核质互作型水稻线粒体不育基因的RAPD分析

采用RAPD对水稻Ⅱ-32A、Ⅱ－32B、Ⅱ优949的mtDNA进行分析,得到两个特异的扩增片段OPJ18-1000、OPJ18－1400。序列测定两个特异片段全长分别为1068bp和1481bp。Southern杂交结果证明了差异片段的真实性。用OPJ18－1000作探针与Ⅱ－32A、Ⅱ－32B、Ⅱ－优949的mtRNA斑点杂交结果表明,除Ⅱ－32B外,都在转录水平上对水稻雄性不育有一定影响。虽然OPJ18－1400对应的RNA斑点杂交呈阴性,但其DNA序列中存在一个七碱基5′-TTC-CCTC-3′的保守系列。据报道它是atp6基因中同源重组热点区,可促使线粒体基因重组形成嵌合基因,从而对水稻雄性不育的形成起着重要作用。经同源性比较和DNA、RNA杂交证实获得的两个片段是新的与水稻细胞质雄性不育相关的mtDNA序列。     

线粒体DNA和疾病

人线粒体DNA是含有16569 bp的闭环双链分子.它为13种氧化磷酸作用酶的亚单位、结构rRNAs和tRNAs编码.近年来很多引起人类疾病的线粒体DNA突变已被确定,如眼盲、耳聋、心力衰竭和人类退行性疾病等.线粒体DNA疾病可能比先前想象的多.     

线粒体DNA突变与相关人类疾病

在过去的20年里, 人们发现线粒体DNA(mitochondrial DNA, mtDNA)突变与多种人类疾病相关, 其致病范围从单器官组织损害到多系统受累。文章目的在于探讨mtDNA突变与人类疾病的关系。文章重点论述: (1)线粒体遗传学特征; (2) mtDNA突变与人类遗传性疾病; (3)体细胞mtDNA突变在衰老和肿瘤中的作用; (4)mtDNA疾病的诊断和治疗。     

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.     

七种蝽mtDNA-16S rRNA基因序列多态性的研究(半翅目:蝽科)

测定蝽亚科2族4属7个种(宽碧蝽,辉蝽,凹肩辉蝽,角肩真蝽,褐真蝽,斑真蝽,全蝽)9个个体线粒体DNA(mtDNA)的16SrRNA基因片段,分析了其遗传多态性。通过测定该基因片段的序列发现,不同种群存在丰富的DNA序列多态性,同一种的不同个体差异较小,9个个体具有9种基因型。在扩增的长为400bp的基因片段中,通过排序,有338个碱基可用于这9个个体的比较。在这一基因片段中,共检测到122个多态性核苷酸位点(约36．1％)。NJ法构建的分子系统树表明碧蝽属归于短中片族,全蝽属的分化较其它属要早。     

线粒体DNA异质性

线粒体 DNA（mitochondrial DNA,mtDNA）是线粒体内最重要的遗传物质。mtDNA 突变普 遍存在,突变型 mtDNA 与野生型 mtDNA 共存的现象被称为 mtDNA 异质性。mtDNA 异质性与衰老和多种疾病密切相关。mtDNA异质性特性、mtDNA 异质性与衰老和疾病相关性以及线粒体疾病的治疗等都是近年来遗传学研究的热点。本文从 mtDNA 异质性的动态变化、组织特异性、mtDNA 异质性与疾病以及线粒体疾病的治疗等方面对 mtDNA 异质性进行综述。     

线粒体DNA靶向治疗

线粒体(mitochondrion)是真核生物细胞中的一种非常重要的细胞器,含有独立于细胞核染色体外的遗传物质,通过氧化磷酸化产生ATP,是细胞的能量工厂,与细胞分化、信号转导、代谢稳态等过程密切联系。线粒体功能的紊乱与癌症、神经退行性疾病、糖尿病等许多疾病的发生、发展及治疗息息相关。线粒体在细胞命运中扮演的关键角色,使对线粒体这一特殊细胞器的探索成为生命科学研究热点之一。人线粒体DNA(mitochondrial DNA, mtDNA)是一相对保守且仅16 kb的环状双链DNA分子,只含37个基因,但这些基因都是维持线粒体功能稳定必不可少的部分。随着对线粒体功能认识的不断深入,研究人员发现mtDNA突变,会导致活性氧自由基过量产生,从而引起细胞衰老,甚至引发诸多疾病,例如遗传性视神经病变、线粒体脑肌病伴高乳酸血症和卒中样发作综合征等。但是,目前针对这些线粒体基因疾病尚无非常有效的治疗手段。为了进一步了解这一关键细胞器,研究人员开发了一些有效的方法来突破线粒体的复杂屏障。本文将重点介绍并讨论近几年靶向mtDNA的研究进展,主要从药物修饰、材料递送、基因编辑等方面进行了总结,希望能为推动线粒体的研究提供一些新的思路。     

A Method for Isolation of Chloroplast DNA and Mitochondrial DNA from Sunflower

We present a method for isolation of chloroplast and mitochondrial DNA from sunflower seedlings. The protocol includes: organelle isolation, deoxyribonuclease treatment, lysis, deproteinisation and a final DNA purification with sodium dodecyl sulphate and potassium acetate. The organelle DNA yield is 5–10 micrograms per gram of tissue and the DNA is fully restrictable. The technique is inexpensive and appropriate for the isolation of multiple samples of organelle DNA from a small amount of tissue.     

Preliminary characterization of carbohydrate stores from chlorarachniophytes (Division: Chlorarachniophyta)

Chlorarachniophytes are amoeboid/flagellate eukaryotes that harbor reduced green algal endosymbionts. The carbohydrate stores of chlorarachniophyte algae have been investigated using methylation analysis to determine monosaccharide composition. An appreciable quantity of long chain β-1,3 glucan occurs in these algae. Immunogold electron microscopy using an antibody specific for (β-1,3 glucans localized (β-1,3 glucans within a vacuole in the host cell cytoplasm. The results suggest that photosynthate produced by the endosymbiont is stored by the host. Implications of the data for endosymbiosis are discussed.     

Mitochondrial DNA coding region sequences support the phylogenetic distinction of two Indian wolf species

Two small endangered populations of Indian wolves were recently shown to be distant from other wolf and dog mtDNA lineages characterized so far. None of the inner branches in the tree of canid species based on partial hypervariable D-loop sequences were, however, statistically supported by the data raising the question whether the two Indian wolf lineages represent two new species, occupying an intermediate position between Canis latrans and C. lupus or have diverged from the sub-species of C. lupus due to isolation and drift. Here we report complete D-loop, cytochrome b, and 16S rRNA sequences data for 23 additional wolves from India analysed in the context of other canid species. Extended analyses of D-loop data and partial sequences of 16S rRNA showed highly reticulated pattern and were unable to resolve unambiguously the phylogenetic relationship of Indian wolves among other canid species. The phylogenetic reconstructions of cytochrome b sequences, however gave significant statistical support for the inner branches supporting genetic distinction of the two Indian wolf lineages within themselves as well as from all other wolves of the world, including individuals belonging to subspecies C. lupus chanco and C. lupus pallipes to which the two Indian wolf populations have been traditionally assigned. Their genetic differentiation relative to worldwide variation of wolves supports the suggestion to treat them as separate wolf species, C. himalayensis and C. indica .     

人体基因组随机单拷贝顺序的分离及其在染色体上的定位

本文从构建杂种细胞14-7-1的基因组文库出发,用种特异的探针分离出含有人体基因组顺序的重组子,并进一步分析了其中13个克隆,得到8个单拷贝顺序。通过与已建立的杂种细胞克隆分布板杂交以及染色体的原位杂交方法,将1个单拷贝顺序FD11-1定位在11p11-q11上。由于已经报道在11号染色体上具有3个连锁群,它们分别位于11p15、11p13和11q13上,因此,FD11-1有可能为11号染色体连锁基因图的建立提供1个有意义的座位。     

Subcellular localization of minicircle DNA in the dinoflagellate Amphidinium massartii

Peridinin‐containing dinoflagellates have small circular DNA molecules called minicircle DNAs, each of which encodes one, or occasionally a few, plastid proteins or ribosomal RNA. Dinoflagellate minicircle DNA is composed of two parts: a gene‐coding sequence and a non‐coding sequence that consists of several variable and core regions. The core regions are identical among the minicircle DNAs with different genes within a species or strain. Because such structure is very different from those of well known plastid DNAs, many functional and evolutionary questions have been raised for the minicircle DNAs, and several studies that focus on answering those questions are underway. However, the localization of minicircle DNA is still controversial: several lines of indirect evidence have implied plastid localization, whereas the nuclear localization of minicircle DNA has also been suggested in a species. In order to understand the evolution and function of minicircle DNA, it is important to know its precise localization. In this study, we sequenced two typical minicircle DNAs, one encodes psbA and the other encodes 23S rRNA genes, from an Amphidinium massartii strain (TM16). To determine the subcellular localization of these minicircle DNAs, we performed DNA‐targeted whole cell fluorescence in situ hybridization with A. massartii minicircle DNA‐specific probes and demonstrated that minicircle DNAs were present in plastids. This study provides the first direct evidence for the plastid localization of dinoflagellate minicircle DNAs.     

Evaluation of Ectopic Mitochondrial DNA in HeLa Cells

The presence of ectopic DNA in the cytoplasm induces inflammation and cell death. It has been widely reported that leakage of nuclear DNA into the cytoplasm can mainly be sensed by cyclic GMP-AMP synthase (cGAS). We recently reported that mitochondria-derived cytoplasmic double-stranded DNA (dsDNA) that has escaped lysosomal degradation induces significant cytotoxicity in cultured cells and in vivo. Cytoplasmic mitochondrial DNA is assumed to be involved in various diseases and disorders, and more and more papers have been published confirming this. On the other hand, the current method for evaluating mitochondrial DNA in the cytoplasm may not be quantitative. Here, we introduce in detail a method to evaluate ectopic mitochondrial DNA in cells. This method is useful in basic research as well as in the study of aging, Parkinson’s disease, Alzheimer’s disease, heart failure, autoimmune diseases, cancer, and other conditions.     

Mitochondrial DNA mutations in multiple symmetric lipomatosis

Multiple symmetric lipomatosis (MSL) is a rare disorder of middle life characterized by large subcutaneous fat masses around the neck, shoulders and other parts of the trunk. Peripheral neuropathy is a common finding in these predominantly male patients. Employing electrophysiological measures, we found additional signs of central nervous system involvement in a majority of patients. Etiologically, there is an association with mitochondrial dysfunction. In muscle biopsy, we found ragged red fibers in 8 of 12 patients. Molecular genetic analysis revealed multiple deletions of mitochondrial DNA in one patient and the MERRF mutation at nucleotide 8344 in another. In this review, we summarize our clinical, electrophysiological morphological, biochemical and molecular genetic findings in 17 MSL patients, and give a survey of the literature. (Mol Cell Biochem 174: 271–275, 1997)     

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.     

DIG标记DNA探针检测noggin在爪蟾胚胎中的表达

整体原位杂交（Whole-mount in situ hybridization)用于基因表达定位和表达分布模式的研究,已经成为一种非常重要的手段。PCR方法进行探针标记,可以获得特异性高,片断大小可变的探针。采用DIG标记,检测已知基因noggin在爪蟾胚胎时空分布,所得结果与文献报道一致,表明PCR方法获得的DNA探针在一定的条件下可以用于爪蟾胚胎整体原位杂交。     

Mitochondrial DNA and RNA isolation from small amounts of potato tissue

We present a fast and simple protocol for purification of mitochondrial DNA and RNA from small amounts of potato tissue including tubers, leaves, flowers, and flower buds. This method uses a high ionic strength medium to isolate mitochondria and extract mitochondrial DNA and RNA from a single preparation and is easily adaptable to other plant species. The mitochondrial DNA was not contaminated by plastid DNA, was fully restrictable and was successfully used for PCR, cloning and Southern analyses. Similarly, the isolated mitochondrial RNA was not contaminated (flower buds) or only slightly contaminated (leaves) by plastid RNA. RNA prepared according to our method was acceptable for northern and RT-PCR analyses.     

Molecular Phylogenetics of Gadidae and Related Gadiformes Based on Mitochondrial DNA Sequences

Mitochondrial DNA sequences of selected regions of the small subunit and large subunit ribosomal RNAs and cytochrome b genes were analyzed for 10 gadid species, representing 8 genera within Gadidae, and 10 species representing 5 other gadiform families. Phylogenetic analyses revealed that Gadiculus is the most basal gadid genus, and that Trisopterus and Micromesistius constitute a relatively basal clade. Lotidae was identified as the family most closely related to Gadidae. Estimation of divergence times indicated that the most ancient Gadidae split between Gadiculus and the remaining gadid genera occurred about 20 million years ago. The clade including the most recent species (Gadus, Boreogadus, Merlangius, Melanogrammus, and Pollachius) diverged from the Trisopterus/Micromesistius clade approximately 12 million years ago.