scholarly journals Overcoming the dichotomy: new insights into the genomic diversity of open and isolated European populations

2016 ◽  
Author(s):  
Paolo Anagnostou ◽  
Valentina Dominici ◽  
Cinzia Battaggia ◽  
Luca Pagani ◽  
Miguel Vilar ◽  
...  
Keyword(s):  
Gene Flow ◽  
Principal Component ◽  
Population Diversity ◽  
Population Variation ◽  
Genomic Diversity ◽  
Effective Size ◽  
Human Populations ◽  
Autosomal Snps ◽  
Size Growth ◽  
Open Populations

ABSTRACTHuman populations are often dichotomized into “isolated” and “open” using cultural and/or geographical barriers to gene flow as differential criteria. Although widespread, the use of these alternative categories could obscure further heterogeneity due to inter-population differences in effective size, growth rate, and timing or amount of gene flow. We compared intra and interpopulation variation measures combining novel and literature data relative to 87,818 autosomal SNPs in 14 open populations and 10 geographic and/or linguistic European isolates. Patterns of intra-population diversity were found to vary significantly more among isolates, probably due to differential levels of drift and inbreeding. The relatively large effective size estimated for some population isolates challenges the generalized view that they originate from small founding groups. Principal component scores based on measures of intra-population variation of isolated and open populations turned out to be distributed along a sort of continuum, with an area of intersection between the two groups. Patterns of inter-population diversity were even closer, as we were able to detect some differences between population groups only for a few multidimensional scaling dimensions. Therefore, different lines of evidence suggest that dichotomizing human populations into open and isolated fails to capture the actual relations among their genomic features.

scholarly journals Genomic characterisation and conservation genetics of the indigenous Irish Kerry cattle breed

2017 ◽  
Author(s):  
Sam Browett ◽  
Gillian McHugo ◽  
Ian W. Richardson ◽  
David A. Magee ◽  
Stephen D. E. Park ◽  
...  
Keyword(s):  
Gene Flow ◽  
Phylogenetic Trees ◽  
Principal Component ◽  
Physical Geography ◽  
Genomic Diversity ◽  
Ancestral Population ◽  
Effective Population ◽  
Cattle Breeds ◽  
Genome Wide ◽  
European Cattle

AbstractKerry cattle are an endangered landrace heritage breed of cultural importance to Ireland. In the present study we have used genome-wide SNP data (Illumina® BovineSNP50 array) to evaluate genomic diversity within the Kerry cattle population and between Kerry cattle and other European cattle breeds. Visualisation of patterns of genetic differentiation and gene flow among cattle breeds using phylogenetic trees with ancestry graphs highlighted, in particular, historical gene flow from the British Shorthorn breed into the ancestral population of modern Kerry cattle. Principal component analysis (PCA) and genetic clustering emphasised the genetic distinctiveness of Kerry cattle relative to comparator British and European cattle breeds. Modelling of genetic effective population size (Ne) revealed a demographic trend of diminishing Ne over time and that recent estimated Ne values for the Kerry breed may be less than the threshold for sustainable genetic conservation. In addition, analysis of genome-wide autozygosity (FROH) showed that genomic inbreeding has increased significantly during the 20 years between 1992 and 2012. Finally, signatures of selection revealed genomic regions subject to natural and artificial selection as Kerry cattle adapted to the climate, physical geography and agro-ecology of southwest Ireland.Note 1: This is an Associate Editor (D.E.M) Inaugural Article submission to Frontiers in Genetics: Livestock GenomicsNote 2: British English language style preferred for publication of this article.

scholarly journals Detecting Sex-Biased Gene Flow in African-americans Through the Analysis of Intra- and Inter-Population Variation at Mitochondrial DNA and Y- Chromosome Microsatellites

2012 ◽  
Vol 15 (2) ◽  
pp. 7-34 ◽  
Author(s):  
C. Battaggia ◽  
P. Anagnostou ◽  
I. Bosch ◽  
F. Brisighelli ◽  
G. Destro-Bisol ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Gene Flow ◽  
African Americans ◽  
Y Chromosome ◽  
Quantitative Methods ◽  
Population Sample ◽  
Hypervariable Region ◽  
Population Diversity ◽  
Population Variation ◽  
Genetic Admixture

ABSTRACT This study reports on variations at the mitochondrial DNA (mtDNA) hypervariable region 1 (HVR-1) and at seven Y-chromosome microsatellites in an African-American population sample from Chicago, IL, USA. Our results support the hypothesis that the population studied had undergone a European malebiased gene flow. We show that comparisons of intraand inter-population diversity parameters between African-Americans, Europeans and Africans may help detect sex-biased gene flow, providing a complement to quantitative methods to estimate genetic admixture.

scholarly journals Genomic Characterization of the Three Balkan Livestock Guardian Dogs

2021 ◽  
Vol 13 (4) ◽  
pp. 2289
Author(s):  
Mateja Janeš ◽  
Minja Zorc ◽  
Maja Ferenčaković ◽  
Ino Curik ◽  
Peter Dovč ◽  
...  
Keyword(s):  
Conservation Management ◽  
Diversity Management ◽  
Genomic Diversity ◽  
Mountainous Areas ◽  
Autosomal Snps ◽  
The Balkans ◽  
Gray Wolves ◽  
Low Diversity ◽  
Genomic Characterization

Balkan Livestock Guardian Dogs (LGD) were bred to help protect sheep flocks in sparsely populated, remote mountainous areas in the Balkans. The aim of this study was genomic characterization (107,403 autosomal SNPs) of the three LGD breeds from the Balkans (Karst Shepherd, Sharplanina Dog, and Tornjak). Our analyses were performed on 44 dogs representing three Balkan LGD breeds, as well as on 79 publicly available genotypes representing eight other LGD breeds, 70 individuals representing seven popular breeds, and 18 gray wolves. The results of multivariate, phylogenetic, clustering (STRUCTURE), and FST differentiation analyses showed that the three Balkan LGD breeds are genetically distinct populations. While the Sharplanina Dog and Tornjak are closely related to other LGD breeds, the Karst Shepherd is a slightly genetically distinct population with estimated influence from German Shepard (Treemix analysis). Estimated genomic diversity was high with low inbreeding in Sharplanina Dog (Ho = 0.315, He = 0.315, and FROH>2Mb = 0.020) and Tornjak (Ho = 0.301, He = 0.301, and FROH>2Mb = 0.033) breeds. Low diversity and high inbreeding were estimated in Karst Shepherds (Ho = 0.241, He = 0.222, and FROH>2Mb = 0.087), indicating the need for proper diversity management. The obtained results will help in the conservation management of Balkan LGD dogs as an essential part of the specific grazing biocultural system and its sustainable maintenance.

scholarly journals Emergence of novel SARS-CoV-2 variants in the Netherlands

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aysun Urhan ◽  
Thomas Abeel
Keyword(s):  
The Netherlands ◽  
Population Diversity ◽  
Genomic Variation ◽  
Population Variation ◽  
Reference Sequence ◽  
Viral Population ◽  
Phylogenetic Study ◽  
First Case ◽  
Novel Variants ◽  
Frequent Mutations

AbstractCoronavirus disease 2019 (COVID-19) has emerged in December 2019 when the first case was reported in Wuhan, China and turned into a pandemic with 27 million (September 9th) cases. Currently, there are over 95,000 complete genome sequences of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus causing COVID-19, in public databases, accompanying a growing number of studies. Nevertheless, there is still much to learn about the viral population variation when the virus is evolving as it continues to spread. We have analyzed SARS-CoV-2 genomes to identify the most variant sites, as well as the stable, conserved ones in samples collected in the Netherlands until June 2020. We identified the most frequent mutations in different geographies. We also performed a phylogenetic study focused on the Netherlands to detect novel variants emerging in the late stages of the pandemic and forming local clusters. We investigated the S and N proteins on SARS-CoV-2 genomes in the Netherlands and found the most variant and stable sites to guide development of diagnostics assays and vaccines. We observed that while the SARS-CoV-2 genome has accumulated mutations, diverging from reference sequence, the variation landscape is dominated by four mutations globally, suggesting the current reference does not represent the virus samples circulating currently. In addition, we detected novel variants of SARS-CoV-2 almost unique to the Netherlands that form localized clusters and region-specific sub-populations indicating community spread. We explored SARS-CoV-2 variants in the Netherlands until June 2020 within a global context; our results provide insight into the viral population diversity for localized efforts in tracking the transmission of COVID-19, as well as sequenced-based approaches in diagnostics and therapeutics. We emphasize that little diversity is observed globally in recent samples despite the increased number of mutations relative to the established reference sequence. We suggest sequence-based analyses should opt for a consensus representation to adequately cover the genomic variation observed to speed up diagnostics and vaccine design.

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 Population genomics and antimicrobial resistance dynamics of Escherichia coli in wastewater and river environments

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jose F. Delgado-Blas ◽  
Cristina M. Ovejero ◽  
Sophia David ◽  
Natalia Montero ◽  
William Calero-Caceres ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Population Genomics ◽  
Population Diversity ◽  
Genomic Diversity ◽  
Resistant Bacteria ◽  
Aquatic Environments ◽  
E Coli ◽  
Water Ecosystems ◽  
Sequence Types

AbstractAquatic environments are key niches for the emergence, evolution and dissemination of antimicrobial resistance. However, the population diversity and the genetic elements that drive the dynamics of resistant bacteria in different aquatic environments are still largely unknown. The aim of this study was to understand the population genomics and evolutionary events of Escherichia coli resistant to clinically important antibiotics including aminoglycosides, in anthropogenic and natural water ecosystems. Here we show that less different E. coli sequence types (STs) are identified in wastewater than in rivers, albeit more resistant to antibiotics, and with significantly more plasmids/cell (6.36 vs 3.72). However, the genomic diversity within E. coli STs in both aquatic environments is similar. Wastewater environments favor the selection of conserved chromosomal structures associated with diverse flexible plasmids, unraveling promiscuous interplasmidic resistance genes flux. On the contrary, the key driver for river E. coli adaptation is a mutable chromosome along with few plasmid types shared between diverse STs harboring a limited resistance gene content.

Genomic diversity of chickpea-nodulating rhizobia in Ningxia (north central China) and gene flow within symbiotic Mesorhizobium muleiense populations

2020 ◽  
Vol 43 (4) ◽  
pp. 126089 ◽  
Author(s):  
Junjie Zhang ◽  
Shanshan Peng ◽  
Yimin Shang ◽  
Brigitte Brunel ◽  
Shuo Li ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genomic Diversity ◽  
Central China ◽  
North Central

scholarly journals Effect of Environmental Factors and Influence of Rumen and Hindgut Biogeography on Bacterial Communities in Steers

2010 ◽  
Vol 77 (1) ◽  
pp. 258-268 ◽  
Author(s):  
Gustavo A. Romero-Pérez ◽  
Kim H. Ominski ◽  
Tim A. McAllister ◽  
Denis O. Krause
Keyword(s):  
Ambient Temperature ◽  
Bacterial Communities ◽  
Volatile Fatty Acids ◽  
Principal Component ◽  
Population Diversity ◽  
Access Time ◽  
Sample Type ◽  
Bacterial Populations ◽  
Fecal Samples ◽  
Alfalfa Silage

ABSTRACTFeces from cattle production are considered important sources of bacterial contamination of food and the environment. Little is known about the combined effects of arctic temperatures and fodder tannins on rumen and hindgut bacterial populations. Individual rumen liquor and rectal fecal samples from donor steers fed either alfalfa silage or sainfoin (Onobrychis viciifoliaScop.) silage and waterad libitumwere collected weekly on the first three sampling days and fortnightly afterwards. The daily ambient temperatures were registered and averaged to weekly mean temperatures. Steers fed sainfoin silage had lower (P< 0.05) concentrations of branched-chain volatile fatty acids (VFA) than those fed alfalfa silage. All VFA concentrations were higher (P< 0.001) in rumen liquor samples than in fecal samples. The interaction of sample type and diet showed a significant effect (P< 0.05) on the proportions of the bacterial community that were from the phylaProteobacteriaandVerrucomicrobia.Ambient temperature had an indirect effect (P< 0.05) on the phylumFirmicutes, as it affected its proportional balance. The bacterial population diversity in samples appeared to decrease concurrently with the ambient temperature. The phylumFirmicutesexplained the first principal component at 64.83 and 42.58% of the total variance in rumen liquor and fecal samples, respectively. The sample type had a larger effect on bacterial communities than diet and temperature. Certain bacterial populations seemed to be better adapted than others to environmentally adverse conditions, such as less access time to nutrients due to higher motility and rate of passage of digesta caused by extreme temperatures, or antimicrobials such as tannins, possibly due to an influence of their biogeographical location within the gut.

Population-specific genome graphs improve high-throughput sequencing data analysis: A case study on the Pan-African genome

2021 ◽  
Author(s):  
H. Serhat Tetikol ◽  
Kubra Narci ◽  
Deniz Turgut ◽  
Gungor Budak ◽  
Ozem Kalay ◽  
...  
Keyword(s):  
High Throughput Sequencing ◽  
Information Overload ◽  
African Ancestry ◽  
Sample Selection ◽  
Variant Calling ◽  
Population Diversity ◽  
Human Populations ◽  
Sequencing Data ◽  
Bioinformatics Pipeline ◽  
Graph Augmentation

ABSTRACTGraph-based genome reference representations have seen significant development, motivated by the inadequacy of the current human genome reference for capturing the diverse genetic information from different human populations and its inability to maintain the same level of accuracy for non-European ancestries. While there have been many efforts to develop computationally efficient graph-based bioinformatics toolkits, how to curate genomic variants and subsequently construct genome graphs remains an understudied problem that inevitably determines the effectiveness of the end-to-end bioinformatics pipeline. In this study, we discuss major obstacles encountered during graph construction and propose methods for sample selection based on population diversity, graph augmentation with structural variants and resolution of graph reference ambiguity caused by information overload. Moreover, we present the case for iteratively augmenting tailored genome graphs for targeted populations and test the proposed approach on the whole-genome samples of African ancestry. Our results show that, as more representative alternatives to linear or generic graph references, population-specific graphs can achieve significantly lower read mapping errors, increased variant calling sensitivity and provide the improvements of joint variant calling without the need of computationally intensive post-processing steps.

scholarly journals Population Diversity and Collective Interactions during Influenza Virus Infection

2017 ◽  
Vol 91 (22) ◽  
Author(s):  
Christopher B. Brooke
Keyword(s):  
Genome Organization ◽  
Influenza A ◽  
Evolutionary Dynamics ◽  
Influenza Virus Infection ◽  
Population Diversity ◽  
Genomic Diversity ◽  
Global Public Health ◽  
Public Health Threat ◽  
Genetic Makeup ◽  
Collective Interactions

ABSTRACT Influenza A virus (IAV) continues to pose an enormous and unpredictable global public health threat, largely due to the continual evolution of escape from preexisting immunity and the potential for zoonotic emergence. Understanding how the unique genetic makeup and structure of IAV populations influences their transmission and evolution is essential for developing more-effective vaccines, therapeutics, and surveillance capabilities. Owing to their mutation-prone replicase and unique genome organization, IAV populations exhibit enormous amounts of diversity both in terms of sequence and functional gene content. Here, I review what is currently known about the genetic and genomic diversity present within IAV populations and how this diversity may shape the replicative and evolutionary dynamics of these viruses.

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