Project description:Investigation of the co-occurance of the ATP-dependent chromatin remodeler SMARCAD1 and the histone modification H3K9me3 in the genome of PGK12.1 XX ES cells. ChIP-seq of endogenous SMARCAD1 was carried out in control and SMARCAD1-knockdown ES cells using a double crosslinking procedure. Additionally, H3K9me3 ChIP-seq was performed in double-cross linked control PGK12.1 XX cells. Input samples and precipitates with an IgG antibody were sequenced (Illumina HiSeq1500) as controls. Antibodies used were SMARCAD1 PAB15737 (Abnova) and H3K9me3 ab8898 (abcam).
Project description:Background: MORC proteins are involved in epigenetic gene silencing in a wide variety of eukaryotic organisms. Deletion of MORCs result in several developmental abnormalities and their dysregulation has been implicated in developmental disease and multiple cancers. Specifically, mutations of mammalian MORC3 have been associated with immune system defects, Down syndrome and human cancers such as bladder, uterine, stomach, and lung cancers, and diffuse large B cell lymphomas. While previous studies have shown that MORC3 binds to H3K4me3 in vitro and overlaps with H3K4me3 ChIP-seq peaks in mouse embryonic stem cells, the mechanism by which MORC3 regulates gene expression is unknown. Results: In this study, we find that MORC3 functions as an epigenetic silencer of endogenous retroviruses (ERVs) in mouse embryonic stem cells (mESCs). Loss of MORC3 results in upregulation of ERVs, specifically those belonging to the LTR class of retrotransposons. Using ChIP-seq, we measure the genome-wide localization of MORC3 in wild-type cells and find that MORC3 binds to ERVs suggesting its direct role in regulating ERV expression. Previous studies have shown that these ERVs are marked by repressive histone mark H3K9me3 which plays a key role in their silencing. Interestingly, we find that the levels of H3K9me3 do not change substantially upon the loss of MORC3 indicating that MORC3 possibly acts downstream of the TRIM28/SETDB1 complex that deposits H3K9me3 at these loci. Instead, we discover that loss of MORC3 results in increased chromatin accessibility at the ERVs suggesting that MORC3 silences ERVs by compacting DNA in mESCs. Conclusions: Our results reveal MORC3 as a novel regulator of ERV silencing in mouse embryonic stem cells. As early mammalian development is characterized by dynamic changes in ERV expression, the role of MORC3 in silencing ERVs is exciting and could potentially explain the abnormalities observed due to its misregulation during mammalian development.
Project description:Heterochromatin is required to restrict aberrant expression of retrotransposons, but it remains poorly defined due to the underlying repeat-rich sequences. We dissected Suv39h-dependent histone H3 lysine 9 trimethylation (H3K9me3) by genome-wide ChIP-sequencing in mouse embryonic stem cells (ESCs). Refined bioinformatic analyses of repeat subfamilies indicated selective accumulation of Suv39h-dependent H3K9me3 at interspersed repetitive elements that cover ~ 5% of the ESC epigenome. The majority of the ~ 8,150 intact long interspersed nuclear elements (LINEs) and endogenous retroviruses (ERVs), but only a minor fraction of the > 1.8 million degenerate and truncated LINEs/ERVs, are enriched for Suv39h-dependent H3K9me3. Transcriptional repression of these intact LINEs and ERVs is differentially regulated by Suv39h and other chromatin modifiers in ESCs but governed by DNA methylation in committed cells. These data provide a novel function for Suv39h-dependent H3K9me3 chromatin to specifically repress intact retrotransposon elements in the ESC epigenome. ChIP-seq and RNA-seq in mouse ES cells, Neural precursors and MEFs wild type and Suv39h double KO. The input for ES cells is accessioned as GSM1251941. A link to this sample can be found below.
Project description:Histone 3 Lysine 9 (H3K9) methylation is known to be associated with pericentric heterochromatin and important in genomic stability. In this study, we show that trimethylation at H3K9 (H3K9me3) is enriched in an adult neural stem cell niche- the subventricular zone (SVZ) on the walls of the lateral ventricle in both rodent and non-human primate baboon brain. Previous studies have shown that there is significant correlation between baboon and human regarding genomic similarity and brain structure, suggesting that findings in baboon are relevant to human. To understand the function of H3K9me3 in this adult neurogenic niche, we performed genome-wide analyses using ChIP-Seq (chromatin immunoprecipitation and deep-sequencing) and RNA-Seq for in vivo SVZ cells purified from baboon brain. Through integrated analyses of ChIP-Seq and RNA-Seq, we found that H3K9me3-enriched genes associated with cellular maintenance, post-transcriptional and translational modifications, signaling pathways, and DNA replication are expressed, while genes involved in axon/neuron, hepatic stellate cell, or immune-response activation are not expressed. As neurogenesis progresses in the adult SVZ, cell fate restriction is essential to direct proper lineage commitment. Our findings highlight that H3K9me3 repression in undifferentiated SVZ cells is engaged in the maintenance of cell type integrity, implicating a role for H3K9me3 as an epigenetic mechanism to control cell fate transition within this adult germinal niche. SVZ H3K9me3 ChIP-seq profile of an adult baboon subventricular zone was generated by deep sequencing with Illumina HiSeq2000
Project description:H3K9me3 ChIP-seq on embryonic 15.5 day mouse embryonic facial prominence For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODE_Data_Use_Policy_for_External_Users_03-07-14.pdf https://www.encodeproject.org/ENCSR137NUN/
Project description:H3K9me3 ChIP-seq on embryonic 13.5 day mouse embryonic facial prominence For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODE_Data_Use_Policy_for_External_Users_03-07-14.pdf https://www.encodeproject.org/ENCSR147PYG/