scholarly journals Human Prehistoric Demography Revealed by the Polymorphic Pattern of CpG Transitions

2020 ◽  
Vol 37 (9) ◽  
pp. 2691-2698 ◽  
Author(s):  
Xiaoming Liu
Keyword(s):  
Population Dynamics ◽  
Population Expansion ◽  
Future Research ◽  
Human Populations ◽  
Neolithic Revolution ◽  
Cpg Sites ◽  
Hunting And Gathering ◽  
Genome Wide ◽  
Polymorphic Pattern ◽  
Improved Model

Abstract The prehistoric demography of human populations is an essential piece of information for illustrating our evolution. Despite its importance and the advancement of ancient DNA studies, our knowledge of human evolution is still limited, which is also the case for relatively recent population dynamics during and around the Holocene. Here, we inferred detailed demographic histories from 1 to 40 ka for 24 population samples using an improved model-flexible method with 36 million genome-wide noncoding CpG sites. Our results showed many population growth events that were likely due to the Neolithic Revolution (i.e., the shift from hunting and gathering to agriculture and settlement). Our results help to provide a clearer picture of human prehistoric demography, confirming the significant impact of agriculture on population expansion, and provide new hypotheses and directions for future research.

scholarly journals Natural selection influenced the genetic architecture of brain structure, behavioral and neuropsychiatric traits

2020 ◽  
Author(s):  
Frank R Wendt ◽  
Gita A Pathak ◽  
Cassie Overstreet ◽  
Daniel S Tylee ◽  
Joel Gelernter ◽  
...  
Keyword(s):  
Natural Selection ◽  
Complex Traits ◽  
Association Studies ◽  
Model Fit ◽  
Human Populations ◽  
Genome Wide Association Studies ◽  
Loss Of Function ◽  
Risk Alleles ◽  
Genome Wide ◽  
Improved Model

AbstractNatural selection has shaped the phenotypic characteristics of human populations. Genome-wide association studies (GWAS) have elucidated contributions of thousands of common variants with small effects on an individual’s predisposition to complex traits (polygenicity), as well as wide-spread sharing of risk alleles across traits in the human phenome (pleiotropy). It remains unclear how the pervasive effects of natural selection influence polygenicity in brain-related traits. We investigate these effects by annotating the genome with measures of background (BGS) and positive selection, indications of Neanderthal introgression, measures of functional significance including loss-of-function (LoF) intolerant and genic regions, and genotype networks in 75 brain-related traits. Evidence of natural selection was determined using binary annotations of top 2%, 1%, and 0.5% of selection scores genome-wide. We detected enrichment (q<0.05) of SNP-heritability at loci with elevated BGS (7 phenotypes) and in genic (34 phenotypes) and LoF-intolerant regions (67 phenotypes). BGS (top 2%) significantly predicted effect size variance for trait-associated loci (σ2 parameter) in 75 brain-related traits (β=4.39×10−5, p=1.43×10−5, model r2=0.548). By including the number of DSM-5 diagnostic combinations per psychiatric disorder, we substantially improved model fit (σ2 ~ BTop2% × Genic × diagnostic combinations; model r2=0.661). We show that GWAS with larger variance in risk locus effect sizes are collectively predicted by the effects of loci under strong BGS and in regulatory regions of the genome. We further show that diagnostic complexity exacerbates this relationship and perhaps dampens the ability to detect psychiatric risk loci.

scholarly journals Population-Specific Genetic and Expression Differentiation in Europeans

2020 ◽  
Vol 12 (4) ◽  
pp. 358-369
Author(s):  
Xueyuan Jiang ◽  
Raquel Assis
Keyword(s):  
Vitamin D ◽  
Copy Number ◽  
Copy Number Variations ◽  
Future Research ◽  
Human Populations ◽  
Rna Seq ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Genome Wide ◽  
The World

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.

scholarly journals Trends in DNA methylation with age replicate across diverse human populations

2016 ◽  
Author(s):  
Shyamalika Gopalan ◽  
Oana Carja ◽  
Maud Fagny ◽  
Etienne Patin ◽  
Justin W. Myrick ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Meta Analysis ◽  
Chronological Age ◽  
Human Populations ◽  
Strongly Correlated ◽  
Hunter Gatherers ◽  
Cpg Sites ◽  
Age Related ◽  
Genome Wide ◽  
Methylation Patterns

AbstractAging is associated with widespread changes in genome-wide patterns of DNA methylation. Thousands of CpG sites whose tissue-specific methylation levels are strongly correlated with chronological age have been previously identified. However, the majority of these studies have focused primarily on cosmopolitan populations living in the developed world; it is not known if age-related patterns of DNA methylation at these loci are similar across a broad range of human genetic and ecological diversity. We investigated genome-wide methylation patterns using saliva and whole blood derived DNA from two traditionally hunting and gathering African populations: the Baka of the western Central African rainforest and the ≠Khomani San of the South African Kalahari Desert. We identify hundreds of CpG sites whose methylation levels are significantly associated with age, thousands that are significant in a meta-analysis, and replicate trends previously reported in populations of non-African descent. We confirm that an age-associated site in the gene ELOVL2 shows a remarkably congruent relationship with aging in humans, despite extensive genetic and environmental variation across populations. We also demonstrate that genotype state at methylation quantitative trait loci (meQTLs) can affect methylation trends at some known age-associated CpG sites. Our study explores the relationship between CpG methylation and chronological age in populations of African hunter-gatherers, who rely on different diets across diverse ecologies. While many age-related CpG sites replicate across populations, we show that considering common genetic variation at meQTLs further improves our ability to detect previously identified age associations.

scholarly journals New insights into malaria susceptibility from the genomes of 17,000 individuals from Africa, Asia, and Oceania

2019 ◽  
Author(s):  
Keyword(s):  
Host Resistance ◽  
Genome Wide Association Study ◽  
Future Research ◽  
Human Populations ◽  
Chromosome 6 ◽  
Genetic Determinants ◽  
Transcription Start ◽  
Genome Wide ◽  
A Genome ◽  
Malaria Susceptibility

AbstractWe conducted a genome-wide association study of host resistance to severe Plasmodium falciparum malaria in over 17,000 individuals from 11 malaria-endemic countries, undertaking a wide ranging analysis which identifies five replicable associations with genome-wide levels of evidence. Our findings include a newly implicated variant on chromosome 6 associated with risk of cerebral malaria, and the discovery of an erythroid-specific transcription start site underlying the association in ATP2B4. Previously reported HLA associations cannot be replicated in this dataset. We estimate substantial heritability of severe malaria (h2 ~ 23%), of which around 10% is explained by the currently identified associations. Our dataset will provide a major building block for future research on the genetic determinants of disease in these diverse human populations.

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

2021 ◽  
Author(s):  
Timothy Jinam ◽  
Yosuke Kawai ◽  
Yoichiro Kamatani ◽  
Shunro Sonoda ◽  
Kanro Makisumi ◽  
...  
Keyword(s):  
Phylogenetic Network ◽  
Principal Component ◽  
Human Populations ◽  
Structure Model ◽  
Rice Farming ◽  
Asian Continent ◽  
Dual Structure ◽  
Snp Data ◽  
Genome Wide ◽  
Kagoshima Prefecture

AbstractThe “Dual Structure” model on the formation of the modern Japanese population assumes that the indigenous hunter-gathering 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.

scholarly journals Four Loci Are Associated with Cardiorespiratory Fitness and Endurance Performance in Young Chinese Females

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ying Zhao ◽  
Guoyuan Huang ◽  
Zuosong Chen ◽  
Xiang Fan ◽  
Tao Huang ◽  
...  
Keyword(s):  
Cardiorespiratory Fitness ◽  
Association Studies ◽  
Endurance Performance ◽  
Young Female ◽  
Future Research ◽  
Genome Wide Association Studies ◽  
Genetic Trait ◽  
Young Females ◽  
Genome Wide ◽  
Fixed Model

AbstractCardiorespiratory fitness (CRF) and endurance performance are characterized by a complex genetic trait with high heritability. Although research has identified many physiological and environmental correlates with CRF, the genetic architecture contributing to CRF remains unclear, especially in non-athlete population. A total of 762 Chinese young female participants were recruited and an endurance run test was used to determine CRF. We used a fixed model of genome-wide association studies (GWAS) for CRF. Genotyping was performed using the Affymetrix Axiom and illumina 1 M arrays. After quality control and imputation, a linear regression-based association analysis was conducted using a total of 5,149,327 variants. Four loci associated with CRF were identified to reach genome-wide significance (P < 5.0 × 10-8), which located in 15q21.3 (rs17240160, P = 1.73 × 10-9, GCOM1), 3q25.31 (rs819865, P = 8.56 × 10-9, GMPS), 21q22.3 (rs117828698, P = 9.59 × 10-9, COL18A1), and 17q24.2 (rs79806428, P = 3.85 × 10-8, PRKCA). These loci (GCOM1, GMPS, COL18A1 and PRKCA) associated with cardiorespiratory fitness and endurance performance in Chinese non-athlete young females. Our results suggest that these gene polymorphisms provide further genetic evidence for the polygenetic nature of cardiorespiratory endurance and be used as genetic biomarkers for future research.

scholarly journals Ecología de las poblaciones de plantas en una selva húmeda de México

2017 ◽  
pp. 121
Author(s):  
Miguel Martínez-Ramos ◽  
Elena Álvarez-Buylla
Keyword(s):  
Population Dynamics ◽  
Life History Evolution ◽  
Life Forms ◽  
Future Research ◽  
Tropical Rain Forests ◽  
Field Station ◽  
Plant Life Forms ◽  
Demographic Patterns ◽  
Plant Population Ecology ◽  
Conservation And Management

This paper reviewing plant population ecology studies that have done in Mexican tropical rain forests, particularly at the Los Tuxtlas Tropical Field Station (UNAM). The review considers next topics: (i) population structure and demographic patterns, (ii) population dynamics, (iii) life-history evolution, and (iv) the importance of demography and genetics for conservation and management of tropical rain forest plant products. The studies show an important advance in the description of patterns, in the analysis of population dynamics, and in the detection of some key demographic elements that can be important for forest conservation and management. However, the understanding of causes that originate such patterns and dynamics is yet poor. The studies have focused mainly on abundant arboreal plant species; other plant life-forms and rare species have received virtually null attention. After pointing out conclusions gained from our review, we propose some perspectives for future research.

scholarly journals DNA methylation mediates the association between breastfeeding and early-life growth trajectories

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Laurent Briollais ◽  
Denis Rustand ◽  
Catherine Allard ◽  
Yanyan Wu ◽  
Jingxiong Xu ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Signaling Pathway ◽  
Exclusive Breastfeeding ◽  
Child Growth ◽  
Postnatal Period ◽  
Overweight And Obesity ◽  
Breastfeeding Duration ◽  
Ampk Signaling ◽  
Cpg Sites ◽  
Genome Wide

Abstract Background The role of breastfeeding in modulating epigenetic factors has been suggested as a possible mechanism conferring its benefits on child development but it lacks evidence. Using extensive DNA methylation data from the ALSPAC child cohort, we characterized the genome-wide landscape of DNA methylation variations associated with the duration of exclusive breastfeeding and assessed whether these variations mediate the association between exclusive breastfeeding and BMI over different epochs of child growth. Results Exclusive breastfeeding elicits more substantial DNA methylation variations during infancy than at other periods of child growth. At the genome-wide level, 13 CpG sites in girls (miR-21, SNAPC3, ATP6V0A1, DHX15/PPARGC1A, LINC00398/ALOX5AP, FAM238C, NATP/NAT2, CUX1, TRAPPC9, OSBPL1A, ZNF185, FAM84A, PDPK1) and 2 CpG sites in boys (IL16 and NREP), mediate the association between exclusive breastfeeding and longitudinal BMI. We found enrichment of CpG sites located within miRNAs and key pathways (AMPK signaling pathway, insulin signaling pathway, endocytosis). Overall DNA methylation variation corresponding to 3 to 5 months of exclusive breastfeeding was associated with slower BMI growth the first 6 years of life compared to no breastfeeding and in a dose–response manner with exclusive breastfeeding duration. Conclusions Our study confirmed the early postnatal period as a critical developmental period associated with substantial DNA methylation variations, which in turn could mitigate the development of overweight and obesity from infancy to early childhood. Since an accelerated growth during these developmental periods has been linked to the development of sustained obesity later in life, exclusive breastfeeding could have a major role in preventing the risks of overweight/obesity and children and adults through DNA methylation mechanisms occurring early in life.

scholarly journals Death and population dynamics affect mutation rate estimates and evolvability under stress in bacteria

2017 ◽  
Author(s):  
Antoine Frénoy ◽  
Sebastian Bonhoeffer
Keyword(s):  
Population Dynamics ◽  
Mutation Rate ◽  
Death Rate ◽  
Mutation Rates ◽  
Resistance Mutations ◽  
Bacterial Populations ◽  
Plasmid Segregation ◽  
Genome Wide ◽  
Response To Stress ◽  
Induced Mutagenesis

AbstractThe stress-induced mutagenesis paradigm postulates that in response to stress, bacteria increase their genome-wide mutation rate, in turn increasing the chances that a descendant is able to withstand the stress. This has implications for antibiotic treatment: exposure to sub-inhibitory doses of antibiotics has been reported to increase bacterial mutation rates, and thus probably the rate at which resistance mutations appear and lead to treatment failure.Measuring mutation rates under stress, however, is problematic, because existing methods assume there is no death. Yet sub-inhibitory stress levels may induce a substantial death rate. Death events need to be compensated by extra replication to reach a given population size, thus giving more opportunities to acquire mutations. We show that ignoring death leads to a systematic overestimation of mutation rates under stress.We developed a system using plasmid segregation to measure death and growth rates simultaneously in bacterial populations. We use it to replicate classical experiments reporting antibiotic-induced mutagenesis. We found that a substantial death rate occurs at the tested sub-inhibitory concentrations, and taking this death into account lowers and sometimes removes the signal for stress-induced mutagenesis. Moreover even when antibiotics increase mutation rate, sub-inhibitory treatments do not increase genetic diversity and evolvability, again because of effects of the antibiotics on population dynamics.Beside showing that population dynamic is a crucial but neglected parameter affecting evolvability, we provide better experimental and computational tools to study evolvability under stress, leading to a re-assessment of the magnitude and significance of the stress-induced mutagenesis paradigm.

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