Genome Analysis of Bacteroides by Pulsed-field Gel Electrophoresis: Chromosome Sizes and Restriction Patterns

The chromosomal DNAs of nine strains of seven Bacteroides speciesincluding B. fragilis, the type species of the genus Bacteroides,were digested with rare-cutting restriction enzymes I-Ceu I,Not I, and Asc I and analysed by pulsed-field gel electrophoresis.The genome sizes of B. fragilis, B. distasonis, B. eggerthii,B. ovatus, B. thetaiotaomicron, B. uniformis, and B. vulgatuswere determined to be 5.3, 4.8, 4.4, 6.9, 4.8, 4.6, and 5.1Mbp, respectively. B. distasonis and B. vulgatus, and also B.uniformis and B. eggerthii, showed simillar I-Ceu I restrictionprofiles. I-Ceu I cut B. uniformis and B. eggerthii genomesinto four, B. ovatus into five, B. fragilis and B. thetaiotaomicroninto six, and B. distasonis and B. vulgatus into seven fragments.On the basis of genome size, restriction profile, and I-CeuI fragment number, a phylogenetic tree of the Bacteroides specieswas proposed. This was in overall agreement with the previousphylogenetic tree obtained by 16S rRNAdata, with the exceptionsof B. distasonis and B. ovatus.     

绿盲蝽和中黑盲蝽对不同抗性和虫害处理棉花的选择趋性

研究绿盲蝽Apolygus lucorum和中黑盲蝽Adelphocoris suturalis对不同抗性和虫害处理棉花的选择趋性,为棉盲蝽的综合治理提供理论依据。本研究以抗性棉花品种BR-S-10（抗性品种）和感性棉花品种科林08-15（感性品种）,以及绿盲蝽和中黑盲蝽分别危害处理后的该两种棉花植株为试验材料,以纯净空气为空白对照,共成对设置15个气味源组合,采用“Y”型昆虫嗅觉仪室内研究了绿盲蝽和中黑盲蝽对不同抗性和虫害处理棉花的选择趋性。结果表明,绿盲蝽显著选择感性品种、中黑盲蝽危害感性品种和绿盲蝽危害感性品种。中黑盲蝽显著选择绿盲蝽危害感性品种、中黑盲蝽危害感性品种和感性品种。总的来说,两种棉盲蝽趋向于选择敏感棉花品种,抗性棉花品种对供试昆虫有显著趋避性;绿盲蝽显著趋向选择中黑盲蝽危害感性品种和绿盲蝽危害感性品种,中黑盲蝽显著趋向选择绿盲蝽危害感性品种和中黑盲蝽危害感性品种。     

Chemical Patterns, Compartments and a Binary Epigenetic Code in Drosophila

I propose a model which accounts for the geometries and sequencein which compartmental boundary lines arise on the differentimaginal discs, and on the blastoderm of Drosophila melanogaster;and propose that successive lines are recorded by differentbinary switches, to create a binary epigenetic code word specifyingeach disc, and disc compartment. I suppose a biochemical systemundergoing reaction and diffusion acts throughout development.As an imaginal disc grows, a succession of differently shapedchemical concentration patterns form at a discrete set of discsizes. I suppose a specific concentration of one chemical isa threshold. Concentrations above or below threshold switchcells to one or another of two commitments. Then the line acrossthe imaginal disc with the threshold concentration is a predictedcompartmental boundary. The sequence and geometries of suchlines predict the compartmental boundaries seen on the wingdisc, the other discs, and on the blastoderm stage egg. Thecompartmental lines on the wing disc suggest that a terminalcompartment is specified by a combination of binary names recordinga sequence of binary commitments: anterior, not posterior; dorsal,not ventral; wing, not thorax; proximal, not distal. Each combinationcomprises a binary epigenetic code word. Recently I constructedan independent model for transdetermination in Drosophila whichproposed a similar binary epigenetic code for the differentdiscs. The clone restriction lines predicted on the blastodermby my transdetermination model, the chemical pattern model,and analogy with the wing disc, are nearly identical. Severalare already confirmed. The resultant binary code scheme correctlypredicts many relative transdetermination frequencies and accountssimply for the action of most homeotic mutants as genes whichalter a single switch state in one or more discs.     

感染稻水象甲的Wolbachia基因组中插入序列的鉴定与分析

共生细菌Wolbachia对宿主的生殖起多种调控作用。以往研究表明, Wolbachia基因组中广泛存在插入序列(insertion sequence, IS), 它们对宿主基因组的可塑性、 多样性和进化起重要作用。稻水象甲Lissorhoptrus oryzophilus Kuschel在东亚是一种外来水稻害虫, 在原产地北美营两性生殖, 而在所有入侵地均营孤雌生殖。本研究采用PCR法从河北唐海孤雌生殖型稻水象甲体内克隆获得了Wolbachia的2条IS序列, 即ISWosp4和ISWosp6; 从美国德克萨斯州两性生殖型稻水象甲成虫体内克隆获得了Wolbachia的2条IS序列, 即ISWosp3和ISWosp5。碱基序列比对显示: ISWosp3和ISWosp4属于IS3家族IS3组成员, ISWosp5为IS4家族IS231组成员, ISWosp6为IS5家族IS1031组成员。对这些IS的ORF结构、 所编码氨基酸序列的结构等进行了分析, 推测ISWosp5具有潜在转座活性。所得结果增进了我们对Wolbachia IS3, IS4和IS5家族插入序列的认识, 同时为今后从IS的角度探讨Wolbachia与稻水象甲生殖的关系奠定了基础。     

Distinguishing between Stage I and Stage II nauplii of the copepods Metridia and Pseudocalanus from the Bering Sea

Stage I nauplii of Metridia pacifica, Stage I and II naupliiof Metridia lucens, and the equivalent stages of Pseudocalanusmimus were reared from eggs to find morphological charactersfor separating the genera at these stages. Differences in naupliarbody shape and caudal armature permit the differentiation ofStage I and II Metridia from Pseudocalanus in southeastern BeringSea plankton.     

PETALIFERA HABEI, A NEW SPECIES FROM JAPAN ADDENDUM

Since Petalifera habei was described in the Proceedings, 34,1, 12–18, April 1960, I have received from Dr. K. Babaa short account of the same species in Publ. Seto. mar. biol.Lab. 7, 3, 337–338. December, 1959, under the title "Thegenus Petalifera and a new species, P. ramosa, from Japan".I was unaware that Dr. Baba intended to describe it. As hispaper antedates mine, his name, Petalifera ramosa, must replaceP. Habei.     

Electrophoretic Variation in Esterases, Peroxidases and Acid Phosphatases in Some Native Greek Taxa of the Genera Hordeum and Taeniatherum

Horizontal starch gel electrophoresis has been applied to thestudy of esterase, peroxidase and acid phosphatase patternsin seven taxa, namely Hordeum diploids (2n=14) (H. marinum,H. marinum I and H. hystrix), tetraploids (2n=28) (H. bulbosumand H. murinum subsp. leporinum) and Taeniatherum (2n=14) (T.caput-medusae and T. caput-medusae I) in order to elucidatetheir phylogenetic relationships. On the basis of our experimentalresults the seven taxa may be placed in the following threegroups; (1) diploid Hordeum (H. marinum, H. marinum I, H. hystrix);(2) tetraploid Hordeum (H. bulbosum, H. murinum subsp. leporinum);(3) Taeniatherum (T. caput-medusae, T. caput-medusae I). Esterase, peroxidase and acid phosphatase patterns of the twoHordeum diploid taxa (H. marinum and H. marinum I) are verysimilar suggesting their close phylogenetic relationship; thesame is true for both the taxa of the genus Taeniatherum (T.caput-medusae and T. caput-medusae I). The taxa of the Taeniatherumgroup compared with the diploid Hordeum (H. marinum, H. marinumI, H. hystrix) and the tetraploid Hordeum (H. bulbosum, H. murinumsubsp. leporinum) show a lower degree of phylogenetic relationshipand seem to be equally distant from them. The tetraploid Hordeumgroup shows a higher phylogenetic relationship with diploidHordeum group than with the Taeniatherum group. These results confirm that the genus Taeniatherum, previouslyconsidered as part of the genus Hordeum, should be regardedas a separate genus. Gramineae (Poaceae), Hordeum L., Taeniatherum Nevski., esterase, peroxidase and acid phosphatase patterns, phylogenetic relationships     

大豆蚜细胞色素氧化酶Ⅱ基因的克隆及其在捕食性天敌昆虫鉴定中的应用

利用通用引物,对大豆蚜Aphis glycines Matsumura的细胞色素氧化酶Ⅱ（COⅡ）基因序列进行克隆和测序。测得的序列长度为810 bp,并与已在GenBank上登录的其他蚜虫COⅡ基因序列进行比较分析,验证其同源性,同时将该序列在GenBank进行了登记 (登录号为DQ265743)。根据此片段的碱基序列设计了1对大豆蚜特异引物,其扩增片段约为270 bp;种特异性检验结果表明,该引物只对大豆蚜具有扩增能力,对其他相关蚜虫种类不具有扩增效果;并用此引物对大豆蚜捕食性天敌进行定性检测,结果表明,在取食过大豆蚜的异色瓢虫Harmonia axyridis、龟纹瓢虫Propylaea japonica、大草蛉Chrysopa septempunctata幼虫以及小花蝽Orius similes 成虫和幼虫等捕食性昆虫的中肠中均能检测到大豆蚜的DNA片段; 而在未取食蚜虫的上述天敌中却未能扩增出来。     

Models of the Use of Root-zone CO2 by Selected North American Isoetids

Sediment CO₂, entering via the roots, contributes a significantportion of the total carbon uptake for isoetids (small, evergreen,submersed, vascular plants). Laboratory studies of inorganiccarbon uptake via the roots and shoots by five isoetids wereused to model the use of root-zone CO₂. Simple first-order linearmodels accounted for at least 75 per cent of the variation inthe data for Gratiola aurea, Isoetes macrospora, Littorellauniflora and Lobelia dortmanna. For Eriocaulon septangulare,which relies almost exclusively on root-zone CO₂, models couldaccount for only about 62 per cent of the variation in root-zoneCO₂ use. For each species, we present the best fitting regressionof root-zone CO₂ use as a function of root- and shoot-zone CO₂concentrations. For the species studied, carbon uptake was not saturated atfield concentrations of root and shoot-zone CO₂. Maximum ratesof carbon uptake were lower for species that naturally occurredat greater depths, compared with species more common in shallowwater. At equal external CO₂ concentrations carbon entry perunit root surface area was several times more rapid than entryper unit shoot surface area for L. dortmanna. The entry ratesper unit root and shoot surface area were about equal for G.aurea and E. septangulare. Shoots were equally or more permeablethan the roots of L. uniflora and I. macrospora, a fact thatmay be related to the functioning of crassulacean acid metabolismin these plants. Carbon, CO₂, photosynthesis, isoetid, Eriocaulon septangulare, Gratiola aurea, Isoetes macrospora, Littorella uniflora, Lobelia dortmanna     

Effect of Light and NaCI Salinity on the Growth of Callus Cultures of Ipomoea pes-caprae (L.) R. Brown and Ipomoea batatas (L.) Lam

Callus cultures of Ipomoea pes-caprae and I. batatas were establishedon MS medium containing 10^–5 M 2,4-D and 10^–8 Mbenzyladenine. Ipomoea pes-caprae calli exhibited green pigmentationand grew better in the light than in darkness. Callus tissuesof I. batatas showed a pale-yellow colouration and they grewat the same rate in light as in dark conditions. I. pes-capraeand I. batatas callus cultures were sensitive to the presenceof 60 mM NaCl in the culture medium, the growth of the formerbeing more sensitive in light than in darkness. The significanceof the responses of I. pes-caprae callus cultures in relationto the mechanism of salt tolerance is discussed. Ipomoea batatas, Ipomoea pes-caprae, sweet potato, railroad vine, callus cultures, salinity, light     

Microheterogeneity of N-glycosylation on a stylar self-incompatibility glycoprotein of Nicotiana alata

Gametophytic self-incompatibility, a mechanism that preventsinbreeding in some families of flowering plants, is mediatedby the products of a single genetic locus, the S-locus. Theproducts of the S-gene in the female sexual tissues of Nicotianaalata are an allelic series of glycoproteins with RNase activity.In this study, we report on the microheterogeneity of N-linkedglycosylation at the four potential N-glycosylation sites ofthe S²-glycoprotein. The S-glycoproteins from N.alata containfrom one to five potential N-glycosylation sites based on theconsensus sequence Asn-Xaa-Ser/Thr. The S²-glycoprotein containsfour potential N-glycosylation sites at Asn²⁷, Asn³⁷, Asn¹³⁸and Asn¹⁵⁰, designated sites I, n, IV and V, respectively. SiteIII is absent from the S₂-glycoprotein. Analysis of glycopeptidesgenerated from the S₂-glycoprotein by trypsin and chymotrypsindigestions revealed the types of glycans and the degree of microheterogeneitypresent at each site. Sites I (Asn²⁷) and IV (Asn¹³⁸) displaymicroheterogeneity, site II (Asn³⁷) contains only a single typeof N-glycan, and site V (Asn¹⁵⁰) is not glycosylated. The microheterogeneityobserved at site I on the S₂-glycoprotein is the same as thatobserved at the only site, site I, on the Srglycoprotein (Woodwardet al., Glycobiology, 2, 241-250, 1992). Since the N-glycosylationconsensus sequence at site I is conserved in all S-glycoproteinsfrom other species of self-incompatible solanaceous plants,glycosylation at this site may be important to their function.No other post-translational modifications (e.g. O-glycosylation,phosphorylation) were detected on the S₂-glycoprotein. fertilization microheterogeneity N-glycans plants RNase     

基于线粒体COI基因序列的文蛤属(软体动物门:帘蛤科)系统发育关系(英文)

测定了4种文蛤属贝类的15个个体的COI基因序列,并从GenBank下载了短文蛤 (M. petechialis)的相应序列。比对后的序列长度为574 bp,包括93个简约信息位点,A、T、C和G的平均含量分别为21.15%、44.71%、14.05%和20.09%。通过对序列的分析,共定义了12个单倍型：文蛤 (M. meretrix) 4个,斧文蛤 (M. lamarckii) 2个,丽文蛤 (M. lusoria) 3个,琴文蛤 (M. lyrata) 1个,短文蛤2个。以青蛤(Cylina sinensis)为外群,用MP法和贝叶斯法构建系统树。结果显示,短文蛤、丽文蛤和文蛤为亲缘关系较近的物种, 支持短文蛤和丽文蛤为文蛤的同物异名的观点。     

Developmental Changes in Amounts of Thylakoid Components in Plastids of Barley Leaves

Changes in the amounts of several components of the photosyntheticelectron-transport system during greening of etiolated barleyleaves were studied on a "per plastid" basis. P700 and Q_A, whichwere initially absent from etioplasts, appeared 2 h after thestart of illumination in complete complexes of PS I and PS II,respectively. From 6 h, they increased rapidly in amount witha constant stoichiometric ratio of 1:1. Amounts of Cyt f, Cytb₆, Cyt b-559 and FeS, initially present in etioplasts at levelsthat were one-third to half of those in mature chloroplasts,also increased rapidly after 6 h of illumination. The molarratio of Cyt f, Cyt b₆ and Cyt b-559 was the same in etioplastsand in mature chloroplasts, namely 1:2:2. After 4 h of illumination,levels of FeS increased at nearly the same rate as those ofthe PS I complex. The increase in levels of all components wasmarked after 6 h of illumination, probably due to the energysupplied by developing plastids that had just become photosyntheticallycompetent. The results are discussed in relation to the timeof appearance of chlorophyll-protein complexes and photochemicalactivities. ¹ Present address: Department of Botany, Faculty of Science,Kyoto University, Kyoto, 606-01 Japan.     

Hair Curling Induced in Heterologous Legumes and Monocots by Flavonoid-Treated Rhizobia

The curling of root hairs and the deformation response wereobserved when white clover was infected with homologous strainsof Rhizobium leguminosarum biovar trifolii 4S and 0403. In thecase of Rhizobium meliloti NZ and Rhizobium leguminosarum biovarviciae 128C53, however, curling was only induced when thesebacteria were pretreated with flavonoids: luteolin in the caseof R. meliloti and naringenin for R.I. viciae. The same resultswere obtained with oat, a monocotyledonous non-leguminous plant.The two flavonoids mentioned are secreted from the host plantsand induce the expression of genes for root hair curling (Hac)on Sym plasmid in homologous rhizobia, therefore, the curlingresponse in both white clover and oat appears to be correlatedwith the activation of the Hac genes. These results suggestthat a factor(s) that activates the Hac genes, such as 7,4'-dihydroxyflavonewhich is known as the factor required by R. I. trifolii, issecreted from the oat roots. (Received June 12, 1989; Accepted November 9, 1989)     

Phylogeography of four frog species in forest fragments of northeastern Brazil--a preliminary study

I contrast mitochondrial DNA genealogies based on 612 bp ofthe cytochrome b gene across four co-distributed species offrogs in Northeastern Brazil. They are Hyla albomarginata, Hylabranneri, Proceratophrys boiei, and Scinax nebulosus. Sampleswere collected from the core or edge of six rainforest remnantsin the states of Pernambuco and Alagoas. Three fragments arelocated within the humid Atlantic Forest morphoclimatic domain(municipalities of Cabo de Santo Agostinho, Ibateguara, andJaqueira), two are located in the transition zone between theAtlantic Forest domain and the semi-arid Caatinga (Caruaru andTimbaúba), and one is found within the Caatinga (Brejoda Madre de Deus). Results show that local patterns and levelsof genetic diversity are influenced by taxon-specific habitatrequirements. Populations of the montane, closed-canopy speciesP. boiei show strong geographical structure, reflecting barriersto gene flow that predate human-driven habitat destruction.Species occurring along forest edges, such as H. albomarginataand S. nebulosus, show genetic patterns similar to those ofP. boiei, but lower levels of genetic divergence. The more generalistHyla branneri shows no geographic pattern. The data are in agreementwith distribution and fossil data gathered for other groupsof organisms, suggesting that mesic forests occupied the currentlyarid Caatinga in the recent past.     

棉铃虫细胞色素P450 CYP6B7基因的克隆与融合表达

细胞色素P450 CYP6B7被推测与棉铃虫Helicoverpa armigera对拟除虫菊酯类杀虫剂的抗性有关,但至今尚无CYP6B7参与杀虫剂代谢方面的直接证据。为揭示CYP6B7的代谢功能,作者以棉铃虫幼虫基因组DNA 为模板,以CYP6B7基因设计特异性引物,扩增出包含321 bp内含子的CYP6B7基因。用反向PCR的方法消除内含子,获得包含完整的CYP6B7基因的开放阅读框。将CYP6B7基因与pMAL-c2X载体连接,并转化E.coli TB1细胞,在IPTG诱导下,CYP6B7能与载体基因编码的麦芽糖结合蛋白（MBP）在大肠杆菌中融合表达,表达产物经直链淀粉（amylose） 柱亲和层析分离洗脱后,得到SDS-PAGE电泳纯的融合蛋白。     

棉花叶片性状（厚度和油点密度）与其对绿盲蝽抗性的关系

为了明确棉花叶片性状（厚度和油点密度）与其对绿盲蝽Apolygus lucorum （Meyer-Dür）抗性的关系,以期为棉花抗盲蝽品种(系)选育提供理论依据,本研究选用对绿盲蝽有不同抗性的20个棉花品种(系)为材料,分别测定其叶片厚度、表皮层厚度和油点密度。结果表明：晋棉26、冀丰989、常D、亚洲棉对绿盲蝽表现为高抗;棉花叶片厚度、表皮层厚度和油点密度在不同生长期均有差异;棉花对绿盲蝽的综合抗性指数与其铃期叶片表皮层厚度和油点密度有显著相关性（y=20.673+0.415x,R²=0.305,P=0.012;y=1.049+0.049x,R²=0.207,P=0.044）。结果显示,在一定的生长期,叶片表皮层厚和多油点棉花品种可以减少绿盲蝽的危害。     

Production of dissolved organic carbon in phyloplankton cultures as measured by high-temperature catalytic oxidation and ultraviolet photo-oxidation methods

The production of dissolved organic carbon (DOC) in culturesof the diatoms Chaetoceros gracilis and Phaeodactylum tricornutum,the flagellate Isochrysis galbana, the dinoflagellate Alexandriumtamarense and a natural algal assemblage from the NorthwestArm, Halifax, Nova Scotia, Canada, was followed using a high-temperaturecatalytic oxidation (HTCO) and a UV photo-oxidation method.Molecular weight fractionation of the DOC was performed fortwo cultures: C.gracilis and I.galbana. While the DOC in theculture medium increased significantly during log-phase growthfor all organisms except the dinoflagellate, this increase wasproportional to the increase in cell numbers; the increase inDOC per cell was either small or zero. In all cultures, maximumrelease took place during stationary and senescent phases, usuallyafter cell numbers had started to decrease. In both C.gracilisand I.galbana, a major portion (>65%) of the organic matterreleased to the medium during log-phase growth had mol. wtsof <10 000 Da. The increase in DOC in the I.galbana culturein stationary and senescent phases was due to the release ofhigh-molecular-weight materials. The differences in extracellularrelease of DOC between species and between different growthstages in the same species suggest that both the species compositionand physiological state of phytoplankton populations must beknown before interpretations and predictions based on fielddata can be made. In order to determine whether the differencesin DOC values found by the HTCO and UV oxidation methods arecaused by the resistance to UV oxidation of some compounds producedby phytoplankton, rather than by less than optimum efficiencyof the UV unit used, standards must be based on naturally occurringcompounds, rather than the pure compounds normally used.     

Biomechanical Attributes of the Leaves of Pine Species

The flexural stiffness EI, elastic modulus E, second momentof area I, length L, and weight Wt of foliage leaves from 26species of pine were measured to determine the manner in whichEI is scaled to leaf size (L or Wt, or both) and to determineif the biomechanical attributes of foliage leaves could be juxtaposedwith the systematic affiliations of species within Pinus Biomechamcaland morphometric data were explored based on a model from engineeringtheory that predicts the relationships among EI, Wt and L providedthat the maximum tip-deflection _max of an untapered cantileveredbeam sustaining its own weight is maintained as the beam eitherincreases in length or weight, or both, I e _max = Wt L²/8EIThe data show that EI disproportionately increased as eitherWt or L, or both increased The allometry of leaves did not conformto that predicted by the model Rather, EI was proportional tothe product of Wt and L raised to an exponent slightly greaterthan one Thus, Omax was predicted not to be maintained as eitherWt or L, or both, increased, as verified by observations Therelationship between El and Wt(L) differed for species typicallyproducing two leaves per fascicle and those bearing more thantwo leaves per fascicle Also, El is geometrically constrainedby the number of leaves produced per fascicle, principally interms of the effects of the number of leaves per fascicle onI Pinus, pine, leaves, biomechanics, Young's modulus     

Amphipods, isopods and surface currents: a case for passive dispersal in the Bay of Fundy, Canada

Six species of isopods and 18 species of amphipods were collectedin the neuston of the Bay of Fundy and adjacent waters. Collectionswere made over a grid of stations covering 2.4x10⁴ km² duringthree spring, three summer and two autumn surveys. No isopodsand only five species of amphipods were found in spring surveys.Isopods and amphipods were diverse and plentiful in the neustonin summer and autumn. Dominant isopods were Idotea baltica andI.metallica, and dominant amphipods were Calliopius laeviusculusand Parathemisto gaudichaudi. Amphipods and isopods reach theneuston of the Bay of Fundy in three ways. Idotea metallica,the only euneustonic species present, was probably advectedinto the Bay of Fundy from southern waters in summer, and didnot appear to overwinter in the Bay. Most species, includingI.baltica, were collected with drifting littoral vegetation,and we suggest that transport by surface currents is an importantfactor in dispersal of some shoreline crustaceans. Midwaterplankton, such as Parathemisto gaudichaudi, reached the neustoneither by advection in upwelling waters or by an extension oftheir normal diel vertical distribution.