scholarly journals Transposable Elements Adaptive Role in Genome Plasticity, Pathogenicity and Evolution in Fungal Phytopathogens

2019 ◽  
Vol 20 (14) ◽  
pp. 3597 ◽  
Author(s):  
Nurhani Mat Razali ◽  
Boon Huat Cheah ◽  
Kalaivani Nadarajah
Keyword(s):  
Transposable Elements ◽  
Regulatory Elements ◽  
Genome Architecture ◽  
Genome Plasticity ◽  
Epigenetic Control ◽  
Effector Genes ◽  
Fungal Phytopathogens ◽  
Induced Changes ◽  
Adaptive Role

Transposable elements (TEs) are agents of genetic variability in phytopathogens as they are a source of adaptive evolution through genome diversification. Although many studies have uncovered information on TEs, the exact mechanism behind TE-induced changes within the genome remains poorly understood. Furthermore, convergent trends towards bigger genomes, emergence of novel genes and gain or loss of genes implicate a TE-regulated genome plasticity of fungal phytopathogens. TEs are able to alter gene expression by revamping the cis-regulatory elements or recruiting epigenetic control. Recent findings show that TEs recruit epigenetic control on the expression of effector genes as part of the coordinated infection strategy. In addition to genome plasticity and diversity, fungal pathogenicity is an area of economic concern. A survey of TE distribution suggests that their proximity to pathogenicity genes TEs may act as sites for emergence of novel pathogenicity factors via nucleotide changes and expansion or reduction of the gene family. Through a systematic survey of literature, we were able to conclude that the role of TEs in fungi is wide: ranging from genome plasticity, pathogenicity to adaptive behavior in evolution. This review also identifies the gaps in knowledge that requires further elucidation for a better understanding of TEs’ contribution to genome architecture and versatility.

Role of transposable elements in heterochromatin and epigenetic control

Nature ◽  
2004 ◽  
Vol 430 (6998) ◽  
pp. 471-476 ◽  
Author(s):  
Zachary Lippman ◽  
Anne-Valérie Gendrel ◽  
Michael Black ◽  
Matthew W. Vaughn ◽  
Neilay Dedhia ◽  
...  
Keyword(s):  
Transposable Elements ◽  
Epigenetic Control

Sensing Non-sense in Animal Sex From Perspective of Transposable Elements

2021 ◽  
Vol 1 (2) ◽  
pp. 1-9
Author(s):  
Ayan Mukherjee
Keyword(s):  
Transposable Elements ◽  
Sex Determination ◽  
Sex Chromosomes ◽  
Chromosomal Rearrangement ◽  
Repetitive Sequences ◽  
Regulatory Elements ◽  
Vertebrate Species ◽  
Temperature Dependent ◽  
Genomic Regions

Evolution of vertebrate species took shape through millions of years, where sex played an important role in maintenance of a lineage, genetic diversifications and reproductive isolation. On due course of sexual evolution, sex determination strategies have been proposed to flow from temperature dependent sex determination to genetic sex determination, which has been demonstrated as XY system in mammals and ZW system in birds. In contrary to this established conception, different lineages showed to have overlapping sex determining strategies. While searching possible reasons for these phenomenons, researchers observed that gene content of sex chromosomes is highly variable as far as their location and prevalence is concerned, which otherwise suggested autosomal origin of sex chromosomes. Although the exact mechanisms of gene transfer and thereby origin of sex chromosomes are yet to be unveiled, but chromosomal rearrangement and introgression has been hypothesized to be the possible effector. Transposable elements (TEs) are long been considered to be ‘Selfish’ or ‘Junk’ DNA material as most of the non-coding genomic regions are comprised by TEs, which did not make any sense to be a part of species genome. But recently, TEs are being considered to be a nature’s tool for biological innovation by creating new regulatory elements, new coding sequences, genetic disruption and chromosomal remodelling. So, this has been postulated that TEs could facilitate rearrangement and introgression, which ultimately lead to evolution of sex chromosomes and sex determining genes through positive selection. Prevalence of highly repetitive sequences in sex chromosomes, particularly in Y, makes it a hot bed for TEs mediated rearrangement and introgression. In this review, I tried to discuss whether it makes any sense to focus on the role of TEs in sexual evolution of animals.

scholarly journals Decoding the Role of Satellite DNA in Genome Architecture and Plasticity—An Evolutionary and Clinical Affair

Genes ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 72 ◽  
Author(s):  
Sandra Louzada ◽  
Mariana Lopes ◽  
Daniela Ferreira ◽  
Filomena Adega ◽  
Ana Escudeiro ◽  
...  
Keyword(s):  
Repetitive Dna ◽  
Current Knowledge ◽  
Genome Architecture ◽  
Genome Plasticity ◽  
Turnover Rates ◽  
High Turnover ◽  
Satellite Dnas ◽  
Genomic Technologies ◽  
Eukaryotic Genomes

Repetitive DNA is a major organizational component of eukaryotic genomes, being intrinsically related with their architecture and evolution. Tandemly repeated satellite DNAs (satDNAs) can be found clustered in specific heterochromatin-rich chromosomal regions, building vital structures like functional centromeres and also dispersed within euchromatin. Interestingly, despite their association to critical chromosomal structures, satDNAs are widely variable among species due to their high turnover rates. This dynamic behavior has been associated with genome plasticity and chromosome rearrangements, leading to the reshaping of genomes. Here we present the current knowledge regarding satDNAs in the light of new genomic technologies, and the challenges in the study of these sequences. Furthermore, we discuss how these sequences, together with other repeats, influence genome architecture, impacting its evolution and association with disease.

scholarly journals The adaptive role of transposable elements in the Drosophila genome

Gene ◽  
2009 ◽  
Vol 448 (2) ◽  
pp. 124-133 ◽  
Author(s):  
Josefa González ◽  
Dmitri A. Petrov
Keyword(s):  
Transposable Elements ◽  
Drosophila Genome ◽  
Adaptive Role

scholarly journals Transposable Elements in the Genome of the Lichen-Forming Fungus Umbilicaria pustulata and Their Distribution in Different Climate Zones along Elevation

Biology ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 24
Author(s):  
Francesco Dal Grande ◽  
Véronique Jamilloux ◽  
Nathalie Choisne ◽  
Anjuli Calchera ◽  
Gregor Rolshausen ◽  
...  
Keyword(s):  
Transposable Elements ◽  
Life History Traits ◽  
Phenotypic Diversity ◽  
Genome Plasticity ◽  
Elevation Gradients ◽  
Climate Niche ◽  
Fungal Evolution ◽  
Specific Distribution ◽  
Insertion Frequency

Transposable elements (TEs) are an important source of genome plasticity across the tree of life. Drift and natural selection are important forces shaping TE distribution and accumulation. Fungi, with their multifaceted phenotypic diversity and relatively small genome size, are ideal models to study the role of TEs in genome evolution and their impact on the host’s ecological and life history traits. Here we present an account of all TEs found in a high-quality reference genome of the lichen-forming fungus Umbilicaria pustulata, a macrolichen species comprising two climatic ecotypes: Mediterranean and cold temperate. We trace the occurrence of the newly identified TEs in populations along three elevation gradients using a Pool-Seq approach to identify TE insertions of potential adaptive significance. We found that TEs cover 21.26% of the 32.9 Mbp genome, with LTR Gypsy and Copia clades being the most common TEs. We identified 28 insertions displaying consistent insertion frequency differences between the two host ecotypes across the elevation gradients. Most of the highly differentiated insertions were located near genes, indicating a putative function. This pioneering study of the content and climate niche-specific distribution of TEs in a lichen-forming fungus contributes to understanding the roles of TEs in fungal evolution.

Digital x-ray mapping of nanometer-size supported bimetallic catalysts

1988 ◽  
Vol 46 ◽  
pp. 530-531
Author(s):  
L. T. Germinario
Keyword(s):  
Background Radiation ◽  
Metal Cluster ◽  
Single Element ◽  
Beam Diameter ◽  
X Rays ◽  
X Ray ◽  
Major Interest ◽  
Induced Changes

Understanding the role of metal cluster composition in determining catalytic selectivity and activity is of major interest in heterogeneous catalysis. The electron microscope is well established as a powerful tool for ultrastructural and compositional characterization of support and catalyst. Because the spatial resolution of x-ray microanalysis is defined by the smallest beam diameter into which the required number of electrons can be focused, the dedicated STEM with FEG is the instrument of choice. The main sources of errors in energy dispersive x-ray analysis (EDS) are: (1) beam-induced changes in specimen composition, (2) specimen drift, (3) instrumental factors which produce background radiation, and (4) basic statistical limitations which result in the detection of a finite number of x-ray photons. Digital beam techniques have been described for supported single-element metal clusters with spatial resolutions of about 10 nm. However, the detection of spurious characteristic x-rays away from catalyst particles produced images requiring several image processing steps.

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