长萼木通属——木通科一新属

缺瓣牛姆瓜Holboellia apetala Q．Xia,J．Z.Suen et Z．X．Peng在一系列特征上与牛姆瓜属Holboellia植物不同,不应隶属于该属,而代表了一个未被描述过的新属—长萼木通属。新属在茎、叶、果实和花的大部分特征上与木通属Akebia相似,但花萼特征又与野木瓜属Stauntonia接近,其系统位置介于这两个属之间,并偏于前者。     

An ultra-pure in vitro phase synchrony method employing centrifugal elutriation and viable flow cytometric cell sorting

We present a method of synchronizing cells in G1-, S-, and G2M-phases employing sequential centrifugal elutriation and viable flow cytometric cell sorting of Hoechst-33342 stained Chinese hamster ovary cells. G1- and S-phase cells can be separated to greater than 99% homogeneity and G2-M to 70% purity. Most of the 30% contamination in the G2-M fraction was due to S-phase cells, whose reproductive integrity could be eliminated through the use of high specific activity 3H-TdR. There were minimal toxic effects or perturbations to growth following the selection procedures. The most significant limitation of this technique appears to be the rate of cell sorting, which, with current equipment, is approximately 3,000 cells per second.     

Inhibition of surfactant release from isolated type II cells by compound 4880

Release of [³H]phosphatidylcholine from pulmonary Type II epithelial cells was stimulated by terbutaline, forskolin and cytochalasin D. Compound $\text{48}\text{80}$ inhibited both basal and agonist-stimulated release of [³H]PC. The IC₅₀ for inhibition by compound $\text{48}\text{80}$ was 1–2 μg/ml, and was similar for inhibition of both basal and stimulated release of [³H]phosphatidylcholine. Inhibitory effects of $\text{48}\text{80}$ were noted following a 1 h exposure to compound $\text{48}\text{80}$ and persisted up to 3 h. The inhibitory effect of compound $\text{48}\text{80}$ was entirely reversed by removing compound $\text{48}\text{80}$ from the external milieu. Compound $\text{48}\text{80}$ had no effect on cytosolic cyclic AMP levels or lactate dehydrogenase release. Inhibition of surfactant release produced by compound $\text{48}\text{80}$ was unaffected by changes in extracellular calcium concentrations. Compound $\text{48}\text{80}$ is a non-toxic inhibitor of phosphatidylcholine release from Type II epithelial cells.     

袋衣属一裂芽新种

本文描述了袋衣属一新种——横断山袋衣。它是本属中第一个以巴巴酸为恒有成分的种类,又是指袋衣种群中第一个具有真正裂芽的成员。这一新种是作者在瑞典乌普萨拉大学植物标本室工作期间从H.Smith于1934年采自中国四川省的大量标本中发现的。对乌普萨拉大学的访问是中国科学院与皇家瑞典科学院之间1982年科学交流项目之一。     

Platelet monoamine oxidase (MAO) activity: evidence for a single major locus.

Monoamine oxidase (MAO), a mitochondrial enzyme involved in the degradation of biogenic amines, has been associated with psychiatric morbidity. Although twin and family studies have indicated that MAO activity is familial, the exact mode of transmission is unclear. We performed segregation analysis on 154 nuclear families containing 419 individuals using the mixed model, which allows for a single major locus with a polygenic background. We were able to reject a dominant and additive locus with or without a heritable background and a recessive locus without background. The acceptable models were: (1) a codominant model without background where the mean of the heterozygote distribution was 30% of the distance from the low to the high homozygote distributions, and (2) a recessive locus with heritable background. In both cases, the gene frequency for the high-MAO allele is approximately .25--at odds with suggestions that low-MAO represents a genetic marker for a disorder such as schizophrenia with a lifetime risk of only 0.85%. To ensure that results were not artifacts from a familial, skewed distribution, the data were also analyzed after power transformation. In addition, hypotheses were tested using both the joint and conditional likelihoods to examine for possible misspecification of the model with respect to intergenerational differences. Finally, we allowed for non-Mendelian transmission probabilities to provide another class of alternatives against which to test the hypothesis of a major locus. All these approaches provided additional confirmation for the presence of a major locus segregating within these families.     

新型有原始肢突胴甲鱼的发现及胴甲鱼早期演化的初步探讨

本文记述的曲靖始突鱼(Procondylolepis qujingensis gen.et sp.nov.)是近几年在云南曲靖早泥盆世地层中发现的有肢突胴甲鱼一原始类型。它和已知胴甲鱼(包括早泥盆世无肢突的和中、晚泥盆世有“盔”状肢突的)不同的最大特点是在其肩带与胸鳍相接的肩关节处有原始的肢突和简单的关节窝;胸鳍甲近端的关节区很小。它展现出胴甲鱼类这一高度特化、长期使人迷惑不解的肢突,在胴甲鱼演化史上发展变化的梗概,填补了肢突从无到有中间的缺环,使人了解到胸鳍的具体结构。文中主要根据肢突的有无和特化程度等,对胴甲鱼早期演化史作了初步探讨,将胴甲鱼分为无肢突超目(Abrachicondylia)和有肢突超目(Brachicondylia)两大部分。始突鱼则代表有肢突超目一早期成员。     

中国下泥盆统脊椎动物化石组合层序

本文综合了滇、黔、川、桂等地的一些早泥盆世地层剖面中的脊椎动物化石的出露情况,粗略地描绘出了早期脊椎动物演化的一般特征,归纳成三个发展阶段。并以此为依据,讨论了下泥盆统的分层与对比。     

大熊猫臼齿釉质的超微结构和氨基酸组成

大熊猫臼齿釉质的超微结构特征主要是施氏明暗带的宽度一般由8—15条釉柱组成;釉柱的横切面一般呈六角形或四角形,由里向外,釉柱的直径逐渐增大。在靠近釉牙本质界处,釉柱数量逐渐减少,有时甚至完全缺失,形成无釉柱结构的釉质。大熊猫臼齿釉质的氨基酸组成主要以甘氨酸,丙氨酸,谷氨酸,天冬氨酸和亮氨酸的含量为最高,而蛋氨酸,胱氨酸和酪氨酸的含量为最低。另外,还含有少量的羟脯氨酸。这种组成模式一般与人类和其它哺乳动物牙齿釉质的氨基酸组成相类似。     

科氏仓鼠(Kowalskia)一新种

山东沂南马牧池区双泉西山红棕色角砾岩层中的Kowalskia yinanensis sp.nov.头骨和下颌是该属迄今所发现的最完整的材料。这种仓鼠大小接近波兰晚上新世的K.magna,具有和Cricetinua varians相似性状的头骨及下颌。臼齿尖(嵴)发育程度较捷克最晚上新世的K.intermedia稍原始,时代上大致可与之相对比。     

A gene between polA and glnA retards growth of Escherichia coli when present in multiple copies: physiological effects of the gene for spot 42 RNA.

We have isolated the single gene for spot 42 RNA of Escherichia coli on a 20-kilobase DNA fragment. Physical characterization of this cloned DNA fragment showed that it is homologous to a region at 86 min on the genetic map and extends from the 23S to 5S rRNA coding region of rrnA to the coding region of glnA, the gene for glutamine synthetase. Other genes included on this cloned DNA fragment are polA, ntrC (glnG), and ntrB (glnL). E coli cells transformed with a multicopy plasmid clone of the gene for spot 42 RNA had about a 10-fold increase in the amount of spot 42 RNA they contained. The amount of 6S RNA in these cells was increased about twofold, although the gene for 6S RNA was not located on this plasmid or on the larger 20-kilobase fragment. Presence of this multicopy plasmid also affected the growth of cells. The generation time was increased under a variety of growth conditions, especially when cells were grown in medium with succinate as the carbon source. In addition, some strains of E. coli which have multicopy plasmids carrying the gene for spot 42 RNA were unable to respond normally to a shift into richer medium: upon upshift from minimal glucose to LB broth or minimal glucose plus 1% Casamino Acids, there was a 3- to 4-h lag before the culture adapted to the new medium. More than 90% of the cells in such cultures stopped dividing, although they remained viable. The plating efficiency of minimal-glucose-grown cells was 100-fold less on rich media than on minimal glucose medium. One revertant was isolated which regained the phenotype of pBR322-transformed cells. Analysis of this strain showed that the plasmid it contained had an insertion of an IS1 element into the 5' end of the coding region for the gene for spot 42 RNA.