bioRxiv Science⌕ Search

bioRxiv · 10.1101/2023.02.17.528965

NSD1 deposits histone H3 lysine 36 dimethylation to pattern non-CG DNA methylation in neurons

Abstract

During postnatal development the DNA methyltransferase DNMT3A deposits high levels of non-CG cytosine methylation in neurons. This unique methylation is critical for transcriptional regulation in the mature mammalian brain, and loss of this mark is implicated in DNMT3A-associated neurodevelopmental disorders (NDDs). The mechanisms determining genomic non-CG methylation profiles are not well defined however, and it is unknown if this pathway is disrupted in additional NDDs. Here we show that genome topology and gene expression converge to shape histone H3 lysine 36 dimethylation (H3K36me2) profiles, which in turn recruit DNMT3A and pattern neuronal non-CG methylation. We show that NSD1, the H3K36 methyltransferase mutated in the NDD, Sotos syndrome, is required for megabase-scale patterning of H3K36me2 and non-CG methylation in neurons. We find that brain-specific deletion of NSD1 causes alterations in DNA methylation that overlap with models of DNMT3A disorders and define convergent disruption in the expression of key neuronal genes in these models that may contribute to shared phenotypes in NSD1- and DNMT3A-associated NDD. Our findings indicate that H3K36me2 deposited by NSD1 is an important determinant of neuronal non-CG DNA methylation and implicates disruption of this methylation in Sotos syndrome. HighlightsO_LITopology-associated DNA methylation and gene expression independently contribute to neuronal gene body and enhancer non-CG DNA methylation patterns. C_LIO_LITopology-associated H3K36me2 patterns and local enrichment of H3K4 methylation impact deposition of non-CG methylation by DNMT3A. C_LIO_LIDisruption of NSD1 in vivo leads to alterations in H3K36me2, DNA methylation, and gene expression that overlap with models of DNMT3A disorders. C_LI

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Hamagami, N., Wu, D. Y., Clemens, A. W., Nettles, S. A., Gabel, H. W.. 2023-02-17. NSD1 deposits histone H3 lysine 36 dimethylation to pattern non-CG DNA methylation in neurons. https://doi.org/10.1101/2023.02.17.528965

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Genome-wide diversity across 130 years reveals drastic post-bottleneck genetic erosion in a recovering population of golden eagles (Aquila chrysaetos)

Many wild populations have experienced severe human-induced declines, but the genetic consequences of such bottlenecks are often poorly understood. In Finland, as well as in many other countries, golden eagles were heavily persecuted during the 19th-20th centuries, disappearing from southern regions and reaching their lowest population size in the 1950-1960s. Although conservation efforts facilitated demographic recovery, the long-term genomic consequences of the bottleneck remained unknown. Here, we used whole-genome sequencing data spanning 136 years to evaluate patterns of genetic diversity in 26 Finnish golden eagles before, during, and after the mid-20th century bottleneck. We found substantial loss of genetic variation, including an 82% reduction in genome-wide heterozygosity, a 42% decline in nucleotide diversity, a 67% reduction in Watterson's theta, and a substantial loss of variable sites. Analyses of the site frequency spectrum and Tajima's D confirmed historical population contraction, and runs of homozygosity analysis indicated elevated post-bottleneck inbreeding. These results indicate strong genetic erosion in Finnish golden eagles despite the census size recovery. Therefore, incorporating genomic indicators in conservation monitoring and performing regional assessments are necessary to guide management and preserve biodiversity in line with the Global Biodiversity Framework's goal of maintaining genetic variation.

genomics↗

Long-read analysis of complete human 5S rDNA arrays reveals a zoned organization with two-state unit methylation linked to chromatin architecture

Despite the fundamental importance of the 5S ribosomal DNA (rDNA) to all cellular life, the landscape of its units by position along its array has remained poorly understood. Here, recent telomere-to-telomere long-read sequencing is used to resolve 5S rDNA arrays from flank to flank and to follow the state of each unit along single molecules. The array is zoned at both the sequence and the epigenetic level. Notably, methylation is bimodal at the level of the unit, and the combination of low-methylation and high-methylation units gives rise to the overall methylation pattern of the array. Moreover, the average number of low-methylation units remains relatively constant regardless of array length. Chromatin fiber sequencing (Fiber-seq) data further show that low-methylation units are more accessible, have lower nucleosome occupancy and are more frequently footprinted at the TFIIIB-binding site, consistent with analyses of ATAC-seq and ChIP-seq data from cell lines. Across species, this pattern is shared among apes, whereas other species show diverse patterns. These results provide a unit-resolved view of the human 5S rDNA array and reveal a zone-specific organization of unit methylation that is associated with chromatin architecture.

genomics↗

Using Oyster Genomics to Understand Human Health

As sessile filter feeders that experience continuous environmental exposure, oysters, particularly Crassostrea virginica, offer a unique opportunity to understand how environmental exposure alters the genome and influence health. Furthermore, oysters must be sorted by size for market value for premium size and taste. However, it requires intensive labor, specialized equipment (tumblers), and is susceptible to environmental risks like pollution. Therefore, it is desirable to produce uniform oysters without machines. However, limitations in the previous reference genome [2] have constrained our understanding of how genes are organized and maintained in oyster populations. To this end, we harvested 240 adult oysters in same location, 120 extremely large size and 120 extremely small, controlled with all confounding factors such as age and water temperature. We perform a genome wise associate study (GWAS) using next generation whole genome sequencing, aiming to discover genomic regions associated with oyster size. Using PacBio HiFi, Illumina, and Hi-C technologies, we generated a 99.7% complete chromosome-level genome assembly for C. virginica (NCBI RefSeq GCF_053477285.1) [75]. We identified a ~13 Mb region on chromosome 1 uniquely expanded in C. virginica and enriched for innate immune and stress-response genes. To evaluate whether these structural features are reflected at the population level, we then conducted a k-mer analysis. This revealed differential sequence patterns by size, including enrichment of bacterial DNA in smaller individuals and host variation at the RNF213 locus within this region. By highlighting genome structure as a mediator of immune resilience, this work supports the use of oysters as sentinels to advance out understanding of how the dynamic reassembly of the genome due to environmental exposures influence health in human populations.

genomics↗