Population genomic diversity and structure at the discontinuous southern range of the Great Gray Owl in North America

2020 ◽  
Vol 21 (4) ◽  
pp. 693-706
Author(s):  
Beth Mendelsohn ◽  
Bryan Bedrosian ◽  
Sierra M. Love Stowell ◽  
Roderick B. Gagne ◽  
Melanie E. F. LaCava ◽  
...  
Keyword(s):  
North America ◽  
Genomic Diversity ◽  
Population Genomic ◽  
Great Gray Owl

scholarly journals Environmental correlates of genetic variation in the invasive and largely panmictic European starling in North America

2019 ◽  
Author(s):  
Natalie R. Hofmeister ◽  
Scott J. Werner ◽  
Irby J. Lovette
Keyword(s):  
North America ◽  
Local Adaptation ◽  
North American ◽  
Winter Season ◽  
Bird Species ◽  
Genomic Diversity ◽  
Rapid Expansion ◽  
Continental Scale ◽  
High Dispersal ◽  
Local Selection

ABSTRACTPopulations of invasive species that colonize and spread in novel environments may differentiate both through demographic processes and local selection. European starlings (Sturnus vulgaris) were introduced to New York in 1890 and subsequently spread throughout North America, becoming one of the most widespread and numerous bird species on the continent. Genome-wide comparisons across starling individuals and populations can identify demographic and/or selective factors that facilitated this rapid and successful expansion. We investigated patterns of genomic diversity and differentiation using reduced-representation genome sequencing (ddRADseq) of 17 winter-season starling populations. Consistent with this species’ high dispersal rate and rapid expansion history, we found low geographic differentiation and few FST outliers even at a continental scale. Despite starting from a founding population of approximately 180 individuals, North American starlings show only a moderate genetic bottleneck, and models suggest a dramatic increase in effective population size since introduction. In genotype-environment associations we found that ∼200 single-nucleotide polymorphisms are correlated with temperature and/or precipitation against a background of negligible genome- and range-wide divergence. Local adaptation in North American starlings may have evolved rapidly even in this wide-ranging and evolutionarily young population. This survey of genomic signatures of expansion in North American starlings is the most comprehensive to date and complements ongoing studies of world-wide local adaptation in these highly dispersive and invasive birds.

scholarly journals Genome wide analysis reveals genetic divergence between Goldsinny wrasse populations 

2020 ◽  
Author(s):  
Eeva Jansson ◽  
Francois Besnier ◽  
Ketil Malde ◽  
Carl André ◽  
Geir Dahle ◽  
...  
Keyword(s):  
Genetic Divergence ◽  
De Novo ◽  
Genomic Structure ◽  
Snp Markers ◽  
Genomic Diversity ◽  
Full Genome Sequencing ◽  
Population Genomic ◽  
Genome Wide ◽  
Ctenolabrus Rupestris ◽  
Goldsinny Wrasse

Abstract Background Marine fish populations are often characterized by high levels of gene flow and correspondingly low genetic divergence. This presents a challenge to define management units. Goldsinny wrasse ( Ctenolabrus rupestris ) is a heavily exploited species due to its importance as a cleaner-fish in commercial salmonid aquaculture. However, at the present, the population genetic structure of this species is still largely unresolved. Here, full-genome sequencing was used to produce the first genomic reference for this species, to study population-genomic divergence among four geographically distinct populations, and, to identify informative SNP markers for future studies. Results After construction of a de novo assembly, the genome was estimated to be highly polymorphic and of ~600Mbp in size. 33 235 genome wide SNPs were thereafter selected to assess genomic diversity and differentiation among four populations collected from Scandinavia, Scotland, and Spain. Global F ST among these populations was 0.015–0.092. Approximately 4% of the investigated loci were identified as putative global outliers, and ~1% within Scandinavia. SNPs showing large divergence ( F ST >0.15) were picked as candidate diagnostic markers for population assignment. 173 of the most diagnostic SNPs between the two Scandinavian populations were validated by genotyping 47 individuals from each end of the species’ Scandinavian distribution range. 69 of these SNPs were significantly ( p <0.05) differentiated (mean F ST_173_loci = 0.065, F ST_69_loci = 0.140). Using these validated SNPs, individuals were assigned with high probability (≥ 94%) to their populations of origin. Conclusions Goldsinny wrasse displays a highly polymorphic genome, and substantial population genomic structure. Diversifying selection likely affects population structuring globally and within Scandinavia. The diagnostic loci identified now provide a promising and cost-efficient tool to investigate goldsinny wrasse populations further.

scholarly journals Fine scale population structure and extensive gene flow within an Eastern Nearctic snake complex (Pituophis melanoleucus)

2021 ◽  
Author(s):  
Zachary L Nikolakis ◽  
Richard Orton ◽  
Brian I Crother
Keyword(s):  
Gene Flow ◽  
Isolation By Distance ◽  
Genomic Structure ◽  
Genomic Variation ◽  
Genomic Diversity ◽  
Evolutionary Relationships ◽  
Population Genomic ◽  
Isolation By Environment ◽  
Pituophis Melanoleucus ◽  
Lineage Divergence

Understanding the processes and mechanisms that promote lineage divergence is a central goal in evolutionary biology. For instance, studies investigating the spatial distribution of genomic variation often highlight biogeographic barriers underpinning geographic isolation, as well as patterns of isolation by environment and isolation by distance that can also lead to lineage divergence. However, the patterns and processes that shape genomic variation and drive lineage divergence may be taxa-specific, even across closely related taxa co-occurring within the same biogeographic region. Here, we use molecular data in the form of ultra-conserved elements (UCEs) to infer the evolutionary relationships and population genomic structure of the Eastern Pinesnake complex (Pituophis melanoleucus) – a polytypic wide-ranging species that occupies much of the Eastern Nearctic. In addition to inferring evolutionary relationships, population genomic structure, and gene flow, we also test relationships between genomic diversity and putative barriers to dispersal, environmental variation, and geographic distance. We present results that reveal shallow population genomic structure and ongoing gene flow, despite an extensive geographic range that transcends geographic features found to reduce gene flow among many taxa, including other squamate reptiles within the Eastern Nearctic. Further, our results indicate that the observed genomic diversity is spatially distributed as a pattern of isolation by distance and suggest that the current subspecific taxonomy do not adhere to independent lineages, but rather, show a significant amount of admixture across the entire P. melanoleucus range.

scholarly journals Broad-scale puma connectivity could restore genomic diversity to fine-scale coastal populations

2021 ◽  
Author(s):  
Kyle D Gustafson ◽  
Roderick B Gagne ◽  
Michael R Buchalski ◽  
T Winston Vickers ◽  
Seth PD Riley ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Linkage Disequilibrium ◽  
Puma Concolor ◽  
Genomic Diversity ◽  
Strong Linkage Disequilibrium ◽  
Fine Scale ◽  
High Genetic Diversity ◽  
Population Genomic ◽  
Genome Wide ◽  
Genetic Clusters

Urbanization is decreasing wildlife habitat and connectivity worldwide, including for apex predators, such as the puma (Puma concolor). Puma populations along California's central and southern coastal habitats have experienced rapid fragmentation from development, leading to calls for demographic and genetic management. To address urgent conservation genomic concerns, we used double-digest restriction-site associated DNA (ddRAD) sequencing to analyze 16,285 genome-wide single-nucleotide polymorphisms (SNPs) from 401 broadly sampled pumas. Our analyses indicated support for 4–10 geographically nested, broad- to fine-scale genetic clusters. At the broadest scale, the 4 genetic clusters had high genetic diversity and exhibited low linkage disequilibrium, indicating pumas have retained statewide genomic diversity. However, multiple lines of evidence indicated substructure, including 10 fine-scale genetic clusters, some of which exhibited allelic fixation and linkage disequilibrium. Fragmented populations along the Southern Coast and Central Coast had particularly low genetic diversity and strong linkage disequilibrium, indicating genetic drift and close inbreeding. Our results demonstrate that genetically at-risk populations are typically nested within a broader-scale group of interconnected populations that collectively retains high genetic diversity and heterogeneous fixations. Thus, extant variation at the broader scale has potential to restore diversity to local populations if management actions can enhance vital gene flow and recombine locally sequestered genetic diversity. These state- and genome-wide results are critically important for science-based conservation and management practices. Our broad- and fine-scale population genomic analysis highlights the information that can be gained from population genomic studies aiming to provide guidance for fragmented population conservation management.

scholarly journals Signatures of selection and genomic diversity of Muskellunge (Esox masquinongy) from two populations in North America.

2021 ◽  
Author(s):  
Josue Chinchilla-Vargas ◽  
Jonathan R. Meerbeek ◽  
Max F. Rothschild ◽  
Francesca Bertolini
Keyword(s):  
Genetic Diversity ◽  
North America ◽  
Related Species ◽  
Reference Genome ◽  
Genetic Differences ◽  
Genomic Diversity ◽  
Closely Related Species ◽  
Esox Masquinongy ◽  
Inbreeding Rate ◽  
Signatures Of Selection

Abstract Background Muskellunge (Esox masquinongy) is the largest and most prized game fish for anglers in North America. However, little is known about Muskellunge genetic diversity in Iowa’s propagation program. We used whole genome sequence from 12 brooding individuals from Iowa and publicly available RAD-seq of 625 individuals from Saint-Lawrence river in Canada to study the genetic differences between populations, analyze signatures of selection that might shed light on environmental adaptations, and evaluate the levels of genetic diversity in both populations. Given that there is no reference genome available for Muskellunge, reads were aligned to the genome of Pike (Esox lucius), a closely-related species.Results Variant calling produced 7,886,471 biallelic variants for the Iowa population and 16,867 high-quality SNPs that overlap with the Canadian samples. The Ti/Tv values were 1.09 and 1.29 for samples from Iowa and Canada, respectively. PCA and Admixture analyses showed a large genetic difference between Canadian and Iowan populations. Moreover, PCA showed clustering by sex in the Iowan population although widow-based Fst did not find outlier regions. Window-based pooled heterozygosity found 6 highly heterozygous windows containing 244 genes in the Iowa population and Fst comparing the Iowa and Canadian populations found 14 windows with Fst values larger than 0.9 containing 641 genes. One enriched GO term (sensory perception of pain) was found through pooled heterozygosity analyzes. Although not significant, several enriched GO terms associated to growth and development were found through Fst analyses.Inbreeding calculated as Froh was 0.03 on average for the Iowa population and 0.32 on average for the Canadian samples. The Canadian inbreeding rate appears to be higher, presumably due to isolation of subpopulations, than the inbreeding rate of the Iowa population.Conclusions This study was the first to document that brood stock Muskellunge from Iowa showed marked genetic differences with the Canadian population. Additionally, despite genetic differentiation based on sex has been observed, no major locus has been detected. Inbreeding does not seem to be an immediate concern for Muskellunge in Iowa, but apparent isolation of subpopulations has caused levels of homozygosity to increase in the Canadian Muskellunge population. Finally, these results prove the validity of using genomes of closely related species to perform genomic analyses when no reference genome assembly is available.

scholarly journals Signatures of selection and genomic diversity of Muskellunge (Esox masquinongy) from two populations in North America.

2021 ◽  
Author(s):  
Josue Chinchilla-Vargas ◽  
Max F. Rothschild ◽  
Francesca Bertolini
Keyword(s):  
Genetic Diversity ◽  
North America ◽  
Related Species ◽  
Reference Genome ◽  
Genetic Differences ◽  
Genomic Diversity ◽  
Whole Genome Sequence ◽  
Closely Related Species ◽  
Esox Masquinongy ◽  
Signatures Of Selection

Abstract Background Muskellunge (Esox masquinongy) is the largest and most prized game fish for anglers in North America. However, little is known about Muskellunge genetic diversity in Iowa’s propagation program. We used whole genome sequence from 12 brooding individuals from Iowa and publicly available RAD-seq of 625 individuals from Saint-Lawrence river in Canada to study the genetic differences between populations, analyze signatures of selection that might shed light on environmental adaptations, and evaluate the levels of genetic diversity in both populations. Given that there is no reference genome available for Muskellunge, reads were aligned to the genome of Pike (Esox lucius), a closely-related species. Results Variant calling produced 7,886,471 biallelic variants for the Iowa population and 16,867 high quality SNPs that overlap with the Canadian samples. The Ti/Tv values were 1.09 and 1.29 for samples from Iowa and Canada, respectively. PCA and Admixture analyses showed a large genetic difference between Canadian and Iowan populations. Moreover, PCA showed a clustering by sex in the Iowan population although widow-based Fst did not find outlier regions. Window based pooled heterozygosity found 6 highly heterozygous windows containing 244 genes in the Iowa population and Fst comparing the Iowa and Canadian populations found 14 windows with Fst values larger than 0.9 containing 641 genes. One enriched GO term (sensory perception of pain) was found through pooled heterozygosity analyzes. Although not significant, several enriched GO terms associated to growth and development were found through Fst analyses. Inbreeding calculated as Froh was 0.03 on average for the Iowa population and 0.32 on average for the Canadian samples. The inbreeding rate appears is presumably due to isolation of subpopulations. Conclusions This study is the first of its kind in Muskellunge from Iowa in which captured brood stock showed marked genetic differences with the Canadian population. Additionally, despite genetic differentiation based on sex has been observed, no major locus has been detected . Inbreeding does not seem to be an immediate concern for Muskellunge in Iowa, isolation of subpopulations has caused levels of homozygosity to increase in the Canadian Muskellunge population. These results prove the validity of using genomes of closely related species to perform genomic analyses when no reference genome assembly is available.

scholarly journals Genome wide analysis reveals genetic divergence between Goldsinny wrasse populations

BMC Genetics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Eeva Jansson ◽  
Francois Besnier ◽  
Ketil Malde ◽  
Carl André ◽  
Geir Dahle ◽  
...  
Keyword(s):  
Genetic Divergence ◽  
De Novo ◽  
Genomic Structure ◽  
Snp Markers ◽  
Genomic Diversity ◽  
Full Genome Sequencing ◽  
Population Genomic ◽  
Cost Efficient ◽  
Ctenolabrus Rupestris ◽  
Goldsinny Wrasse

Abstract Background Marine fish populations are often characterized by high levels of gene flow and correspondingly low genetic divergence. This presents a challenge to define management units. Goldsinny wrasse (Ctenolabrus rupestris) is a heavily exploited species due to its importance as a cleaner-fish in commercial salmonid aquaculture. However, at the present, the population genetic structure of this species is still largely unresolved. Here, full-genome sequencing was used to produce the first genomic reference for this species, to study population-genomic divergence among four geographically distinct populations, and, to identify informative SNP markers for future studies. Results After construction of a de novo assembly, the genome was estimated to be highly polymorphic and of ~600Mbp in size. 33,235 SNPs were thereafter selected to assess genomic diversity and differentiation among four populations collected from Scandinavia, Scotland, and Spain. Global FST among these populations was 0.015–0.092. Approximately 4% of the investigated loci were identified as putative global outliers, and ~ 1% within Scandinavia. SNPs showing large divergence (FST > 0.15) were picked as candidate diagnostic markers for population assignment. One hundred seventy-three of the most diagnostic SNPs between the two Scandinavian populations were validated by genotyping 47 individuals from each end of the species’ Scandinavian distribution range. Sixty-nine of these SNPs were significantly (p < 0.05) differentiated (mean FST_173_loci = 0.065, FST_69_loci = 0.140). Using these validated SNPs, individuals were assigned with high probability (≥ 94%) to their populations of origin. Conclusions Goldsinny wrasse displays a highly polymorphic genome, and substantial population genomic structure. Diversifying selection likely affects population structuring globally and within Scandinavia. The diagnostic loci identified now provide a promising and cost-efficient tool to investigate goldsinny wrasse populations further.

scholarly journals Genome Sequence of Verticillium dahliae Race 1 Isolate VdLs.16 From Lettuce

2020 ◽  
Vol 33 (11) ◽  
pp. 1265-1269
Author(s):  
Jie-Yin Chen ◽  
Dan-Dan Zhang ◽  
Jin-Qun Huang ◽  
Dan Wang ◽  
Shi-Jun Hao ◽  
...  
Keyword(s):  
Verticillium Dahliae ◽  
Genetic Basis ◽  
Reference Genome ◽  
Genomic Diversity ◽  
Host Responses ◽  
Ongoing Research ◽  
Differential Host ◽  
Population Genomic ◽  
Race 1 ◽  
Race 2

Verticillium dahliae is a widespread fungal pathogen that causes Verticillium wilt on many economically important crops and ornamentals worldwide. Populations of V. dahliae have been divided into two distinct races based upon differential host responses in tomato and lettuce. Recently, the contemporary race 2 isolates were further divided into an additional race in tomato. Herein, we provide a high-quality reference genome for the race 1 strain VdLs.16 isolated from lettuce in California, U.S.A. This resource will contribute to ongoing research that aims to elucidate the genetic basis of V. dahliae pathogenicity and population genomic diversity.

scholarly journals The population genomics of adaptive loss of function

Heredity ◽  
2021 ◽  
Author(s):  
J. Grey Monroe ◽  
John K. McKay ◽  
Detlef Weigel ◽  
Pádraic J. Flood
Keyword(s):  
Population Genetics ◽  
Evolutionary Dynamics ◽  
Population Genomics ◽  
Genomic Variation ◽  
Genomic Diversity ◽  
Loss Of Function ◽  
Population Genomic ◽  
Genomic Tools ◽  
Challenges And Opportunities ◽  
Early View

AbstractDiscoveries of adaptive gene knockouts and widespread losses of complete genes have in recent years led to a major rethink of the early view that loss-of-function alleles are almost always deleterious. Today, surveys of population genomic diversity are revealing extensive loss-of-function and gene content variation, yet the adaptive significance of much of this variation remains unknown. Here we examine the evolutionary dynamics of adaptive loss of function through the lens of population genomics and consider the challenges and opportunities of studying adaptive loss-of-function alleles using population genetics models. We discuss how the theoretically expected existence of allelic heterogeneity, defined as multiple functionally analogous mutations at the same locus, has proven consistent with empirical evidence and why this impedes both the detection of selection and causal relationships with phenotypes. We then review technical progress towards new functionally explicit population genomic tools and genotype-phenotype methods to overcome these limitations. More broadly, we discuss how the challenges of studying adaptive loss of function highlight the value of classifying genomic variation in a way consistent with the functional concept of an allele from classical population genetics.

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