Project description:CpG islands (CGIs) including those at imprinting control regions (ICRs) are protected from de novo methylation in somatic cells. However, many cancers often exhibit CGI hypermethylation, implying that the machinery is impaired in cancer cells. Here, we conducted a comprehensive analysis of CGI methylation during the somatic cell reprogramming. Although most CGIs remain hypomethylated, a small subset of CGIs, particularly at several ICRs, were often de novo methylated in reprogrammed pluripotent stem cells (PSCs). Such de novo ICR methylation was linked with the silencing of reprogramming factors, which occurs at a late stage of reprogramming. The ICR-preferred CGI hypermethylation was similarly observed in human PSCs. Mechanistically, ablation of Dnmt3a prevented PSCs from de novo ICR methylation. Notably, the ICR-preferred CGI hypermethylation was observed in pediatric cancers, while adult cancers exhibit genome-wide CGI hypermethylation. These results may have important implications in the pathogenesis of pediatric cancers and the application of PSCs.
Project description:De novo copy number variations in cloned dogs from the same nuclear donor In this study, we aimed to identify de novo post-cloning CNV events and estimated the rate of CNV mosaicism in cloned dogs with the identical genetic background. We analyzed CNVs in seven cloned dogs using the nuclear donor genome as reference by array-CGH
Project description:This is the validation data for candidate de novo CNV calls made in the asthma trios by Itsara et al., Genome Research 2010. In this study, de novo CNV calls in the asthma data set were initially made with Illumina 550K SNP arrays. Validation was performed with custom Nimblegen array CGH for which DNA was available. de novo CNVs would be expected to validate in the child of each trio tested, and not be detected in either parent. We attempted to validate 9 de novo CNVs in the same number of trios. In 3 cases, paternal DNA was not available leaving a total of 24 distinct samples for hybridization. All samples were hybridized against a previously well-characterized reference (NA15510; see Tuzun et al., Nat Genet 2005).
Project description:We describe a multiple de novo CNV (MdnCNV) phenomenon in which individuals with genomic disorders carry five to ten constitutional de novo CNVs. Five such families are studied, which consists of four trios and one singleton. Various array platforms are used to interogate these families to identify de novo CNVs.
Project description:We describe a multiple de novo CNV (MdnCNV) phenomenon in which individuals with genomic disorders carry five to ten constitutional de novo CNVs. Five such families are studied, which consists of four trios and one singleton. Various array platforms are used to interogate these families to identify de novo CNVs.