scholarly journals Transposable elements activity reveals punctuated patterns of speciation in mammals

2016 ◽  
Author(s):  
Marco Ricci ◽  
Valentina Peona ◽  
Etienne Guichard ◽  
Cristian Taccioli ◽  
Alessio Boattini
Keyword(s):  
Transposable Elements ◽  
Adaptive Radiation ◽  
Essential Role ◽  
Relative Rate ◽  
Mammalian Species ◽  
Punctuated Equilibria ◽  
A Genome ◽  
Eukaryotic Genomes

ABSTRACTTransposable elements (TEs) play an essential role in shaping eukaryotic genomes and generating variability. Our “Cold Genome” hypothesis postulates that speciation and TEs activity are strongly related in mammals. In order to test this hypothesis, we created two new parameters: the Density of Insertion (DI) and the Relative Rate of Speciation (RRS). The DI is the ratio between the number of TE insertions in a genome and its size, whereas the RRS is a conditional parameter designed to identify potential speciation bursts. Thus, by analyzing TEs insertions in mammals, we defined the genomes as “hot” (low DI) and “cold” (high DI). Then, comparing TEs activity among 16 intra-order pairs of mammalian species, 4 superorders of Eutheria and 29 taxonomical families of the whole Mammalia class, we showed that taxa with positive RRS correlate with “hot” genomes, whereas taxa with negative RRS correlate with “cold” genomes. In addition, our study supports the “Punctuated Equilibria” theory in mammals for both adaptive radiation and stasis.

scholarly journals Transposable Elements and Teleost Migratory Behaviour

2021 ◽  
Vol 22 (2) ◽  
pp. 602
Author(s):  
Elisa Carotti ◽  
Federica Carducci ◽  
Adriana Canapa ◽  
Marco Barucca ◽  
Samuele Greco ◽  
...  
Keyword(s):  
Transposable Elements ◽  
Environmental Changes ◽  
Chromosomal Rearrangements ◽  
Quantitative Difference ◽  
Regulatory Elements ◽  
Phylogenetic Position ◽  
Migratory Behaviour ◽  
Relative Contribution ◽  
Migratory Routes ◽  
Eukaryotic Genomes

Transposable elements (TEs) represent a considerable fraction of eukaryotic genomes, thereby contributing to genome size, chromosomal rearrangements, and to the generation of new coding genes or regulatory elements. An increasing number of works have reported a link between the genomic abundance of TEs and the adaptation to specific environmental conditions. Diadromy represents a fascinating feature of fish, protagonists of migratory routes between marine and freshwater for reproduction. In this work, we investigated the genomes of 24 fish species, including 15 teleosts with a migratory behaviour. The expected higher relative abundance of DNA transposons in ray-finned fish compared with the other fish groups was not confirmed by the analysis of the dataset considered. The relative contribution of different TE types in migratory ray-finned species did not show clear differences between oceanodromous and potamodromous fish. On the contrary, a remarkable relationship between migratory behaviour and the quantitative difference reported for short interspersed nuclear (retro)elements (SINEs) emerged from the comparison between anadromous and catadromous species, independently from their phylogenetic position. This aspect is likely due to the substantial environmental changes faced by diadromous species during their migratory routes.

scholarly journals The intrinsic combinatorial organization and information theoretic content of a sequence are correlated to the DNA encoded nucleosome organization of eukaryotic genomes

2015 ◽  
Vol 32 (6) ◽  
pp. 835-842 ◽  
Author(s):  
Filippo Utro ◽  
Valeria Di Benedetto ◽  
Davide F.V. Corona ◽  
Raffaele Giancarlo
Keyword(s):  
Closed Form ◽  
Dna Sequence ◽  
Chemical Properties ◽  
Supplementary Information ◽  
Information Theoretic ◽  
Nucleosome Organization ◽  
A Genome ◽  
Intrinsic Complexity ◽  
Mathematical Formulas ◽  
Eukaryotic Genomes

Abstract Motivation: Thanks to research spanning nearly 30 years, two major models have emerged that account for nucleosome organization in chromatin: statistical and sequence specific. The first is based on elegant, easy to compute, closed-form mathematical formulas that make no assumptions of the physical and chemical properties of the underlying DNA sequence. Moreover, they need no training on the data for their computation. The latter is based on some sequence regularities but, as opposed to the statistical model, it lacks the same type of closed-form formulas that, in this case, should be based on the DNA sequence only. Results: We contribute to close this important methodological gap between the two models by providing three very simple formulas for the sequence specific one. They are all based on well-known formulas in Computer Science and Bioinformatics, and they give different quantifications of how complex a sequence is. In view of how remarkably well they perform, it is very surprising that measures of sequence complexity have not even been considered as candidates to close the mentioned gap. We provide experimental evidence that the intrinsic level of combinatorial organization and information-theoretic content of subsequences within a genome are strongly correlated to the level of DNA encoded nucleosome organization discovered by Kaplan et al. Our results establish an important connection between the intrinsic complexity of subsequences in a genome and the intrinsic, i.e. DNA encoded, nucleosome organization of eukaryotic genomes. It is a first step towards a mathematical characterization of this latter ‘encoding’. Supplementary information: Supplementary data are available at Bioinformatics online. Contact: [email protected].

scholarly journals Unique mobile elements and scalable gene flow at the prokaryote–eukaryote boundary revealed by circularized Asgard archaea genomes

2022 ◽  
Author(s):  
Fabai Wu ◽  
Daan R. Speth ◽  
Alon Philosof ◽  
Antoine Crémière ◽  
Aditi Narayanan ◽  
...  
Keyword(s):  
Viral Genome ◽  
Scaling Laws ◽  
Continuous Process ◽  
Mobile Elements ◽  
Gene Repertoire ◽  
Bacterial Gene ◽  
Size Dependent ◽  
Sequence Of Events ◽  
A Genome ◽  
Eukaryotic Genomes

AbstractEukaryotic genomes are known to have garnered innovations from both archaeal and bacterial domains but the sequence of events that led to the complex gene repertoire of eukaryotes is largely unresolved. Here, through the enrichment of hydrothermal vent microorganisms, we recovered two circularized genomes of Heimdallarchaeum species that belong to an Asgard archaea clade phylogenetically closest to eukaryotes. These genomes reveal diverse mobile elements, including an integrative viral genome that bidirectionally replicates in a circular form and aloposons, transposons that encode the 5,000 amino acid-sized proteins Otus and Ephialtes. Heimdallaechaeal mobile elements have garnered various genes from bacteria and bacteriophages, likely playing a role in shuffling functions across domains. The number of archaea- and bacteria-related genes follow strikingly different scaling laws in Asgard archaea, exhibiting a genome size-dependent ratio and a functional division resembling the bacteria- and archaea-derived gene repertoire across eukaryotes. Bacterial gene import has thus likely been a continuous process unaltered by eukaryogenesis and scaled up through genome expansion. Our data further highlight the importance of viewing eukaryogenesis in a pan-Asgard context, which led to the proposal of a conceptual framework, that is, the Heimdall nucleation–decentralized innovation–hierarchical import model that accounts for the emergence of eukaryotic complexity.

scholarly journals Software Evaluation for de novo Detection of Transposons

2021 ◽  
Author(s):  
Matias Rodriguez ◽  
Wojciech Makałowski
Keyword(s):  
Transposable Elements ◽  
Genome Evolution ◽  
De Novo ◽  
Simulated Data ◽  
Genomic Sequences ◽  
Software Evaluation ◽  
Easy Task ◽  
Eukaryotic Genomes

AbstractTransposable elements (TEs) are major genomic components in most eukaryotic genomes and play an important role in genome evolution. However, despite their relevance the identification of TEs is not an easy task and a number of tools were developed to tackle this problem. To better understand how they perform, we tested several widely used tools for de novo TE detection and compared their performance on both simulated data and well curated genomic sequences. The results will be helpful for identifying common issues associated with TE-annotation and for evaluating how comparable are the results obtained with different tools.

scholarly journals Prioritization of genes associated with the pathogenesis of leukosis in cattle

2019 ◽  
Vol 22 (8) ◽  
pp. 1063-1069 ◽  
Author(s):  
N. S. Yudin ◽  
N. L. Podkolodnyy ◽  
T. A. Agarkova ◽  
E. V. Ignatieva
Keyword(s):  
Protein Interactions ◽  
Genome Wide Association Study ◽  
Association Studies ◽  
Mammalian Species ◽  
Genome Wide Association ◽  
Farm Animals ◽  
Genome Wide Association Studies ◽  
Protein Protein Interactions ◽  
Genome Wide ◽  
A Genome

Selection by means of genetic markers is a promising approach to the eradication of infectious diseases in farm animals, especially in the absence of effective methods of treatment and prevention. Bovine leukemia virus (BLV) is spread throughout the world and represents one of the biggest problems for the livestock production and food security in Russia. However, recent genome-wide association studies have shown that sensitivity/resistance to BLV is polygenic. The aim of this study was to create a catalog of cattle genes and genes of other mammalian species involved in the pathogenesis of BLV-induced infection and to perform gene prioritization using bioinformatics methods. Based on manually collected information from a range of open sources, a total of 446 genes were included in the catalog of cattle genes and genes of other mammals involved in the pathogenesis of BLV-induced infection. The following criteria were used to prioritize 446 genes from the catalog: (1) the gene is associated with leukemia according to a genome-wide association study; (2) the gene is associated with leukemia according to a case-control study; (3) the role of the gene in leukemia development has been studied using knockout mice; (4) protein-protein interactions exist between the gene-encoded protein and either viral particles or individual viral proteins; (5) the gene is annotated with Gene Ontology terms that are overrepresented for a given list of genes; (6) the gene participates in biological pathways from the KEGG or REACTOME databases, which are over-represented for a given list of genes; (7) the protein encoded by the gene has a high number of protein-protein interactions with proteins encoded by other genes from the catalog. Based on each criterion, a rank was assigned to each gene. Then the ranks were summarized and an overall rank was determined. Prioritization of 446 candidate genes allowed us to identify 5 genes of interest (TNF,LTB,BOLA-DQA1,BOLA-DRB3,ATF2), which can affect the sensitivity/resistance of cattle to leukemia.

scholarly journals Low temperature triggers genome-wide hypermethylation of transposable elements and centromeres in maize

2019 ◽  
Author(s):  
Zeineb Achour ◽  
Johann Joets ◽  
Martine Leguilloux ◽  
Hélène Sellier ◽  
Jean-Philippe Pichon ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Transposable Elements ◽  
Transcriptional Activation ◽  
Gene Expression Regulation ◽  
Environmental Cues ◽  
Specific Response ◽  
Genome Wide ◽  
A Genome ◽  
Response To Stress ◽  
Context Specific

ABSTRACTCharacterizing the molecular processes developed by plants to respond to environmental cues is a major task to better understand local adaptation. DNA methylation is a chromatin mark involved in the transcriptional silencing of transposable elements (TEs) and gene expression regulation. While the molecular bases of DNA methylation regulation are now well described, involvement of DNA methylation in plant response to environmental cues remains poorly characterized. Here, using the TE-rich maize genome and analyzing methylome response to prolonged cold at the chromosome and feature scales, we investigate how genomic architecture affects methylome response to stress in a cold-sensitive genotype. Interestingly, we show that cold stress induces a genome-wide methylation increase through the hypermethylation of TE sequences and centromeres. Our work highlights a cytosine context-specific response of TE methylation that depends on TE types, chromosomal location and proximity to genes. The patterns observed can be explained by the parallel transcriptional activation of multiple DNA methylation pathways that methylate TEs in the various chromatin locations where they reside. Our results open new insights into the possible role of genome-wide DNA methylation in phenotypic response to stress.

scholarly journals Benchmarking transposable element annotation methods for creation of a streamlined, comprehensive pipeline

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Shujun Ou ◽  
Weija Su ◽  
Yi Liao ◽  
Kapeel Chougule ◽  
Jireh R. A. Agda ◽  
...  
Keyword(s):  
Transposable Elements ◽  
Animal Species ◽  
Performance Metrics ◽  
De Novo ◽  
Terminal Inverted Repeat ◽  
Miniature Inverted Transposable Elements ◽  
Sensitivity Specificity ◽  
Genomic Regions ◽  
Assembly Algorithms ◽  
Eukaryotic Genomes

Abstract Background Sequencing technology and assembly algorithms have matured to the point that high-quality de novo assembly is possible for large, repetitive genomes. Current assemblies traverse transposable elements (TEs) and provide an opportunity for comprehensive annotation of TEs. Numerous methods exist for annotation of each class of TEs, but their relative performances have not been systematically compared. Moreover, a comprehensive pipeline is needed to produce a non-redundant library of TEs for species lacking this resource to generate whole-genome TE annotations. Results We benchmark existing programs based on a carefully curated library of rice TEs. We evaluate the performance of methods annotating long terminal repeat (LTR) retrotransposons, terminal inverted repeat (TIR) transposons, short TIR transposons known as miniature inverted transposable elements (MITEs), and Helitrons. Performance metrics include sensitivity, specificity, accuracy, precision, FDR, and F1. Using the most robust programs, we create a comprehensive pipeline called Extensive de-novo TE Annotator (EDTA) that produces a filtered non-redundant TE library for annotation of structurally intact and fragmented elements. EDTA also deconvolutes nested TE insertions frequently found in highly repetitive genomic regions. Using other model species with curated TE libraries (maize and Drosophila), EDTA is shown to be robust across both plant and animal species. Conclusions The benchmarking results and pipeline developed here will greatly facilitate TE annotation in eukaryotic genomes. These annotations will promote a much more in-depth understanding of the diversity and evolution of TEs at both intra- and inter-species levels. EDTA is open-source and freely available: https://github.com/oushujun/EDTA.

scholarly journals Roles of Transposable Elements in the Different Layers of Gene Expression Regulation

2019 ◽  
Vol 20 (22) ◽  
pp. 5755 ◽  
Author(s):  
Denise Drongitis ◽  
Francesco Aniello ◽  
Laura Fucci ◽  
Aldo Donizetti
Keyword(s):  
Gene Expression ◽  
Transposable Elements ◽  
Gene Expression Regulation ◽  
Regulation Of Gene Expression ◽  
Chromatin Modification ◽  
Essential Element ◽  
Protein Translation ◽  
Expression Regulation ◽  
Molecular Processes ◽  
Eukaryotic Genomes

The biology of transposable elements (TEs) is a fascinating and complex field of investigation. TEs represent a substantial fraction of many eukaryotic genomes and can influence many aspects of DNA function that range from the evolution of genetic information to duplication, stability, and gene expression. Their ability to move inside the genome has been largely recognized as a double-edged sword, as both useful and deleterious effects can result. A fundamental role has been played by the evolution of the molecular processes needed to properly control the expression of TEs. Today, we are far removed from the original reductive vision of TEs as “junk DNA”, and are more convinced that TEs represent an essential element in the regulation of gene expression. In this review, we summarize some of the more recent findings, mainly in the animal kingdom, concerning the active roles that TEs play at every level of gene expression regulation, including chromatin modification, splicing, and protein translation.

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