scholarly journals From conservation genetics to conservation genomics: a genome-wide assessment of blue whales ( Balaenoptera musculus ) in Australian feeding aggregations

2018 ◽  
Vol 5 (1) ◽  
pp. 170925 ◽  
Author(s):  
Catherine R. M. Attard ◽  
Luciano B. Beheregaray ◽  
Jonathan Sandoval-Castillo ◽  
K. Curt S. Jenner ◽  
Peter C. Gill ◽  
...  
Keyword(s):  
Population Structure ◽  
Adaptive Divergence ◽  
Balaenoptera Musculus ◽  
Blue Whale ◽  
Conservation Genomics ◽  
Next Generation Sequencing Technology ◽  
Genome Wide ◽  
A Genome ◽  
Wide Range ◽  
Blue Whales

Genetic datasets of tens of markers have been superseded through next-generation sequencing technology with genome-wide datasets of thousands of markers. Genomic datasets improve our power to detect low population structure and identify adaptive divergence. The increased population-level knowledge can inform the conservation management of endangered species, such as the blue whale ( Balaenoptera musculus ). In Australia, there are two known feeding aggregations of the pygmy blue whale ( B. m. brevicauda ) which have shown no evidence of genetic structure based on a small dataset of 10 microsatellites and mtDNA. Here, we develop and implement a high-resolution dataset of 8294 genome-wide filtered single nucleotide polymorphisms, the first of its kind for blue whales. We use these data to assess whether the Australian feeding aggregations constitute one population and to test for the first time whether there is adaptive divergence between the feeding aggregations. We found no evidence of neutral population structure and negligible evidence of adaptive divergence. We propose that individuals likely travel widely between feeding areas and to breeding areas, which would require them to be adapted to a wide range of environmental conditions. This has important implications for their conservation as this blue whale population is likely vulnerable to a range of anthropogenic threats both off Australia and elsewhere.

scholarly journals Blue whale (Balaenoptera musculus musculus) genome: population structure and history in the North Atlantic

2021 ◽  
Author(s):  
Sushma Jossey ◽  
Oliver Haddrath ◽  
Livia Loureiro ◽  
Burton Lim ◽  
Jacqueline Miller ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
North Atlantic ◽  
Conservation Strategies ◽  
Balaenoptera Musculus ◽  
Blue Whale ◽  
Genetic Diversity And Structure ◽  
Population Structuring ◽  
The Impact ◽  
Blue Whales

Knowledge of genetic diversity and structure is essential for developing conservation strategies for endangered species. The advances in museum genomics can assist in better understanding the effects of over-hunting on the genome by comparing historical to present-day samples. Blue whales were hunted to the point of near extinction in the mid-twentieth century. Herein, we use whole genome sequencing to elucidate the poorly understood population structure of North Atlantic (NA) blue whales (Balaenoptera musculus musculus). We generated a de novo genome assembly of 2.49 Mbp for a NA blue whale (N50 of 1.46 Mb) to analyze 19 whole genomic sequences and 28 complete mitochondrial genomes. We included present-day and historical samples (earliest from 1900) from the Atlantic and Antarctica to understand the impact of whaling on the genetic diversity. We found low population structuring, but high genetic diversity, suggesting a single, panmictic population in the NA. We identified gene flow from fin whale to blue whales, accounting for ~3.5% of the genome. Introgression between blue and fin whales was observed in all the present-day samples but were lacking in some whales sampled early in the 20th century, which suggests increasing disruption in mate choice concomitant with decline in blue whale population. We also assembled and analyzed the transcriptome and revealed positive selection of oncogenes, which may be involved in reduced cancer rates in this largest of mammals ever known. Our sequencing and population structuring studies provide a genomic framework to guide ongoing conservation strategies for this iconic species.

The Genetics and Genomics of Asthma

2018 ◽  
Vol 19 (1) ◽  
pp. 223-246 ◽  
Author(s):  
Saffron A.G. Willis-Owen ◽  
William O.C. Cookson ◽  
Miriam F. Moffatt
Keyword(s):  
Sequence Variation ◽  
Human Microbiome ◽  
Technological Advances ◽  
Genome Wide ◽  
A Genome ◽  
Wide Range ◽  
Health And Disease ◽  
Wide Scale ◽  
Genetics And Genomics ◽  
The Individual

Asthma is a common, clinically heterogeneous disease with strong evidence of heritability. Progress in defining the genetic underpinnings of asthma, however, has been slow and hampered by issues of inconsistency. Recent advances in the tools available for analysis—assaying transcription, sequence variation, and epigenetic marks on a genome-wide scale—have substantially altered this landscape. Applications of such approaches are consistent with heterogeneity at the level of causation and specify patterns of commonality with a wide range of alternative disease traits. Looking beyond the individual as the unit of study, advances in technology have also fostered comprehensive analysis of the human microbiome and its varied roles in health and disease. In this article, we consider the implications of these technological advances for our current understanding of the genetics and genomics of asthma.

scholarly journals Population structure of modern-day Italians reveals patterns of ancient and archaic ancestries in Southern Europe

2019 ◽  
Vol 5 (9) ◽  
pp. eaaw3492 ◽  
Author(s):  
A. Raveane ◽  
S. Aneli ◽  
F. Montinaro ◽  
G. Athanasiadis ◽  
S. Barlera ◽  
...  
Keyword(s):  
Population Structure ◽  
Bronze Age ◽  
The Caucasus ◽  
Italian Peninsula ◽  
Nomadic Pastoralists ◽  
Genome Wide ◽  
A Genome ◽  
The World ◽  
European Populations

European populations display low genetic differentiation as the result of long-term blending of their ancient founding ancestries. However, it is unclear how the combination of ancient ancestries related to early foragers, Neolithic farmers, and Bronze Age nomadic pastoralists can explain the distribution of genetic variation across Europe. Populations in natural crossroads like the Italian peninsula are expected to recapitulate the continental diversity, but have been systematically understudied. Here, we characterize the ancestry profiles of Italian populations using a genome-wide dataset representative of modern and ancient samples from across Italy, Europe, and the rest of the world. Italian genomes capture several ancient signatures, including a non–steppe contribution derived ultimately from the Caucasus. Differences in ancestry composition, as the result of migration and admixture, have generated in Italy the largest degree of population structure detected so far in the continent, as well as shaping the amount of Neanderthal DNA in modern-day populations.

Genome-wide identification of SSR markers in the Brassica A genome and their utility in breeding

2016 ◽  
Vol 96 (5) ◽  
pp. 808-818 ◽  
Author(s):  
Neil Hobson ◽  
Habibur Rahman
Keyword(s):  
Genetic Diversity ◽  
Ssr Markers ◽  
Low Cost ◽  
Pak Choi ◽  
Genome Wide ◽  
A Genome ◽  
Wide Range ◽  
Genetic Pools ◽  
High Level ◽  
Simple Sequence

Simple sequence repeat (SSR) markers can be applied to genotyping projects at low cost with inexpensive equipment. The objective of this study was to develop SSR markers from the publically-available genome sequence of Brassica rapa and provide the physical position of these markers on the chromosomes for use in breeding and research. To assess the utility of these new markers, a subset of 60 markers were used to genotype 43 accessions of B. rapa. Fifty-five markers from the 10 chromosome scaffolds produced a total of 730 amplicons, which were then used to perform a phylogenetic analysis of the accessions, illustrating their utility in distinguishing between a wide range of germplasm. In agreement with similar studies of genetic diversity, our markers separated accessions into distinct genetic pools including Chinese cabbage, Chinese winter oilseed, European winter oilseed, Canadian spring oilseed, pak-choi, turnip, and yellow sarson. The results further illustrate the presence of a high level of genetic diversity in B. rapa, and demonstrate the potential of these SSR markers for use in breeding and research.

scholarly journals The maternal environment interacts with genetic variation in regulating seed dormancy in Arabidopsis thaliana

2017 ◽  
Author(s):  
Envel Kerdaffrec ◽  
Magnus Nordborg
Keyword(s):  
Arabidopsis Thaliana ◽  
Association Study ◽  
Seed Dormancy ◽  
Genome Wide Association Study ◽  
Seed Maturation ◽  
Genome Wide Association ◽  
Maternal Environment ◽  
Genome Wide ◽  
A Genome ◽  
Wide Range

AbstractSeed dormancy is a complex adaptive trait that controls the timing of seed germination, one of the major fitness components in many plant species. Despite being highly heritable, seed dormancy is extremely plastic and influenced by a wide range of environmental cues. Here, using a set of 92 Arabidopsis thaliana lines from Sweden, we investigate the effect of seed maturation temperature on dormancy variation at the population level. The response to temperature differs dramatically between lines, demonstrating that genotype and the maternal environment interact in controlling the trait. By performing a genome-wide association study (GWAS), we identified several candidate genes that could account for this plasticity, two of which are involved in the photoinduction of germination. Altogether, our results provide insight into both the molecular mechanisms and the evolution of dormancy plasticity, and can serve to improve our understanding of environmentally dependent life-history transitions.HighlightThe effect of low seed-maturation temperatures on seed dormancy is highly variable in Arabidopsis thaliana accessions from Sweden, denoting strong genotype-environment interactions, and a genome-wide association study identified compelling candidates that could account for this plasticity.

scholarly journals Genome-wide Association Study of Anxiety and Stress-related Disorders in the iPSYCH Cohort

2018 ◽  
Author(s):  
Sandra M. Meier ◽  
Kalevi Trontti ◽  
Thomas Damm Als ◽  
Mikaela Laine ◽  
Marianne Giørtz Pedersen ◽  
...  
Keyword(s):  
Association Study ◽  
Genome Wide Association Study ◽  
Common Mental Disorders ◽  
Twin Studies ◽  
Genome Wide Association ◽  
Sensitivity Analyses ◽  
Association Analyses ◽  
Genome Wide ◽  
A Genome ◽  
Wide Range

AbstractAnxiety and stress-related disorders (ASRD) are among the most common mental disorders with the majority of patients suffering from additional disorders. Family and twin studies indicate that genetic and environmental factors are underlying their etiology. As ASRD are likely to configure various expressions of abnormalities in the basic stress-response system, we conducted a genome-wide association study including 12,655 cases with various anxiety and stress-related diagnoses and 19,225 controls. Standard association analyses were performed supplemented by a framework of sensitivity analyses. Variants in PDE4B showed consistent association with ASRD across a wide range of our analyses. In mice models, alternations in PDE4B expression were observed in those mice displaying anxious behavior after exposure to chronic stress. We also showed that 28% of the variance in ASRD was accounted for by common variants and that the genetic signature of ASRD overlapped with psychiatric traits, educational outcomes, obesity-related phenotypes, smoking, and reproductive success.

scholarly journals Review: Population Structure in Genetic Studies: Confounding Factors and Mixed Models

2016 ◽  
Author(s):  
Lana S. Martin ◽  
Eleazar Eskin
Keyword(s):  
Population Structure ◽  
Mixed Models ◽  
Genome Wide Association Study ◽  
Association Studies ◽  
Laboratory Mouse ◽  
Mouse Strains ◽  
Genetic Studies ◽  
The Past ◽  
Genome Wide ◽  
A Genome

AbstractA genome-wide association study (GWAS) seeks to identify genetic variants that contribute to the development and progression of a specific disease. Over the past 10 years, new approaches using mixed models have emerged to mitigate the deleterious effects of population structure and relatedness in association studies. However, developing GWAS techniques to effectively test for association while correcting for population structure is a computational and statistical challenge. Using laboratory mouse strains as an example, our review characterizes the problem of population structure in association studies and describes how it can cause false positive associations. We then motivate mixed models in the context of unmodeled factors.

scholarly journals Inference of Population Genetic Structure and High Linkage Disequilibrium Among Alternaria spp. Collected from Tomato and Potato Using Genotyping by Sequencing

2019 ◽  
Author(s):  
Tika B. Adhikari ◽  
Brian J. Knaus ◽  
Niklaus J. Grünwald ◽  
Dennis Halterman ◽  
Frank J. Louws
Keyword(s):  
Population Structure ◽  
Linkage Disequilibrium ◽  
Plant Pathogens ◽  
Principal Component ◽  
Genotyping By Sequencing ◽  
Allelic Association ◽  
Nucleotide Polymorphisms ◽  
Entire Genome ◽  
Genome Wide ◽  
A Genome

ABSTRACTGenotyping by sequencing (GBS) is considered a powerful tool to discover single nucleotide polymorphisms (SNPs), which are useful to characterize closely related genomes of plant species and plant pathogens. We applied GBS to determine genome-wide variations in a panel of 187 isolates of three closely related Alternaria spp. that cause diseases on tomato and potato in North Carolina (NC) and Wisconsin (WI). To compare genetic variations, reads were mapped to both A. alternata and A. solani draft reference genomes and detected dramatic differences in SNPs among them. Comparison of A. linariae and A. solani populations by principal component analysis revealed the first (83.8% of variation) and second (8.0% of variation) components contained A. linariae from tomato in NC and A. solani from potato in WI, respectively, providing evidence of population structure. Genetic differentiation (Hedrick’s G’ST) in A. linariae populations from Haywood, Macon, and Madison counties in NC were little or no differentiated (G’ST 0.0 - 0.2). However, A. linariae population from Swain county appeared to be highly differentiated (G’ST > 0.8). To measure the strength of the linkage disequilibrium (LD), we also calculated the allelic association between pairs of loci. Lewontin’s D (measures the fraction of allelic variations) and physical distances provided evidence of linkage throughout the entire genome, consistent with the hypothesis of non-random association of alleles among loci. Our findings provide new insights into the understanding of clonal populations on a genome-wide scale and microevolutionary factors that might play an important role in population structure. Although we found limited genetic diversity, the three Alternaria spp. studied here are genetically distinct and each species is preferentially associated with one host.

scholarly journals Genomic analysis reveals the genetic diversity, population structure, evolutionary history and relationships of Chinese pepper

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Shijing Feng ◽  
Zhenshan Liu ◽  
Yang Hu ◽  
Jieyun Tian ◽  
Tuxi Yang ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Demographic History ◽  
Genomic Analysis ◽  
Genotyping By Sequencing ◽  
Gansu Province ◽  
Climatic Oscillations ◽  
Genome Wide ◽  
A Genome ◽  
Wild Accessions

Abstract Chinese pepper, mainly including Zanthoxylum bungeanum and Zanthoxylum armatum, is an economically important crop popular in Asian countries due to its unique taste characteristics and potential medical uses. Numerous cultivars of Chinese pepper have been developed in China through long-term domestication. To better understand the population structure, demographic history, and speciation of Chinese pepper, we performed a comprehensive analysis at a genome-wide level by analyzing 38,395 genomic SNPs that were identified in 112 cultivated and wild accessions using a high-throughput genome-wide genotyping-by-sequencing (GBS) approach. Our analysis provides genetic evidence of multiple splitting events occurring between and within species, resulting in at least four clades in Z. bungeanum and two clades in Z. armatum. Despite no evidence of recent admixture between species, we detected substantial gene flow within species. Estimates of demographic dynamics and species distribution modeling suggest that climatic oscillations during the Pleistocene (including the Penultimate Glaciation and the Last Glacial Maximum) and recent domestication events together shaped the demography and evolution of Chinese pepper. Our analyses also suggest that southeastern Gansu province is the most likely origin of Z. bungeanum in China. These findings provide comprehensive insights into genetic diversity, population structure, demography, and adaptation in Zanthoxylum.

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