神经肌肉性疾病患者线粒体DNA突变的分析 Analysis on the Mitochondrial DNA of Patients with Neuromuscular Diseases

为了探讨神经肌肉性疾病的发病与线粒体DNA突变的关系,采用PCR技术检测了 20例患有不同神经肌肉性疾病儿童的外周血和骨骼肌细胞中的线粒体DNA(mtDNA),发现其中6例患儿有mtDNA缺失,其中1例至少有2968bp片段的缺失, 另5例至少有2000bp片段的缺失,此缺失区位于线粒体呼吸链复合物1、 4、5、编码区,表明该突变对神经肌肉性疾病的发生有一定作用。 Abstract:To understand the relation to mechanism of neuromuscular disease and mtDNA mutation,using PCR technique,we investigated blood and /or skeletal muscle of 20 patients with neuromuscular diseases.A deletion in the length of 2000~2968bp was found in blood mitochondrial DNA of 6 patients with neuromuscular disease.The deletion region partially lies in the coding region of resoiratony chain complex 1,4,5.It is suggested that this mutation ois related with neuromuscular diseases.     

神经肌肉性疾病患者线粒体DNA突变的分析

为了探讨神经肌肉性疾病的发病与线粒体DNA突变的关系,采用PCR技术检测了 20例患有不同神经肌肉性疾病儿童的外周血和骨骼肌细胞中的线粒体DNA(mtDNA),发现其中6例患儿有mtDNA缺失,其中1例至少有2968bp片段的缺失, 另5例至少有2000bp片段的缺失,此缺失区位于线粒体呼吸链复合物1、 4、5、编码区,表明该突变对神经肌肉性疾病的发生有一定作用。 Abstract:To understand the relation to mechanism of neuromuscular disease and mtDNA mutation,using PCR technique,we investigated blood and /or skeletal muscle of 20 patients with neuromuscular diseases.A deletion in the length of 2000~2968bp was found in blood mitochondrial DNA of 6 patients with neuromuscular disease.The deletion region partially lies in the coding region of resoiratony chain complex 1,4,5.It is suggested that this mutation ois related with neuromuscular diseases.     

神经肌肉性疾病患者线粒体DNA突变的分析

为了探讨神经肌肉性疾病的发病与线粒体ＤＮＡ突变的关系,采用ＰＣＲ技术检测了２０例患有不同神经肌肉性疾病儿童的外周血和骨骼肌细胞中的线粒体ＤＮＡ（ｍｔＤＮＡ）,发现其中６例患儿有ｍｔＤＮＡ缺失,其中１例至少有２９６８ｂｐ片段的缺失,另５例至少有２０００ｂｐ片段的缺失,此缺失区位于线粒体呼吸链复合物１、４、５、编码区,表明该突变对神经肌肉性疾病的发生有一定作用。     

鸟类线粒体DNA研究概述

线粒体DNA作为理想的分子标记已被广泛用于鸟类种群遗传学和进化遗传学的研究,并取得了许多有意义的结果。本文介绍鸟类线粒体DNA的组成、结构特点及多态性的研究,综述近年来有关鸟类分子进化研究的进展情况,对今后的发展进行了初步的探讨。 Abstract:Mitochondrial DNA as a genetic marker has been successfully applied to the study of molecular evolution of birds.The apparently maternal inheritance of mitochondrial DNA and its fast evolution in primary sequence has made it attractive in population and evolutionary genetics.Mitochondrial DNA of birds displays two characteristics not seen in other vertebrates mtDNA,that is,a novel gene order and the absence of an equivalent to the light-strand replication origin.The research on polymorphism of mtDNA can resolve phylogenies of birds both at lower and higher taxonomic levels.Here we review progress on avian molecular evolution in recent years,and make preliminary studies of the development in this field.     

肥厚型心肌病患者心肌mtDNA大片段缺失的探讨

应用Long PCR及Primer Shift Long PCR 技术对3例肥厚型心肌病(HCM）患者和10例正常引产胎儿的13份心肌标本予以线粒体 DNA缺失检测,结果在1例HCM患者心肌线粒体DNA中发现约5.0kb缺失,而在正常引产胎儿的标本未见该缺失,提示HCM的发生可能与mtDNA缺失相关。 Astract　Using long PCR and primer shift long PCR techniques, we analyzed the mitochondrial DNA (mtDNA) isolated from the heart muscles of 3 hypertrophic cardiomyopathy (HCM) patients and 10 normal abortive fetuses. Almost 5.0kb deletion was found in the heart mtDNA of one HCM patient, while no deletion was detected in that of 10 fetuses. It is concluded that HCM may correlate with mtDNA deletion.     

线粒体DNA修复系统相关酶的研究进展

线粒体DNA（mtDNA）编码线粒体电子传递系统的亚单位以及构建翻译机器所需的各种rRAN和tRNA。mtDNA编码的每一个亚单位都是线粒体完成正常的氧化磷酸化过程所必需的,因此,线粒体DNA的完整性对于生物体的生存十分重要。长期以来,人们一直认为线粒体中不存在DNA的修复。近年来在线粒体提取物中却检测到了一定数量的修复因子,提示线粒体中存在DNA的修复。主要对线粒体修复系统中相关酶的研究进展进行综述。Abstract: Mitochondrial DNA（mtDNA） encodes subunits of the mitochondrial electron transport system and the rRNAs and tRNAs required for constructing the mitochondrial tranlational machinery.Each subunit encoded by mtDNA is essential for normal oxidative phosphorylation.Thus,integrity of the mtDNA is crucial for the survival of organisms.It has long been held that there is no DNA repair in mitochondria.But in recent years,a number of repair factors have been found in mitochondrial extracts,suggesting the presence of DNA repair in mitochondria.This review summarized recent progress of enzyme in mitochondrial DNA repair processes.     

与神经肌肉病关联的DNA重复

与神经肌肉病关联的ＤＮＡ重复两年前，遗传学家们认为，他们已发现了一种独特的基因缺陷，它是被称为脆性Ｘ综合征（ｆｒａｇｉｌｅＸｓｙｎｄｒｏｍｅ）的病因。后来，研究者们找到另三个疾病属类似的基因缺陷，其中包括Ｈｕｎｔｉｎｇｔｏｎ（亨亭顿）氏病和强直性肌营...     

条纹斑竹鲨线粒体DNA的研究

用6种限制性内切酶分析了4条条纹斑竹鲨的线粒体DNA(mtDNA)。PstⅠ、Hpa Ⅰ、XbaⅠ、EcoRⅠ、EcoRⅤ、BglⅡ在条纹斑竹鲨mtDNA分子上分别具有0至2个切点, mtDNA分子大小为16.6kb,根据单酶和双酶完全酶解片段的大小,构建了条纹斑竹鲨mtDNA 的限制性酶切图谱。 Abstract:Mitochondrial DNA(mtDNA)form 4 samples of Chiloscyllium plagiosum was analyzed by 6 kinds of restriction.The number of cleavage sites were as follow:2 for HpaI,XbaI and EcoRI respectively;1 for BglII and EcoRV respectively;None for PstI.Molecular size of mtDNA was found to be 16.6kb.According to analysis of single and double enzyme cleavage,the map of restriction enzyme was constructed.     

广东地区汉族群体线粒体DNA 9bp序列缺失频率研究

旨在研究中国广东省部分地区汉族人群线粒体DNA RegionⅤ9bp序列缺失情况.采用PCR-PAGE和直接测序法对3个群体144份样本mtDNA RegionⅤ进行序列分析.结果只检测到标准型和短型(即9 bp缺失)两种多态.广东汉族人群的平均缺失频率为21.5%,广州、东莞和湛江汉族人群的缺失频率依次为20.8%、19.2%和25.0%.由此得出,广东汉族人群mtDNA 9 bp缺失频率较高,与其它地区汉族群体存在一定的差异.     

线粒体DNA用作分子标记的可靠性和研究前景

mtDNA作为分子标记的广泛应用,使得系统进化、生物地理、群体遗传、人类学及法医鉴定等领域的研究得到前所未有的发展.但随着对线粒体基因组遗传特性的了解不断加深,以mtDNA作为分子标记的潜在问题便逐渐暴露出来.本文从7个方面对mtDNA应用的可靠性问题进行了讨论,并对今后线粒体基因的应用前景做了初步分析。 Abstract:With some special features,mtDNA is used widely as molecular marker in the fields of systematic evolution,biogeography,population genetics,anthropology,and forensic medicine.However,more and more evidences that challenge the traditional concept on mtDNA features re found increasingly.In this paper,seven facts that could affect the reliability of mtDNA used as molecular marker are reviewed,then the perspective on application of mtDNA is discussed.     

拉萨郊区藏族跖纹主线走向分析

本文用茚三酮－味精法采集跖纹,体视显微镜下追踪跖纹主线走向,分析了２５０（男女各１２５人）拉萨效区藏族健康人的跖纹样本。结果显示：Ａ线主要走向１区,其次是７区;Ｂ线亦多止于１区和７区;Ｃ线主要止于和９区;Ｄ线止于１区 频率最高;Ｅ线主要走向１３区;Ｐ三叉缺失较多。Ｐｚ＾ｄ线止共位置较高（１３区和１１区）,而Ｐ＾ｆ线止区较低（７区）。在民族和人种间进行了比较,提示藏族践纹主线走向有自己的特点,又呈现     

线粒体基因突变与NIDDM发生的关系

采用PCR-SSCP、PCR-RFLP及PCR产物直接测序等技术对90例NIDDM(即非胰岛素依赖型糖尿病)及80例正常对照个体的血细胞线粒体DNA进行了突变分析。结果在2例患者中发现线粒体DNA(mitochondrial DNA,mtDNA) ND1 (NaDH Dehydrogenase subunitⅠ)基因上3316位点存在G→A的点突变,导致丙氨酸错义突变成苏氨酸,而在80例正常对照个体中均不存在此位点突变。国内外已证实的和1.5%NIDDM发生有关的mtDNA tRNA Leu^(UUR)|基因上3243位点A→G的突变在本实验中并未发现。由此推断,3316位点G→A的突变可能与NIDDM的发生在关,3243位点A→G的突变率确实很低,可见糖尿病的发生在线粒体遗传上具有广泛的异质性。 Abstract:Using PCR-SSCP,PCR-RFLP and PCR product direct sequencing techniques,we analysed the mitochondrial DNAs(mtDNAs)of 90 patients with NIDDM (Non Insulin-Dependent Diabetes Mellitus)and those of 80 normal controls.The results showed that a G to A mutation which leads alanine’s missence mutaton to threonine in the mitochondrial ND1(NaDH Dehydrogenase subunit I) gene at nucleotide pair 3316 occurred in the blood cells of 2 patients.We have not however,indentified with the A to G mutation at nucleotide pair 3243 of the mitochondrial tRNA Leu(UUR) gene,which has been reported to associate with NIDDM in about 1.5% of the diabetic population.We infer that the mutation at position 3316 is perhaps associated with the development of NIDDM,the occurance of the mutation at position 3243 is actually rare,and NIDDM has an intensive mitochondrial genetic heterogenous background.     

Mitochondrial Dysfunction in Neurodegenerative Diseases Associated with Copper Imbalance

Copper is an essential transition metal ion for the function of key metabolic enzymes, but its uncontrolled redox reactivity is source of reactive oxygen species. Therefore a network of transporters strictly controls the trafficking of copper in living systems. Deficit, excess, or aberrant coordination of copper are conditions that may be detrimental, especially for neuronal cells, which are particularly sensitive to oxidative stress. Indeed, the genetic disturbances of copper homeostasis, Menkes' and Wilson's diseases, are associated with neurodegeneration. Furthermore, copper interacts with the proteins that are the hallmarks of neurodegenerative disorders, such as Alzheimer's disease, Parkinson's disease, prion diseases, and familial amyotrophic lateral sclerosis. In all cases, copper-mediated oxidative stress is linked to mitochondrial dysfunction, which is a common feature of neurodegeneration. In particular we recently demonstrated that in copper deficiency, mitochondrial function is impaired due to decreased activity of cytochrome c oxidase, leading to production of reactive oxygen species, which in turn triggers mitochondria-mediated apoptotic neurodegeneration.     

DNA损伤与眼病相关性的研究进展

DNA损伤是复制过程中发生的DNA核苷酸序列永久性改变,并导致遗传特征改变的现象。对DNA损伤与修复的研究是现代分子生物学研究的热点之一。目前,DNA损伤对眼组织细胞凋亡、基因改变、细胞活性的影响已成为眼科疾病研究的热点。在年龄相关性白内障、老年性黄斑病变等眼科疾病的病因研究中证实氧化应激是其主要致病因素,当机体遭受有害刺激导致氧化应激时,机体、组织、细胞受到一系列损伤,而DNA的损伤对氧化应激最为敏感。本文就DNA损伤及其与晶状体上皮细胞及视网膜色素上皮细胞相关性的研究进展作一综述,为眼科疾病的研究以及防治提供新的方法及思路。     

Metabolic and Antioxidant System Alterations in an Astrocytoma Cell Line Challenged with Mitochondrial DNA Deletion

Oxidative stress can induce mitochondrial dysfunction, mitochondrial DNA (mtDNA) depletion, and neurodegeneration, although the underlying mechanisms are poorly understood. The major mitochondrial antioxidant system that protects cells consists of manganese superoxide dismutase (MnSOD), glutathione peroxidase (GPx) and glutathione (GSH). To investigate the putative adaptive changes in antioxidant enzyme protein expression and targeting to mitochondria as mtDNA depletion occurs, we progressively depleted U87 astrocytoma cells of mtDNA by chronic treatment with ethidium bromide (EB, 50 ng/ml). Cellular MnSOD protein expression was markedly increased in a time-related manner while that of GPx showed time-related decreases. The mtDNA depletion also altered targeting or subcellular distribution of GPx, suggesting the importance of intact mtDNA in mitochondrial genome-nuclear genome signaling/communication. Cellular NADP⁺-ICDH activity also showed marked, time-related increases while their GSH content decreased. Thus, our findings suggest that interventions to elevate MnSOD, GPx, NADP⁺-ICDH, and GSH levels may protect brain cells from oxidative stress.     

Mitochondrial DNA 3644T-->C mutation associated with bipolar disorder

Mitochondrial dysfunction associated with mutant mitochondrial DNA (mtDNA) has been suggested in bipolar disorder, and comorbidity with neurodegenerative diseases was often noted. We examined the entire sequence of mtDNA in six subjects with bipolar disorder having comorbid somatic symptoms suggestive of mitochondrial disorders and found several uncharacterized homoplasmic nonsynonymous nucleotide substitutions of mtDNA. Of these, 3644C was found in 5 of 199 patients with bipolar disorder but in none of 258 controls (p = 0.015). The association was significant in the extended samples [bipolar disorder, 9/630 (1.43%); controls, 1/734 (0.14%); p = 0.007]. On the other hand, only 5 of 25 family members with this mutation developed bipolar disorder, of which 4 patients with 3644C had comorbid physical symptoms. The 3644T-->C mutation converts amino acid 113, valine, to alanine in the NADH-ubiquinone dehydrogenase subunit I, a subunit of complex I, and 113 valine is well conserved from Drosophila to 61 mammalian species. Using transmitochondrial cybrids, 3644T-->C was shown to decrease mitochondrial membrane potential and complex I activity compared with haplogroup-matched controls. According to human mitochondrial genome polymorphism databases, 3644C was not found in centenarians but was found in 3% of patients with Alzheimer disease and 2% with Parkinson disease. The result of modest functional impairment caused by 3644T-->C suggests that this mutation could increase the risk for bipolar disorder.     

Mitochondrial DNA analysis of Tunisians reveals a mosaic genetic structure with recent population expansion

Tunisia is a country of great interest for human population genetics due to its strategic geographic position and rich human settlement history. These factors significantly contributed to the genetic makeup of present-day Tunisians harbouring components of diverse geographic origins. Here, we investigated the genetic structure of Tunisians by performing a mitochondrial DNA (mtDNA) comparison of 15 Tunisian population groups, in order to explore their complex genetic landscape. All Tunisian data were also analysed against 40 worldwide populations. Statistical results (Tajima's D and Fu's F_S tests) suggested recent population expansion for the majority of studied populations, as well as showed (AMOVA test) that all populations were significantly different from each other, which is evidence of population structure even if it is not guided by geographic and ethnic effects. Gene flow analysis revealed the assignment of Tunisians to multiple ancestries, which agrees with their genetic heterogeneity. The resulting picture for the mtDNA pool confirms the evidence of a recent expansion of the Tunisian population and is in accordance with a mosaic structure, composed by North African, Middle Easterner, European and Sub-Saharan lineages, resulting from a complex settlement history.     

玉米S型CMS线粒体DNA R区双向转录模式及其与不育相关性

玉米(Zea mays L.)S型CMS胞质育性基因被认为与其线粒体DNA高频重组R区相关.R区含orf355和orf77两个开放阅读框,其中orf77被认为是重要的胞质候选基因.RT-PCR分析发现R区为双链转录.其中一条为orf77-orf355的模板链,它的转录受植株核育性基因及生长发育时期的影响,在S(rf3rf3)(不育)基因型材料的黄化苗、S(Rf3-)(恢复)基因型材料的黄化苗及雄穗中,RT-PCR检测到这条模板链上R区的转录本完全相同,但S(rf3rf3)(不育)基因型材料雄穗的转录本则与上述三者不同,其转录本在5'端缩短了近238 b的长度.R区的另一模板链与coxⅠ或coxⅡ基因的模板链毗连,转录方向相同,这条链的转录不受核基因型和生长发育时期的影响,不育和恢复基因型材料的黄化苗及雄穗中的转录本完全相同.将orf77进行体外表达,制备抗体后对线粒体蛋白质进行Western杂交分析,未能检测到R区中ORF77蛋白质或多肽.推测orf77无翻译产物而且这可能与R区的双链转录有关.RT-PCR及Western分析结果表明玉米CMS-S可能与R区5'端DNA的转录调控相关.