Rhodosorusmarinus中澡红蛋白的纯化及其性质的研究

从Ｒｈｏｄｏｓｏｒｕｓｍａｒｉｎｕｓ中提取了藻红蛋白,通过改进纯化方法,得到了三种电泳纯的藻红蛋白：Ｂ－型藻红蛋白１,Ｂ－型藻红蛋白２和ｂ－型藻红蛋白（以下简称Ｂ—ＰＥ１,Ｂ—ＰＥ２和ｂ－ＰＥ）。分别测定这三种藻红蛋白聚合体和亚单位的分子量。测定了它们的可见光的吸收光谱和荧光光谱。两种Ｂ—ＰＥ的可见光的吸收光谱比ｂ—ＰＥ的多一个４９８ｎｍ的吸收峰。三种藻红蛋白的氨基酸组成以酸性氨基酸和疏水性氨基酸为主,所以经等电聚焦测定的它们的等电点都是偏酸性的。     

Fertilization and the cytoskeleton in the red alga Bostrychia moritziana (Rhodomelaceae,Rhodophyta)

Time-lapse videomicroscopy was used to observe the effects of various cytoskeletal inhibitors on three important fertilization events in Bostrychia moritziana: spermatial mitosis, gamete fusion (formation of a fertilization pore) and nuclear migration along the trichogyne. The microtubule inhibitor oryzalin disrupted spermatial mitosis but had no other effect on fertilization. The actin inhibitors, jasplakinolide, cytochalasin B, latrunculin A and B and mycalolide B inhibited gamete fusion while BDM, a myosin-disrupting drug, inhibited all three major fertilization events. FL-Phallacidin was used to stain actin filaments in spermatia and trichogynes while microtubules were labelled with antibodies at appropriate stages of fertilization. Microtubules were only evident during spermatial nuclear division. Actin filaments were present in both trichogynes and spermatia throughout fertilization; they formed a discrete ring around the fertilization pore and ensheathed male nuclei as the latter migrated into and along the trichogyne. These results suggest that the actin/myosin system plays a role in the events of fertilization.     

The extra-limital spread of an invasive species via 'stowaway' dispersal: toad to nowhere?

The mechanisms by which invasive species spread through new areas can influence the spatial scale of their impact. Although previous research has focused on 'natural' dispersal rates following initial introductions, human-aided inadvertent dispersal by 'stowaways' on commercial and domestic transport is thought to be a major contributor to long-distance dispersal. Few data exist to support this assumption. Cane toads Bufo marinus were introduced to north-eastern Australia in 1935, and have since dispersed rapidly through the tropics. Based on information accumulated by community groups in Sydney, 400 km south of the cane toads' current Australian distribution, we document high rates of translocation (at least 50 toads arriving in Sydney per year). Most toads were translocated on commercial truck transport carrying landscaping and building materials from the current range of the cane toads in New South Wales and Queensland, and resulted in highly clumped locations of toad arrival reflecting primary truck transport destinations. Most introductions involved single toads (68 of 102 translocation events), but some introductions involved two to 19 animals. Adults of both sexes were represented equally but juveniles were rarely detected. High rates of translocation of adult toads of both sexes suggest that the eventual distribution of cane toads in Australia may be limited by the animals' bioclimatic tolerances rather than by an inability to reach suitable habitats, even in areas far distant from the toads' current range.     

一株红孢囊藻(Rhodosorus sp.SCSIO-45730)总糖和β-葡聚糖的积累特性研究

红孢囊藻(Rhodosorus sp.)可以积累高含量多糖,在医药保健和生物能源领域具有潜在开发价值。为进一步评估红孢囊藻(Rhodosorus sp.)产业化潜力,研究了一株红孢囊藻SCSIO-45730在盐度不同的4种培养基中生长及总糖和β-葡聚糖积累特性,结果表明:改良的ASW培养基相对于其他培养基(f/2、Conway和Erdschreiber)更有利于红孢囊藻SCSIO-45730生物量和总糖的积累。以ASW培养基为基础培养基,研究该藻盐度适应性,结果显示:该藻可在18‰-58‰盐度范围内正常生长,随着盐度增加,藻细胞体积逐渐增大且出现聚团现象;在盐度为38‰时,获得最大生物量、总糖含量和产率以及β-葡聚糖产率,分别为13.70 g/L、48.52%DW、412.58 mg/L·d和119.70 mg/L·d,β-葡聚糖含量随着盐度增加而降低;该藻在户外平板光生物反应器中总糖和β-葡聚糖单位体积产量分别为0.73 g/L和0.23 g/L。结果表明,红孢囊藻SCSIO-45730具有较广的盐度适应性、高产总糖和β-葡聚糖潜力,是生产生物乙醇和β-葡聚糖的理想原料。     

Characterization of intein homing endonuclease encoded in the DNA polymerase gene of Thermococcus marinus

The DNA polymerase gene of Thermococcus marinus ( Tma ) contains an intein inserted at the pol-b site that possesses a 1611-bp ORF encoding a 537-amino acid residue. The LAGLIDADG motif, often found in site-specific DNA endonucleases, was detected within the amino acid sequence of the intein. The intein endonuclease, denoted as PI- Tma , was purified as a naturally spliced product from the expression of the complete DNA polymerase gene in Escherichia coli . PI- Tma cleaved intein-less DNA sequences, leaving four-base-long, 3'-hydroxyl overhangs with 5'-phosphate. Nonpalindromic recognition sequences 19 bp long were also identified using partially complementary oligonucleotide pair sequences inserted into the plasmid pET-22b(+). Cleavage by PI- Tma was optimal when present in 50 mM glycine–NaOH (pH 10.5), 150 mM KCl and 12 mM MgCl₂ at 70 °C.     

Application of Videomicroscopy to the Study of Interstitial Fauna

This paper deals with a method of employing videomicroscopy in the study of meiofauna. The apparatus is inexpensive, easy to use, and offers a high degree of resolution. Accurate measurements of the specimen can be made directly from the video monitor screen. With the addition of a videocassette recorder, live footage can be recorded for analysis, correspondence, or as an aid in teaching.     

环境条件对芽孢杆菌B-9987菌株防御酶诱导效应的影响

研究室内外条件下,海洋芽孢杆菌不同处理物对番茄防御酶系的诱导作用。分别使用不同浓度芽孢杆菌B-9987发酵液和无细胞滤液喷施番茄植株,于室内外两种环境条件下养殖,测定了处理11d内番茄5种防御酶的变化趋势。两种处理诱导抗性结果显示,在两种环境条件下处理植株苯丙氨酸解氨酶（PAL）、多酚氧化酶（ppo）、过氧化物酶（POD）、过氧化氢酶（CAT）较空白对照植株酶活性均有不同程度增加。除超氧化物歧化酶（SOD）外,室内环境较室外更利于B-9987菌株处理液对番茄防御酶系的诱导作用发挥;相同环境条件下,发酵液的处理诱导活性较强。B-9987菌株对番茄防御酶系有较好的诱导作用,但诱导作用的发挥受环境条件影响明显。     

Computer-assisted motion analysis of sperm from the common carp

Computer-assisted semen analysis (CASA) technology was applied to the measurement of sperm motility parameters in the common carp Cyprinus carpio. Activated sperm were videotaped at 200 frames s⁻¹ and analysed with the CellTrak/S CASA research system. The percentage of motile cells and both sperm head curvilinear velocity and straight-line velocity were measured following exposure of carp sperm to three predilution conditions and activation in media of differing ionic strengths and osmotic pressures. The highest percentage of motile sperm was obtained following predilution of sperm in seminal plasma and activation in Na-HEPES buffer pH 8.0. This level of motility was equalled after predilution in 200 m m KCl for 2 h. Straight-line velocities and curvilinear velocities of 130 μm s⁻¹ and 210 μm s⁻¹, respectively, were observed. Duration of motility was higher under seminal plasma predilution conditions (over 50% motile sperm at 55 s post-activation). The application provides a sound basis for the assessment of Sperm Characteristics in fish.     

植物基因工程新途径：叶绿体转化

在植物基因工程研究中,叶绿体是继核转化之后又一新的遗传转化和表达受体,叶绿体转化体系具有可同时进行多基因转化,表达原核性,超量表达,后代遗传稳定,定点整合,不会产生基因沉默及母性遗传和安全性好等特点,本文着重介绍叶绿体转化体系的特点,国内外研究动态,存在的问题及未来发展方向。     

Dynamic analysis of drug action on in vitro reconstituted thyroid follicle by microinjection of tracer molecules and videomicroscopy

Thyroid cells isolated from the gland by trypsinization are capable in culture of reconstituting histiotypic structures, the thyroid follicles. This morphological differentiation requires the presence of the main thyroid regulator; thyrotropin. We have analyzed some structural and functional aspects of in vitro reconstituted thyroid follicles (RTF) using microinjection of fluorescent probes and videomicroscopy. This experimental approach allowed to visualize biological processes and actions of drugs, signalling factors, etc. in living cells. We describe here some examples of what can be studied with this powerful still-undervalued method. Microinjection of a cell-impermeant fluorescent probe of either high or low molecular mass into the lumen of RTF allowed to check the tightness of this compartment and therefore to analyze the control of tight junctions assembly. A small cell-impermeant probe like Lucifer Yellow microinjected into a cell was used to demonstrate and then to study the regulation of cell to cell communication via gap junctions. The presence of calcium in the lumen of RTF was detected by microinjection of a properly designed probe: Calcium Green which becomes fluorescent in the presence of the ligand. The lumen to cell transport or endocytosis of thyroglobulin, the thyroid prohormone, which is stored into the lumen of the follicles, is currently studied by microinjection of TRITC-labeled thyroglobulin. Coupled to image processing and videorecorder systems, kinetic analysis and quantitative measurements can be performed.Abbreviations CG Calcium Green - FITC-D Dextran labeled with fluorescein isothiocyanate - LY Lucifer Yellow - RTF Reconstituted thyroid follicle - Tg Thyroglobulin - Tg-TRITC Thyrogloblin labeled with tetramethyl rhodamine isothiocyanate - TSH Thyrotropin     

Isolation of biochemically active chloroplasts from chlamydomonas

Chloroplasts from the cell wall mutant cw-15-2 of Chlamydomonas reinhardii were isolated by disruption of the cells in the Yeda press and fractionation through step gradients of Percoll. The resulting chloroplast fraction contained 80–85% intact chloroplasts. Electron micrographs of thin sections of the chloroplast fraction showed some cytoplasmic impurities, although almost no cytoplasmic ribosomes were detected by analysis of the ribosomal subunits.The isolated chloroplasts are active in photosynthetic O₂-evolution and CO₂-fixation, with the highest rates obtained in the presence of ATP.The chloroplast fraction also showed high rates of light-dependent in organello protein synthesis, with labelling of discrete chloroplast proteins known to be synthesized in the chloroplasts.     

Retrospective of a botanist

An autobiographic report of studies on the elucidation of the structure of the chloroplast is presented here. It deals with the discovery of the lamellar structure of chloroplasts by polarization-microscopy, the representation of their layer-like structure with the ultraviolet microscope and the results obtained by the electron-microscope leading to the discovery of the structural elements of the lamellar system. These lamellar structures were in the form of vesicles, and were named thylakoids. Isolation of the chloroplasts made it possible to determine their chemical composition. Amphiphilic lipids, together with water, create bimolecular layers and, therefore, are responsible for the structure of the thylakoid-membranes. The role of membrane proteins was emphasized. The isolation of the individual polypeptides was possible after dissociation in sodium-dodecyl-sulfate. Antisera to these polypeptides were used to localize them in the membrane. These antisera are able to inhibit special steps in the electron transport. Our results of the spectroscopic examination of photosynthetic membrane components are also discussed.This article was written at the invitation of Dr Govindjee.     

Rapid isolation of genes from bacterial lambda libraries by direct polymerase chain reaction screening

Abstract Ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO) was purified from an obligately autotrophic hydrogen-oxidizing bacterium, Hydrogenovibrio marinus MH-110. The protein has a M _r value of approximately 110 000, and is composed of two identical subunits of 55 000. To our knowledge, the existence of L₂-form RubisCO in a chemolithoautotrophic bacterium is first reported in this paper. The N-terminal amino acid sequence determination of the purified enzyme showed high homology with those of the L₂-form RubisCO of Rhodospirillum rubrum and the L _x -form RubisCO from Rhodobacter sphaeroides .     

The giant and complex genital plug of the asper group of Bothriurus (Scorpiones, Bothriuridae): morphology and comparison with other genital plugs in scorpions

The genital plugs of two species of the asper group of Bothriurus (Scorpiones: Bothriuridae) are described and compared with other genital plugs reported in the family Bothriuridae. In both species, B. asper and Bothriurus sp., the genital plug is cone-shaped and formed by fusion of the basal lobes of the hemispermatophore. Fusion is complete in B. asper and the surface of the plug has many microspines that anchor it to the female genital atrium. In Bothriurus sp., the basal lobes are partially fused, but free on the dorsal side, and the plug has a smooth surface with a dorsal curvature. Both genital plugs completely fill the genital atrium of inseminated females, pressing against the cuticular wall of the atrium. Given the large size and complex shape, the genital plug of the B. asper group is unique, not only among Bothriuridae, but in the order Scorpiones. This new type of genital plug resembles the genital plugs of the scorpion families Urodacidae and Vaejovidae. A comparison of the four major types of genital plugs reported in Bothriurus species and some other bothriurids is provided, as well as a comparison with other genital plugs reported in more distantly related families of scorpions.     

衣藻叶绿体遗传转化的研究

叶绿体遗传转人是近几年发展起来的新领域。本文主要介绍了叶绿体遗传转化的特点、基本原理和衣藻叶绿体遗传转化的方法与技术;