Age-related changes in DNA methylation have been demonstrated in mammals, but it remains unclear as to the generality of this phenomenon in vertebrates, which is a criterion for the fundamental cause of senescence. Here we showed that the zebrafish genome gradually and clearly lost methylcytosine in somatic cells, but not in male germ cells during aging, and that age-dependent hypomethylation preferentially occurred at a particular domain called the CpG island shore, which is associated with vertebrates' genes and has been shown to be hypomethylated in humans with age. We also found that two CpG island shores hypomethylated in zebrafish oocytes were de novo methylated in fertilized eggs, which suggests that the zebrafish epigenome is reset upon fertilization, enabling new generations to restart with a heavily methylated genome. Furthermore, we observed an increase in cleavage of the zebrafish genome to an oligonucleosome length in somatic cells from the age of 12 months, which is suggestive of an elevated rate of apoptosis in the senescent stage.
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http://dx.doi.org/10.1007/s11357-013-9548-5 | DOI Listing |
Epigenetics
December 2025
Survey Research Center, Institute for Social Research, University of Michigan, Ann Arbor, MI, USA.
Perceived discrimination, recognized as a chronic psychosocial stressor, has adverse consequences on health. DNA methylation (DNAm) may be a potential mechanism by which stressors get embedded into the human body at the molecular level and subsequently affect health outcomes. However, relatively little is known about the effects of perceived discrimination on DNAm.
View Article and Find Full Text PDFHum Mol Genet
January 2025
Biomedical Research Centre, School of Biological Sciences, University of East Anglia, Norwich Research Park, Earlham Road, Norwich NR4 6PN, United Kingdom.
Genomic imprinting is the parent-of-origin dependent monoallelic expression of genes often associated with regions of germline-derived DNA methylation that are maintained as differentially methylated regions (gDMRs) in somatic tissues. This form of epigenetic regulation is highly conserved in mammals and is thought to have co-evolved with placentation. Tissue-specific gDMRs have been identified in human placenta, suggesting that species-specific imprinting dependent on unorthodox epigenetic establishment or maintenance may be more widespread than previously anticipated.
View Article and Find Full Text PDFBreast Cancer Res
January 2025
Precision Medicine, School of Clinical Sciences at Monash Health, Monash University, 246 Clayton Road, Clayton, VIC, 3168, Australia.
Background: Tumour DNA methylation has been investigated as a potential marker for breast cancer survival, but findings often lack replication across studies.
Methods: This study sought to replicate previously reported associations for individual CpG sites and multi-CpG signatures using an Australian sample of 425 women with breast cancer from the Melbourne Collaborative Cohort Study (MCCS). Candidate methylation sites (N = 22) and signatures (N = 3) potentially associated with breast cancer survival were identified from five prior studies that used The Cancer Genome Atlas (TCGA) methylation dataset, which shares key characteristics with the MCCS: comparable sample size, tissue type (formalin-fixed paraffin-embedded; FFPE), technology (Illumina HumanMethylation450 array), and participant characteristics (age, ancestry, and disease subtype and severity).
Cancer Sci
January 2025
Oncology Innovation Center, Fujita Health University, Toyoake, Aichi, Japan.
Colorectal cancer (CRC) is well characterized in terms of genetic mutations and the mechanisms by which they contribute to carcinogenesis. Mutations in APC, TP53, and KRAS are common in CRC, indicating key roles for these genes in tumor development and progression. However, for certain tumors with low frequencies of these mutations that are defined by tumor location and molecular phenotypes, a carcinogenic mechanism dependent on BRAF mutations has been proposed.
View Article and Find Full Text PDFBMC Cancer
January 2025
Department of Urology, Sir Run-Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, 310016, Zhejiang Province, China.
Purpose: Renal cell carcinoma (RCC) is a common malignancy, with patients frequently diagnosed at an advanced stage due to the absence of sufficiently sensitive detection technologies, significantly compromising patient survival and quality of life. Advances in cell-free DNA (cfDNA) methylation profiling using liquid biopsies offer a promising non-invasive diagnostic option, but robust biomarkers for early detection are current not available. This study aimed to identify methylation biomarkers for RCC and establish a DNA methylation signature-based prognostic model for this disease.
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