scholarly journals Patterns of Genomic Instability in Interspecific Yeast Hybrids With Diverse Ancestries

2021 ◽  
Vol 2 ◽  
Author(s):  
Devin P. Bendixsen ◽  
David Peris ◽  
Rike Stelkens
Keyword(s):  
Phenotypic Diversity ◽  
Chromosomal Rearrangements ◽  
Nuclear Genome ◽  
Read Depth ◽  
Genomic Variation ◽  
Genomic Diversity ◽  
Ecological Niches ◽  
Parent Species ◽  
Genomic Architecture ◽  
Gains And Losses

The genomes of hybrids often show substantial deviations from the features of the parent genomes, including genomic instabilities characterized by chromosomal rearrangements, gains, and losses. This plastic genomic architecture generates phenotypic diversity, potentially giving hybrids access to new ecological niches. It is however unclear if there are any generalizable patterns and predictability in the type and prevalence of genomic variation and instability across hybrids with different genetic and ecological backgrounds. Here, we analyzed the genomic architecture of 204 interspecific Saccharomyces yeast hybrids isolated from natural, industrial fermentation, clinical, and laboratory environments. Synchronous mapping to all eight putative parental species showed significant variation in read depth indicating frequent aneuploidy, affecting 44% of all hybrid genomes and particularly smaller chromosomes. Early generation hybrids with largely equal genomic content from both parent species were more likely to contain aneuploidies than introgressed genomes with an older hybridization history, which presumably stabilized the genome. Shared k-mer analysis showed that the degree of genomic diversity and variability varied among hybrids with different parent species. Interestingly, more genetically distant crosses produced more similar hybrid genomes, which may be a result of stronger negative epistasis at larger genomic divergence, putting constraints on hybridization outcomes. Mitochondrial genomes were typically inherited from the species also contributing the majority nuclear genome, but there were clear exceptions to this rule. Together, we find reliable genomic predictors of instability in hybrids, but also report interesting cross- and environment-specific idiosyncrasies. Our results are an important step in understanding the factors shaping divergent hybrid genomes and their role in adaptive evolution.

scholarly journals Single-Nucleotide Polymorphism-Based Genetic Diversity Analysis of Clinical Pseudomonas aeruginosa Isolates

2020 ◽  
Vol 12 (4) ◽  
pp. 396-406 ◽  
Author(s):  
Uthayakumar Muthukumarasamy ◽  
Matthias Preusse ◽  
Adrian Kordes ◽  
Michal Koska ◽  
Monika Schniederjans ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Single Nucleotide Polymorphisms ◽  
Core Genome ◽  
Phenotypic Diversity ◽  
Bacterial Species ◽  
Genomic Variation ◽  
Genomic Diversity ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Genetic Changes

Abstract Extensive use of next-generation sequencing has the potential to transform our knowledge on how genomic variation within bacterial species impacts phenotypic versatility. Because different environments have unique selection pressures, they drive divergent evolution. However, there is also parallel or convergent evolution of traits in independent bacterial isolates inhabiting similar environments. The application of tools to describe population-wide genomic diversity provides an opportunity to measure the predictability of genetic changes underlying adaptation. Here, we describe patterns of sequence variations in the core genome among 99 individual Pseudomonas aeruginosa clinical isolates and identified single-nucleotide polymorphisms that are the basis for branching of the phylogenetic tree. We also identified single-nucleotide polymorphisms that were acquired independently, in separate lineages, and not through inheritance from a common ancestor. Although our results demonstrate that the Pseudomonas aeruginosa core genome is highly conserved and in general, not subject to adaptive evolution, instances of parallel evolution will provide an opportunity to uncover genetic changes that underlie phenotypic diversity.

scholarly journals Assessing genomic diversity and signatures of selection in Jiaxian Red cattle using whole-genome sequencing data

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Xiaoting Xia ◽  
Shunjin Zhang ◽  
Huaju Zhang ◽  
Zijing Zhang ◽  
Ningbo Chen ◽  
...  
Keyword(s):  
Population Structure ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Genomic Variation ◽  
Genomic Diversity ◽  
System Response ◽  
Whole Genome ◽  
Population Structure Analysis ◽  
Native Cattle ◽  
Genomic Regions

Abstract Background Native cattle breeds are an important source of genetic variation because they might carry alleles that enable them to adapt to local environment and tough feeding conditions. Jiaxian Red, a Chinese native cattle breed, is reported to have originated from crossbreeding between taurine and indicine cattle; their history as a draft and meat animal dates back at least 30 years. Using whole-genome sequencing (WGS) data of 30 animals from the core breeding farm, we investigated the genetic diversity, population structure and genomic regions under selection of Jiaxian Red cattle. Furthermore, we used 131 published genomes of world-wide cattle to characterize the genomic variation of Jiaxian Red cattle. Results The population structure analysis revealed that Jiaxian Red cattle harboured the ancestry with East Asian taurine (0.493), Chinese indicine (0.379), European taurine (0.095) and Indian indicine (0.033). Three methods (nucleotide diversity, linkage disequilibrium decay and runs of homozygosity) implied the relatively high genomic diversity in Jiaxian Red cattle. We used θπ, CLR, FST and XP-EHH methods to look for the candidate signatures of positive selection in Jiaxian Red cattle. A total number of 171 (θπ and CLR) and 17 (FST and XP-EHH) shared genes were identified using different detection strategies. Functional annotation analysis revealed that these genes are potentially responsible for growth and feed efficiency (CCSER1), meat quality traits (ROCK2, PPP1R12A, CYB5R4, EYA3, PHACTR1), fertility (RFX4, SRD5A2) and immune system response (SLAMF1, CD84 and SLAMF6). Conclusion We provide a comprehensive overview of sequence variations in Jiaxian Red cattle genomes. Selection signatures were detected in genomic regions that are possibly related to economically important traits in Jiaxian Red cattle. We observed a high level of genomic diversity and low inbreeding in Jiaxian Red cattle. These results provide a basis for further resource protection and breeding improvement of this breed.

scholarly journals Whole-Genome Sequencing and Characterization of Buffalo Genetic Resources: Recent Advances and Future Challenges

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 904
Author(s):  
Saif ur Rehman ◽  
Faiz-ul Hassan ◽  
Xier Luo ◽  
Zhipeng Li ◽  
Qingyou Liu
Keyword(s):  
Selective Breeding ◽  
Reference Genome ◽  
De Novo ◽  
Phenotypic Diversity ◽  
Molecular Data ◽  
Genomic Diversity ◽  
Production Performance ◽  
Phylogeographic Structure ◽  
Economic Significance ◽  
And Performance

The buffalo was domesticated around 3000–6000 years ago and has substantial economic significance as a meat, dairy, and draught animal. The buffalo has remained underutilized in terms of the development of a well-annotated and assembled reference genome de novo. It is mandatory to explore the genetic architecture of a species to understand the biology that helps to manage its genetic variability, which is ultimately used for selective breeding and genomic selection. Morphological and molecular data have revealed that the swamp buffalo population has strong geographical genomic diversity with low gene flow but strong phenotypic consistency, while the river buffalo population has higher phenotypic diversity with a weak phylogeographic structure. The availability of recent high-quality reference genome and genotyping marker panels has invigorated many genome-based studies on evolutionary history, genetic diversity, functional elements, and performance traits. The increasing molecular knowledge syndicate with selective breeding should pave the way for genetic improvement in the climatic resilience, disease resistance, and production performance of water buffalo populations globally.

scholarly journals Genomic diversity of Mycobacterium avium subsp. paratuberculosis: pangenomic approach for highlighting unique genomic features with newly constructed complete genomes

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Jaewon Lim ◽  
Hong-Tae Park ◽  
Seyoung Ko ◽  
Hyun-Eui Park ◽  
Gyumin Lee ◽  
...  
Keyword(s):  
Mycobacterium Avium ◽  
Phenotypic Diversity ◽  
Control Strategies ◽  
Genomic Diversity ◽  
Phenotypic Traits ◽  
Whole Genome ◽  
Genomic Features ◽  
Phenotypic Differences ◽  
Mycobacterium Avium Subsp Paratuberculosis ◽  
Type Strains

AbstractMycobacterium avium subsp. paratuberculosis (MAP) is a causative agent of Johne’s disease, which is a chronic granulomatous enteropathy in ruminants. Determining the genetic diversity of MAP is necessary to understand the epidemiology and biology of MAP, as well as establishing disease control strategies. In the present study, whole genome-based alignment and comparative analysis were performed using 40 publicly available MAP genomes, including newly sequenced Korean isolates. First, whole genome-based alignment was employed to identify new genomic structures in MAP genomes. Second, the genomic diversity of the MAP population was described by pangenome analysis. A phylogenetic tree based on the core genome and pangenome showed that the MAP was differentiated into two major types (C- and S-type), which was in keeping with the findings of previous studies. However, B-type strains were discriminated from C-type strains. Finally, functional analysis of the pangenome was performed using three virulence factor databases (i.e., PATRIC, VFDB, and Victors) to predict the phenotypic diversity of MAP in terms of pathogenicity. Based on the results of the pangenome analysis, we developed a real-time PCR technique to distinguish among S-, B- and C-type strains. In conclusion, the results of our study suggest that the phenotypic differences between MAP strains can be explained by their genetic polymorphisms. These results may help to elucidate the diversity of MAP, extending from genomic features to phenotypic traits.

scholarly journals Phylogeographic Genetic Diversity in the White Sucker Hepatitis B Virus across the Great Lakes Region and Alberta, Canada

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 285
Author(s):  
Cynthia R. Adams ◽  
Vicki S. Blazer ◽  
Jim Sherry ◽  
Robert Scott Cornman ◽  
Luke R. Iwanowicz
Keyword(s):  
Genetic Diversity ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Lake Michigan ◽  
Illumina Miseq ◽  
Genomic Variation ◽  
Genomic Diversity ◽  
White Sucker ◽  
Fish Health ◽  
B Virus

Hepatitis B viruses belong to a family of circular, double-stranded DNA viruses that infect a range of organisms, with host responses that vary from mild infection to chronic infection and cancer. The white sucker hepatitis B virus (WSHBV) was first described in the white sucker (Catostomus commersonii), a freshwater teleost, and belongs to the genus Parahepadnavirus. At present, the host range of WSHBV and its impact on fish health are unknown, and neither genetic diversity nor association with fish health have been studied in any parahepadnavirus. Given the relevance of genomic diversity to disease outcome for the orthohepadnaviruses, we sought to characterize genomic variation in WSHBV and determine how it is structured among watersheds. We identified WSHBV-positive white sucker inhabiting tributaries of Lake Michigan, Lake Superior, Lake Erie (USA), and Lake Athabasca (Canada). Copy number in plasma and in liver tissue was estimated via qPCR. Templates from 27 virus-positive fish were amplified and sequenced using a primer-specific, circular long-range amplification method coupled with amplicon sequencing on the Illumina MiSeq. Phylogenetic analysis of the WSHBV genome identified phylogeographical clustering reminiscent of that observed with human hepatitis B virus genotypes. Notably, most non-synonymous substitutions were found to cluster in the pre-S/spacer overlap region, which is relevant for both viral entry and replication. The observed predominance of p1/s3 mutations in this region is indicative of adaptive change in the polymerase open reading frame (ORF), while, at the same time, the surface ORF is under purifying selection. Although the levels of variation we observed do not meet the criteria used to define sub/genotypes of human and avian hepadnaviruses, we identified geographically associated genome variation in the pre-S and spacer domain sufficient to define five WSHBV haplotypes. This study of WSHBV genetic diversity should facilitate the development of molecular markers for future identification of genotypes and provide evidence in future investigations of possible differential disease outcomes.

Evaluation of Four Methods to Identify the Homozygotic Sex Chromosome in Small Populations

2021 ◽  
Author(s):  
Charles Christian Riis Hansen ◽  
Kristen M. Westfall ◽  
Snaebjörn Pálsson
Keyword(s):  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Read Depth ◽  
Mapping Method ◽  
Small Population ◽  
Genomic Variation ◽  
Z Chromosome ◽  
Effective Population ◽  
Organelle Genomes ◽  
Heterogametic Sex

Abstract BackgroundWhole genomes are commonly assembled into a collection of scaffolds and often lack annotations of autosomes, sex chromosomes, and organelle genomes (i.e., mitochondrial and chloroplast). As these chromosome types differ in effective population size and can have highly disparate evolutionary histories, it is imperative to take this information into account when analysing genomic variation. Here we assessed the accuracy of four methods for identifying the homogametic sex chromosome in a small population using two whole genome sequences (WGS) and 133 RAD sequences of white-tailed eagles (Haliaeetus albicilla): i) difference in read depth per scaffold in a male and a female, ii) heterozygosity per scaffold in a male and a female, iii) mapping to a reference genome of a related species (chicken) with identified sex chromosomes, and iv) analysis of SNP-loadings from a principal components analysis (PCA), based on the low-depth RADseq data. ResultsThe best performing approach was the reference mapping (method iii), which identified 98.12% of the expected homogametic sex chromosome (Z). The read depth per scaffold (method i) identified 86.41% of the homogametic sex chromosome with few false positives. The SNP-loading scores (method iv) found 78.6% of the Z-chromosome and had a false positive discovery rate of more than 10%. The heterozygosity per scaffold (method ii) did not provide clear results due to a lack of diversity in both the Z and autosomal chromosomes, and potential interference from the heterogametic sex chromosome (W). The evaluation of these methods also revealed 10 Mb of likely PAR and gametologous regions.ConclusionIdentification of the homogametic sex chromosome in a small population is best accomplished by reference mapping or examining read depth differences between sexes.

scholarly journals Genomic Variation between PRSV Resistant Transgenic SunUp and Its Progenitor Cultivar Sunset

2020 ◽  
Author(s):  
Jingping Fang ◽  
Andrew Wood ◽  
Youqiang Chen ◽  
Jingjing Yue ◽  
Ray Ming
Keyword(s):  
Spontaneous Mutation ◽  
Nuclear Genome ◽  
Plastid Dna ◽  
High Impact ◽  
Genomic Variation ◽  
Reliable Estimate ◽  
Nucleotide Polymorphisms ◽  
Structural Variations ◽  
Transgenic Papaya ◽  
Organelle Genomes

Abstract Background: The safety of genetically transformed plants remains a subject of scrutiny. Genomic variants in PRSV resistant transgenic papaya will provide evidence to rationally address such concerns. Results: In this study, a total of more than 74 million Illumina reads for progenitor ‘Sunset’ were mapped onto transgenic papaya ‘SunUp’ reference genome. 310,364 single nucleotide polymorphisms (SNPs), 34,071 small Inserts/deletions (InDels) and 1,200 large structural variations (SVs) were detected between ‘Sunset’ and ‘SunUp’. Those variations have an uneven distribution across nine chromosomes in papaya. Only 0.27% of mutations were predicted to be high-impact mutations. ATP-related categories were highly enriched among these high-impact genes. The SNP mutation rate was about 8.4×10-4 per site, comparable with the rate induced by spontaneous mutation over numerous generations. The transition-to-transversion ratio was 1.439 and the predominant mutations were C/G to T/A transitions. Spontaneous mutations were the leading cause of SNPs in transgenic papaya ‘SunUp’. A total of 3,430 nuclear plastid DNA (NUPT) and 2,764 nuclear mitochondrial DNA (NUMT) junction sites have been found in ‘SunUp’, which is proportionally higher than the predicted total NUPT and NUMT junction sites in ‘Sunset’ (3,346 and 2,745, respectively). Among all nuclear organelle DNA (norgDNA) junction sites, 96% of junction sites were shared by ‘SunUp’ and ‘Sunset’. The average identity between ‘SunUp’ specific norgDNA and corresponding organelle genomes was higher than that of norgDNA shared by ‘SunUp’ and ‘Sunset’. Six ‘SunUp’ organelle-like borders of transgenic insertions were nearly identical to corresponding sequences in organelle genomes (98.18~100%). None of the paired-end spans of mapped ‘Sunset’ reads were elongated by any ‘SunUp’ transformation plasmid derived inserts. Significant amounts of DNA were transferred from organelles to the nuclear genome during bombardment, including the six flanking sequences of the three transgenic insertions.Conclusions: Comparative whole-genome analyses between ‘SunUp’ and ‘Sunset’ provide a reliable estimate of genome-wide variations and evidence of organelle-to-nucleus transfer of DNA associated with biolistic transformation.

scholarly journals Characterizing the genomic variation and population dynamics of Plasmodium falciparum malaria parasites in and around Lake Victoria, Kenya

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ashley Osborne ◽  
Emilia Manko ◽  
Mika Takeda ◽  
Akira Kaneko ◽  
Wataru Kagaya ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Population Dynamics ◽  
Malaria Elimination ◽  
Lake Victoria ◽  
Genomic Variation ◽  
Genomic Diversity ◽  
Sub Saharan Africa ◽  
Lake Victoria Basin ◽  
East African ◽  
Lake Region

AbstractCharacterising the genomic variation and population dynamics of Plasmodium falciparum parasites in high transmission regions of Sub-Saharan Africa is crucial to the long-term efficacy of regional malaria elimination campaigns and eradication. Whole-genome sequencing (WGS) technologies can contribute towards understanding the epidemiology and structural variation landscape of P. falciparum populations, including those within the Lake Victoria basin, a region of intense transmission. Here we provide a baseline assessment of the genomic diversity of P. falciparum isolates in the Lake region of Kenya, which has sparse genetic data. Lake region isolates are placed within the context of African-wide populations using Illumina WGS data and population genomic analyses. Our analysis revealed that P. falciparum isolates from Lake Victoria form a cluster within the East African parasite population. These isolates also appear to have distinct ancestral origins, containing genome-wide signatures from both Central and East African lineages. Known drug resistance biomarkers were observed at similar frequencies to those of East African parasite populations, including the S160N/T mutation in the pfap2mu gene, which has been associated with delayed clearance by artemisinin-based combination therapy. Overall, our work provides a first assessment of P. falciparum genetic diversity within the Lake Victoria basin, a region targeting malaria elimination.

scholarly journals Phenotypic diversity of bread wheat lines with introgressions from the diploid cereal Aegilops speltoides for technological properties of grain and f lour

2020 ◽  
Vol 24 (7) ◽  
pp. 738-746
Author(s):  
L. V. Shchukina ◽  
I. F. Lapochkina ◽  
T. A. Pshenichnikova
Keyword(s):  
Genetic Diversity ◽  
Bread Wheat ◽  
Phenotypic Diversity ◽  
Chromosomal Rearrangements ◽  
Diploid Species ◽  
Aegilops Speltoides ◽  
Technological Properties ◽  
Gluten Content ◽  
Spring Variety ◽  
Growing Conditions

The creation of varieties adapted to changing environmental conditions, resistant to various pathogens, and satisfying various grain purposes is impossible without using the genetic diversity of wheat. One of the ways to expand the genetic diversity of wheat is to introduce new variants of genes from the genetic pool of congeners and wild relatives into the genotypes of existing varieties. In this study, we used 10 lines from the Arsenal collection created on the genetic basis of the spring variety ‘Rodina’ and the diploid species Aegilops speltoides in the Federal Research Center “Nemchinovka” in 1994. The lines were previously characterized for the presence of translocations and chromosomal rearrangements cytologically and using molecular markers. Technological analyses were performed on grain obtained in Western Siberia and Moscow region. The aim of this study was to establish the possibilities of expanding the phenotypic diversity for technological properties of grain and flour as a result of such hybridization of bread wheat and the diploid cereal Aegilops speltoides. The variety ‘Rodina’ forms a vitreous grain with a high gluten content in Siberia, but has low physical properties of flour and dough. Five derived lines were found to have significantly higher protein and gluten content in grain. The highest values under both growing conditions were found in lines 73/00i, 82/00i, and 84/00i. Two lines (69/00i and 76/00i) showed a high flour strength and dough elasticity, characterizing the lines as strong and valuable in quality. These lines can be used for baking bread. Line 82/00i inherited from Ae. speltoides a soft-grain endosperm, which indicates the introgression of the Ha-Sp gene, homoeoallelic to the Ha gene of bread wheat, into ‘Rodina’. Flour of this line is suitable for the manufacture of confectionery without the use of technological additives. The lines generally retained their characteristics in different growing conditions. They can be attracted as donors of new alleles of genes that determine the technological properties of grain and resistance to biotic stresses.

scholarly journals Intraspecific genomic variation and local adaptation in a young hybrid species

2019 ◽  
Author(s):  
Angélica Cuevas ◽  
Mark Ravinet ◽  
Glenn-Peter Sætre ◽  
Fabrice Eroukhmanoff
Keyword(s):  
Genetic Variation ◽  
Local Adaptation ◽  
Climatic Variation ◽  
Genomic Variation ◽  
Population Divergence ◽  
Parent Species ◽  
Evolutionary Potential ◽  
Variable Environment ◽  
Hybrid Species ◽  
Species Population

ABSTRACTHybridization increases genetic variation, hence hybrid species may have a strong evolutionary potential once their admixed genomes have stabilized and incompatibilities have been purged. Yet, little is known about how such hybrid lineages evolve at the genomic level following their formation, in particular the characteristics of their adaptive potential, i.e. constraints and facilitations of diversification. Here we investigate how the Italian sparrow (Passer italiae), a homoploid hybrid species, has evolved and locally adapted to its variable environment. Using restriction site-associated DNA sequencing (RAD-seq) on several populations across the Italian peninsula, we evaluate how genomic constraints and novel genetic variation have influenced population divergence and adaptation. We show that population divergence within this hybrid species has evolved in response to climatic variation. As in non-hybrid species, climatic differences may even reduce gene flow between populations, suggesting ongoing local adaptation. We report outlier genes associated with adaptation to climatic variation, known to be involved in beak morphology in other species. Most of the strongly divergent loci among Italian sparrow populations seem not to be differentiated between its parent species, the house and Spanish sparrow. Within the parental species, population divergence has occurred mostly in loci where different alleles segregate in the parent species, unlike in the hybrid, suggesting that novel combinations of parental alleles in the hybrid have not necessarily enhanced its evolutionary potential. Rather, our study suggests that constraints linked to incompatibilities may have restricted the evolution of this admixed genome, both during and after hybrid species formation.

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