scholarly journals Comparative Genomic Analyses Reveal Core-Genome-Wide Genes Under Positive Selection and Major Regulatory Hubs in Outlier Strains of Pseudomonas aeruginosa

2019 ◽  
Vol 10 ◽  
Author(s):  
Utkarsh Sood ◽  
Princy Hira ◽  
Roshan Kumar ◽  
Abhay Bajaj ◽  
Desiraju Lakshmi Narsimha Rao ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Positive Selection ◽  
Core Genome ◽  
Comparative Genomic ◽  
Genome Wide ◽  
Genomic Analyses

scholarly journals Comparative genomic and transcriptomic analyses of transposable elements in polychaetous annelids highlight LTR retrotransposon diversity and evolution

Mobile DNA ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jonathan Filée ◽  
Sarah Farhat ◽  
Dominique Higuet ◽  
Laure Teysset ◽  
Dominique Marie ◽  
...  
Keyword(s):  
Transposable Elements ◽  
High Throughput Sequencing ◽  
Comparative Genomic ◽  
Ltr Retrotransposon ◽  
Genomic Evolution ◽  
Genome Wide ◽  
Genomic Analyses ◽  
Different Types ◽  
Evolutionary Success ◽  
Low Coverage

Abstract Background With the expansion of high throughput sequencing, we now have access to a larger number of genome-wide studies analyzing the Transposable elements (TEs) composition in a wide variety of organisms. However, genomic analyses often remain too limited in number and diversity of species investigated to study in depth the dynamics and evolutionary success of the different types of TEs among metazoans. Therefore, we chose to investigate the use of transcriptomes to describe the diversity of TEs in phylogenetically related species by conducting the first comparative analysis of TEs in two groups of polychaetes and evaluate the diversity of TEs that might impact genomic evolution as a result of their mobility. Results We present a detailed analysis of TEs distribution in transcriptomes extracted from 15 polychaetes depending on the number of reads used during assembly, and also compare these results with additional TE scans on associated low-coverage genomes. We then characterized the clades defined by 1021 LTR-retrotransposon families identified in 26 species. Clade richness was highly dependent on the considered superfamily. Copia elements appear rare and are equally distributed in only three clades, GalEa, Hydra and CoMol. Among the eight BEL/Pao clades identified in annelids, two small clades within the Sailor lineage are new for science. We characterized 17 Gypsy clades of which only 4 are new; the C-clade largely dominates with a quarter of the families. Finally, all species also expressed for the majority two distinct transcripts encoding PIWI proteins, known to be involved in control of TEs mobilities. Conclusions This study shows that the use of transcriptomes assembled from 40 million reads was sufficient to access to the diversity and proportion of the transposable elements compared to those obtained by low coverage sequencing. Among LTR-retrotransposons Gypsy elements were unequivocally dominant but results suggest that the number of Gypsy clades, although high, may be more limited than previously thought in metazoans. For BEL/Pao elements, the organization of clades within the Sailor lineage appears more difficult to establish clearly. The Copia elements remain rare and result from the evolutionary consistent success of the same three clades.

scholarly journals The Sinorhizobium fredii HH103 Genome: A Comparative Analysis With S. fredii Strains Differing in Their Symbiotic Behavior With Soybean

2015 ◽  
Vol 28 (7) ◽  
pp. 811-824 ◽  
Author(s):  
José-María Vinardell ◽  
Sebastián Acosta-Jurado ◽  
Susanne Zehner ◽  
Michael Göttfert ◽  
Anke Becker ◽  
...  
Keyword(s):  
Core Genome ◽  
Comparative Genomic ◽  
Secretion Systems ◽  
Sinorhizobium Fredii ◽  
The Core ◽  
Sensing Systems ◽  
Plot Analysis ◽  
Genomic Analyses ◽  
Surface Polysaccharide ◽  
Protein Secretion Systems

Sinorhizobium fredii HH103 is a fast-growing rhizobial strain infecting a broad range of legumes including both American and Asiatic soybeans. In this work, we present the sequencing and annotation of the HH103 genome (7.25 Mb), consisting of one chromosome and six plasmids and representing the structurally most complex sinorhizobial genome sequenced so far. Comparative genomic analyses of S. fredii HH103 with strains USDA257 and NGR234 showed that the core genome of these three strains contains 4,212 genes (61.7% of the HH103 genes). Synteny plot analysis revealed that the much larger chromosome of USDA257 (6.48 Mb) is colinear to the HH103 (4.3 Mb) and NGR324 chromosomes (3.9 Mb). An additional region of the USDA257 chromosome of about 2 Mb displays similarity to plasmid pSfHH103e. Remarkable differences exist between HH103 and NGR234 concerning nod genes, flavonoid effect on surface polysaccharide production, and quorum-sensing systems. Furthermore a number of protein secretion systems have been found. Two genes coding for putative type III–secreted effectors not previously described in S. fredii, nopI and gunA, have been located on the HH103 genome. These differences could be important to understand the different symbiotic behavior of S. fredii strains HH103, USDA257, and NGR234 with soybean.

scholarly journals Comparative genomics reveals high rates of horizontal transfer and strong purifying selection on rhizobial symbiosis genes

2021 ◽  
Vol 288 (1942) ◽  
pp. 20201804
Author(s):  
Brendan Epstein ◽  
Peter Tiffin
Keyword(s):  
Positive Selection ◽  
Horizontal Transfer ◽  
Purifying Selection ◽  
Comparative Genomic ◽  
N Fixation ◽  
Functional Roles ◽  
Genome Wide ◽  
Rhizobial Symbiosis ◽  
Legume Symbiosis ◽  
Insight Into

Horizontal transfer (HT) alters the repertoire of symbiosis genes in rhizobial genomes and may play an important role in the on-going evolution of the rhizobia–legume symbiosis. To gain insight into the extent of HT of symbiosis genes with different functional roles (nodulation, N-fixation, host benefit and rhizobial fitness), we conducted comparative genomic and selection analyses of the full-genome sequences from 27 rhizobial genomes. We find that symbiosis genes experience high rates of HT among rhizobial lineages but also bear signatures of purifying selection (low Ka : Ks). HT and purifying selection appear to be particularly strong in genes involved in initiating the symbiosis (e.g. nodulation) and in genome-wide association candidates for mediating benefits provided to the host. These patterns are consistent with rhizobia adapting to the host environment through the loss and gain of symbiosis genes, but not with host-imposed positive selection driving divergence of symbiosis genes through recurring bouts of positive selection.

scholarly journals Comparative genomic analysis of Mycobacterium tuberculosis reveals evolution and genomic instability within Uganda I sub-lineage

2020 ◽  
Author(s):  
Stephen Kanyerezi ◽  
Patricia Nabisubi
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Core Genome ◽  
Variant Calling ◽  
Genomic Analysis ◽  
Comparative Genomic Analysis ◽  
Genome Wide Association ◽  
Comparative Genomic ◽  
Pan Genome ◽  
Genome Wide

AbstractIntroductionTuberculosis (TB) is the leading cause of morbidity and mortality globally, responsible for an estimated annual 10.0 million new cases and 1.3 million deaths among infectious diseases with Africa contributing a quarter of these cases in 2019. Classification of Mycobacterium tuberculosis (MTB) strains is important in understanding their geographical predominance and pathogenicity. Different studies have gone ahead to classify MTB using different methods. Some of these include; RFLP, spoligotyping, MIRU-VNTR and SNP set based phylogeny. The SNP set based classification has been found to be in concordance with the region of difference (RD) analysis of MTB complex classification system. In Uganda, the most common cause of pulmonary tuberculosis (PTB) is Uganda genotype of MTB and accounts for up to 70 % of isolates.MethodsSequenced MTB genome samples were retrieved from NCBI and others from local sequencing projects. The genomes were subjected to snippy (a rapid haploid variant calling and core genome alignment) to call variants and annotate them. Outputs from snippy were used to classify the isolates into Uganda genotypes and Non Ugandan genotypes based on 62 SNP set. The Ugandan genotype isolates were later subjected to 413 SNP set and then to a pan genome wide association analysis.Results6 Uganda genotype isolates were found not to classify as either Uganda I or II genotypes based on the 62 SNP set. Using the 413 SNP set, the 6 Uganda genotype isolates were found to have only one SNP out of the 7 SNPs that classify the Uganda I genotypes. They were also found to have both missense and frameshift mutations within the ctpH gene whereas the rest of Uganda I that had a mutation within this gene, was a missense.ConclusionAmong the Uganda genotypes genomes, Uganda I genomes are unstable. We used publicly available datasets to perform analysis like mapping, variant calling, mixed infection, pan-genome analysis to investigate and compare evolution of the Ugandan genotype.

scholarly journals Comparative Genomics Highlight the Importance of Lineage-Specific Gene Families in Evolutionary Divergence of the Coral Genus, Montipora

2021 ◽  
Author(s):  
Yuki Yoshioka ◽  
Go Suzuki ◽  
Yuna Zayasu ◽  
Hiroshi Yamashita ◽  
Chuya Shinzato
Keyword(s):  
Positive Selection ◽  
Early Life ◽  
Gene Families ◽  
Comparative Genomic ◽  
Specific Gene ◽  
Biological Traits ◽  
Life Stages ◽  
Early Life Stages ◽  
Genomic Analyses ◽  
Lineage Specific Gene

Abstract Background: Scleractinian corals of the genus Montipora (Anthozoa, Cnidaria) possess some unusual biological traits, such as vertical transmission of algal symbionts; however, the genetic bases for those traits remain unknown. We performed extensive comparative genomic analyses among members of the family Acroporidae (Montipora, Acropora and Astreopora) to explore genomic novelties to explain unique biological traits of Montipora using improved genome assemblies and gene predictions for M. cactus, M. efflorescens and Astreopora myriophthalma. Results: We obtained genomic data for the three species, of comparable high quality to other published coral genomes. Comparative genomic analyses revealed that the number of gene families restricted to Montipora are significantly higher than those of Acropora and Astreopora, but their functions are largely unknown. The number of gene families specifically expanded in Montipora was much lower than the number specifically expanded in Acropora. In addition, we found that evolutionary rates of the Montipora-specific gene families were significantly higher than other gene families shared with Acropora and/or Astreopora. Of 40 gene families under positive selection (Ka/Ks ratio > 1) in Montipora, 30 were specifically detected in Montipora-specific gene families. Comparative transcriptome analysis of early life stages of Montipora, which possesses maternally inherited symbionts, and Acropora, which lacks them, revealed that most gene families continuously expressed in Montipora, but not expressed in Acropora do not have orthologs in Acropora. Among the 30 Montipora-specific gene families under positive selection, 27 are expressed in early life stages. Conclusions: Lineage-specific gene families were important to establish the genus Montipora, particularly genes expressed throughout early life stages, which under positive selection, gave rise to biological traits unique to Montipora. Our findings highlight evolutionarily acquired genomic bases that may support symbiosis in these stony corals and provide novel insights into mechanisms of coral-algal symbiosis, the physiological foundation of coral reefs.

scholarly journals Evolutionary basis of high-frequency hearing in the cochleae of echolocators revealed by comparative genomics

2019 ◽  
Author(s):  
Hui Wang ◽  
Hanbo Zhao ◽  
Keping Sun ◽  
Xiaobin Huang ◽  
Longru Jin ◽  
...  
Keyword(s):  
Positive Selection ◽  
High Frequency ◽  
Genetic Basis ◽  
Comparative Genomic ◽  
Rna Seq ◽  
Physiological Processes ◽  
Genomic Analyses ◽  
Physiological Pathways ◽  
Almost All ◽  
Auditory Processes

Abstract High-frequency hearing is important for the survival of both echolocating bats and whales, but our understanding of its genetic basis is scattered and segmented. In this study, we combined RNA-Seq and comparative genomic analyses to obtain insights into the comprehensive gene expression profile of the cochlea and the adaptive evolution of hearing-related genes. A total of 144 genes were found to have been under positive selection in various species of echolocating bats and toothed whales, 34 of which were identified to be related to hearing behavior or auditory processes. Subsequently, multiple physiological processes associated with those genes were found to have adaptively evolved in echolocating bats and toothed whales, including cochlear bony development, antioxidant activity, ion balance, and homeostatic processes, along with signal transduction. In addition, abundant convergent/parallel genes and sites were detected between different pairs of echolocator species; however, no specific hearing-related physiological pathways were enriched by them and almost all of the convergent/parallel signals were selectively neutral, as previously reported. Notably, two adaptive parallel evolved sites in TECPR2 were shown to have been under positive selection, indicating their functional importance for the evolution of echolocation and high-frequency hearing in laryngeal echolocating bats. This study deepens our understanding of the genetic bases underlying high-frequency hearing in the cochlea of echolocating bats and toothed whales.

scholarly journals Genetic Contribution of Endometriosis to the Risk of Developing Hormone-Related Cancers

2021 ◽  
Vol 22 (11) ◽  
pp. 6083
Author(s):  
Aintzane Rueda-Martínez ◽  
Aiara Garitazelaia ◽  
Ariadna Cilleros-Portet ◽  
Sergi Marí ◽  
Rebeca Arauzo ◽  
...  
Keyword(s):  
Mendelian Randomization ◽  
Clear Cell ◽  
Association Studies ◽  
Epidemiological Data ◽  
Epidemiological Studies ◽  
Genome Wide Association Studies ◽  
Genome Wide ◽  
Genomic Analyses ◽  
Gynecological Disorder ◽  
Robust Evidence

Endometriosis is a common gynecological disorder that has been associated with endometrial, breast and epithelial ovarian cancers in epidemiological studies. Since complex diseases are a result of multiple environmental and genetic factors, we hypothesized that the biological mechanism underlying their comorbidity might be explained, at least in part, by shared genetics. To assess their potential genetic relationship, we performed a two-sample mendelian randomization (2SMR) analysis on results from public genome-wide association studies (GWAS). This analysis confirmed previously reported genetic pleiotropy between endometriosis and endometrial cancer. We present robust evidence supporting a causal genetic association between endometriosis and ovarian cancer, particularly with the clear cell and endometrioid subtypes. Our study also identified genetic variants that could explain those associations, opening the door to further functional experiments. Overall, this work demonstrates the value of genomic analyses to support epidemiological data, and to identify targets of relevance in multiple disorders.

scholarly journals The domestication of Cucurbita argyrosperma as revealed by the genome of its wild relative

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Josué Barrera-Redondo ◽  
Guillermo Sánchez-de la Vega ◽  
Jonás A. Aguirre-Liguori ◽  
Gabriela Castellanos-Morales ◽  
Yocelyn T. Gutiérrez-Guerrero ◽  
...  
Keyword(s):  
Defense Mechanisms ◽  
Population Level ◽  
Growth Hormones ◽  
Comparative Genomic ◽  
Structural Variants ◽  
Closely Related Species ◽  
Level Data ◽  
Genomic Analyses ◽  
Genotype By Sequencing ◽  
Regulation Of Growth

AbstractDespite their economic importance and well-characterized domestication syndrome, the genomic impact of domestication and the identification of variants underlying the domestication traits in Cucurbita species (pumpkins and squashes) is currently lacking. Cucurbita argyrosperma, also known as cushaw pumpkin or silver-seed gourd, is a Mexican crop consumed primarily for its seeds rather than fruit flesh. This makes it a good model to study Cucurbita domestication, as seeds were an essential component of early Mesoamerican diet and likely the first targets of human-guided selection in pumpkins and squashes. We obtained population-level data using tunable Genotype by Sequencing libraries for 192 individuals of the wild and domesticated subspecies of C. argyrosperma across Mexico. We also assembled the first high-quality wild Cucurbita genome. Comparative genomic analyses revealed several structural variants and presence/absence of genes related to domestication. Our results indicate a monophyletic origin of this domesticated crop in the lowlands of Jalisco. We found evidence of gene flow between the domesticated and wild subspecies, which likely alleviated the effects of the domestication bottleneck. We uncovered candidate domestication genes that are involved in the regulation of growth hormones, plant defense mechanisms, seed development, and germination. The presence of shared selected alleles with the closely related species Cucurbita moschata suggests domestication-related introgression between both taxa.

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