NOVEL NUCLEOSIDE TRIPHOSPHATE ANALOGS FOR THE ENZYMATIC LABELING OF NUCLEIC ACIDS

We have evaluated several novel nucleotide analogs suitable for enzymatic labeling of nucleic acid targets for a variety of array-based assays. Two new reagents in particular, a C4-labeled 1-(2′,3′-dideoxy-β-D-ribofuranosyl) imid- azole-4-carboxamide 5′-triphosphate 5 and an N1-labeled 5-(β-D- ribofuranosyl)-2,4(1H,3H)-pyrimidinedione 5′-triphosphate 3, were found to be excellent substrates for labeling with terminal deoxynucleotidyl transferase and T7 RNA polymerase, respectively.     

核苷酸序列比对在生物系统发育研究中的应用

作为确定分子数据初级同源性(primary homology)的过程,比对的重要性在于后续算法的选择.本文对其在生物系统发育研究中的作用及其基本步骤与算法做了简要说明;从理论与实践相结合的角度介绍了使用最为广泛的软件,讨论了其中的空位(gap)问题、参数问题和比对结果校正等问题;并且对此领域中前沿的基因组比对研究进展做了概述.     

INTERRELATIONS BETWEEN POLYAMINES AND NUCLEIC ACIDS: CHANGES OF POLYAMINE AND NUCLEIC ACID CONCENTRATIONS IN THE DEVELOPING RAT BRAIN

The rat brain concentrations of protein, RNA, DNA, putrescine, and of the polyamines spermidine and spermine, were studied during development. Putrescine formation is apparently controlled by ornithine decarboxylase. Spermidine and spermine concentrations change in inverse directions to their anabolic enzymes. It has been presumed, therefore, that the low concentrations of the polyamine-synthesizing enzymes in immature brain are compensated for, by high putrescine and S-adenosylmethionine concentrations. In agreement with previous findings for fish brain, the changes in RNA and spermidine concentrations were most closely correlated. The functions of DNA: spermine are directly correlated only during the periods of brain maturation, after cell proliferation has nearly ceased.     

三甲基月桂基硫酸钠（TLS）在蓝细菌核酸提取中的作用

本文首次把三甲基月桂基硫酸钠(TLS)应用于蓝细菌(蓝藻)总核酸的提取。在用溶菌酶破坏满江红鱼腥藻的细胞壁后,再用TLS分别取代常用法中的各种试剂,即:Triton X-100 Sarkosyl,蛋白酶K,总核酸产率分别是常用法的98.9％,47.3％,103.8％。用TLS取代蛋白酶K处理不同生长期的满江红鱼腥藻,总核酸产率随生长期延长而降低。TLS取代蛋白酶K提取的DNA和常用法提取的DNA,都能被限制性内切酶EcoR I水解。用光学显微镜观察到,满江红鱼腥藻经TLS处理后,丝状体断裂,细胞破裂成碎片。在扫描电子显徽镜下,未经TLS处理的细胞表面光滑平整,而经TLS处理的细胞表面有鳞片状突起、皱褶、凹陷,甚至穿孔。     

COMPARISON OF NUCLEIC ACIDS IN MAIZE SHOOTS AND PEA EPICOTYLS

A nucleic acid component (x-RNA) has been found in high concentration in maize shoots. It is eluted from a MAK (methylated albumin kieselguhr) column at about the same position as messenger RNA. The amount of x-RNA in pea epicotyls is absent or very low. It is suggested that x-RNA is long-lived messenger RNA and is found in high concentration in monocotyledonous plants, especially in the case of plants of the Gramineae family. Dicotyledonous plants, typically, contain little or no detectable x-RNA as observed by ultraviolet absorbancy. In the case of corn shoots, x-RNA is in highest concentration in the ribosomal fraction (78,500 × g, 70 min). In both maize shoots and pea epicotyls the newly synthesized nucleic acids were confined to the nuclear fraction (10,000 × g, 10 min).     

A CYTOPHOTOMETRIC STUDY OF NUCLEIC ACIDS AND PROTEINS IN THE SHOOT APEX OF WHITE SPRUCE

During the annual three-phase growth cycle of white spruce [Picea glauca (Moench) Voss] the vegetative shoot apex changed in anatomical configuration. Relative amounts of DNA, histones, RNA, and proteins were measured in three cytohistological zones and were related to the anatomical changes during ontogeny. An extended period of DNA synthesis (S) and G₂ preceded an increase in the number of apical initial cells which were part of the mammillary apex. While DNA and histones were generally synchronous during ontogeny, the ratio of DNA to histone increased on June 20. This loss of histone and subsequent increases in RNA and cytoplasmic proteins preceded the appearance of needle primordia on next year's apex. We propose that induction of the apex to reorganize and form needle primordia occurred when the DNA was in a 2C condition, following the loss of histone on June 20.     

柞蚕卵巢中核酸和蛋白质的分布与含量的变化

本文报道柞蚕卵巢亚细胞组分中核酸和蛋白质的分布与含量变化。首先以差速离心盼方法从卵巢匀浆中分离出细胞核、重线粒体、轻线粒体、重微粒体、轻微粒体和105,000g上清六个组分,然后分别测定了各种组分中的DNA、RNA和蛋白质的含量。 结果表明,卵巢DNA主要分布在细胞核组分中(约占75%以上);RNA在佩粒体中含量较离(约占20—51%);蛋白质则主要分布于105,000g上清组分中(约占56—83%)。卵巢中核酸和蛋白质含量(毫克/头)在滞育蛹期很低,随着卵巢的发育迅速增长。DNA在发育蛹4期最高,比滞育蛹期增长61倍;RNA在发育蛹5期最高,比滞育蛹期增长144倍;蛋自质在成虫期达到高峰,约比滞育蛹期增长490倍。并讨论了核酸和蛋白质的含量变化与卵巢细胞分裂分化之间的关系。 为了获得进一步的生化资料,对不同时期的柞蚕卵巢105,000g上清组分中的蛋白质进行了聚丙烯酰胺凝获也泳和SDS-电泳的分析。初步推测柞蚕卵巢中卵黄蛋白亚基之一的分子量大约为200,000道尔顿。     

SELECTIVE RETENTION AND FILTRATION OF BRAIN NUCLEIC ACIDS IN AGAROSE GELS

Abstract— Total nucleic acids of rat brain have been separated by agarose gel chromatography at 2 m -NaCl into DNA. transfer RNA plus low molecular weight RNA. and high molecular weight RNA fractions. The DNA fraction contained less than 1 per cent RNA by weight judged by either short-term or long-term labelling with ortho[³²P]phosphate. The high molecular weight RNA fraction contained 28 s and 18 s ribosomal RNAs and a heterogeneous population of 20-60 s RNAs, apparent after short-term labelling and characterized by a high content of nearest-neighbour-labelled uridylic acid. The rapidly sedimenting (>30 s ) portion of these RNAs could be largely separated from ribosomal RNAs by gel filtration using 4% agarose. The ribosomal RNAs could be fully resolved into 28 s and 18 s components by agarose gel chromatography at 0.5 m -0.6 m -NaCl, as shown by analysis of their sedimentation and nucleotide composition.     

THE DEVELOPMENT OF GOLGI COMPLEXES AND THEIR DEPENDENCE UPON THE NUCLEUS IN AMEBAE

The production of Golgi complexes was investigated in Amoeba proteus by introducing a nucleus into cells that had been enucleated for 5 days. Golgi complexes were not detected in 5 day enucleates, nor were they observed in amebae fixed 15 min after renucleation. Samples taken at longer intervals after the introduction of a nucleus exhibited an increase in the size and abundance of Golgi complexes. Small curved smooth cisternae, some of which were aligned in parallel to form small Golgi complexes, were observed 30 min after the operation. Aggregations of small Golgi complexes increased in number in amebae fixed 1 to 6 hr after renucleation. Golgi complexes of normal size were present 6 hr after the operation and became more abundant in samples fixed 12 hr, and 1, 2, and 3 days after renucleation. The possible participation of the granular endoplasmic reticulum in the development of Golgi complexes was suggested by two observations. First, the Golgi complexes in renucleates contained a dense material similar to the content of the endoplasmic reticulum in enucleates and early renucleates. Second, examples of continuity between the endoplasmic reticulum and Golgi cisternae were present in renucleates. The possibility that Golgi complexes can be produced in the absence of preexisting Golgi complexes is discussed.     

部分柔性的核酸双螺旋构象的模型化研究

基于核酸结构单元的基本思想,在分析给出任意碱基对片段的自由度集合和两碱基对片段的简化自由度集合的基础上,建立了DNA/m5cDNA/RNA双螺旋结构的理论模型和两碱基对部分柔性的构象计算方法.利用本方法获得的标准B-DNA双螺旋构象参数与实验基本一致.根据DNA嵌插受体的统计性实验约束,优化产生了适用于阿霉素类抗癌药的三碱基对DNA片段的理论嵌插受体模型.     

CHANGES IN THE CARBOHYDRATES, PROTEINS AND NUCLEIC ACIDS IN THE OVULES OF ZEPHYRANTHES LANCASTERI AT DIFFERENT STAGES OF MATURATION

The major changes in the levels of soluble and insoluble carbohydrates,nitrogenous compounds and nucleic acids were investigated atdifferent stages of seed development in Zephyranthes lancasteri.The activities of amylases, glutamic-alanine transaminase, ribonucleaseand deoxyribonuclease were also studied. The alcohol-solublenitrogen and carbohydrates attain their maximal levels priorto the elongation ofthe cotyledon. Both of these decrease markedlyduring further maturation of the seed. The accumulation of totalnitrogen in the ovule follows a sigmoid pattern. The glutamic-alaninetransaminase activity appears to be exclusively localized inthe endosperm and is absent from the embryo. The embryo seemsto derive its organic nitrogen fromthe endosperm. The peak inthe level of DNA per ovule is attainedprior to the elongationof the cotyledon while that of RNA is foundsoon after. ¹Present address: AEC Plant Research Laboratory, Michigan StateUniversity, East Lansing, Mich., U.S.A.     

AUTORADIOGRAPHIC STUDIES OF NUCLEIC ACIDS AND PROTEINS DURING MEIOSIS IN LILIUM LONGIFLORUM

Taylor , J. Herbert (Columbia U., New York, N. Y.) Autoradiographic studies of nucleic acids and proteins during meiosis in Lilium longiflorum. Amer. Jour. Bot. 46(7): 477–484. Illus. 1959.—A study was made of the incorporation of glycine-C¹⁴, orotic acid-C¹⁴ and cytidine-H³ into nucleic acids and proteins of sporogenous and tapetal cells of lily anthers preceding and during meiosis. Methods for differential extraction of nucleic acids from tissue sections, which had been frozen, dehydrated by alcohol-substitution, and fixed in hot alcohol, were tested by chromatographic analysis of extracts. Both acid and enzyme hydrolysis were shown to be useful for quantitative or, at least, semi-quantitative work. DNA synthesis was shown to occur only during premeiotic interphase in sporogenous cells, but at two intervals in tapetal nuclei, once when the microsporocytes are in zygotene and again during pachytene. Each time the synthetic period was followed by a normal mitosis. Accumulation of RNA in microsporocytes occurred at stages up to late leptotene. After this period, labeled RNA accumulated almost exclusively in their nuclei and at a slower rate than in earlier stages. DNA synthesis, as measured by incorporation of glycine-C¹⁴ and orotic acid-C¹⁴, gave the same results and confirm earlier results with inorganic phosphate-P³². For RNA, glycine-C¹⁴ and orotic acid-C¹⁴ gave different results. When glycine-C¹⁴ was the source of label, incorporation of C¹⁴ in RNA stopped during DNA synthesis in sporogenous cells. Glycine-C¹⁴ was not utilized to a significant extent at any time by tapetal cells for RNA synthesis, but extensively for DNA and protein synthesis. Orotic acid-C¹⁴ was incorporated into RNA of both tapetum and sporogenous cells at various periods in development apparently including the interval of DNA synthesis. Protein synthesis as measured by incorporation of glycine is relatively rapid during premeiotic interphase and leptotene. It continues during the remainder of prophase, but at a much reduced rate. In tapetal cells the rate is rapid in the nuclei during periods of DNA synthesis, but even faster in both cytoplasm and nucleus after divisions are completed and the microsporocytes are in late prophase and division stages. This period of synthesis is perhaps necessary for the postmeiotic functioning of tapetum when it appears to secrete the wall materials for the microspores.