Project description:DNA methylation is a key epigenetic modification regulating genome organization, stability, and gene expression. Stable DNA methylation critically relies on methyl groups provided through folate-mediated one-carbon (C1) metabolism, yet the origin and regulation of C1 supply remain elusive. Here we demonstrate that photorespiration serves as a major C1 source for DNA methylation in Arabidopsis. We show that C1 from formate, a photorespiratory byproduct, is incorporated into 5-methyl-cytosine via the reductive cytosolic folate pathway. This occurs predominantly during the day, negatively regulating serine utilization as alternative C1 source. Consequently, suppression of photorespiration under elevated CO₂ levels alters the DNA methylation landscape, an effect exacerbated when regulation of C1 metabolism by the formate-dependent pathway is impaired. Thus, our findings link the fundamental metabolic process of photorespiration to epigenetic stability, highlighting how rising atmospheric CO₂ levels can induce DNA methylation changes.
Project description:Genome-wide DNA Methylation Data from Illumina HumanMethylationEPIC arrays for whole blood samples from 570 healthy individuals. Raw IDAT files are available for a subset of 403 samples on EGA. Raw data (IDAT files) and associated phenotype information are available for all individuals included in this study (n=570) directly from CIBMTR. Data are available under controlled access release upon reasonable request and execution of a data use agreement. Requests should be submitted to CIBMTR at info-request@mcw.edu and include the study reference IB17-04.
Project description:Interventions: Gold Standard:colonoscopy;Index test:Stool DNA methylation biomarkers.
Primary outcome(s): accuracy
Study Design: Diagnostic test for accuracy
Project description:In mammals, the acquisition of the germline from the soma provides the germline with an essential challenge, the necessity to erase and reset genomic methylation. In the male germline RNA-directed DNA methylation silences young active transposable elements (TEs). The PIWI protein MIWI2 (PIWIL4) and its associated PIWI-interacting RNAs (piRNAs) are proposed to tether MIWI2 to nascent TE transcripts and instruct DNA methylation. The mechanism by which MIWI2 directs de novo TE methylation is poorly understood but central to the immortality of the germline. Here, we define the interactome of MIWI2 in foetal gonocytes that are undergoing de novo genome methylation and identify a novel MIWI2-associated factor, SPOCD1, that is essential for young TE methylation and silencing. The loss of Spocd1 in mice results in male specific infertility and does not impact on piRNA biogenesis nor localization of MIWI2 to the nucleus. SPOCD1 is a nuclear protein and its expression is restricted to the period of de novo genome methylation. We found SPOCD1 co-purified in vivo with DNMT3L and DNMT3A, components of the de novo methylation machinery as well as constituents of the NURD and BAF chromatin remodelling complexes. We propose a model whereby tethering of MIWI2 to a nascent TE transcript recruits repressive chromatin remodelling activities and the de novo methylation apparatus through its association with SPOCD1. In summary, we have identified a novel and essential executor of mammalian piRNA-directed DNA methylation.
Project description:We intend to establish an efficient method for plasma cfDNA extraction and Bisulfite transformation to facilitate the detection of DNA methylation status using multiplex fluorescence PCR. Meanwhile, we expect to identify several plasma methylation markers that can be highly sensitive for multi-cancer detection. Finally, we will provide a pan-cancer blood test that is easy to operate, low cost, accurate and easy to promote.
Project description:Using post mortem prefrontal cortex material provided by the Harvard Brain Tissue Resource Center at McLean Hospital, DNA methylation data was generated using CHARM.
Project description:Pivotal trials of SDC2 methylation biomarker test in stool DNA to estimate clinical sensitivity and specificity in detection of colorectal cancer.