Changes in genome structure and gene expression have been documented in both resynthesized and natural allopolyploids that contain two or more divergent genomes. The underlying mechanisms for rapid and stochastic changes in gene expression are unknown. Arabidopsis suecica is a natural allotetraploid derived from the extant A. thaliana and A. arenosa genomes that are homeologous in the allotetraploid. Here we report that RNAi of met1 reduced DNA methylation and altered the expression of approximately 200 genes, many of which encode transposons, predicted proteins, and centromeric and heterochromatic RNAs. Reduced DNA methylation occurred frequently in promoter regions of the upregulated genes, and an En/Spm-like transposon was reactivated in met1-RNAi A. suecica lines. Derepression of transposons, heterochromatic repeats, and centromeric small RNAs was primarily derived from the A. thaliana genome, and A. arenosa homeologous loci were less affected by methylation defects. A high level of A. thaliana centromeric small RNA accumulation was correlated with hypermethylation of A. thaliana centromeres. The greater effects of reduced DNA methylation on transposons and centromeric repeats in A. thaliana than in A. arenosa are consistent with the repression of many genes that are expressed at higher levels in A. thaliana than in A. arenosa in the resynthesized allotetraploids. Moreover, non-CG (CC) methylation in the promoter region of A. thaliana At2g23810 remained in the resynthesized allotetraploids, and the methylation spread within the promoter region in natural A. suecica, leading to silencing of At2g23810. At2g23810 was demethylated and reactivated in met1-RNAi A. suecica lines. We suggest that many A. thaliana genes are transcriptionally repressed in resynthesized allotetraploids, and a subset of A. thaliana loci including transposons and centromeric repeats are heavily methylated and subjected to homeologous genome-specific RNA-mediated DNA methylation in natural allopolyploids.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2323781 | PMC |
http://dx.doi.org/10.1534/genetics.107.086272 | DOI Listing |
Plant Cell
January 2025
National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China.
Plant architecture greatly contributes to grain yield, but the epigenetic regulation of plant architecture remains elusive. Here, we identified the maize (Zea mays L.) mutant plant architecture 1 (par1), which shows reduced plant height, shorter and narrower leaves, and larger leaf angles than the wild type.
View Article and Find Full Text PDFJ Cell Mol Med
January 2025
Department of Hepatobiliary Surgery, The People's Hospital of Tongnan District Chongqing city, Chongqing, China.
Hepatocellular carcinoma (HCC) is a malignant tumour that poses a serious threat to human health and places a heavy burden on individuals and society. However, the role of GPC1 in the malignant progression of HCC is unknown. In this study, we analysed the expression of GPC1 in HCC, and its association with poor patient prognosis.
View Article and Find Full Text PDFBrain Pathol
January 2025
Department of Laboratory Medicine and Pathology, Tokyo Metropolitan Neurological Hospital, Tokyo Metropolitan Hospital Organization, Tokyo, Japan.
The shift toward a histo-molecular approach in World Health Organization classification of central nervous system tumors (WHO CNS5) emphasizes the critical role of molecular testing, such as next-generation sequencing (NGS) and DNA methylation profiling, for accurate diagnosis. However, implementing these advanced techniques is particularly challenging in resource-constrained countries. To address this, the Asian Oceanian Society of Neuropathology committee for Adapting Diagnostic Approaches for Practical Taxonomy in Resource-Restrained Regions (AOSNP-ADAPTR) was initiated to help pathologists in resource-limited regions to implement WHO CNS5 diagnoses using simpler diagnostic tools, mainly immunohistochemistry.
View Article and Find Full Text PDFSmall
January 2025
Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310016, China.
DNA methylation is an epigenetic mechanism that regulates gene expression and is implicated in diseases such as cancer and atherosclerosis. However, traditional clinical methods for detecting DNA methylation often lack sensitivity and specificity, making early diagnosis challenging. Nanomaterials offer a solution with their unique properties, enabling highly sensitive photochemical and electrochemical detection techniques.
View Article and Find Full Text PDFEur J Epidemiol
January 2025
Gerontology Research Center (GEREC), Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland.
Objectives: The association between leisure-time physical activity (LTPA) and a lower risk of mortality is susceptible to bias from multiple sources. We investigated the potential of biological ageing to mediate the association between long-term LTPA and mortality and whether the methods used to account for reverse causality affect the interpretation of this association.
Methods: Study participants were twins from the older Finnish Twin Cohort (n = 22,750; 18-50 years at baseline).
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!