There has been debate over the mechanisms that control the copy number of transposable elements in the genome of Drosophila melanogaster. Target sites in D. melanogaster populations are occupied at low frequencies, suggesting that there is some form of selection acting against transposable elements. Three main theories have been proposed to explain how selection acts against transposable elements: insertions of a copy of a transposable element are selected against; chromosomal rearrangements caused by ectopic exchange between element copies are selected against; or the process of transposition itself is selected against. The three theories give different predictions for the pattern of transposable element insertions in the chromosomes of D. melanogaster. We analysed the abundance of six LTR (long terminal repeat) retrotransposons on the X and fourth chromosomes of multiple strains of D. melanogaster, which we compare with the predictions of each theory. The data suggest that no one theory can account for the insertion patterns of all six retrotransposons. Comparing our results with earlier work using these transposable element families, we find a significant correlation between studies in the particular model of copy number regulation supported by the proportion of elements on the X for the different transposable element families. This suggests that different retrotransposon families are regulated by different mechanisms.
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http://dx.doi.org/10.1007/s00412-001-0174-0 | DOI Listing |
Somatic mutations in individual cells lead to genomic mosaicism, contributing to the intricate regulatory landscape of genetic disorders and cancers. To evaluate and refine the detection of somatic mosaicism across different technologies with personalized donor-specific assembly (DSA), we obtained tissue from the dorsolateral prefrontal cortex (DLPFC) of a post-mortem neurotypical 31-year-old individual. We sequenced bulk DLPFC tissue using Oxford Nanopore Technologies (∼60X), NovaSeq (∼30X), and linked-read sequencing (∼28X).
View Article and Find Full Text PDFNatl Sci Rev
January 2025
State Key Laboratory of Cardiology and Medical Innovation Center, Department of Reproductive Medicine Center, Shanghai East Hospital, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China.
The overactivation of transposable elements (TEs) is a significant threat to male reproduction, particularly during the delicate process of spermatogenesis. Here, we report that zinc finger protein ZCCHC8-a key component of the nuclear exosome targeting (NEXT) complex that is involved in ribonucleic acid (RNA) surveillance-is required for TE silencing during spermatogenesis. Loss of ZCCHC8 results in delayed meiotic progression and reduced production of round spermatids (RS).
View Article and Find Full Text PDFMol Cell
January 2025
State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing 100084, China. Electronic address:
In a recent issue of Cell, Arribas et al. and Pasquesi et al. explore the phenomenon of transposable element (TE) exonization and its impact on proteomic and immune diversity, highlighting its potential role as a driver of evolutionary innovation.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Signaling and Gene Expression, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037.
is one of the three most frequently mutated genes in age-related clonal hematopoiesis (CH), alongside and (. CH can progress to myeloid malignancies including chronic monomyelocytic leukemia (CMML) and is also strongly associated with inflammatory cardiovascular disease and all-cause mortality in humans. DNMT3A and TET2 regulate DNA methylation and demethylation pathways, respectively, and loss-of-function mutations in these genes reduce DNA methylation in heterochromatin, allowing derepression of silenced elements in heterochromatin.
View Article and Find Full Text PDFNat Microbiol
January 2025
Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.
Transposase genes are ubiquitous in all domains of life and provide a rich reservoir for the evolution of novel protein functions. Here we report deep evolutionary links between bacterial IS110-family transposases, which catalyse RNA-guided DNA recombination using bridge RNAs, and archaeal/eukaryotic Nop5-family proteins, which promote RNA-guided RNA 2'-O-methylation using C/D-box snoRNAs. On the basis of conservation of protein sequence, domain architecture, three-dimensional structure and non-coding RNA features, alongside phylogenetic analyses, we propose that programmable RNA modification emerged through the exaptation of components derived from IS110-like transposons.
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