{"title":"The transgenic IG-DMR sequence of the mouse Dlk1-Dio3 domain acquired imprinted DNA methylation during the post-fertilization period.","authors":"Hitomi Matsuzaki, Shokichi Sugihara, Keiji Tanimoto","doi":"10.1186/s13072-023-00482-x","DOIUrl":"https://doi.org/10.1186/s13072-023-00482-x","url":null,"abstract":"<p><strong>Background: </strong>Allele-specific methylation of the imprinting control region (ICR) is the molecular basis for the genomic imprinting phenomenon that is unique to placental mammals. We previously showed that the ICR at the mouse H19 gene locus (H19 ICR) was unexpectedly established after fertilization and not during spermatogenesis in transgenic mice (TgM), and that the same activity was essential for the maintenance of paternal methylation of the H19 ICR at the endogenous locus in pre-implantation embryos. To examine the universality of post-fertilization imprinted methylation across animal species or imprinted loci, we generated TgM with two additional sequences.</p><p><strong>Results: </strong>The rat H19 ICR, which is very similar in structure to the mouse H19 ICR, unexpectedly did not acquire imprinted methylation even after fertilization, suggesting a lack of essential sequences in the transgene fragment. In contrast, the mouse IG-DMR, the methylation of which is acquired during spermatogenesis at the endogenous locus, did not acquire methylation in the sperm of TgM, yet became highly methylated in blastocysts after fertilization, but only when the transgene was paternally inherited. Since these two sequences were evaluated at the same genomic site by employing the transgene co-placement strategy, it is likely that the phenotype reflects the intrinsic activity of these fragments rather than position-effect variegation.</p><p><strong>Conclusions: </strong>Our results suggested that post-fertilization imprinted methylation is a versatile mechanism for protecting paternal imprinted methylation from reprogramming during the pre-implantation period.</p>","PeriodicalId":49253,"journal":{"name":"Epigenetics & Chromatin","volume":"16 1","pages":"7"},"PeriodicalIF":3.9,"publicationDate":"2023-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9936741/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9522200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L Mahrik, B Stefanovie, A Maresova, J Princova, P Kolesar, E Lelkes, C Faux, D Helmlinger, M Prevorovsky, J J Palecek
{"title":"The SAGA histone acetyltransferase module targets SMC5/6 to specific genes.","authors":"L Mahrik, B Stefanovie, A Maresova, J Princova, P Kolesar, E Lelkes, C Faux, D Helmlinger, M Prevorovsky, J J Palecek","doi":"10.1186/s13072-023-00480-z","DOIUrl":"10.1186/s13072-023-00480-z","url":null,"abstract":"<p><strong>Background: </strong>Structural Maintenance of Chromosomes (SMC) complexes are molecular machines driving chromatin organization at higher levels. In eukaryotes, three SMC complexes (cohesin, condensin and SMC5/6) play key roles in cohesion, condensation, replication, transcription and DNA repair. Their physical binding to DNA requires accessible chromatin.</p><p><strong>Results: </strong>We performed a genetic screen in fission yeast to identify novel factors required for SMC5/6 binding to DNA. We identified 79 genes of which histone acetyltransferases (HATs) were the most represented. Genetic and phenotypic analyses suggested a particularly strong functional relationship between the SMC5/6 and SAGA complexes. Furthermore, several SMC5/6 subunits physically interacted with SAGA HAT module components Gcn5 and Ada2. As Gcn5-dependent acetylation facilitates the accessibility of chromatin to DNA-repair proteins, we first analysed the formation of DNA-damage-induced SMC5/6 foci in the Δgcn5 mutant. The SMC5/6 foci formed normally in Δgcn5, suggesting SAGA-independent SMC5/6 localization to DNA-damaged sites. Next, we used Nse4-FLAG chromatin-immunoprecipitation (ChIP-seq) analysis in unchallenged cells to assess SMC5/6 distribution. A significant portion of SMC5/6 accumulated within gene regions in wild-type cells, which was reduced in Δgcn5 and Δada2 mutants. The drop in SMC5/6 levels was also observed in gcn5-E191Q acetyltransferase-dead mutant.</p><p><strong>Conclusion: </strong>Our data show genetic and physical interactions between SMC5/6 and SAGA complexes. The ChIP-seq analysis suggests that SAGA HAT module targets SMC5/6 to specific gene regions and facilitates their accessibility for SMC5/6 loading.</p>","PeriodicalId":49253,"journal":{"name":"Epigenetics & Chromatin","volume":"16 1","pages":"6"},"PeriodicalIF":4.2,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9933293/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10280166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The impact of spatial correlation on methylation entropy with application to mouse brain methylome.","authors":"Xiaowei Wu, Joung Min Choi","doi":"10.1186/s13072-023-00479-6","DOIUrl":"https://doi.org/10.1186/s13072-023-00479-6","url":null,"abstract":"<p><strong>Background: </strong>With the advance of bisulfite sequencing technologies, massive amount of methylation data have been generated, which provide unprecedented opportunities to study the epigenetic mechanism and its relationship to other biological processes. A commonly seen feature of the methylation data is the correlation between nearby CpG sites. Although such a spatial correlation was utilized in several epigenetic studies, its interaction to other characteristics of the methylation data has not been fully investigated.</p><p><strong>Results: </strong>We filled this research gap from an information theoretic perspective, by exploring the impact of the spatial correlation on the methylation entropy (ME). With the spatial correlation taken into account, we derived the analytical relation between the ME and another key parameter, the methylation probability. By comparing it to the empirical relation between the two corresponding statistics, the observed ME and the mean methylation level, genomic loci under strong epigenetic control can be identified, which may serve as potential markers for cell-type specific methylation. The proposed method was validated by simulation studies, and applied to analyze a published dataset of mouse brain methylome.</p><p><strong>Conclusions: </strong>Compared to other sophisticated methods developed in literature, the proposed method provides a simple but effective way to detect CpG segments under strong epigenetic control (e.g., with bipolar methylation pattern). Findings from this study shed light on the identification of cell-type specific genes/pathways based on methylation data from a mixed cell population.</p>","PeriodicalId":49253,"journal":{"name":"Epigenetics & Chromatin","volume":"16 1","pages":"5"},"PeriodicalIF":3.9,"publicationDate":"2023-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9898941/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9170308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
William Chang, Yilin Zhao, Danielle Rayêe, Qing Xie, Masako Suzuki, Deyou Zheng, Ales Cvekl
{"title":"Dynamic changes in whole genome DNA methylation, chromatin and gene expression during mouse lens differentiation.","authors":"William Chang, Yilin Zhao, Danielle Rayêe, Qing Xie, Masako Suzuki, Deyou Zheng, Ales Cvekl","doi":"10.1186/s13072-023-00478-7","DOIUrl":"10.1186/s13072-023-00478-7","url":null,"abstract":"<p><strong>Background: </strong>Cellular differentiation is marked by temporally and spatially coordinated gene expression regulated at multiple levels. DNA methylation represents a universal mechanism to control chromatin organization and its accessibility. Cytosine methylation of CpG dinucleotides regulates binding of methylation-sensitive DNA-binding transcription factors within regulatory regions of transcription, including promoters and distal enhancers. Ocular lens differentiation represents an advantageous model system to examine these processes as lens comprises only two cell types, the proliferating lens epithelium and postmitotic lens fiber cells all originating from the epithelium.</p><p><strong>Results: </strong>Using whole genome bisulfite sequencing (WGBS) and microdissected lenses, we investigated dynamics of DNA methylation and chromatin changes during mouse lens fiber and epithelium differentiation between embryos (E14.5) and newborns (P0.5). Histone H3.3 variant chromatin landscapes were also generated for both P0.5 lens epithelium and fibers by chromatin immunoprecipitation followed by next generation sequencing (ChIP-seq). Tissue-specific features of DNA methylation patterns are demonstrated via comparative studies with embryonic stem (ES) cells and neural progenitor cells (NPCs) at Nanog, Pou5f1, Sox2, Pax6 and Six3 loci. Comparisons with ATAC-seq and RNA-seq data demonstrate that reduced methylation is associated with increased expression of fiber cell abundant genes, including crystallins, intermediate filament (Bfsp1 and Bfsp2) and gap junction proteins (Gja3 and Gja8), marked by high levels of histone H3.3 within their transcribed regions. Interestingly, Pax6-binding sites exhibited predominantly DNA hypomethylation in lens chromatin. In vitro binding of Pax6 proteins showed Pax6's ability to interact with sites containing one or two methylated CpG dinucleotides.</p><p><strong>Conclusions: </strong>Our study has generated the first data on methylation changes between two different stages of mammalian lens development and linked these data with chromatin accessibility maps, presence of histone H3.3 and gene expression. Reduced DNA methylation correlates with expression of important genes involved in lens morphogenesis and lens fiber cell differentiation.</p>","PeriodicalId":49253,"journal":{"name":"Epigenetics & Chromatin","volume":"16 1","pages":"4"},"PeriodicalIF":3.9,"publicationDate":"2023-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9875507/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9238953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G M Swanson, F L Nassan, J B Ford, R Hauser, J R Pilsner, S A Krawetz
{"title":"Phthalates impact on the epigenetic factors contributed specifically by the father at fertilization.","authors":"G M Swanson, F L Nassan, J B Ford, R Hauser, J R Pilsner, S A Krawetz","doi":"10.1186/s13072-022-00475-2","DOIUrl":"https://doi.org/10.1186/s13072-022-00475-2","url":null,"abstract":"<p><strong>Background: </strong>Preconception exposure to phthalates such as the anti-androgenic dibutyl-phthalate (DBP) impacts both male and female reproduction, yet how this occurs largely remains unknown. Previously we defined a series of RNAs expressly provided by sperm at fertilization and separately, and in parallel, those that responded to high DBP exposure. Utilizing both populations of RNAs, we now begin to unravel the impact of high-DBP exposure on those RNAs specifically delivered by the father.</p><p><strong>Results: </strong>Enrichment of RNAs altered by DBP exposure within the Molecular Signature Database highlighted cellular stress, cell cycle, apoptosis, DNA damage response, and gene regulation pathways. Overlap within each of these five pathways identified those RNAs that were specifically (≥ fivefold enriched) or primarily (≥ twofold enriched) provided as part of the paternal contribution compared to the oocyte at fertilization. Key RNAs consistently altered by DBP, including CAMTA2 and PSME4, were delivered by sperm reflective of these pathways. The majority (64/103) of overlapping enriched gene sets were related to gene regulation. Many of these RNAs (45 RNAs) corresponded to key interconnected CRREWs (Chromatin remodeler cofactors, RNA interactors, Readers, Erasers, and Writers). Modeling suggests that CUL2, PHF10, and SMARCC1 may coordinate and mechanistically modulate the phthalate response.</p><p><strong>Conclusions: </strong>Mediated through a CRREW regulatory network, the cell responded to exposure presenting stressed-induced changes in the cell cycle-DNA damage-apoptosis. Interestingly, the majority of these DBP-responsive epigenetic mediators' direct acetylation or deacetylation, impacting the sperm's cargo delivered at fertilization and that of the embryo.</p>","PeriodicalId":49253,"journal":{"name":"Epigenetics & Chromatin","volume":"16 1","pages":"3"},"PeriodicalIF":3.9,"publicationDate":"2023-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9872317/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9537565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"ATAC-seq and RNA-seq analysis unravel the mechanism of sex differentiation and infertility in sex reversal chicken.","authors":"Xiuan Zhang, Jianbo Li, Xiqiong Wang, Yuchen Jie, Congjiao Sun, Jiangxia Zheng, Junying Li, Ning Yang, Sirui Chen","doi":"10.1186/s13072-022-00476-1","DOIUrl":"10.1186/s13072-022-00476-1","url":null,"abstract":"<p><strong>Background: </strong>Sex determination and differentiation are complex and delicate processes. In female chickens, the process of sex differentiation is sensitive and prone to be affected by the administration of aromatase inhibitors, which result in chicken sex reversal and infertility. However, the molecular mechanisms underlying sex differentiation and infertility in chicken sex reversal remain unclear. Therefore, we established a sex-reversed chicken flock by injecting an aromatase inhibitor, fadrozole, and constructed relatively high-resolution profiles of the gene expression and chromatin accessibility of embryonic gonads.</p><p><strong>Results: </strong>We revealed that fadrozole affected the transcriptional activities of several genes, such as DMRT1, SOX9, FOXL2, and CYP19A1, related to sex determination and differentiation, and the expression of a set of gonadal development-related genes, such as FGFR3 and TOX3, by regulating nearby open chromatin regions in sex-reversed chicken embryos. After sexual maturity, the sex-reversed chickens were confirmed to be infertile, and the possible causes of this infertility were further investigated. We found that the structure of the gonads and sperm were greatly deformed, and we identified several promising genes related to spermatogenesis and infertility, such as SPEF2, DNAI1, and TACR3, through RNA-seq.</p><p><strong>Conclusions: </strong>This study provides clear insights into the exploration of potential molecular basis underlying sex differentiation and infertility in sex-reversed chickens and lays a foundation for further research into the sex development of birds.</p>","PeriodicalId":49253,"journal":{"name":"Epigenetics & Chromatin","volume":"16 1","pages":"2"},"PeriodicalIF":4.2,"publicationDate":"2023-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9827654/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9222978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amy M Inkster, Martin T Wong, Allison M Matthews, Carolyn J Brown, Wendy P Robinson
{"title":"Who's afraid of the X? Incorporating the X and Y chromosomes into the analysis of DNA methylation array data.","authors":"Amy M Inkster, Martin T Wong, Allison M Matthews, Carolyn J Brown, Wendy P Robinson","doi":"10.1186/s13072-022-00477-0","DOIUrl":"10.1186/s13072-022-00477-0","url":null,"abstract":"<p><strong>Background: </strong>Many human disease phenotypes manifest differently by sex, making the development of methods for incorporating X and Y-chromosome data into analyses vital. Unfortunately, X and Y chromosome data are frequently excluded from large-scale analyses of the human genome and epigenome due to analytical complexity associated with sex chromosome dosage differences between XX and XY individuals, and the impact of X-chromosome inactivation (XCI) on the epigenome. As such, little attention has been given to considering the methods by which sex chromosome data may be included in analyses of DNA methylation (DNAme) array data.</p><p><strong>Results: </strong>With Illumina Infinium HumanMethylation450 DNAme array data from 634 placental samples, we investigated the effects of probe filtering, normalization, and batch correction on DNAme data from the X and Y chromosomes. Processing steps were evaluated in both mixed-sex and sex-stratified subsets of the analysis cohort to identify whether including both sexes impacted processing results. We found that identification of probes that have a high detection p-value, or that are non-variable, should be performed in sex-stratified data subsets to avoid over- and under-estimation of the quantity of probes eligible for removal, respectively. All normalization techniques investigated returned X and Y DNAme data that were highly correlated with the raw data from the same samples. We found no difference in batch correction results after application to mixed-sex or sex-stratified cohorts. Additionally, we identify two analytical methods suitable for XY chromosome data, the choice between which should be guided by the research question of interest, and we performed a proof-of-concept analysis studying differential DNAme on the X and Y chromosome in the context of placental acute chorioamnionitis. Finally, we provide an annotation of probe types that may be desirable to filter in X and Y chromosome analyses, including probes in repetitive elements, the X-transposed region, and cancer-testis gene promoters.</p><p><strong>Conclusion: </strong>While there may be no single \"best\" approach for analyzing DNAme array data from the X and Y chromosome, analysts must consider key factors during processing and analysis of sex chromosome data to accommodate the underlying biology of these chromosomes, and the technical limitations of DNA methylation arrays.</p>","PeriodicalId":49253,"journal":{"name":"Epigenetics & Chromatin","volume":"16 1","pages":"1"},"PeriodicalIF":4.2,"publicationDate":"2023-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9825011/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9537538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Characterizing chromatin interactions of regulatory elements and nucleosome positions, using Hi-C, Micro-C, and promoter capture Micro-C.","authors":"Beoung Hun Lee, Zexun Wu, Suhn K Rhie","doi":"10.1186/s13072-022-00473-4","DOIUrl":"https://doi.org/10.1186/s13072-022-00473-4","url":null,"abstract":"<p><strong>Background: </strong>Regulatory elements such as promoters, enhancers, and insulators interact each other to mediate molecular processes. To capture chromatin interactions of regulatory elements, 3C-derived methods such as Hi-C and Micro-C are developed. Here, we generated and analyzed Hi-C, Micro-C, and promoter capture Micro-C datasets with different sequencing depths to study chromatin interactions of regulatory elements and nucleosome positions in human prostate cancer cells.</p><p><strong>Results: </strong>Compared to Hi-C, Micro-C identifies more high-resolution loops, including ones around structural variants. By evaluating the effect of sequencing depth, we revealed that more than 2 billion reads of Micro-C are needed to detect chromatin interactions at 1 kb resolution. Moreover, we found that deep-sequencing identifies additional long-range loops that are longer than 1 Mb in distance. Furthermore, we found that more than 50% of the loops are involved in insulators while less than 10% of the loops are promoter-enhancer loops. To comprehensively capture chromatin interactions that promoters are involved in, we performed promoter capture Micro-C. Promoter capture Micro-C identifies loops near promoters with a lower amount of sequencing reads. Sequencing of 160 million reads of promoter capture Micro-C resulted in reaching a plateau of identifying loops. However, there was still a subset of promoters that are not involved in loops even after deep-sequencing. By integrating Micro-C with NOMe-seq and ChIP-seq, we found that active promoters involved in loops have a more accessible region with lower levels of DNA methylation and more highly phased nucleosomes, compared to active promoters that are not involved in loops.</p><p><strong>Conclusion: </strong>We determined the required sequencing depth for Micro-C and promoter capture Micro-C to generate high-resolution chromatin interaction maps and loops. We also investigated the effect of sequencing coverage of Hi-C, Micro-C, and promoter capture Micro-C on detecting chromatin loops. Our analyses suggest the presence of distinct regulatory element groups, which are differently involved in nucleosome positions and chromatin interactions. This study does not only provide valuable insights on understanding chromatin interactions of regulatory elements, but also present guidelines for designing research projects on chromatin interactions among regulatory elements.</p>","PeriodicalId":49253,"journal":{"name":"Epigenetics & Chromatin","volume":"15 1","pages":"41"},"PeriodicalIF":3.9,"publicationDate":"2022-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9768916/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10279118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Takuro Horii, Sumiyo Morita, Mika Kimura, Izuho Hatada
{"title":"Efficient generation of epigenetic disease model mice by epigenome editing using the piggyBac transposon system.","authors":"Takuro Horii, Sumiyo Morita, Mika Kimura, Izuho Hatada","doi":"10.1186/s13072-022-00474-3","DOIUrl":"https://doi.org/10.1186/s13072-022-00474-3","url":null,"abstract":"<p><strong>Background: </strong>Epigenome-edited animal models enable direct demonstration of disease causing epigenetic mutations. Transgenic (TG) mice stably expressing epigenome-editing factors exhibit dramatic and stable changes in target epigenome modifications. Successful germline transmission of a transgene from founder mice to offspring will yield a sufficient number of epigenome-edited mice for phenotypic analysis; however, if the epigenetic mutation has a detrimental phenotypic effect, it can become difficult to obtain the next generation of animals. In this case, the phenotype of founder mice must be analyzed directly. Unfortunately, current TG mouse production efficiency (TG founders per pups born) is relatively low, and improvements would increase the versatility of this technology.</p><p><strong>Results: </strong>In the current study, we describe an approach to generate epigenome-edited TG mice using a combination of both the dCas9-SunTag and piggyBac (PB) transposon systems. Using this system, we successfully generated mice with demethylation of the differential methylated region of the H19 gene (H19-DMR), as a model for Silver-Russell syndrome (SRS). SRS is a disorder leading to growth retardation, resulting from low insulin-like growth factor 2 (IGF2) gene expression, often caused by epimutations at the H19-IGF2 locus. Under optimized conditions, the efficiency of TG mice production using the PB system was approximately threefold higher than that using the conventional method. TG mice generated by this system showed demethylation of the targeted DNA region and associated changes in gene expression. In addition, these mice exhibited some features of SRS, including intrauterine and postnatal growth retardation, due to demethylation of H19-DMR.</p><p><strong>Conclusions: </strong>The dCas9-SunTag and PB systems serve as a simple and reliable platform for conducting direct experiments using epigenome-edited founder mice.</p>","PeriodicalId":49253,"journal":{"name":"Epigenetics & Chromatin","volume":"15 1","pages":"40"},"PeriodicalIF":3.9,"publicationDate":"2022-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9756621/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9740738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Shaking up the silence: consequences of HMGN1 antagonizing PRC2 in the Down syndrome brain.","authors":"Sean J Farley, Alla Grishok, Ella Zeldich","doi":"10.1186/s13072-022-00471-6","DOIUrl":"https://doi.org/10.1186/s13072-022-00471-6","url":null,"abstract":"<p><p>Intellectual disability is a well-known hallmark of Down Syndrome (DS) that results from the triplication of the critical region of human chromosome 21 (HSA21). Major studies were conducted in recent years to gain an understanding about the contribution of individual triplicated genes to DS-related brain pathology. Global transcriptomic alterations and widespread changes in the establishment of neural lineages, as well as their differentiation and functional maturity, suggest genome-wide chromatin organization alterations in trisomy. High Mobility Group Nucleosome Binding Domain 1 (HMGN1), expressed from HSA21, is a chromatin remodeling protein that facilitates chromatin decompaction and is associated with acetylated lysine 27 on histone H3 (H3K27ac), a mark correlated with active transcription. Recent studies causatively linked overexpression of HMGN1 in trisomy and the development of DS-associated B cell acute lymphoblastic leukemia (B-ALL). HMGN1 has been shown to antagonize the activity of the Polycomb Repressive Complex 2 (PRC2) and prevent the deposition of histone H3 lysine 27 trimethylation mark (H3K27me3), which is associated with transcriptional repression and gene silencing. However, the possible ramifications of the increased levels of HMGN1 through the derepression of PRC2 target genes on brain cell pathology have not gained attention. In this review, we discuss the functional significance of HMGN1 in brain development and summarize accumulating reports about the essential role of PRC2 in the development of the neural system. Mechanistic understanding of how overexpression of HMGN1 may contribute to aberrant brain cell phenotypes in DS, such as altered proliferation of neural progenitors, abnormal cortical architecture, diminished myelination, neurodegeneration, and Alzheimer's disease-related pathology in trisomy 21, will facilitate the development of DS therapeutic approaches targeting chromatin.</p>","PeriodicalId":49253,"journal":{"name":"Epigenetics & Chromatin","volume":"15 1","pages":"39"},"PeriodicalIF":3.9,"publicationDate":"2022-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9719135/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9638776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}