DNA序列在植物系统进化研究中的应用

DNA序列分析已广泛应用于植物系统与进化学研究 ,根据不同的研究对象和问题选择相对应的DNA序列来进行研究显得十分重要 .目前在植物系统与进化学中主要一些DNA的应用 ,主要是讨论叶绿体基因组(rbcL等 )和核基因组 (18S ,ITS等 )中的特定DNA序列区段 .研究表明 ,18S ,rbcL等编码基因一般适用于较高分类阶元甚至整个种子植物谱系间的系统发育的探讨 ,而ITS及cpDNA的非编码区序列等因其较快的进化速率多用于较低分类阶元的系统关系研究 .

从微量血中快速制备线粒体DNA片段

目的 建立并鉴定用于从微量血中快速制备线粒体DNA片段的技术 .方法 采用微量血样品 ,改进提取线粒体DNA的方法 ;以不同的方法提取的血DNA为模板 ,同时扩增nDNA上的基因片段和mtDNA上的基因片段 ,PCR相对定量分析比较各种方法提取的mtDNA片段的纯度 ;结果 用华美公司生产的ReadyPCR(tm)微量全血DNA纯化系统和作者的方法都得到了mtDNA ,而用作者的方法获得的mtDNA的纯度较高 ;结论 由于线粒体DNA与核DNA存在有同源片段 ,ReadyPCR(tm)微量全血DNA纯化系统和常规酶解法提取DNA不适合用于对mtDNA的鉴定 ,作者的方法简便快捷地排除了核DNA的污染 ,非常适合于对mtDNA进行PCR分析 .

家猪核DNA多态标记的克隆与序列分析

在太湖猪各类群遗传多样性RAPD分析的基础上,对太湖猪类群间或与其他猪品种间有差异的核DNA标记位点SANDX 1、SANDX 2及SANDX 3进行了克隆,并对SANDX 2、SANDX 3位点的序列进行了测定及e PCR、BLAST分析.

从微量血中快速制备线粒体DNA片段

目的建立从微量血中快速制备线粒体DNA(mtDNA)片段。方法取50μl抗凝血和常规酶解法提取的血DNA,同时扩增核DNA(nDNA)上的基因片段和mtDNA上的基因片段,华美公司生产的RedyPCR(tm)微量全血DNA纯化系统进行比较,PCR相对定量分析比较这3种方法提取的mtDNA片段的纯度。结果RedyPCR(tm)微量全血DNA纯化系统得到的mtDNA和常规酶解法提取的mtDNA有nDNA污染,而作者建立的方法获得的mtDNA纯度较高。结论同时与该法简便快捷地排除了nDNA的污染,适合于对mtDNA进行PCR分析和研究。

线粒体DNA损伤与细胞凋亡

细胞核DNA(nuclear DNA,nDNA)损伤后诱导细胞凋亡的信号转导途径已经逐渐清晰,而线粒体DNA(mitochondrial DNA,mtDNA)损伤与细胞凋亡之间的关系尚有待进一步明确。目前已有研究结果表明:mtDNA断裂、缺失或功能缺陷能够显著影响细胞凋亡发生率;线粒体缺失细胞(ρ0细胞)同其亲代细胞相比,对多种凋亡诱导因素的反应存在显著差异;ROS的产生并非mtDNA损伤诱导凋亡的必要条件,mtDNA损伤断裂本身可能启动了凋亡的级联反应。但mtDNA的损伤,在细胞凋亡的信号转导途径具体扮演何种角色,还有待深入研究。

DNA Variation of <i>Capoeta</i><i>damascina</i>(Valenciennes, 1842) in Three Rivers in Northern Israel

The present study is in agreement with the hypothesis that the variation of ecological conditions in three rivers in northern Israel—the Dan, Hasbani and Hermon Rivers—affects the genetic variations of the species Capoeta damascina. Using mitochondrial DNA (mtDNA), cytochrome b gene (Cytb), 16S and nuclear DNA (nDNA), and Random Amplified Polymorphic DNA (RAPD), four different clusters were found in the Cytb of the Hasbani and Hermon Rivers and only two in the Dan River. Moreover, the clusters in the Hasbani River differed from those found in the Hermon River. A similar result was found when an analysis was made of a different sequence from five different haplotype frequencies using the MegAlign program, the lowest being in the Dan River (only two haplotypes) and the highest in the Hasbani River (four haplotypes). The analysis of molecular variance of Cytb and 16S (AMOVA) for individuals of C. damascina from eight populations in northern Israel showed significant differences between the rivers and the populations. The analysis by mitochondrial 16S of haplotype frequencies of C. damascina populations in the rivers in northern Israel was very low compared to Ctb. Sixteen different haplotypes were found in the different rivers: eight in the Hasbani River, seven in the Dan River and only five in the Hermon River.

FISH Loci of 18-26s rDNA in Four Gossypium Species

Detection of specific nucleic acid sequences suchas RNA or DNA in chromosomes by in situhybridization has important applications in manyareas of biology.The genes encoding 18-26srRNA are located nucleus organizer regions(NORs)in plant chromosomes.Fluorescent insitu hybridization(FISH)with 18-26s rDNA

DNA methylation of the Monoamine Oxidases A and B genes in postmortem brains of subjects with schizophrenia

Aims: We focused on DNA methylation of the promoter regions of the Monoamine Oxidase (MAO) A and B genes from postmortem brains of subjects with schizophrenia. Methods: We determined levels of DNA methylation using genomic DNA samples purified from four brain areas: prefrontal cortex (PFC), hippocampus, occipital cortex and nucleus accumbens (NAc), by a bisulfite sequencing method from seven normal subjects and six subjects with schizophrenia. Results: Although very few methylated CpGs of the MAOA and MAOB genes were detected in male samples, various DNA methylation patterns were present in female samples, and some differences were found in such patterns between normal subjects and subjects with schizophrenia. In the PFC, the average level of methylation of both genes was significantly higher in subjects with schizophrenia than in normal subjects. The content of highly methylated alleles of the MAOA gene in the NAc was significantly associated with schizophrenia, with similar results obtained for the MAOB gene in both the NAc and PFC. Some CpG sites showed higher levels of methylation in schizophrenia than in normal subjects. Conclusions: Levels of methylation were quite high in NAc and PFC in female subjects with schizophrenia compared with those in female normal subjects.

烟草雄性不育的分子机理研究进展

综述了烟草雄性不育分子机理研究的最新进展 ,包括 :线粒体DNA与雄性不育 ;叶绿体DNA与雄性不育 ;核DNA与雄性不育等研究。

Microsatellite DNA analysis proves nucleus of interspecies reconstructed blastocyst coming from that of donor giant panda

A method for DNA isolation from early development of blastocyst and further analysis of nuclear and mitochondrial DNA was developed in present study. Total DNA was prepared from interspecies reconstructed blastocyst and a giant panda specific microsatellite locus g010 was successfully amplified. DNA sequencing of the PCR product showed that two sequences of reconstructed blastocysts are the same as that of positive control giant panda. Our results prove that the nucleus of interspecies reconstructed blastocyst comes from somatic nucleus of donor giant panda.

Hoechst-naphthalimide dyad with dual emissions as specific and ratiometric sensor for nucleus DNA damage

A ratiometric fluorescent sensor（Hoe-NI） was developed by connecting a nucleus targeted Hoechst unit to a naphthalimide dye via ＂click chemistry＂. The sensor achieves high specific nucleus labeling with wash-free staining method in various kinds of living cells. The fluorescence ratio of the two emission bands（450 nm for Hoechst and 505 nm for naphthalimide） is changed sensitively to the variation of DNA concentrations, which provides the quantitative information in the processes of DNA damage induced by hydroxyl radicals and antitumor drug. Therefore, Hoe-NI is a recommendable sensor for the monitoring of nuclear DNA damage that reveals the health status of cells.

Epigenetic Enabled Normal Human Cells, Lead to <i>First Cell</i>’s Unique Division System, Driving Tumorigenesis Evolution

Normal cells must become cancer-enabling before anything else occurs, according to latest literature. The goal in this mini-review is to demonstrate special tetraploidy in the enabling process. This we have shown from genomic damage, DDR (DNA Damage Response) activity with skip of mitosis leading to diploid G2 cells at the G1 border in need of chromatin repair for continued cell cycling to the special tetraploid division system. In several studies specific methylation transferase genes were activated in normal human cells in tissue fields, containing different cell growth stages of the cancerous process. Histology studies, in addition to molecular chemistry for identification of oncogenic mutational change, were a welcome change (see below). In a study on melanoma origin, DDR also showed arrested diploid cells regaining cycling from methylation transferase activity with causation of 2n melanocytes transforming to 4n melanoblasts, giving rise to epigenetic tumorigenesis enabled First Cells. Such First Cells were from Barrett’s esophagus shown to have inherited the unique division system from 4n diplochromosomal cells, first described in mouse ascites cancer cells (below). We discovered that the large nucleus prior to chromosomal division turned 90° relative to the cytoskeleton axis, and divided genome reductive to diploid, First Cells, in a perpendicular orientation to the surrounding normal cells they had originated from. This unique division system was herein shown to occur at metastasis stage, implying activity throughout the cancerous evolution. Another study showed 4-chromatid tetraploidy in development to B-cell lymphoma, and that such cancer cells also proliferated with participation of this unusual division system. Such participation has long been known from Bloom’s inherited syndrome with repair chiasmas between the four chromatids, also an in vitro observation by us. Our cytogenetic approach also revealed that they believed mitotic division in cancer cells is wrong because such cell divisions were found to be from an adaptation between amitosis and mitosis, called amitotic-mitosis. Amitosis means division without centrosomes, which has long been known from oral cancer cells, in that MOTCs (microtubule organizing center) were lacking centrioles. This observation calls for re-introduction of karyotype and cell division studies in cancer cell proliferation. It has high probability of contributing novel approaches to cancer control from screening of drugs against the amitotic-mitotic division apparatus.

线粒体病的继发表现

线粒体病(MID)是由线粒体DNA(mt DNA)或核DNA(n DNA)基因突变引起的一组异质性遗传代谢疾病。由于其广泛的遗传异质性,MID具有多种表型。有时,受MID影响的器官可能会因另一器官、组织、系统的继发性疾病而变得复杂。继发性并发症可通过动脉、神经或内分泌信号从原发部位传播。动脉受MID影响可能会导致动脉高压、缺血、出血或动脉瘤形成。癫痫发作可能与创伤性脑损伤、Takotsubo综合征或癫痫猝死(SUDEP)有关。垂体腺瘤可能引起皮质功能减退、动脉低血压、性腺功能减退或身材矮小。糖尿病或甲状旁腺功能减退可能与神经病变、动脉低血压、低钙血症或视野缺损有关。肾脏受累可引起动脉高压。肝脏或免疫细胞受累可能会导致感染。MID的继发性表现可能会严重影响治疗管理、疾病轨迹和患者预后,因此需要仔细评估。

Applications of image analysis in plant chromosome and chromatin structure study

Background:The use of image analysis to understand the structure of chromosome and chromatin is critical to the study of genetic evolution and diversification.Furthermore,a detailed chromosome map and the structure of chromatin in the nucleus may contribute to the plant breeding and the study of fundamental biology and genetics in organisms.Results:In plants with a fully annotated genome project,such as the Leguminosae species,the integration of genetic information,including DNA sequence data,a linkage map,and the cytological quantitative chromosome map could further improve their genetic value.The numerical parameters of chromocenters in 3D can provide useful genetic information for phylogenetic studies of plant diversity and heterochromatic markers whose epigenetic changes may explain the developmental and environmental changes in the plant genome.Extended DNA fibers combined with fluorescence in situ hybridization revealed the highest spatial resolution of the obtained genome structure.Moreover,image analysis at the nano-scale level using a helium ion microscope revealed the surface structure of chromatin,which consists of chromatin fibers compacted into plant chromosomes.Conclusions:The studies described in this review sought to measure and evaluate chromosome and chromatin using the image analysis method,which may reduce measurement time and improve resolution.Further,we discussed the development of an effective image analysis to evaluate the structure of chromosome and chromatin.An effective application study of cell biology and the genetics of plants using image analysis methods is expected to be a major propeller in the development of new applications.