMuch of the enormous phenotypic variation observed across human populations is thought to have arisen from events experienced as our ancestors peopled different regions of the world. However, little is known about the genes involved in these population-specific adaptations. Here we explore this problem by simultaneously examining population-specific sequence and expression differentiation in four human populations. In particular, we design a branch-based statistic to estimate population-specific differentiation in four populations, and apply this statistic to single nucleotide polymorphism (SNP) and RNA-seq data from Italian, British, Finish, and Yoruban populations. As expected, genome-wide estimates of sequence and expression differentiation each independently recapitulate the known demographic history of these four human populations, highlighting the utility of our statistic for identifying genic targets of population-specific adaptations. Application of our statistic reveals that genes containing large copy number variations (CNVs) have elevated levels of population-specific sequence and expression differentiation, consistent with the hypothesis that gene turnover is a key reservoir of adaptive variation. Further, European genes displaying population-specific sequence and expression differentiation are enriched for functions related to epigenetic regulation, immunity, and reproduction. Together, our findings illustrate that population-specific sequence and expression differentiation in humans may preferentially target genes with CNVs and play important roles in a diversity of adaptive and disease-related phenotypes.

2020 ◽  
Vol 12 (4) ◽  
pp. 358-369
Author(s):  
Xueyuan Jiang ◽  
Raquel Assis

Abstract Much of the enormous phenotypic variation observed across human populations is thought to have arisen from events experienced as our ancestors peopled different regions of the world. However, little is known about the genes involved in these population-specific adaptations. Here, we explore this problem by simultaneously examining population-specific genetic and expression differentiation in four human populations. In particular, we derive a branch-based estimator of population-specific differentiation in four populations, and apply this statistic to single-nucleotide polymorphism and RNA-seq data from Italian, British, Finish, and Yoruban populations. As expected, genome-wide estimates of genetic and expression differentiation each independently recapitulate the known relationships among these four human populations, highlighting the utility of our statistic for identifying putative targets of population-specific adaptations. Moreover, genes with large copy number variations display elevated levels of population-specific genetic and expression differentiation, consistent with the hypothesis that gene duplication and deletion events are key reservoirs of adaptive variation. Further, many top-scoring genes are well-known targets of adaptation in Europeans, including those involved in lactase persistence and vitamin D absorption, and a handful of novel candidates represent promising avenues for future research. Together, these analyses reveal that our statistic can aid in uncovering genes involved in population-specific genetic and expression differentiation, and that such genes often play important roles in a diversity of adaptive and disease-related phenotypes in humans.


2008 ◽  
Vol 4 (6) ◽  
pp. 752-754 ◽  
Author(s):  
Emma Svensson ◽  
Anders Götherström

Phylogeography has recently become more abundant in studies of demographic history of both wild and domestic species. A single nucleotide polymorphism (SNP) in the intron of the Y-chromosomal gene UTY19 displays a north–south gradient in modern cattle. Support for this geographical distribution of haplogroups has previously also been seen in ancient cattle from Germany. However, when analysing 38 historic remains of domestic bulls and three aurochs from northern Europe for this SNP we found no such association. Instead, we noted extensive amounts of temporal variation that can be attributed to transportation of cattle and late breed formation.


Genes ◽  
2018 ◽  
Vol 9 (7) ◽  
pp. 358 ◽  
Author(s):  
Olga Dolgova ◽  
Oscar Lao

The demographic history of anatomically modern humans (AMH) involves multiple migration events, population extinctions and genetic adaptations. As genome-wide data from complete genome sequencing becomes increasingly abundant and available even from extinct hominins, new insights of the evolutionary history of our species are discovered. It is currently known that AMH interbred with archaic hominins once they left the African continent. Current non-African human genomes carry fragments of archaic origin. This review focuses on the fitness consequences of archaic interbreeding in current human populations. We discuss new insights and challenges that researchers face when interpreting the potential impact of introgression on fitness and testing hypotheses about the role of selection within the context of health and disease.


Author(s):  
Olga Dolgova ◽  
Oscar Lao

The demographic history of anatomically modern humans (AMH) involves multiple migration events, population extinctions and genetic adaptations. As genome-wide data from complete genome sequencing becomes increasingly abundant and available even from extinct hominins, new insights of the evolutionary history of our species are discovered. It is currently known that AMH introgressed with archaic hominins once they left the African continent. Current out of African human genomes carry fragments of archaic origin. This review focuses on the fitness consequences of archaic interbreeding in current human populations. We discuss new insights and challenges that researchers face when interpreting the potential impact of introgression on fitness and testing hypotheses about the role of selection within the context of health and disease.


2021 ◽  
Vol 11 (1) ◽  
pp. 33
Author(s):  
Nayoung Han ◽  
Jung Mi Oh ◽  
In-Wha Kim

For predicting phenotypes and executing precision medicine, combination analysis of single nucleotide variants (SNVs) genotyping with copy number variations (CNVs) is required. The aim of this study was to discover SNVs or common copy CNVs and examine the combined frequencies of SNVs and CNVs in pharmacogenes using the Korean genome and epidemiology study (KoGES), a consortium project. The genotypes (N = 72,299) and CNV data (N = 1000) were provided by the Korean National Institute of Health, Korea Centers for Disease Control and Prevention. The allele frequencies of SNVs, CNVs, and combined SNVs with CNVs were calculated and haplotype analysis was performed. CYP2D6 rs1065852 (c.100C>T, p.P34S) was the most common variant allele (48.23%). A total of 8454 haplotype blocks in 18 pharmacogenes were estimated. DMD ranked the highest in frequency for gene gain (64.52%), while TPMT ranked the highest in frequency for gene loss (51.80%). Copy number gain of CYP4F2 was observed in 22 subjects; 13 of those subjects were carriers with CYP4F2*3 gain. In the case of TPMT, approximately one-half of the participants (N = 308) had loss of the TPMT*1*1 diplotype. The frequencies of SNVs and CNVs in pharmacogenes were determined using the Korean cohort-based genome-wide association study.


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