辣椒细胞质雄性不育系与其保持系线粒体DNA的RAPD分析

以辣椒细胞质雄性不育系21A及其相应的保持系21B为试材,从苗龄10~15 d的黄化苗中分离纯化线粒体并提取线粒体DNA。线粒体负染后电镜观察发现,分离纯化的线粒体形态完整,呈椭球形,杂质较少。电泳检测提取的线粒体DNA的琼脂糖,结果表明,线粒体DNA纯度较高,无降解现象,浓度为20~50 ng/μl,可用作RAPD分析。经初步筛选,100个RAPD随机引物中有8个引物表现出多态性,经再次重复筛选,获得了辣椒细胞质雄性不育系21A线粒体DNA与雄性不育性相关的RAPD标记CMSAG3430。     

烟草胞质雄性不育系与保持系线粒体DNA的RAPD分析

用124个10碱基随机引物对烟草2对雄性不育系及其保持系线粒体DNA的RAPD分析表明，不育系与保持系间有112个引物未扩增出多态性片段，占引物总数的92．56％．这反映了不育系和保持系线粒体的同源性。同时，在不育系与保持系的线粒体基因组间也发现了明显的差异，这些差异片段与雄性不育的关系还需进一步研究。     

辣椒细胞质雄性不育系与其保持系基因组DNA的RAPD分析

利用RAPD技术对细胞质雄性不育系21A与其相应保持系21B的基因组DNA进行了比较分析,共使用了380个随机引物,其中有213个引物在两系之间都得到了扩增产物,不育系21A与相应保持系21B基因组DNA用213个引物扩增后有6条主差异带,主要表现为条带数目、条带位置和条带强弱的差异.找到了辣椒细胞质雄性不育系21A基因组DNA特异的RAPD片段CMS Y15500、CMS BE5850和CMS BG1900,并对这些特异片段的来源及其在细胞质雄性不育中的作用进行了讨论.     

大白菜胞质雄性不育线粒体基因特异分子RAPD标记及克隆

用随机引物对大白菜细胞质雄性不育系及其保持系线粒体DNA的RAPD分析,在不育系与保持系的线粒体基因组间存在明显的差异,用引物S259在不育系中扩增并克隆得到特异片断(mt)S259-600bp,序列分析表明该片断与油菜线粒体基因NADH脱氢酶第四亚基序列有部分相似性,片段与雄性不育的关系还需进一步研究.     

洋葱细胞质雄性不育系与相应保持系线粒体DNA的RAPD分析

运用RAPD技术对洋葱细胞质雄性不育系A和相应保持系B的线粒体DNA(mtDNA)进行了100个单引物的多态性研究。结果表明69个引物有扩增,表现出多态性的有12个,然后随机选取不育系A和保持系B各9株验证多态性片段在单株中的稳定性,有两种引物A13和E14扩增出的多态性片段表现稳定。     

与大白菜细胞质不育相关RAPD特征片段的克隆和序列分析

为了研究和获得大白菜细胞质不育系和保持系线粒体DNA的多态性,选用153个RAPD随机引物,对3套材料,每套中包含不同来源、同核异质的大白菜细胞质不育系(Pol-CMS、Ogu-CMS和CMS96)和保持系线粒体DNA进行RAPD分析。结果表明,有4个RAPD随机引物可以在全部Ogu-CMS和CMS96不育系中扩增出特异带,有1个随机引物仅在所有Ogu-CMS不育系中扩增出特异带;同时将OPAH16随机引物扩增的与不育相关的特异带进行了克隆和测序。结果表明,所获得的特异片段均与拟南芥和甘蓝型油菜的线粒体基因组序列部分同源,但与已发表的不育基因序列没有同源性。由这5个序列推导出的蛋白质与拟南芥中的一种未知功能蛋白AtMg00760(ORF109b)具有部分同源性。这5个序列的可能功能正在验证中。     

苜蓿基因组DNA的RAPD指纹图谱

在建立可靠的苜蓿基因组DNA提取分离和RAPD-PCR扩增技术体系的基础上,筛选具有稳定的多态性位点的RAPD引物。利用RAPD标记检测苜蓿品种(系)的DNA分子标记多态性,构建苜蓿品种的DNA指纹图谱。筛选的引物扩增条带清晰,具有5～10个多态性位点。利用琼脂糖凝胶电泳可以便捷地检测扩增的DNA多态性。从大量RAPD随机引物中筛选出36个RAPD引物,确定了180多个多态性位点。对几个抗寒苜蓿进行了RAPD分析,构建了55个苜蓿品种(系)的DNA指纹图谱,用于苜蓿品种鉴定。     

水稻配子体雄性不育细胞质多态性及恢保关系差异研究

为解释育种实践中常出现的相同类型不育系与不同恢复系杂交组合F1代育性恢复有明显差异的现象,笔者通过对同核异质的5个配子体不育系W15A、W20A、W34A、W46A和YA线粒体DNA进行RAPD扩增聚类,不育基因orf(H)79基因及基因间区序列测序,测配F1分析其恢保关系,展示同型细胞质的差异与恢保差异的关系。结果表明,通过RAPD扩增聚类,这5个配子体细胞质雄性不育系在线粒体基因组可聚分为3类,而W34A与其他4个不育系的细胞质亲源关系较远。不育基因及基因间区序列均存在多个差异位点,5个水稻配子体雄性不育细胞质在大部分水稻材料的测恢中,恢保关系一致,而一部分材料的恢保关系差异较大。该研究为新型配子体不育系的选育、组合配制和同核多胞质混合杂交水稻亲本的选择提供一定的理论依据。     

陆地棉胞质雄性不育系与保持系线粒体基因组RFLP分析

【目的】研究棉花细胞质雄性不育（CMS）系与保持系线粒体基因组的差异,为克隆棉花CMS基因奠定基础。【方法】以atpA, atp6, atp9, ccmB, ccmC, ccmFN1, cob, coxI, coxII, coxIII, matR, nad1bc, nad2, nad4, nad5, nad6, nad7c, nad9, rpl5, rrn18等20个线粒体基因保守序列为探针,利用Southern blot方法对棉花细胞质雄性不育系、保持系线粒体基因组进行RFLP分析。【结果】发现atpA、atp9、ccmB、nad1bc、nad6、nad7c、rrn18等基因在棉花不育系和保持系间存在明显RFLP多态性,其中atpA的差异最明显。【结论】atpA是棉花CMS系和保持系线粒体基因组间的一个明显差异位点。CMS系比保持系缺失一个rrn18拷贝。     

V型小麦细胞质雄性不育“三系”及杂交种线粒体DNA的比较研究

以V型小麦细胞质雄性不育系及相应的保持系、恢复系以及其杂种F1为材料,用ISSR、SRAP、RAPD分子标记技术对它们的线粒体DNA进行了比较分析。结果如下:(1)153个SRAP引物组合中139个组合扩增出了多态性,9个组合扩增出不育系特有而保持系、恢复系、F1均缺失的片段,3个组合扩增出不育系特异缺失的片段。(2)92个ISSR引物中45个扩增出了多态性,筛选到了6个不育系特有而保持系、恢复系及杂种F1均缺失的片段。(3)288个RAPD引物中281个扩增出了多态性,4个引物扩增出不育系特有的片段,3个引物扩增出不育系特异缺失的片段。在对线粒体DNA进行分析时,SRAP比ISSR多态性好,比RAPD稳定性好。     

Postfertilization autophagy of sperm organelles prevents paternal mitochondrial DNA transmission

In sexual reproduction of most animals, the spermatozoon provides DNA and centrioles, together with some cytoplasm and organelles, to the oocyte that is being fertilized. Paternal mitochondria and their genomes are generally eliminated in the embryo by an unknown degradation mechanism. We show that, upon fertilization, a Caenorhabditis elegans spermatozoon triggers the recruitment of autophagosomes within minutes and subsequent paternal mitochondria degradation. Whereas the nematode-specific sperm membranous organelles are ubiquitinated before autophagosome formation, the mitochondria are not. The degradation of both paternal structures and mitochondrial DNA requires an LC3-dependent autophagy. Analysis of fertilized mouse embryos shows the localization of autophagy markers, which suggests that this autophagy event is evolutionarily conserved to prevent both the transmission of paternal mitochondrial DNA to the offspring and the establishment of heteroplasmy.     

Mitochondrial transformation in yeast by bombardment with microprojectiles

The genetic transformation of mitochondria and chloroplasts has been an intractable problem. The newly developed "biolistic" (biological ballistic) process was used to deliver DNA into yeast cells to stably transform their mitochondria. A nonreverting strain, which is respiratory deficient because of a deletion in the mitochondrial oxi3 gene, was bombarded with tungsten microprojectiles coated with DNA bearing sequences that could correct the oxi3 deletion. Respiratory-competent transformants were obtained in which the introduced oxi3 DNA is integrated at the homologous site in the mitochondrial genome. Organelle genomes can now be manipulated by molecular genetic techniques in the same way as nuclear genomes.     

A direct repeat is a hotspot for large-scale deletion of human mitochondrial DNA

Kearns-Sayre syndrome (KSS) and progressive external ophthalmoplegia (PEO) are related neuromuscular disorders characterized by ocular myopathy and ophthalmoplegia. Almost all patients with KSS and about half with PEO harbor large deletions in their mitochondrial genomes. The deletions differ in both size and location, except for one, 5 kilobases long, that is found in more than one-third of all patients examined. This common deletion was found to be flanked by a perfect 13-base pair direct repeat in the normal mitochondrial genome. This result suggests that homologous recombination deleting large regions of intervening mitochondrial DNA, which previously had been observed only in lower eukaryotes and plants, operates in mammalian mitochondrial genomes as well, and is at least one cause of the deletions found in these two related mitochondrial myopathies.     

红莲型水稻不育系与保持系线粒体DNA酶切分析

为研究水稻细胞质雄性不育的分子基础,我们提取纯化了红莲型水稻丛广４１Ａ 和丛广４１Ｂ 的线粒体ＤＮＡ,采用限制性内切酶酶切片段长度多态性（ＲＦＬＰ） 方法比较了红莲型不育系和保持系线粒体ＤＮＡ酶切图谱,发现两者之间存在一定的差异,部分支持了细胞质雄性不育与线粒体ＤＮＡ 有关的结论     

高等植物线粒体基因组研究进展

高等植物线粒体基因组在目前已知生物中是最大、最复杂的, 阐述了高等植物线粒体基因组的最新研究进展。从全基因组的测序方法开始,重点介绍了高等植物线粒体基因组的组成和结构特点,特别是基因含量、内含子、基因间隔序列、RNA编辑、重复序列、叶绿体和细胞核与线粒体之间的DNA交换以及线粒体基因的遗传起源和进化等热点问题,以期为更好的了解核质互作、植物进化等科学问题奠定基础。     

利用线粒体DNA(mtDNA)鉴别玉米各类不育胞质种子的研究

提取黑暗中培养的玉米雄性不育胞质材料Ｔ群、Ｃ群、Ｓ群、ＹⅡ－１型和正常可育胞质的黄化苗体内的线粒体ＤＮＡ（ｍｔＤＮＡ）,通过琼脂糖凝胶电泳分析未经酶切和酶切（限制性核酸内切酶分别为ｘｈｏＩ和ＢａｍＨＩ）的ｍｔＤＮＡ的电泳特性。发现：Ｔ群、Ｃ群、Ｓ群以及ＹⅡ－１型彼此ｍｔＤＮＡ组成上都存在差异。据此,可用ｍｔＤＮＡ鉴别玉米各类不育胞质种子。     

Nuclear and mitochondrial DNA comparisons reveal extreme rate variation in the molecular clock

The discovery that the rate of evolution of vertebrate mitochondrial DNA is rapid, compared to the rate for vertebrate nuclear DNA, has resulted in its widespread use in evolutionary studies. Comparison of mitochondrial and nuclear DNA divergences among echinoid and vertebrate taxa of similar ages indicates that the rapid rate of vertebrate mitochondrial DNA evolution is, in part, an artifact of a widely divergent rate of nuclear DNA evolution. This disparity in relative rates of mitochondrial and nuclear DNA divergence suggests that the controls and constraints under which the mitochondrial and nuclear genomes operate are evolving independently, and provides evidence that is independent of fossil dating for a robust rejection of a generalized molecular clock hypothesis of DNA evolution.     

植物水平基因转移研究进展

水平基因转移,一般分为细胞内部或者跨越物种边界的遗传物质交流。跨界直接介导方式,包括共生、内共生、寄生、嫁接等。细胞内的基因转移,主要包括细胞核与细胞器基因组间的相互渗透;跨越物种边界的遗传物质交流,主要涉及寄生与寄主植物的基因横向转移,寄主与寄生植物mRNA也会发生大规模的水平转移。基于基因组学研究进展,本研究综述了植物水平基因转移的迁移序列类型、迁移方向及迁移机制:首先,植物细胞的线粒体基因组能够整合细胞核转座元件以及叶绿体起源的tRNA基因,线粒体和叶绿体基因组的功能基因及间区序列能够迁移到核基因组;其次,植物种间,通过寄生、嫁接等方式转移大量的DNA(如线粒体基因、叶绿体基因和转座元件)和RNA(如mRNA)序列;迁移机制涉及到DNA介导和RNA介导方式,迁移方向包括单向和双向转移。迁移序列的基因功能活性研究是重要的后续研究方向。     

Cytoplasmic Reversion of cms-S in Maize: Association with a Transpositional Event

Spontaneous reversion to fertility in S male-sterile cytoplasm of maize is correlated with the disappearance of the mitochondrial plasmid-like DNA's, S-1 and S-2, and changes in the mitochondrial chromosomal DNA. Hybridization data indicate that one of the plasmid-like DNA's, S-2, is prominently involved in the mitochondrial DNA rearrangements.