卵母细胞成熟过程受组蛋白H3K4me3(trimethylation of lysine 4 on histone 3)和H3K27me3(trimethylation of lysine 27 on histone 3)及其相关的甲基化和去甲基化酶的调控,因此考虑对鸡的卵泡发育也存在一定的影响。选取“苏禽3号”配...卵母细胞成熟过程受组蛋白H3K4me3(trimethylation of lysine 4 on histone 3)和H3K27me3(trimethylation of lysine 27 on histone 3)及其相关的甲基化和去甲基化酶的调控,因此考虑对鸡的卵泡发育也存在一定的影响。选取“苏禽3号”配套系第一母本为研究对象,采用Western blot法探究组蛋白H3K4me3和H3K27me3在鸡卵泡不同发育阶段颗粒层中蛋白的表达模式。结果表明:在苏禽3号卵泡颗粒层中,组蛋白H3K4me3在卵泡发育不同阶段表达模式呈降低→升高→降低→升高的波浪形趋势,波浪变化较为平缓,在F5、F2和F13个表达高点的表达量与SWF(small white follicle)、LWF(large white follicle)、SYF(small yellow follicle)和F34个表达低点的表达差异显著(P<0.05)。组蛋白H3K27me3在不同发育阶段表达模式亦呈波浪形表达趋势,波浪变化起伏较明显,在SWF、SYF和F33个表达高点的表达量与F5、F4、F1和F24个表达低点的表达差异显著(P<0.05)。相关性分析显示,组蛋白H3K4me3与H3K27me3在不同发育阶段卵泡颗粒细胞中的表达呈较强的负线性相关(R=-0.808,P=0.000)。结果提示:组蛋白H3K4me3和H3K27me3在不同发育阶段卵泡颗粒层中的表达具有组织差异性,呈负相关的动态修饰性,可能共同协调卵泡生长过程中各基因的表达与功能,研究结果为鸡繁殖性状调控机理提供了理论依据。展开更多
目的:探讨检测肝癌组织中组蛋白第三亚基四号赖氨酸的三甲基化(H3K4me3)蛋白的表达与肿瘤病理特点和肝癌患者生存预后的相关性。方法:免疫组化和Western-blot检测H3K4me3和组蛋白甲基转移酶(SET and MYND domain-containing protein 3,S...目的:探讨检测肝癌组织中组蛋白第三亚基四号赖氨酸的三甲基化(H3K4me3)蛋白的表达与肿瘤病理特点和肝癌患者生存预后的相关性。方法:免疫组化和Western-blot检测H3K4me3和组蛋白甲基转移酶(SET and MYND domain-containing protein 3,SMYD3)在肝癌组织(n=168)和细胞株中的表达。此外,实验结果还在另外一个肝癌组织芯片(n=147)中进行验证。H3K4me3表达的最佳分界点(optimal cut-point)由X-tile程序确定,患者的预后由Kaplan-meier生存曲线描述。结果:H3K4me3高表达于肝癌细胞系和肝癌组织,其高表达与肝癌尤其是早期TNM1/2期患者的较差总体生存显著相关。单因素和多因素分析均提示H3K4me3表达水平是患者预后的独立危险因素。此外,H3K4me3和SMYD3在两组肝癌组织中均存在正相关表达。结论:H3K4me3表达水平能成为肝癌患者术后生存的预测因子,其高表达可能与SMYD3有关。展开更多
Lin28A and Lin28B are homologous RNA-binding proteins that participate in the development of primordial germ cells. The mechanisms underlying expression and regulation of Lin28A have been well documented, but such inf...Lin28A and Lin28B are homologous RNA-binding proteins that participate in the development of primordial germ cells. The mechanisms underlying expression and regulation of Lin28A have been well documented, but such information for Lin28B is limited. In this study, a fragment of the Lin28B promoter was cloned, the pEGFP-pLin28B vector was constructed. DF-1 chicken fibroblasts were transfected and the expression of green fluorescent protein (GFP) was measured. Furtherly, Lin28B promoter of different lengths fragments was cloned using the chromosome-walking method and the fragments were ligated into the PGL3-Basic vector, and transfected into DF-1 cells. Results of dual-luciferase reporter assay showed that the core of the Lin28B promoter was included in the sequence from –1 431 to –1 034 bp. The binding sites of the transcription factor TCF7L2 was showed within this sequence by bioinformatics analysis. The promoter activity of Lin28B was downregulated (P<0.05) when the TCF7L2 binding site was mutated. Further experiments suggested that Lin28B promoter activity responded to the activation or inhibition of Wnt signaling. Results of chromatin immunoprecipitation and quantitative PCR showed that β-catenin-TCF7L2 may be enriched in the Lin28B promoter core area. In vivo and in vitro activation or inhibition of Wnt signaling significantly up- or down-regulated (P<0.05) Lin28B expression. H3K4me2 enriched in the promoter of Lin28B, which affected the regulation of Wnt signaling to Lin28B. In conclusion, our results showed that H3K4me2 and Wnt5a/β-catenin/TCF7L2 were the positive regulators of Lin28B expression. Findings of this study may lay a theoretical foundation for illuminating the mechanism underlying Lin28B expression.展开更多
Histone methylation is a kind of important epigenetic modification which occurs on the lysine residue or arginine residue of histone tails（Zhang and Reinberg,2001）.It takes part in multiple biological processes,incl...Histone methylation is a kind of important epigenetic modification which occurs on the lysine residue or arginine residue of histone tails（Zhang and Reinberg,2001）.It takes part in multiple biological processes,including gene expression,genomic stability,stem cell maturity,genetic imprinting,mitosis and development（Fischle et al.,2005）.展开更多
Gastrokine 1 (GKN1) is a highly secreted gastric mucosal protein in normal individuals but strongly down-regulated or totally absent in gastric cancer subjects. An epigenetic mechanism might be responsible for GKN1 ge...Gastrokine 1 (GKN1) is a highly secreted gastric mucosal protein in normal individuals but strongly down-regulated or totally absent in gastric cancer subjects. An epigenetic mechanism might be responsible for GKN1 gene silencing probably through the activity of a transcription factor in association with the enzymes SUV39H1 and HDACs on the GKN1 promoter. In fact, compared to non-tumor tissues, a high increase of H3K9me3 level was observed in the corresponding tumor ones. Because H3K4me3 seems to be a possible epigenetic mark for active euchromatin, we try to verify the H3K4me3 level on the GKN1 promoter in gastric cancer tumor specimens. In addition, we also attempt to highlight if CBX7 could be the possible regulatory transcription factor correlated to GKN1 gene promoter. Therefore, we evaluated if the CBX7 expression levels could be associated with GKN1 down-regulation in gastric cancer. To this purpose, 2 pairs of non-tumor and tumor surgical specimens from patients with gastric cancer were analyzed for H3K4me3 by chromatin immunoprecipitation (ChiP) assays, and 9 pairs were instead analyzed by Western blotting for GKN1, and CBX7 expression levels, respectively. The results suggested that the observed increase of H3K4me3 in tumor samples was not in agreement with its proposed function whereas the expression of CBX7 was not associated with the down-regulation of GKN1. In particular, the expression levels of CBX7 in tumor samples might suggest a survival role in gastric cancer.展开更多
Trimethylation of histone H3K4(H3K4me3)is widely distributed at numerous actively transcribed protein-coding genes throughout the genome.However,the interplay between H3K4me3 and other chromatin modifications in plant...Trimethylation of histone H3K4(H3K4me3)is widely distributed at numerous actively transcribed protein-coding genes throughout the genome.However,the interplay between H3K4me3 and other chromatin modifications in plants remains poorly understood.In this study,we show that the Arabidopsis thaliana ALFIN-LIKE(AL)proteins contain a C-terminal PHD finger capable of binding to H3K4me3 and a PHD-associated AL(PAL)domain that interacts with components of the Polycomb repressive complex 1,thereby facilitating H2A ubiquitination(H2Aub)at H3K4me3-enriched genes throughout the genome.Furthermore,we demonstrate that loss of function of SDG2,encoding a key histone H3K4 methyltransferase,leads to a reduction in H3K4me3 level,which subsequently causes a genome-wide decrease in H2Aub,revealing a strong association between H3K4me3 and H2Aub.Finally,we discover that the PAL domain of AL proteins interacts with various other chromatin-related proteins or complexes,including those involved in regulating H2A.Z deposition,H3K27me3 demethylation,histone deacetylation,and chromatin accessibility.Our genome-wide analysis suggests that the AL proteins play a crucial role in coordinating H3K4me3 with multiple other chromatin modifications across the genome.展开更多
Pre-exposure to a stress may alter the plant＇s cellular, biochemical, and/or transcriptional responses during future encounters as a ＂memory＇ from the previous stress. Genes increasing transcription in response to ...Pre-exposure to a stress may alter the plant＇s cellular, biochemical, and/or transcriptional responses during future encounters as a ＂memory＇ from the previous stress. Genes increasing transcription in response to a first dehydra- tion stress, but producing much higher transcript levels in a subsequent stress, represent the super-induced ＇transcription memory＇ genes in Arabidopsis thaliana. The chromatin environment （histone H3 tri-methylations of Lys 4 and Lys 27, H3K4me3, and H3K27me3） studied at five dehydration stress memory genes revealed existence of distinct memory- response subclasses that responded differently to CLF deficiency and displayed different transcriptional activities dur- ing the watered recovery periods. Among the most important findings is the novel aspect of the H3K27me3 function observed at specific dehydration stress memory genes. In contrast to its well-known role as a chromatin repressive mechanism at developmentally regulated genes, H3K27me3 did not prevent transcription from the dehydration stress- responding genes. The high H3K27me3 levels present during transcriptionally inactive states did not interfere with the transition to active transcription and with H3K4me3 accumulation. H3K4me3 and H3K27me3 marks function indepen- dently and are not mutually exclusive at the dehydration stress-responding memory genes.展开更多
KDM5B is a histone H3K4me2/3 demethylase. The PHD1 domain of KDM5B is critical for demethylation, but the mechanism underlying the action of this domain is unclear. In this paper, we observed that PHDIKDMSB interacts ...KDM5B is a histone H3K4me2/3 demethylase. The PHD1 domain of KDM5B is critical for demethylation, but the mechanism underlying the action of this domain is unclear. In this paper, we observed that PHDIKDMSB interacts with unmethylated H3K4me0. Our NMR structure of PHDIKDMSB in complex with H3K4me0 revealed that the binding mode is slightly different from that of other reported PHD fingers. The disruption of this interaction by double mutations on the residues in the interface （L325A/D328A） decreases the H3K4me2/3 demethylation activity of KDM5B in cells by approximately 50% and increases the transcriptional repression of tumor suppressor genes by approximately twofold. These findings imply that PHDIKDMSB may help maintain KDM5B at target genes to mediate the demethylation activities of KDM5B.展开更多
Histone H3 lysine 4 trimethylation(H3K4me3)is a canonical chromatin modification associated with active gene transcription,playing a pivotal role in regulating various cellular functions.Components of the H3K4me3 meth...Histone H3 lysine 4 trimethylation(H3K4me3)is a canonical chromatin modification associated with active gene transcription,playing a pivotal role in regulating various cellular functions.Components of the H3K4me3 methyltransferase complex,known as the proteins associated with SET1(COMPASS),have been implicated in exerting cancer-protective or cancer-inhibitory effects through inducive H3K4me3 modification.However,the role of the indispensable non-catalytic component of COMPASS CXXC-type zinc finger protein 1(CFP1)in malignant progression remains unclear.展开更多
Histone H3 lysine 4 trimethylation （H3K4me3） is well known to occur in the promoter region of genes for transcription activation. How- ever, when investigating the H3K4me3 profiles in the mouse cerebrum and testis, ...Histone H3 lysine 4 trimethylation （H3K4me3） is well known to occur in the promoter region of genes for transcription activation. How- ever, when investigating the H3K4me3 profiles in the mouse cerebrum and testis, we discovered that H3K4me3 also has a significant enrichment at the 3＇ end of actively transcribed （sense） genes, named as 3＇-H3K4me3. 3＇-H3K4me3 is associated with ~15% of pro- tein-coding genes in both tissues. In addition, we examined the transcriptional initiation signals including RNA polymerase II （RNAPII） binding sites and Y-CAGE-tag that marks transcriptional start sites. Interestingly, we found that 3＇-H3K4me3 is associated with the ini- tiation of antisense transcription. Furthermore, 3＇-H3K4me3 modification levels correlate positively with the antisense expression levels of the associated sense genes, implying that 3＇-H3K4me3 is involved in the activation of antisense transcription. Taken together, our findings suggest that H3K4me3 may be involved in the regulation of antisense transcription that initiates from the 3＇ end of sense genes. In addition, a positive correlation was also observed between the expression of antisense and the associated sense genes with 3＇-H3K4me3 modification. More importantly, we observed the 3＇-H3K4me3 enrichment among genes in human, fruitfly and Arabidopsis, and found that the sequences of 3＇-H3K4me3-marked regions are highly conserved and essentially indistinguishable from known promoters in ver- tebrate. Therefore, we speculate that these 3＇-H3K4me3-marked regions may serve as potential promoters for antisense transcription and 3＇-H3K4me3 appear to be a universal epigenetic feature in eukaryotes. Our results provide a novel insight into the epigenetic roles of H3K4me3 and the regulatory mechanism of antisense transcription.展开更多
文摘卵母细胞成熟过程受组蛋白H3K4me3(trimethylation of lysine 4 on histone 3)和H3K27me3(trimethylation of lysine 27 on histone 3)及其相关的甲基化和去甲基化酶的调控,因此考虑对鸡的卵泡发育也存在一定的影响。选取“苏禽3号”配套系第一母本为研究对象,采用Western blot法探究组蛋白H3K4me3和H3K27me3在鸡卵泡不同发育阶段颗粒层中蛋白的表达模式。结果表明:在苏禽3号卵泡颗粒层中,组蛋白H3K4me3在卵泡发育不同阶段表达模式呈降低→升高→降低→升高的波浪形趋势,波浪变化较为平缓,在F5、F2和F13个表达高点的表达量与SWF(small white follicle)、LWF(large white follicle)、SYF(small yellow follicle)和F34个表达低点的表达差异显著(P<0.05)。组蛋白H3K27me3在不同发育阶段表达模式亦呈波浪形表达趋势,波浪变化起伏较明显,在SWF、SYF和F33个表达高点的表达量与F5、F4、F1和F24个表达低点的表达差异显著(P<0.05)。相关性分析显示,组蛋白H3K4me3与H3K27me3在不同发育阶段卵泡颗粒细胞中的表达呈较强的负线性相关(R=-0.808,P=0.000)。结果提示:组蛋白H3K4me3和H3K27me3在不同发育阶段卵泡颗粒层中的表达具有组织差异性,呈负相关的动态修饰性,可能共同协调卵泡生长过程中各基因的表达与功能,研究结果为鸡繁殖性状调控机理提供了理论依据。
文摘目的:探讨检测肝癌组织中组蛋白第三亚基四号赖氨酸的三甲基化(H3K4me3)蛋白的表达与肿瘤病理特点和肝癌患者生存预后的相关性。方法:免疫组化和Western-blot检测H3K4me3和组蛋白甲基转移酶(SET and MYND domain-containing protein 3,SMYD3)在肝癌组织(n=168)和细胞株中的表达。此外,实验结果还在另外一个肝癌组织芯片(n=147)中进行验证。H3K4me3表达的最佳分界点(optimal cut-point)由X-tile程序确定,患者的预后由Kaplan-meier生存曲线描述。结果:H3K4me3高表达于肝癌细胞系和肝癌组织,其高表达与肝癌尤其是早期TNM1/2期患者的较差总体生存显著相关。单因素和多因素分析均提示H3K4me3表达水平是患者预后的独立危险因素。此外,H3K4me3和SMYD3在两组肝癌组织中均存在正相关表达。结论:H3K4me3表达水平能成为肝癌患者术后生存的预测因子,其高表达可能与SMYD3有关。
基金We thank the Experimental Poultry Farm of the Poultry Institute,Chinese Academy of Agricultural Sciences,for providing experimental materialsThis work was supported by the Key Research and Development Program of China(2017YFE0108000)+1 种基金the National Natural Science Foundation of China(31872341,31572390)the High-Level Talent Support Program of Yangzhou University,China.
文摘Lin28A and Lin28B are homologous RNA-binding proteins that participate in the development of primordial germ cells. The mechanisms underlying expression and regulation of Lin28A have been well documented, but such information for Lin28B is limited. In this study, a fragment of the Lin28B promoter was cloned, the pEGFP-pLin28B vector was constructed. DF-1 chicken fibroblasts were transfected and the expression of green fluorescent protein (GFP) was measured. Furtherly, Lin28B promoter of different lengths fragments was cloned using the chromosome-walking method and the fragments were ligated into the PGL3-Basic vector, and transfected into DF-1 cells. Results of dual-luciferase reporter assay showed that the core of the Lin28B promoter was included in the sequence from –1 431 to –1 034 bp. The binding sites of the transcription factor TCF7L2 was showed within this sequence by bioinformatics analysis. The promoter activity of Lin28B was downregulated (P<0.05) when the TCF7L2 binding site was mutated. Further experiments suggested that Lin28B promoter activity responded to the activation or inhibition of Wnt signaling. Results of chromatin immunoprecipitation and quantitative PCR showed that β-catenin-TCF7L2 may be enriched in the Lin28B promoter core area. In vivo and in vitro activation or inhibition of Wnt signaling significantly up- or down-regulated (P<0.05) Lin28B expression. H3K4me2 enriched in the promoter of Lin28B, which affected the regulation of Wnt signaling to Lin28B. In conclusion, our results showed that H3K4me2 and Wnt5a/β-catenin/TCF7L2 were the positive regulators of Lin28B expression. Findings of this study may lay a theoretical foundation for illuminating the mechanism underlying Lin28B expression.
基金supported by the National Natural Science Foundation of China(Nos.31540033 and91131002)the Precision Medicine Research Program of the Chinese Academy of Sciences(KJZD-EW-L14)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA12020343)the National Basic Research Program of China(2013CB911001 and 2012CB518302)the National Excellent Youth Science Foundation of China(No.31222030)
文摘Histone methylation is a kind of important epigenetic modification which occurs on the lysine residue or arginine residue of histone tails（Zhang and Reinberg,2001）.It takes part in multiple biological processes,including gene expression,genomic stability,stem cell maturity,genetic imprinting,mitosis and development（Fischle et al.,2005）.
文摘Gastrokine 1 (GKN1) is a highly secreted gastric mucosal protein in normal individuals but strongly down-regulated or totally absent in gastric cancer subjects. An epigenetic mechanism might be responsible for GKN1 gene silencing probably through the activity of a transcription factor in association with the enzymes SUV39H1 and HDACs on the GKN1 promoter. In fact, compared to non-tumor tissues, a high increase of H3K9me3 level was observed in the corresponding tumor ones. Because H3K4me3 seems to be a possible epigenetic mark for active euchromatin, we try to verify the H3K4me3 level on the GKN1 promoter in gastric cancer tumor specimens. In addition, we also attempt to highlight if CBX7 could be the possible regulatory transcription factor correlated to GKN1 gene promoter. Therefore, we evaluated if the CBX7 expression levels could be associated with GKN1 down-regulation in gastric cancer. To this purpose, 2 pairs of non-tumor and tumor surgical specimens from patients with gastric cancer were analyzed for H3K4me3 by chromatin immunoprecipitation (ChiP) assays, and 9 pairs were instead analyzed by Western blotting for GKN1, and CBX7 expression levels, respectively. The results suggested that the observed increase of H3K4me3 in tumor samples was not in agreement with its proposed function whereas the expression of CBX7 was not associated with the down-regulation of GKN1. In particular, the expression levels of CBX7 in tumor samples might suggest a survival role in gastric cancer.
基金supported by the National Natural Science Foundation of China to X.-J.H.(grant numbers 32025003 and 32470628).
文摘Trimethylation of histone H3K4(H3K4me3)is widely distributed at numerous actively transcribed protein-coding genes throughout the genome.However,the interplay between H3K4me3 and other chromatin modifications in plants remains poorly understood.In this study,we show that the Arabidopsis thaliana ALFIN-LIKE(AL)proteins contain a C-terminal PHD finger capable of binding to H3K4me3 and a PHD-associated AL(PAL)domain that interacts with components of the Polycomb repressive complex 1,thereby facilitating H2A ubiquitination(H2Aub)at H3K4me3-enriched genes throughout the genome.Furthermore,we demonstrate that loss of function of SDG2,encoding a key histone H3K4 methyltransferase,leads to a reduction in H3K4me3 level,which subsequently causes a genome-wide decrease in H2Aub,revealing a strong association between H3K4me3 and H2Aub.Finally,we discover that the PAL domain of AL proteins interacts with various other chromatin-related proteins or complexes,including those involved in regulating H2A.Z deposition,H3K27me3 demethylation,histone deacetylation,and chromatin accessibility.Our genome-wide analysis suggests that the AL proteins play a crucial role in coordinating H3K4me3 with multiple other chromatin modifications across the genome.
文摘Pre-exposure to a stress may alter the plant＇s cellular, biochemical, and/or transcriptional responses during future encounters as a ＂memory＇ from the previous stress. Genes increasing transcription in response to a first dehydra- tion stress, but producing much higher transcript levels in a subsequent stress, represent the super-induced ＇transcription memory＇ genes in Arabidopsis thaliana. The chromatin environment （histone H3 tri-methylations of Lys 4 and Lys 27, H3K4me3, and H3K27me3） studied at five dehydration stress memory genes revealed existence of distinct memory- response subclasses that responded differently to CLF deficiency and displayed different transcriptional activities dur- ing the watered recovery periods. Among the most important findings is the novel aspect of the H3K27me3 function observed at specific dehydration stress memory genes. In contrast to its well-known role as a chromatin repressive mechanism at developmentally regulated genes, H3K27me3 did not prevent transcription from the dehydration stress- responding genes. The high H3K27me3 levels present during transcriptionally inactive states did not interfere with the transition to active transcription and with H3K4me3 accumulation. H3K4me3 and H3K27me3 marks function indepen- dently and are not mutually exclusive at the dehydration stress-responding memory genes.
文摘KDM5B is a histone H3K4me2/3 demethylase. The PHD1 domain of KDM5B is critical for demethylation, but the mechanism underlying the action of this domain is unclear. In this paper, we observed that PHDIKDMSB interacts with unmethylated H3K4me0. Our NMR structure of PHDIKDMSB in complex with H3K4me0 revealed that the binding mode is slightly different from that of other reported PHD fingers. The disruption of this interaction by double mutations on the residues in the interface （L325A/D328A） decreases the H3K4me2/3 demethylation activity of KDM5B in cells by approximately 50% and increases the transcriptional repression of tumor suppressor genes by approximately twofold. These findings imply that PHDIKDMSB may help maintain KDM5B at target genes to mediate the demethylation activities of KDM5B.
基金This work was supported by the National Key R&D Program of China(2021YFF1201303)the National Natural Science Foundation of China(81972196)+1 种基金the CAMS Innovation Fund for Medical Sciences(CIFMS)(2021-1-12M-012)the R&D Program of Beijing Municipal Education Commission(KJZD20191002302).
文摘Histone H3 lysine 4 trimethylation(H3K4me3)is a canonical chromatin modification associated with active gene transcription,playing a pivotal role in regulating various cellular functions.Components of the H3K4me3 methyltransferase complex,known as the proteins associated with SET1(COMPASS),have been implicated in exerting cancer-protective or cancer-inhibitory effects through inducive H3K4me3 modification.However,the role of the indispensable non-catalytic component of COMPASS CXXC-type zinc finger protein 1(CFP1)in malignant progression remains unclear.
基金supported by Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No.KSCX2-EW-R-01-04)Natural Science Foundation of China (Grant No. 90919024 and 30900831)the National Basic Research Program (973 Program) from the Ministry of Science and Technology of China (GrantNo. 2011CB944100)
文摘Histone H3 lysine 4 trimethylation （H3K4me3） is well known to occur in the promoter region of genes for transcription activation. How- ever, when investigating the H3K4me3 profiles in the mouse cerebrum and testis, we discovered that H3K4me3 also has a significant enrichment at the 3＇ end of actively transcribed （sense） genes, named as 3＇-H3K4me3. 3＇-H3K4me3 is associated with ~15% of pro- tein-coding genes in both tissues. In addition, we examined the transcriptional initiation signals including RNA polymerase II （RNAPII） binding sites and Y-CAGE-tag that marks transcriptional start sites. Interestingly, we found that 3＇-H3K4me3 is associated with the ini- tiation of antisense transcription. Furthermore, 3＇-H3K4me3 modification levels correlate positively with the antisense expression levels of the associated sense genes, implying that 3＇-H3K4me3 is involved in the activation of antisense transcription. Taken together, our findings suggest that H3K4me3 may be involved in the regulation of antisense transcription that initiates from the 3＇ end of sense genes. In addition, a positive correlation was also observed between the expression of antisense and the associated sense genes with 3＇-H3K4me3 modification. More importantly, we observed the 3＇-H3K4me3 enrichment among genes in human, fruitfly and Arabidopsis, and found that the sequences of 3＇-H3K4me3-marked regions are highly conserved and essentially indistinguishable from known promoters in ver- tebrate. Therefore, we speculate that these 3＇-H3K4me3-marked regions may serve as potential promoters for antisense transcription and 3＇-H3K4me3 appear to be a universal epigenetic feature in eukaryotes. Our results provide a novel insight into the epigenetic roles of H3K4me3 and the regulatory mechanism of antisense transcription.
