共查询到20条相似文献，搜索用时 15 毫秒
1.
Wallace DC 《Science (New York, N.Y.)》1999,283(5407):1482-1488
Over the past 10 years, mitochondrial defects have been implicated in a wide variety of degenerative diseases, aging, and cancer. Studies on patients with these diseases have revealed much about the complexities of mitochondrial genetics, which involves an interplay between mutations in the mitochondrial and nuclear genomes. However, the pathophysiology of mitochondrial diseases has remained perplexing. The essential role of mitochondrial oxidative phosphorylation in cellular energy production, the generation of reactive oxygen species, and the initiation of apoptosis has suggested a number of novel mechanisms for mitochondrial pathology. The importance and interrelationship of these functions are now being studied in mouse models of mitochondrial disease. 相似文献
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B J Murphy E D Robin D P Tapper R J Wong D A Clayton 《Science (New York, N.Y.)》1984,223(4637):707-709
The effect of hypoxic exposure on various mitochondrial enzymes and on cell mitochondrial genomic content was studied in two types of mammalian cells. Hypoxia depressed the activity of six enzymes to the same degree. The kinetics of depression and of recovery during reexposure to normoxia were statistically similar for three marker enzymes. Despite the global and symmetrical decrease in enzyme activities, mitochondrial DNA remained constant. This suggests either symmetrical loss of mitochondrial enzymes from all mitochondria or complete loss of enzymes from a subpopulation of mitochondria with retention of an intact mitochondrial genome. 相似文献
4.
研究线粒体靶向抗氧化剂Mitoquinone(MitoQ)对犬骨髓间充质干细胞(bone marrow mesenchymal stem cells, BMSCs)的线粒体功能与抗氧化基因表达的作用,为进一步提高犬BMSCs的临床应用效率提供理论依据。以犬BMSCs为材料,添加MitoQ预处理48 h,采用荧光定量PCR、荧光探针等方法评估BMSCs线粒体功能以及抗氧化基因的表达水平。结果显示,随着传代次数的增加,BMSCs线粒体融合明显增强,线粒体分裂明显减弱;线粒体膜电位与ATP含量均显著下降;抗氧化基因的表达显著下调。添加MitoQ预处理后,BMSCs线粒体融合基因Mfn2的表达略有上调,且线粒体分裂基因Drp1和线粒体生物合成相关基因PGC-1α的表达显著上调;线粒体膜电位与ATP生成显著增加;抗氧化基因SOD1、SOD2、CAT和GSH-Px的表达显著上调。结果表明,MitoQ可改善犬BMSCs线粒体功能,增强BMSCs抗氧化能力。 相似文献
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【目的】分析一氧化氮(NO)对冷藏过程中桃果实线粒体氧化损伤的影响。【方法】分别用15 μmol/L NO、5 μmol/L c-PTIO (NO清除剂)、对照(去离子水)浸泡30 min处理桃果实。测定0℃下桃果实的线粒体完整性、活性氧含量、抗氧化酶的活性及相关品质指标。【结果】在桃果实低温冷藏过程中,NO处理可以维持桃果实硬度、色差L值及可溶性固形物含量,降低线粒体耗氧量和减少活性氧的积累,调节线粒体呼吸控制率(RCR)、线粒体膜电势,线粒体细胞色素C含量以及线粒体抗氧化酶活性。【结论】NO通过减少线粒体氧化损伤,维持线粒体的完整性,延长桃果实的贮藏期。 相似文献
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The mitochondrial DNA's of two closely related cricket species (genus Gryllus) share a size polymorphism as evidenced by analysis of restriction fragment patterns. Moreover, 12 of 100 field-collected crickets are heteroplasmic, that is these individuals have more than one size class of mitochondrial DNA. No heteroplasmy for restriction site variation is observed. Intraindividual variation in cricket mitochondrial DNA provides a useful marker for studying the transmission genetics of mitochondrial DNA. Available data on patterns of variation in mothers and offspring suggest that random segregation of mitochondrial DNA variants does not occur rapidly in cricket germ-cell lineages. 相似文献
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为研究不同驯化温度对体质量为(6.26±0.21)g的施氏鲟Acipenser schrenckii Brandt幼鱼肝脏线粒体代谢的影响,将试验分为8个温度驯化组,分别设16、19、22、25℃4个恒温组,以及(16±2)、(19±2)、(22±2)、(25±2)℃4个变温组,驯化6周后取样,分别测定各驯化组施氏鲟幼鱼肝脏组织线粒体的蛋白含量、呼吸率和细胞色素C氧化酶(CCO)活性。结果表明:施氏鲟肝脏组织线粒体蛋白含量在各驯化组间均无显著性差异(P0.05);鱼体肝脏组织线粒体状态3呼吸率和状态4呼吸率均随着驯化温度的升高显著增加(P0.05),在16℃和19℃驯化组中,恒温处理和变温处理间均无显著差异(P0.05),而在22℃和25℃驯化组中,变温驯化组的线粒体状态3呼吸率和状态4呼吸率均显著高于恒温驯化组(P0.05);鱼体肝脏组织线粒体的呼吸控制率(RCR)随驯化温度的升高呈显著降低的趋势(P0.05),在各温度驯化组中,线粒体的RCR在恒温和变温处理间均无显著性差异(P0.05);鱼体肝脏组织线粒体CCO活性随着驯化温度的升高显著增加(P0.05),但酶活性在恒温和变温处理间均无显著性差异(P0.05)。研究表明,20~27℃的变温驯化能够显著诱导施氏鲟线粒体呼吸率升高。 相似文献
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High copy number and random segregation confound genetic analysis of the mitochondrial genome. We developed an efficient selection for heritable mitochondrial genome (mtDNA) mutations in Drosophila, thereby enhancing a metazoan model for study of mitochondrial genetics and mutations causing human mitochondrial disease. Targeting a restriction enzyme to mitochondria in the germline compromised fertility, but escaper progeny carried homoplasmic mtDNA mutations lacking the cleavage site. Among mutations eliminating a site in the cytochrome c oxidase gene, mt:CoI(A302T) was healthy, mt:CoI(R301L) was male sterile but otherwise healthy, and mt:CoI(R301S) exhibited a wide range of defects, including growth retardation, neurodegeneration, muscular atrophy, male sterility, and reduced life span. Thus, germline expression of mitochondrial restriction enzymes creates a powerful selection and has allowed direct isolation of mitochondrial mutants in a metazoan. 相似文献
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Beech PL Nheu T Schultz T Herbert S Lithgow T Gilson PR McFadden GI 《Science (New York, N.Y.)》2000,287(5456):1276-1279
A homolog of the bacterial cell division gene ftsZ was isolated from the alga Mallomonas splendens. The nuclear-encoded protein (MsFtsZ-mt) was closely related to FtsZs of the alpha-proteobacteria, possessed a mitochondrial targeting signal, and localized in a pattern consistent with a role in mitochondrial division. Although FtsZs are known to act in the division of chloroplasts, MsFtsZ-mt appears to be a mitochondrial FtsZ and may represent a mitochondrial division protein. 相似文献
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龙眼胚性愈伤组织线粒体ATP合酶β亚基基因克隆及其在龙眼体胚发生过程中的表达分析 总被引：5，自引：1，他引：5
【目的】克隆龙眼(Dimocarpus longan Lour.)胚性愈伤组织线粒体ATP合酶β亚基基因(mitochondrial F1-ATPase beta subunit gene),并分析该基因在龙眼体胚发生过程中的表达情况。【方法】采用RT-PCR结合RACE法,通过T/A克隆测序,获得龙眼胚性愈伤组织线粒体ATP合酶β亚基基因全长序列;随后通过实时荧光定量PCR(qRT-PCR)法研究该基因在龙眼体胚发生过程中的表达规律。【结果】成功克隆龙眼胚性愈伤组织线粒体ATP合酶β亚基基因完整cDNA序列(GenBank登录号:FJ222749),该序列全长2099bp,由1677bp核苷酸组成的ORF,编码558个氨基酸。该基因与其它植物的线粒体ATP合酶β亚基基因在核苷酸序列和推导的氨基酸序列方面相似性较高。对来源于动、植物的28条线粒体ATP合酶β亚基基因编码区序列所构建的进化树分析表明,由线粒体ATP合酶β亚基基因编码区序列所建立的系统关系树与真实的动、植物进化基本一致,龙眼处在双子叶植物中,由于该基因在龙眼同科属的植物中为首次克隆,所以有自己单独的分支。qRT-PCR结果分析表明,随着龙眼体胚的发育,线粒体ATP合酶β亚基基因转录水平逐渐升高,到球形胚阶段达到最高,而后又急剧下降,到鱼雷形胚阶段降到最低,子叶形胚阶段略有升高。【结论】龙眼线粒体ATP合酶β亚基基因与其它植物相应序列具有较高同源性,在龙眼体胚发育过程中,以球形胚阶段的表达最高。 相似文献
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Nuclear and mitochondrial DNA comparisons reveal extreme rate variation in the molecular clock 总被引：28，自引：0，他引：28
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. 相似文献
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V S Parikh M M Morgan R Scott L S Clements R A Butow 《Science (New York, N.Y.)》1987,235(4788):576-580
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Levings CS Kim BD Pring DR Conde MF Mans RJ Laughnan JR Gabay-Laughnan SJ 《Science (New York, N.Y.)》1980,209(4460):1021-1023
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. 相似文献
14.
The rate of pyruvate oxidation by mitochondria from blowfly flight muscle decreased in the presence of tris (hydroxymethyl) aminomethane (Tris). An increase in the rate of mitochondrial swelling was concomitant with the loss of pyruvate oxidation. These changes were prevented by bovine serum albumin, adenosine triphosphate, and magnesium ions, factors required for mitochondrial contraction. Proline, but not glutamate or malate, restored the rate of pyruvate oxidation to original values. These findings suggest that mitochondrial swelling leads to leakage of intramitochondrial intermediates of the Krebs cycle, accounting for the decrease in the rate of pyruvate oxidation. Exogenous proline penetrates the mitochondrial membrane and is rapidly oxidized, via glutamate, forming intramitochondrial precursors of oxaloacetate. Malate and glutamate were ineffective because of the selective permeability of the mitochondrial membrane. 相似文献
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Wu H Kanatous SB Thurmond FA Gallardo T Isotani E Bassel-Duby R Williams RS 《Science (New York, N.Y.)》2002,296(5566):349-352
Endurance exercise training promotes mitochondrial biogenesis in skeletal muscle and enhances muscle oxidative capacity, but the signaling mechanisms involved are poorly understood. To investigate this adaptive process, we generated transgenic mice that selectively express in skeletal muscle a constitutively active form of calcium/calmodulin-dependent protein kinase IV (CaMKIV*). Skeletal muscles from these mice showed augmented mitochondrial DNA replication and mitochondrial biogenesis, up-regulation of mitochondrial enzymes involved in fatty acid metabolism and electron transport, and reduced susceptibility to fatigue during repetitive contractions. CaMK induced expression of peroxisome proliferator-activated receptor gamma coactivator 1 (PGC-1), a master regulator of mitochondrial biogenesis in vivo, and activated the PGC-1 gene promoter in cultured myocytes. Thus, a calcium-regulated signaling pathway controls mitochondrial biogenesis in mammalian cells. 相似文献
16.
Spierings D McStay G Saleh M Bender C Chipuk J Maurer U Green DR 《Science (New York, N.Y.)》2005,310(5745):66-67
The mitochondrial pathway of apoptosis in vertebrates is dependent on the process of mitochondrial outer membrane permeabilization (MOMP), which leads to the release of proteins from the mitochondrial intermembrane space into the cytosol. "Upstairs" of this event are the Bcl-2 family proteins that regulate and mediate MOMP; "downstairs" is the activation of caspases that orchestrate the dismantling of the cell. In the Connections Map database at Science's Signal Transduction Knowledge Environment (STKE), the pathways that define the mitochondrial pathway of apotosis are illustrated, with the bulk of control occurring "upstairs" of MOMP. 相似文献
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URF6, last unidentified reading frame of human mtDNA, codes for an NADH dehydrogenase subunit 总被引：26，自引：0，他引：26
A Chomyn M W Cleeter C I Ragan M Riley R F Doolittle G Attardi 《Science (New York, N.Y.)》1986,234(4776):614-618
The polypeptide encoded in URF6, the last unassigned reading frame of human mitochondrial DNA, has been identified with antibodies to peptides predicted from the DNA sequence. Antibodies prepared against highly purified respiratory chain NADH dehydrogenase from beef heart or against the cytoplasmically synthesized 49-kilodalton iron-sulfur subunit isolated from this enzyme complex, when added to a deoxycholate or a Triton X-100 mitochondrial lysate of HeLa cells, specifically precipitated the URF6 product together with the six other URF products previously identified as subunits of NADH dehydrogenase. These results strongly point to the URF6 product as being another subunit of this enzyme complex. Thus, almost 60% of the protein coding capacity of mammalian mitochondrial DNA is utilized for the assembly of the first enzyme complex of the respiratory chain. The absence of such information in yeast mitochondrial DNA dramatizes the variability in gene content of different mitochondrial genomes. 相似文献
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E A Schon R Rizzuto C T Moraes H Nakase M Zeviani S DiMauro 《Science (New York, N.Y.)》1989,244(4902):346-349
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. 相似文献
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Xu W Liu Y Wang S McDonald T Van Eyk JE Sidor A O'Rourke B 《Science (New York, N.Y.)》2002,298(5595):1029-1033
Ion channels on the mitochondrial inner membrane influence cell function in specific ways that can be detrimental or beneficial to cell survival. At least one type of potassium (K+) channel, the mitochondrial adenosine triphosphate-sensitive K+ channel (mitoKATP), is an important effector of protection against necrotic and apoptotic cell injury after ischemia. Here another channel with properties similar to the surface membrane calcium-activated K+ channel was found on the mitochondrial inner membrane (mitoKCa) of guinea pig ventricular cells. MitoKCa significantly contributed to mitochondrial K+ uptake of the myocyte, and an opener of mitoKCa protected hearts against infarction. 相似文献
20.
东北野猪线粒体DNA序列的测定与分析 总被引：2，自引：1，他引：2
通过PCR扩增获得东北野猪(Northeastern wild boar)线粒体全基因组序列,研究表明东北野猪线粒体全基因组序列全长16581bp,共有13个蛋白质编码基因、2个rRNA基因、22个tRNA基因和1个D-loop区。利用MEGA4软件构建系统进化树,推测东北野猪在分类上属于亚洲群,是亚洲猪种中最为古老的。 相似文献