共查询到20条相似文献，搜索用时 46 毫秒
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Yamanaka K Sakatani M Kubota K Balboula AZ Sawai K Takahashi M 《The Journal of reproduction and development》2011,57(3):393-402
For the successful production of cloned animals by somatic cell nuclear transfer (NT), the epigenetic status of the differentiated donor cell is reversed to an embryonic totipotent status. However, in NT embryos, this process is aberrant, with genomic hypermethylation consistently observed. Here, we investigated the effects of silencing DNA methyltransferase 1 (DNMT1) mRNA by small interfering RNA (siRNA) on the DNA methylation status of the satellite I region and in vitro development of bovine NT embryos. First, the levels of DNMT1 expression were analyzed at 0, 24, 48, 72, 120 and 192 h after in vitro culture. Real-time PCR and western blotting analyses detected a significant decrease in DNMT1 mRNA in the siRNA-injected NT (siRNA-NT) group up to 72 h after in vitro culture. Next, the levels of DNA methylation of the satellite I region were analyzed at several time points after in vitro culture. The level of DNA methylation detected in siRNA-NT embryos was significantly less than those in NT embryos throughout in vitro development. Moreover, the developmental rate of embryos to blastocysts in the siRNA-NT group was significantly higher than that of NT embryos. Our data suggest that knockdown of DNMT1 mRNA in NT embryos can induce DNA demethylation, which may enhance reprogramming efficiency. 相似文献
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Buffalo SCNT embryos exhibit abnormal gene expression of ERK/MAPK pathway and DNA methylation 
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下载免费PDF全文 Disha Ashok Tanushri Jerath Sood Shrutika Sah Prabhat Palta Manishi Mukesh Manmohan Singh Chauhan Radhey Sham Manik Suresh Kumar Singla 《Reproduction in domestic animals》2018,53(5):1247-1252
Inhibition of ERK/MAPK pathway has been shown to decrease DNA methylation via down‐regulation of DNA methyltransferases (DNMTs) in several studies suggesting that this pathway plays an important role in regulation of DNA methylation. We examined the relative expression level of seven important genes related to ERK/MAPK pathway and DNMTs (DNMT1, DNMT3a and DNMT3b) by quantitative real‐time PCR in buffalo blastocysts produced by Hand‐made cloning and compared it with that in blastocyst‐stage embryos produced by in vitro fertilization (IVF). The expression level of six of seven genes related to ERK/MAPK pathway examined i.e., p21RAS, RAF1, AKT1, ERK2, PIK3R2 and c‐Myc was significantly higher (p < 0.05) in cloned than in IVF embryos. However, the expression level of FOS was lower (p < 0.005) in cloned than in IVF embryos. The relative expression level of DNMT3a and DNMT3b but not that of DNMT1 was significantly higher (p < 0.05) in cloned than in IVF embryos. These results indicate that the cloned embryos exhibit an abnormal expression of several important genes related to ERK/MAPK pathway and DNMTs. Although a direct link between ERK/MAPK pathway and DNMTs was not examined in the present study, it can be speculated that ERK/MAPK pathway may have a role in regulating the expression of DNMTs in embryos, as also observed in other tissues. 相似文献
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DNA methylation and targeted sequencing of methyltransferases family genes in canine acute myeloid leukaemia,modelling human myeloid leukaemia 下载免费PDF全文
下载免费PDF全文 I. Bronzini L. Aresu M. Paganin L. Marchioretto S. Comazzi F. Cian F. Riondato L. Marconato V. Martini G. te Kronnie 《Veterinary and comparative oncology》2017,15(3):910-918
Tumours shows aberrant DNA methylation patterns, being hypermethylated or hypomethylated compared with normal tissues. In human acute myeloid leukaemia (hAML) mutations in DNA methyltransferase (DNMT3A) are associated to a more aggressive tumour behaviour. As AML is lethal in dogs, we defined global DNA methylation content, and screened the C‐terminal domain of DNMT3 family of genes for sequence variants in 39 canine acute myeloid leukaemia (cAML) cases. A heterogeneous pattern of DNA methylation was found among cAML samples, with subsets of cases being hypermethylated or hypomethylated compared with healthy controls; four recurrent single nucleotide variations (SNVs) were found in DNMT3L gene. Although SNVs were not directly correlated to whole genome DNA methylation levels, all hypomethylated cAML cases were homozygous for the deleterious mutation at p.Arg222Trp. This study contributes to understand genetic modifications of cAML, leading up to studies that will elucidate the role of methylome alterations in the pathogenesis of AML in dogs. 相似文献
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DNA甲基化与去甲基化调控脂肪沉积的研究进展 总被引：2，自引：2，他引：0
脂肪沉积是一个复杂的生物学过程,受遗传和表观遗传的调控作用。DNA甲基化和去甲基化是表观遗传修饰的重要方式,可通过与转录因子的相互作用或改变染色质的结构调控基因的表达,进而参与机体生长发育和细胞分化等重要的生命过程。动物脂肪沉积是脂肪细胞增殖分化和肥大的结果,脂肪细胞分化是由多能干细胞经前体脂肪细胞向成熟脂肪细胞转化的过程。相关研究表明,转录因子过氧化物酶体增殖物激活受体γ(peroxi-some proliferator activiated receptorγ,PPARγ)和CCAAT增强子结合蛋白家族(CCAAT enchancer binding proteinfamily,CEBPs)在脂肪沉积过程中起关键调控作用。近期研究发现,DNA甲基化可以通过调控脂肪形成过程中相关基因的表达而参与脂肪细胞的分化和脂肪组织的生长发育。去甲基化也可影响动物脂肪沉积过程,但其具体机制目前尚不清楚。作者主要介绍了DNA甲基化和去甲基化的定义、发生位点、生物学功能、参与DNA甲基化和去甲基化过程中的酶及其作用机制,概述了脂肪沉积过程及PPARγ、C/EBPα等转录因子在脂肪沉积过程中的调控作用,重点阐述了DNA甲基化和去甲基化对脂肪形成相关基因的表达和对脂肪细胞分化的影响,旨在为阐明脂肪沉积机制及改善动物肉质品质提供参考。 相似文献
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DNA甲基化与去甲基化调控肌肉发育研究进展 总被引：2，自引：0，他引：2
肌肉发育是一个复杂的生物学过程,其调控机制尚不完善。但近年来表观遗传修饰对肌肉发育的调控作用逐渐成为热点领域,研究发现DNA甲基化与去甲基化修饰对肌肉发生与发育起到重要的调控作用。肌肉干细胞特异位点通过DNA甲基化修饰,影响肌肉发育过程关键基因的表达,进而调控早期发育的生肌过程。本文主要围绕肌肉发育过程中DNA甲基化及去甲基化修饰的变化、重要的甲基转移酶和去甲基化酶以及营养物质通过DNA甲基化修饰影响肌肉发生的作用进行论述。 相似文献
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Marlene Paibomesai Brendan Hussey Maria Nino-Soto Bonnie A. Mallard 《Canadian journal of veterinary research》2013,77(1):54-62
This study investigated epigenetic mechanisms by which DNA methylation affects the function of bovine adaptive immune system cells, particularly during the peripartum period, when shifts in type 1 and type 2 immune response (IR) biases are thought to occur. Stimulation of CD4+ T-lymphocytes isolated from 5 Holstein dairy cows before and after parturition with concanavalin A (ConA) and stimulation of CD4+ T-lymphocytes isolated from 3 Holstein dairy cows in mid-lactation with ConA alone or ConA plus dexamethasone (Dex) had significant effects on production of the cytokines interferon gamma (IFN-γ, type 1) and interleukin 4 (IL-4, type 2) that were consistent with DNA methylation profiles of the IFN-γ gene promoter region but not consistent for the IL-4 promoter region. ConA stimulation increased the production of both cytokines before and after parturition. It decreased DNA methylation in the IFN-γ promoter region but increased for IL-4 promoter region. Parturition was associated with an increase in IFN-γ production in ConA-stimulated cells that approached significance. Overall, DNA methylation in both promoter regions increased between the prepartum and postpartum periods, although this did not correlate with secreted cytokine concentrations. Dexamethasone treated cells acted in a manner consistent with the glucocorticoid’s immunosuppressive activity, which mimicked the change at the IFN-γ promoter region observed during parturition. These results support pregnancy as type 2 IR biased, with increases of IFN-γ occurring after parturition and an increase in IL-4 production before calving. It is likely that these changes may be epigenetically controlled. 相似文献
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干旱胁迫下高羊茅基因组甲基化分析 总被引：3，自引：0，他引：3
DNA甲基化是真核细胞基因组重要的一种表观遗传调控。DNA甲基化影响基因表达,在植物逆境胁迫适应中起着重要作用。高羊茅是禾本科单子叶羊茅属植物,具有良好的耐寒、耐热性,大量用作运动场草坪和防护草坪,也可用做牧草。干旱是限制高羊茅分布和产量的主要因素之一。本研究利用甲基化敏感扩增多态性技术(MSAP),比较了高羊茅在干旱胁迫15 d后基因组胞嘧啶甲基化的变化。在干旱胁迫下,植株生长受到严重抑制。MSAP分析显示,10对选择性扩增引物,共扩增出475个CCGG位点,其中131个位点发生了甲基化或去甲基化变化,占27.58%。对照组和干旱处理组,总甲基化水平分别是43.16%和42.11%,显示干旱胁迫诱导高羊茅总的甲基化率下降了1.05%。对差异条带进行归类分析,并克隆、测序,获得13条不同变化类型的序列。序列同源分析显示,大多数序列是参与胁迫应答的基因片段。其中2个片段,Fa6和Fa7为干旱诱导下发生甲基化的位点,分别与小麦和大麦的一个逆转录转座子具有较高的同源性,在干旱胁迫下它们的甲基化程度增加,表明干旱诱导二者进一步甲基化。甲基化的转座子在维持基因组稳定性具有重要作用。综上,干旱胁迫诱导的甲基化的变化,可能参与高羊茅对环境的适应性调节。 相似文献
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Sawai K Takahashi M Fujii T Moriyasu S Hirayama H Minamihashi A Hashizume T Onoe S 《The Journal of reproduction and development》2011,57(2):236-241
DNA methylation is an important factor for the regulation of gene expression in early embryos. It is well known that the satellite I sequence is more heavily methylated in bovine somatic cell nuclear transfer (NT-SC) embryos than in embryos derived from in vitro fertilization (IVF). However, the methylation status of bovine embryos obtained by other procedures is not well known. To clarify DNA methylation levels of bovine embryos obtained from various procedures, we examined satellite I sequences in bovine blastocyst (BC) embryos derived from NT-SC, NT using embryonic blastomeres (NT-EM), in vivo (Vivo), IVF and parthenogenetic treatment (PA). Furthermore, in order to evaluate the efficacy of DNA demethylation by the NT procedure, we determined the DNA methylation levels in bovine embryos in which NT was recapitulated (Re-NT). Although the DNA methylation levels in the NT-SC embryos were higher than those in the other embryos, the NT-EM embryos exhibited lower DNA methylation levels. The satellite I sequence in the NT-SC embryos was more demethylated than that in the donor cells. Although the DNA methylation level in the individual NT-SC embryos showed variation, the full-term developmental efficacy of these embryos were not different. These findings suggest that the methylation level of the satellite I sequence at the BC stage is not related to the abnormalities of bovine embryos produced by NT-SC. There was no difference in methylation levels between Re-NT and NT-SC embryos. Our results indicated that the DNA methylation status differed among embryos produced by various methods and that at least some of the demethylation of the donor cell genome occurred in the recipient cytoplast after NT-SC, but the demethylation ability of the NT procedure was noted in the first NT but not in the second NT. 相似文献
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《动物营养（英文）》2015,(3)
It is well known that phenotype of animals may be modified by the nutritional modulations through epigenetic mechanisms. As a key and central component of epigenetic network, DNA methylation is labile in response to nutritional influences. Alterations in DNA methylation profiles can lead to changes in gene expression, resulting in diverse phenotypes with the potential for decreased growth and health.Here, I reviewed the biological process of DNA methylation that results in the addition of methyl groups to DNA; the possible ways including methyl donors, DNA methyltransferase(DNMT) activity and other cofactors, the critical periods including prenatal, postnatal and dietary transition periods, and tissue specific of epigenetic modulation of DNA methylation by nutrition and its mechanisms in animals. 相似文献
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Nawapen Phutikanit Junpen Suwimonteerabutr Dion Harrison Michael D'Occhio Bernie Carroll Mongkol Techakumphu 《Acta veterinaria Scandinavica》2010,52(1):18
Background
The purpose of this study was to apply an arbitrarily primed methylation sensitive polymerase chain reaction (PCR) assay called Amplified Methylation Polymorphism Polymerase Chain Reaction (AMP PCR) to investigate the methylation profiles of somatic and germ cells obtained from Holstein bulls.Methods
Genomic DNA was extracted from sperm, leukocytes and fibroblasts obtained from three bulls and digested with a methylation sensitive endonuclease (HpaII). The native genomic and enzyme treated DNA samples were used as templates in an arbitrarily primed-PCR assay with 30 sets of single short oligonucleotide primer. The PCR products were separated on silver stained denaturing polyacrylamide gels. Three types of PCR markers; digestion resistant-, digestion sensitive-, and digestion dependent markers, were analyzed based on the presence/absence polymorphism of the markers between the two templates.Results
Approximately 1,000 PCR markers per sample were produced from 27 sets of primer and most of them (>90%) were digestion resistant markers. The highest percentage of digestion resistant markers was found in leukocytic DNA (94.8%) and the lowest in fibroblastic DNA (92.3%, P ≤ 0.05). Spermatozoa contained a higher number of digestion sensitive markers when compared with the others (3.6% vs. 2.2% and 2.6% in leukocytes and fibroblasts respectively, P ≤ 0.05).Conclusions
The powerfulness of the AMP PCR assay was the generation of methylation-associated markers without any prior knowledge of the genomic sequence. The data obtained from different primers provided an overview of genome wide DNA methylation content in different cell types. By using this technique, we found that DNA methylation profile is tissue-specific. Male germ cells were hypomethylated at the HpaII locations when compared with somatic cells, while the chromatin of the well-characterized somatic cells was heavily methylated when compared with that of the versatile somatic cells. 相似文献19.
Julia Devos Amir Behrouzi Francois Paradis Christina Straathof Changxi Li Marcos Colazo Hushton Block Carolyn Fitzsimmons 《Journal of animal science》2021,99(5)
Discovery of epigenetic modifications associated with feed efficiency or other economically important traits would increase our understanding of the molecular mechanisms underlying these traits. In combination with known genetic markers, this would provide opportunity to improve genomic selection accuracy in cattle breeding programs. It would also allow cattle to be managed to improve favorable gene expression. The objective of this study was to identify variation in DNA methylation between beef cattle of differential pre-natal nutrition and divergent genetic potential for residual feed intake (RFI). Purebred Angus offspring with the genetic potential for either high (HRFI) or low (LRFI) RFI were prenatally exposed to either a restricted maternal diet of 0.5 kg/d average daily gain (ADG) or a moderate maternal diet of 0.7 kg/d ADG from 30 to 150 d of gestation. We performed DNA methylation analysis of differentially methylated regions (DMR) of imprinted genes (Insulin-like growth factor 2 (IGF2) DMR2, IGF2/H19 imprinting control region (ICR) and IGF2 receptor (IGF2R) DMR2) using post-natal samples of longissimus dorsi (LD) muscle taken from male and female calves at birth and weaning, and of LD muscle, semimembranosus (SM) muscle, and liver samples collected from steers at slaughter (17 months of age). Interestingly, for all three DMR investigated in liver, LRFI steers had higher levels of methylation than HRFI steers. In LD muscle, IGF2/H19 ICR methylation differences for heifers at birth were due to pre-natal diet, while for steers at birth they were mostly the result of genetic potential for RFI with LRFI steers again having higher levels of methylation than HRFI steers. While results from repeated measures analysis of DNA methylation in steers grouped by RFI revealed few differences, in steers grouped by diet, we found higher methylation levels of IGF2 DMR2 and IGF2R DMR2 in LD muscle of restricted diet steers at weaning and slaughter than at birth, as well as increased methylation in LD muscle of restricted diet steers compared with moderate diet steers at weaning and/or slaughter. Our results suggest that differential pre-natal nutrition, and divergent genetic potential for RFI, induces tissue- and sex-specific alterations in post-natal IGF2 and IGF2R methylation patterns and that these patterns can vary with age in Angus beef cattle. 相似文献
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Satoshi HARA Takashi TAKANO Mio OGATA Reina YAMAKAMI Yusuke SATO Tomohiro KONO Yayoi OBATA 《The Journal of reproduction and development》2014,60(3):250-255
Transgenic mice are essential research tools in developmental biology studies. The 2A peptide allows multiple genes to be
expressed simultaneously at comparable levels in somatic cells, but there are no reports of it being used successfully in
germ cells. We constructed a Cre/loxP-based conditional vector containing the 2A peptide to significantly enhance the
expression of a reporter and target gene from a constitutive promoter in oocytes. Mice with a transgene insertion containing
the chicken β-actin promoter, floxed EGFP-polyA cassette, mCherry reporter, 2A peptide and target gene DNA methyltransferase
3A2 (Dnmt3a2) were crossed with TNAP- or Vasa-Cre mice to produce offspring, in which mCherry and DNMT3A2
proteins were highly expressed in oocytes upon Cre-mediated removal of EGFP-polyA. This novel transgenic mouse line based on
the 2A expression system can serve as a useful tool for examining gene function during oogenesis. 相似文献