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运用聚丙烯酰胺凝胶电泳的方法对角类肥蛛(Lariniodes cornuta)头胸部和腹部的酯酶同工酶酶谱进行了比较分析。结果表明,角类肥蛛的酯酶是单体酶,头胸部和腹部的酯酶酶谱差异显著。腹部的酯酶呈现4个位点:Est-1、Est-2、Est-3、Est-4。Est-1和Est-4位点为纯合基因型,Est-2和Est-3位点为杂合基因型。头胸部的酯酶仅表现出2个位点:Est-2和Est-3,且这2个位点是纯合基因型。不同个体之间头胸部的酯酶没有明显差异,Est-2b和Est-3a可以作为鉴别角类肥蛛的特征酶带;腹部的酯酶则存在明显的个体差异,在Est-2和Est-3位点的基因杂合度为h2=h3=0·4779。由此可见,酯酶同工酶可以作为角类肥蛛遗传变异的分子标记,是研究个体间遗传差异、居群的遗传结构以及种间进化关系的基础。 相似文献
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染色体组蛋白的共价修饰在调节染色体结构,控制基因的转录等方面发挥重要的作用。组蛋白H3第4赖氨酸的甲基化作为共价修饰的方式之一,可以调控基因的转录激活。随着对组蛋白甲基化转移酶及相关作用蛋白研究的深入,人们对组蛋白H3第4赖氨酸的甲基化的功能也有了更深的了解。目前研究发现它与癌症也有很密切的关系。 相似文献
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为了研究组蛋白H3在中华绒螯蟹(Eriocheir sinensis)精子发生中的动态特征,采用PCR技术扩增中华绒螯蟹H3基因编码区的DNA片段,将其重组至含有6个His标签序列的原核表达质粒pET-30a(+)上,转化入大肠杆菌(Escherichia coli)Rosetta(DE3)感受态细胞中,以0.2 mmol/L的异丙基β-D硫代半乳糖苷(IPTG)诱导产生pET-30a-H3重组蛋白。SDS-PAGE表明,重组菌成功表达出了分子量约为21 ku的目标蛋白质,融合蛋白以上清和包涵体的形式存在。采用镍柱亲和层析的方法纯化目的蛋白,免疫新西兰大白兔(Oryctolagus cuniculus),制备兔抗血清。Western blot结果表明,制备的多克隆抗体具有较好的特异性。至此,成功地克隆了中华绒螯蟹H3编码区基因并制备了多克隆抗体,为进一步研究其在精子发生中的动态特征提供了基础。 相似文献
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水稻H3.2型组蛋白基因RH3.2A的克隆与盐胁迫下的表达分析 总被引:1,自引:0,他引:1
组蛋白H3与其他类型的组蛋白分子H2A,H2B,H4共同构成了真核生物核小体的八聚体核心。研究发现组蛋白H3的多种翻译修饰,如甲基化、乙酰化、磷酸化等在调控基因转录过程种发挥了重要的作用。本研究从盐胁迫处理的水稻幼苗组织中分离了一个新的水稻组蛋白H3基因RH3.2A,编码具有136个氨基酸残基的多肽,与多种植物的组蛋白H3蛋白具有高度的氨基酸一致性。多序列比较发现,除了基因结构差异之外,还有3个位置的氨基酸残基(32、88、91)在H3.1与H3.2型组蛋白H3中存在差异。研究了RH3.2A基因在高盐和ABA胁迫下的表达,结果发现在水稻根部RH3.2A基因受高盐的强烈诱导,而在叶片RH3.2A基因的表达则不受高盐诱导,此外RH3.2A基因也受外源ABA的诱导,结合启动子分析的结果,我们认为RH3.2A基因可能参与了依赖于ABA的高盐胁迫应答反应。文章讨论了植物组蛋白H3基因在高盐胁迫应答反应中可能的作用。 相似文献
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组蛋白甲基化是一种重要的表观遗传学修饰,在基因表达调节方面发挥着重要的作用.组蛋白H3赖氨酸27三甲基化(H3K27me3)是一种抑制性组蛋白标记,可被去甲基化酶UTX和JMJD3催化而移去甲基.UTX和JMJD3通过激活HOX基因而参与细胞分化和多能细胞抑制过程.在多种肿瘤中检测到UTX和JMJD3突变或表达下降,同时多种基因启动子区H3K27me3含量增多.UTX和JMJD3均被看作肿瘤抑制基因,其中UTX调节了RB依赖的细胞命运控制,而JMJD3通过激活INK4b-ARF-INK4a位点而参与了癌基因诱导的衰老.组蛋白H3K27去甲基化酶与肿瘤发生的研究使我们对癌症发展过程有了更好的理解,同时也为癌症诊断和治疗提供了新靶点. 相似文献
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构建了球毛壳菌菌丝的cDNA文库,并获得了1410条ESTs序列,用里氏木霉(Hypocrea jecorina,AAM76068)和粗糙脉胞菌(Neurospora crassa,CAA25761)的组蛋白H3基因(Histone H3)蛋白序列对球毛壳菌(Chaetomium globosum)ESTs序列本地数据库进行tBlastn检索,获得了球毛壳菌组蛋白H3cDNA序列。cDNA序列全长739bp,开放阅读框411bp,编码136个氨基酸组成的多肽,蛋白分子量为15.4kD。BlastP同源性分析表明该基因与里氏木霉同源性最高为100%;与地钱(Marchantia polymorpha)同源性最低为95%。三级结构预测表明,该蛋白C端为球状结构域,而N端结构对其发挥调控作用起重要作用。该基因的cDNA序列及推测的氨基酸序列在GenBank登录(登录号分别为AY669068,AAT74576)。 相似文献
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磷酸化组蛋白H3在小麦有丝分裂与减数分裂中的分布 总被引:2,自引:0,他引:2
在细胞周期中 ,与染色质凝集偶联的一类组蛋白修饰是组蛋白H3的磷酸化。运用H3_Ser 10磷酸化的特异性抗体 ,通过间接免疫荧光标记检测了磷酸化组蛋白H3在小麦 (TriticumaestivumL .)有丝分裂与减数分裂细胞中的分布。有丝分裂时 ,H3磷酸化起始于早前期 ,消失于末期 ,在中期与后期 ,H3磷酸化主要分布在着丝粒两侧的异染色质区。减数分裂时 ,H3磷酸化起始于细线期向偶线期转换时 ,并且从前期Ⅰ到后期Ⅰ保持均一分布于整个染色体上 ,直到末期Ⅰ消失 ,而中期Ⅱ与后期Ⅱ在着丝粒两侧的异染色质区的信号略强于染色体臂 ,直至消失于末期Ⅱ。磷酸化组蛋白H3在两类细胞分裂中的不同分布暗示这种保守的翻译后修饰可能发挥着除参与染色体凝集外的更复杂的作用。 相似文献
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Silverman BD 《Journal of molecular evolution》2005,60(3):354-364
The eukaryotic histone dimers, H3–H4 and H2A–H2B, are formed in the cytosol prior to being transported into the nucleus and assembled into the nucleosome. Residue side-chain distances from the interior of the histone dimers are obtained with an ellipsoidal spatial metric and structural information provided by X-ray analyses at atomic resolution of the nucleosome core particles. While the spatial hydrophobic moment profiles of the dimers are comparable with profiles obtained previously that characterize the hydrophobic core of single-chain, single-domain globular soluble proteins, correlation coefficients between the side-chain hydrophobicities and distances from the interior of the H3–H4 dimer and H2A–H2B dimer differ significantly. This difference is traced to the H3 histone fold, which segregates fewer hydrophobic residues within the protein interior than the three other folds. Examination of the correlation coefficient between residue hydrophobicity and side-chain distance from the dimer interior over local regions of the fold sequence shows that the region of reduced correlation is associated mainly with the residues at the carboxyl end of the H3 histone fold, the helical region of the fold involved in the H3–H3 binding of the (H3–H4)2 tetramer of the nucleosome. Hydrophobic interactions apparently contribute to the binding of this fourfold helical bundle and this evolutionary requirement may trade off against the requirement for H3–H4 dimer stability. The present results provide a different view than previously proposed, albeit of similar origin, to account for the reduced stability of the H3–H4 dimer compared with the H2A–H2B dimer.Reviewing Editor: Dr. Martin Kreitman 相似文献
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Sheng-Ping QIU 《Acta Genetica Sinica》2006,33(9):833-840
Histone H3 is one of the four histones, along with H2A, H2B, and H4, which form the eukaryotic nucleosome octamer core. In this study, a new gene RH3.2A encoding an H3.2-type histone H3 protein from rice (Oryza sativa L.) was reported. RH3.2A was cloned through RT-PCR from salt-treated rice seedlings. This gene encoded a protein of 136 amino acid residues that were similar to some plant histone H3 proteins reported previously. However, the cDNA sequence of RH3.2A and other rice H3 genes were different. Alignment of RH3.2A encoding protein with other plant histone H3 proteins revealed that three amino acid residues (32, 88, and 91) were markedly different between H3.1-type and H3.2-type proteins. The mRNA expression analysis of RH3.2A revealed that RH3.2A gene was upregulated by salt stress in rice roots and ABA treatment in seedlings. The potential role of RH3.2A during salt stress was discussed. 相似文献
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在细胞周期中, 与染色质凝集偶联的一类组蛋白修饰是组蛋白H3的磷酸化.运用H3-Ser 10磷酸化的特异性抗体,通过间接免疫荧光标记检测了磷酸化组蛋白H3在小麦(Triticum aestivum L.)有丝分裂与减数分裂细胞中的分布.有丝分裂时,H3磷酸化起始于早前期,消失于末期,在中期与后期,H3磷酸化主要分布在着丝粒两侧的异染色质区.减数分裂时,H3磷酸化起始于细线期向偶线期转换时,并且从前期Ⅰ到后期Ⅰ保持均一分布于整个染色体上,直到末期Ⅰ消失,而中期Ⅱ与后期Ⅱ在着丝粒两侧的异染色质区的信号略强于染色体臂,直至消失于末期Ⅱ.磷酸化组蛋白H3在两类细胞分裂中的不同分布暗示这种保守的翻译后修饰可能发挥着除参与染色体凝集外的更复杂的作用. 相似文献
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Histone H3 variants in male gametic cells of lily and H3 methylation in mature pollen 总被引:5,自引:0,他引:5
Histones are vital structural proteins of chromatin that influence its dynamics and function. The tissue-specific expression of histone variants has been shown to regulate the expression of specific genes and genomic stability in animal systems. Here we report on the characterization of five histone H3 variants expressed in Lilium generative cell. The gcH3 and leH3 variants show unique sequence diversity by lacking a conserved lysine residue at position 9 (H3K9). The gH3 shares conserved structural features with centromeric H3 of Arabidopsis. The gH3 variant gene is strongly expressed in generative cells and gH3 histone is incorporated in to generative cell chromatin. The lysine residue of H3 at position 4 (H3K4) is highly methylated in the nuclei of generative cells of mature pollen, while methylation of H3K4 is low in vegetative cell nuclei. Taken together, these results suggest that male gametic cells of Lilium have unique chromatin state and histone H3 variants and their methylation might be involved in gene regulation of male gametic cells.Accession numbers for the sequence data The sequences reported in this paper have been deposited in the DDBJ database gcH3 GC1174 (accession no. AB195644), gH3 GC1008 (accession no. AB195646), leH3 GC1126 (accession no. AB195648), soH3-1 GC0075 (accession no. AB195650), soH3-2 GC1661 (accession no. AB195652), genomic sequence of gcH3 (accession no. AB195645), genomic sequence of gH3 (accession no. AB195647), genomic sequence of leH3 (accession no. AB195649), genomic sequence of soH3-2 (accession no. AB195651), genomic sequence of soH3-2 (accession no. AB195653). 相似文献
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含有组蛋白脱乙酰化酶活性的分子有两类:一类是与酵母RPD3同源的分子,另一类是与RPD3不同源的分子.它们各有其不同的来源,存在于各自的复合物中,催化不完全相同的组蛋白或其他蛋白质脱乙酰化;这些脱乙酰化酶与基因转录的调控存在着密切的关系, 主要是介导基因转录的抑制. 相似文献