scholarly journals An unexpected donor in the adaptive introgression candidate Helianthus annuus subsp. texanus

2020 ◽  
Author(s):  
Gregory. L Owens ◽  
Marco Todesco ◽  
Natalia Bercovich ◽  
Jean-Sébastien Légaré ◽  
Nora Mitchell ◽  
...  
Keyword(s):  
Helianthus Annuus ◽  
Entire Range ◽  
Common Garden ◽  
Whole Genome Sequencing Data ◽  
Sequencing Data ◽  
Phenotypic Data ◽  
Adaptive Introgression ◽  
Genome Wide ◽  
Potential Test ◽  
Donor Species

AbstractHybridization is widely acknowledged as an important mechanism of acquiring adaptive variation. In Texas, the sunflower Helianthus annuus subsp. texanus is thought to have acquired herbivore resistance and morphological traits via introgression from a local congener, H. debilis. Here we test this hypothesis using whole genome sequencing data from across the entire range of H. annuus and possible donor species, as well as phenotypic data from a common garden study. We find that although it is morphologically convergent with H. debilis, H. a. texanus has conflicting signals of introgression. Genome wide tests (Patterson’s D and TreeMix) only find evidence of introgression from H. argophyllus (sister species to H. annuus and also sympatric), but not H. debilis, with the exception of one individual of 109 analysed. We further scanned the genome for localized signals of introgression using PCAdmix and found minimal but non-zero introgression from H. debilis and significant introgression from H. argophyllus. Putative introgressions mainly occur in high recombination regions as predicted by theory if introgressed ancestry contains maladaptive alleles. To reconcile the disparate findings of our analyses, we discuss potential test-specific confounding features, including introgression from other taxa. Given the paucity of introgression from H. debilis, we argue that the morphological convergence observed in Texas is likely independent of introgression.

scholarly journals Adaptive introgression as a driver of local adaptation to climate in European white oaks

2019 ◽  
Author(s):  
Thibault Leroy ◽  
Jean-Marc Louvet ◽  
Céline Lalanne ◽  
Grégoire Le Provost ◽  
Karine Labadie ◽  
...  
Keyword(s):  
Common Garden ◽  
Adaptive Divergence ◽  
Climatic Data ◽  
Sequencing Data ◽  
White Oak ◽  
Elevational Gradients ◽  
Adaptive Introgression ◽  
Genome Wide ◽  
A Genome ◽  
Common Garden Experiments

AbstractLatitudinal and elevational gradients provide valuable experimental settings for studies of the potential impact of global warming on forest tree species. The availability of long-term phenological surveys in common garden experiments for traits associated with climate, such as bud flushing, for sessile oaks (Quercus petraea), provides an ideal opportunity to investigate this impact.We sequenced 18 sessile oak populations, and used available sequencing data for three other closely related European white oak species (Q. pyrenaica, Q. pubescens, Q. robur), to explore the evolutionary processes responsible for shaping the genetic variation across latitudinal and elevational gradients in extant sessile oaks. We used phenotypic surveys in common garden experiments and climatic data for the population of origin, to perform genome-wide scans for population differentiation, genotype-environment (GEA) and genotype-phenotype associations (GPA).The inferred historical relationships betweenQ. petraeapopulations suggest that interspecific gene flow occurred betweenQ. roburandQ. petraeapopulations from cooler or wetter areas. A genome-wide scan of differentiation betweenQ. petraeapopulations identified SNPs displaying strong interspecific relative divergence between these two species. These SNPs followed genetic clines along climatic or phenotypic gradients, providing further support for the likely contribution of introgression to the adaptive divergence ofQ. petraeapopulations.Overall, the results of this study indicate that adaptive introgression ofQ. roburalleles has occurred. We discuss the results of this study in the framework of the post-glacial colonization scenario, in which introgression and diversifying selection have been proposed as essential drivers ofQ. petraeamicroevolution.

scholarly journals EagleImp: Fast and Accurate Genome-wide Phasing and Imputation in a Single Tool

2022 ◽  
Author(s):  
Lars Wienbrandt ◽  
David Ellinghaus
Keyword(s):  
Memory Management ◽  
Imputation Accuracy ◽  
Simulated Data ◽  
Genotype Imputation ◽  
Whole Genome Sequencing Data ◽  
Common Variants ◽  
Sequencing Data ◽  
1000 Genomes ◽  
Genome Wide ◽  
Reference Genomes

Background: Reference-based phasing and genotype imputation algorithms have been developed with sublinear theoretical runtime behaviour, but runtimes are still high in practice when large genome-wide reference datasets are used. Methods: We developed EagleImp, a software with algorithmic and technical improvements and new features for accurate and accelerated phasing and imputation in a single tool. Results: We compared accuracy and runtime of EagleImp with Eagle2, PBWT and prominent imputation servers using whole-genome sequencing data from the 1000 Genomes Project, the Haplotype Reference Consortium and simulated data with more than 1 million reference genomes. EagleImp is 2 to 10 times faster (depending on the single or multiprocessor configuration selected) than Eagle2/PBWT, with the same or better phasing and imputation quality in all tested scenarios. For common variants investigated in typical GWAS studies, EagleImp provides same or higher imputation accuracy than the Sanger Imputation Service, Michigan Imputation Server and the newly developed TOPMed Imputation Server, despite larger (not publicly available) reference panels. It has many new features, including automated chromosome splitting and memory management at runtime to avoid job aborts, fast reading and writing of large files, and various user-configurable algorithm and output options. Conclusions: Due to the technical optimisations, EagleImp can perform fast and accurate reference-based phasing and imputation for future very large reference panels with more than 1 million genomes. EagleImp is freely available for download from https://github.com/ikmb/eagleimp.

scholarly journals Novel protein-altering variants associated with serum apolipoprotein and lipid levels

2021 ◽  
Author(s):  
Niina Sandholm ◽  
Ronja Hotakainen ◽  
Jani K Haukka ◽  
Fanny Jansson Sigfrids ◽  
Emma H Dahlström ◽  
...  
Keyword(s):  
Apolipoprotein B ◽  
Serum Lipid ◽  
Clinical Laboratory ◽  
Genetic Disorders ◽  
Lipoprotein Metabolism ◽  
Apolipoprotein A1 ◽  
Whole Genome Sequencing Data ◽  
Sequencing Data ◽  
Phenotypic Data ◽  
Common Genetic Variants

AbstractDyslipidemia is a major risk factor for cardiovascular disease. While common genetic variants are known to modestly affect the serum lipid concentrations, rare genetic mutations can cause monogenic forms of hypercholesteremia and other genetic disorders of lipid metabolism. Aiming to identify low-frequency protein-altering variants (PAVs) affecting lipoprotein and lipid traits, we analyzed whole-exome and whole-genome sequencing data of 481 and 573 individuals with type 1 diabetes, respectively. The phenotypic data consisted of 97 serum lipid, apolipoprotein, or other metabolic phenotypes obtained with clinical laboratory measurements and nuclear magnetic resonance (NMR) technology. Single variant analysis identified a novel association between LIPC p.Thr405Met (rs113298164) and serum apolipoprotein-A1 levels (p=7.8×10−8). In the APOB gene, we identified novel associations at two protein-truncating variants (PTVs) resulting in lower serum apolipoprotein B levels (p=5.6×10−4). The burden of PAVs was significantly associated with lipid phenotypes in LIPC, RBM47, TRMT5, and GTF3C5 (p<2.9×10−6). The RBM47 gene is required for apolipoprotein-B post-translational modifications, and in our data, the association between RBM47 and apolipoprotein C-III levels was led by a rare 21 base pair Ala496-Ala502 deletion; as replication, the burden of rare deleterious variants in RBM47 was associated with TG-to-HDLC ratio in WES of 20,917 individuals (p=0.0093). Two PAVs in GTF3C5 were highly Finnish-enriched and associated with cardiovascular phenotypes in external data, whereby the TRMT5 p.Ser185Cys lead variant was associated with stroke phenotypes. Altogether, we identified both novel variant associations in known lipid genes, as well as novel genes implicated in lipoprotein metabolism.

scholarly journals Population-level genome-wide STR typing in Plasmodium species reveals higher resolution population structure and genetic diversity relative to SNP typing

2021 ◽  
Author(s):  
Jiru Han ◽  
Jacob E Munro ◽  
Anthony Kocoski ◽  
Alyssa E Barry ◽  
Melanie Bahlo
Keyword(s):  
Genetic Diversity ◽  
Large Scale ◽  
Tandem Repeats ◽  
Plasmodium Species ◽  
Whole Genome Sequence ◽  
Whole Genome Sequencing Data ◽  
Whole Genome ◽  
Sequencing Data ◽  
Genome Wide ◽  
Field Samples

Short tandem repeats (STRs) are highly informative genetic markers that have been used extensively in population genetics analysis. They are an important source of genetic diversity and can also have functional impact. Despite the availability of bioinformatic methods that permit large-scale genome-wide genotyping of STRs from whole genome sequencing data, they have not previously been applied to sequencing data from large collections of malaria parasite field samples. Here, we have genotyped STRs using HipSTR in more than 3,000 Plasmodium falciparum and 174 Plasmodium vivax published whole-genome sequence data from samples collected across the globe. High levels of noise and variability in the resultant callset necessitated the development of a novel method for quality control of STR genotype calls. A set of high-quality STR loci (6,768 from P. falciparum and 3,496 from P. vivax) were used to study Plasmodium genetic diversity, population structures and genomic signatures of selection and these were compared to genome-wide single nucleotide polymorphism (SNP) genotyping data. In addition, the genome-wide information about genetic variation and other characteristics of STRs in P. falciparum and P. vivax have been made available in an interactive web-based R Shiny application PlasmoSTR (https://github.com/bahlolab/PlasmoSTR).

scholarly journals Transposable element profiles reveal cell line identity and loss of heterozygosity in Drosophila cell culture

Genetics ◽  
2021 ◽  
Author(s):  
Shunhua Han ◽  
Preston J Basting ◽  
Guilherme B Dias ◽  
Arthur Luhur ◽  
Andrew C Zelhof ◽  
...  
Keyword(s):  
Cell Culture ◽  
Cell Line ◽  
Loss Of Heterozygosity ◽  
Cell Lines ◽  
Whole Genome Sequencing Data ◽  
Sequencing Data ◽  
Drosophila Cell ◽  
Genome Wide ◽  
Cell Culture Systems ◽  
Cell Line Identity

Abstract Cell culture systems allow key insights into biological mechanisms yet suffer from irreproducible outcomes in part because of cross-contamination or mislabelling of cell lines. Cell line misidentification can be mitigated by the use of genotyping protocols, which have been developed for human cell lines but are lacking for many important model species. Here we leverage the classical observation that transposable elements (TEs) proliferate in cultured Drosophila cells to demonstrate that genome-wide TE insertion profiles can reveal the identity and provenance of Drosophila cell lines. We identify multiple cases where TE profiles clarify the origin of Drosophila cell lines (Sg4, mbn2, and OSS_E) relative to published reports, and also provide evidence that insertions from only a subset of LTR retrotransposon families are necessary to mark Drosophila cell line identity. We also develop a new bioinformatics approach to detect TE insertions and estimate intra-sample allele frequencies in legacy whole-genome sequencing data (called ngs_te_mapper2), which revealed loss of heterozygosity as a mechanism shaping the unique TE profiles that identify Drosophila cell lines. Our work contributes to the general understanding of the forces impacting metazoan genomes as they evolve in cell culture and paves the way for high-throughput protocols that use TE insertions to authenticate cell lines in Drosophila and other organisms.

scholarly journals A high-quality reference panel reveals the complexity and distribution of structural genome changes in a human population

2016 ◽  
Author(s):  
Jayne Y. Hehir-Kwa ◽  
Tobias Marschall ◽  
Wigard P. Kloosterman ◽  
Laurent C. Francioli ◽  
Jasmijn A. Baaijens ◽  
...  
Keyword(s):  
Association Studies ◽  
Whole Genome Sequencing Data ◽  
Strong Linkage Disequilibrium ◽  
Genome Wide Association Studies ◽  
Sequencing Data ◽  
Full Spectrum ◽  
Disease Phenotypes ◽  
Human Genomes ◽  
Genome Wide ◽  
Genome Variants

AbstractStructural variation (SV) represents a major source of differences between individual human genomes and has been linked to disease phenotypes. However, the majority of studies provide neither a global view of the full spectrum of these variants nor integrate them into reference panels of genetic variation.Here, we analyse whole genome sequencing data of 769 individuals from 250 Dutch families, and provide a haplotype-resolved map of 1.9 million genome variants across 9 different variant classes, including novel forms of complex indels, and retrotransposition-mediated insertions of mobile elements and processed RNAs. A large proportion are previously under reported variants sized between 21 and 100bp. We detect 4 megabases of novel sequence, encoding 11 new transcripts. Finally, we show 191 known, trait-associated SNPs to be in strong linkage disequilibrium with SVs and demonstrate that our panel facilitates accurate imputation of SVs in unrelated individuals. Our findings are essential for genome-wide association studies.

scholarly journals The use of genomic data and imputation methods in dairy cattle breeding

2020 ◽  
Vol 65 (No. 12) ◽  
pp. 445-453
Author(s):  
Anita Klímová ◽  
Eva Kašná ◽  
Karolína Machová ◽  
Michaela Brzáková ◽  
Josef Přibyl ◽  
...  
Keyword(s):  
Association Studies ◽  
Genome Wide Association Studies ◽  
Nucleotide Polymorphisms ◽  
Sequencing Data ◽  
Phenotypic Data ◽  
Single Nucleotide ◽  
Imputation Methods ◽  
Genome Wide ◽  
Dairy Cattle Breeding ◽  
Combine Information

The inclusion of animal genotype data has contributed to the development of genomic selection. Animals are selected not only based on pedigree and phenotypic data but also on the basis of information about their genotypes. Genomic information helps to increase the accuracy of selection of young animals and thus enables a reduction of the generation interval. Obtaining information about genotypes in the form of SNPs (single nucleotide polymorphisms) has led to the development of new chips for genotyping. Several methods of genomic comparison have been developed as a result. One of the methods is data imputation, which allows the missing SNPs to be calculated using low-density chips to high-density chips. Through imputations, it is possible to combine information from diverse sets of chips and thus obtain more information about genotypes at a lower cost. Increasing the amount of data helps increase the reliability of predicting genomic breeding values. Imputation methods are increasingly used in genome-wide association studies. When classical genotyping and genome-wide sequencing data are combined, this option helps to increase the chances of identifying loci that are associated with economically significant traits.

scholarly journals Genome-wide profiling of heritable and de novo STR variations

2016 ◽  
Author(s):  
Thomas Willems ◽  
Dina Zielinski ◽  
Assaf Gordon ◽  
Melissa Gymrek ◽  
Yaniv Erlich
Keyword(s):  
Tandem Repeats ◽  
High Throughput Sequencing ◽  
De Novo ◽  
Genetic Diseases ◽  
Whole Genome Sequencing Data ◽  
Sequencing Data ◽  
High Throughput Sequencing Data ◽  
Genome Wide ◽  
A Genome ◽  
Short Tandem

AbstractShort tandem repeats (STRs) are highly variable elements that play a pivotal role in multiple genetic diseases, population genetics applications, and forensic casework. However, STRs have proven problematic to genotype from high-throughput sequencing data. Here, we describe HipSTR, a novel haplotype-based method for robustly genotyping, haplotyping, and phasing STRs from whole genome sequencing data and report a genome-wide analysis and validation of de novo STR mutations.

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