Project description:Identifying functional changes in gene regulatory elements in the human lineage is essential to understanding how humans emerged as a species. We performed genome-wide comparative genomic analysis of humans and great apes to identify 1581 Human Ancestor Quickly-Evolved Regions (HAQERs), which we identify as the fastest-evolved regions of the human genome (hg38). To detect how rapid sequence divergence contributed to divergent gene regulatory functionality in HAQERs, we designed in vivo STARR-seq as a multiplex single-cell assay of enhancer activity in the developing mouse brain. We tested multiple haplotypes from hominins (Human/Neanderthal/Denisova) and non-hominins (Chimpanzee and the inferred Human-Chimpanzee ancestor) for 13 HAQERs to assess their enhancer activity in the developing brain. We found significant differences in enhancer activity between hominins and non-hominins in 8 of these sequences.
Project description:Post-mitotic neurons exhibit DNA methylation changes, contrary to the longstanding belief that the epigenetic pattern in terminally differentiated cells is essentially unchanging. While the mechanism and physiological significance of DNA demethylation in neurons have been extensively elucidated, occurrence of de novo DNA methylation and its impacts have been much less investigated. Here we show that neuronal activation induces global de novo DNA methylation at enhancer regions that can repress target genes in primary cultured hippocampal neurons. The functional significance of this de novo DNA methylation was underpinned by the demonstration that inhibition of DNA methyltransferase (DNMT) activity decreased neuronal activity-induced excitatory synaptogenesis. Overexpression of WW and C2 Domain containing 1 (Wwc1), a representative target gene of de novo DNA methylation, could phenocopy this DNMT inhibition-induced decrease in the synaptogenesis. We found that both DNMT1 and DNMT3a were required for the neuronal activity-induced de novo DNA methylation of Wwc1 enhancer. Taking these findings altogether, we concluded that activity-induced de novo DNA methylation affecting gene expression has impacts on neuronal physiology comparable to those of DNA demethylation.
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.