The genus Ptyssiglottis (Acanthaceae). A taxonomic monograph

A taxonomic treatment of the genus Ptyssiglottis including Ancylacanthus, Hallieru-cantha, Oreothyrsus , and Polytrema is given. The phylogeny is briefly dealt with. Leaf morphology, inflorescence morphology and pollen morphology yield important characters. The distribution of selected characters is mapped. The distribution of all species is mapped. Eight new species are published viz. P. campanulata, P. decurrens, P. fusca, P. glandulifera, P. longisepala, P mucronata, P. pubescens , and P. staminodifera . Fifteen new combinations are made viz. P. caudata, P. creaghii, P. cuprea, P. cyrtandroides, P. dulcamarioides, P. fastidiosa, P. glabrisepala, P. granulata, P. nigrescens, P. peranthera, P. psychotriifolia, P. pubisepala, P. salicifolia, P. sanguinolenta , and P. undulata .     

The genus Ptyssiglottis (Acanthaceae). A taxonomic monograph

A taxonomic treatment of the genus Ptyssiglottis including Ancylacanthus, Hallieracantha, Oreothyrsus , and Polytrema is given. The phylogeny is briefly dealt with. Leaf morphology, inflorescence morphology and pollen morphology yield important characters. The distribution of selected characters is mapped. The distribution of all species is mapped. Eight new species are published viz. P. campanulata, P. decurrens, P. fusca, P. glandulifera, P. longisepala, P. mucronata, P. pubescens , and P. stamino-difera . Fifteen new combinations are made viz. P. caudata, P. creaghii, P. cuprea, P. cyrtandroides, P. dulcamarioides, P. fastidiosa, P. glabrisepala, P. granulata, P. nigrescens, P. peranthera, P. psychotriifolia, P. pubisepala, P. salicifolia, P. sanguinolenta , and P. undulata .     

Mechanism for the regulation of mammalian cGMP phosphodiesterase6. 2: Isolation and characterization of the transducin-activated form

Rod photoreceptor cGMP phosphodiesterase (PDE6) consists of a catalytic subunit complex (Pαβ) and two inhibitory subunits (Pγ). In the accompanying article, using bovine photoreceptor outer segment homogenates, we show that Pγ as a complex with the GTP-bound transducin α subunit (GTP-Tα) dissociates from Pαβγγ on membranes, and the Pαβγγ becomes Pγ-depleted. Here, we identify and characterize the Pγ-depleted PDE. After incubation with or without guanosine 5′-O-(3-thiotriphosphate) (GTPγS), Pαβ complexes are extracted. When a hypotonic buffer is used, Pαβγγ, Pαβγ, and a negligible amount of a Pαβ complex containing Pγ are isolated with GTPγS, and only Pαβγγ is obtained without GTPγS. When an isotonic buffer containing Pδ, a prenyl-binding protein, is used, Pαβγγδ, Pαβγδδ, and a negligible amount of a Pαβ complex containing Pγ and Pδ are isolated with GTPγS, and Pαβγγδ is obtained without GTPγS. Neither Pαβ nor Pαβγγ complexed with GTPγS-Tα is found under any condition we examined. Pαβγ has ~12 times higher PDE activity and ~30 times higher Pγ sensitivity than those of Pαβγγ. These results indicate that the Pγ-depleted PDE is Pαβγ. Isolation of Pαβγγδ and Pαβγδδ suggests that one C-terminus of Pαβ is involved in the Pαβγγ interaction with membranes, and that Pγ dissociation opens another C-terminus for Pδ binding, which may lead to the expression of high PDE activity. Cone PDE behaves similarly to rod PDE in the anion exchange column chromatography. We conclude that the mechanisms for PDE activation are similar in mammalian and amphibian photoreceptors as well as in rods and cones.     

Gametophyte morphogenesis of Mexican species of Pleopeltis (Polypodiaceae, subfamily Pleopeltoideae)

The development and morphology of the gametophytes of seven species of ferns from genus Pleopeltis are described and compared. The spore germination is Vittaria-type in P. astrolepis, P. crassinervata, P. macrocarpa, P. polylepis and P. revoluta. For P. angusta and P. mexicana it was proposed a new germination pattern is Pleopeltis-type. The prothallial development is Drynaria-type in P. astrolepis, P. crassinervata, P. macrocarpa, P. polylepis and P. revoluta and Ceratopteris-type for P. angusta and P. mexicana. The gametangia are typical of the leptosporangiate ferns, sporophytes after six and a half months in culture did not appeared.     

Asymmetric interactions between the acidic P1 and P2 proteins in the Saccharomyces cerevisiae ribosomal stalk.

The Saccharomyces cerevisiae ribosomal stalk is made of five components, the 32-kDa P0 and four 12-kDa acidic proteins, P1alpha, P1beta, P2alpha, and P2beta. The P0 carboxyl-terminal domain is involved in the interaction with the acidic proteins and resembles their structure. Protein chimeras were constructed in which the last 112 amino acids of P0 were replaced by the sequence of each acidic protein, yielding four fusion proteins, P0-1alpha, P0-1beta, P0-2alpha, and P0-2beta. The chimeras were expressed in P0 conditional null mutant strains in which wild-type P0 is not present. In S. cerevisiae D4567, which is totally deprived of acidic proteins, the four fusion proteins can replace the wild-type P0 with little effect on cell growth. In other genetic backgrounds, the chimeras either reduce or increase cell growth because of their effect on the ribosomal stalk composition. An analysis of the stalk proteins showed that each P0 chimera is able to strongly interact with only one acidic protein. The following associations were found: P0-1alpha.P2beta, P0-1beta.P2alpha, P0-2alpha.P1beta, and P0-2beta.P1alpha. These results indicate that the four acidic proteins do not form dimers in the yeast ribosomal stalk but interact with each other forming two specific associations, P1alpha.P2beta and P1beta.P2alpha, which have different structural and functional roles.     

Phosphorylation and N-terminal region of yeast ribosomal protein P1 mediate its degradation, which is prevented by protein P2

The stalk proteins P1 and P2, which are fundamental for ribosome activity, are the only ribosomal components for which there is a cytoplasmic pool. Accumulation of these two proteins is differentially regulated in Saccharomyces cerevisiae by degradation. In the absence of P2, the amount of P1 is drastically reduced; in contrast, P2 proteins are not affected by a deficiency in P1. However, association with P2 protects P1 proteins. The half-life of P1 is a few minutes, while that of P2 is several hours. The proteasome is not involved in the degradation of P1 proteins. The different sensitivity to degradation of these two proteins is associated with two structural features: phosphorylation and N-terminus structure. A phosphorylation site at the C-terminus is required for P1 proteolysis. P2 proteins, despite being phosphorylated, are protected by their N-terminal peptide. An exchange of the first five amino acids between the two types of protein makes P1 resistant and P2 sensitive to degradation.     

凤尾蕨属植物在中国的分布新资料

凤尾蕨属植物具有较高的观赏价值和药用价值。弄清其在我国的分布状况,有利于资源的开发利用。本文报道了台湾凤尾蕨Pteris taiwanensis Ching ex Ching et S. H. Wu为中国大陆分布新记录,另外11种凤尾蕨属植物为省新记录,分别是海南凤尾蕨、指叶凤尾蕨、多羽凤尾蕨、大明凤尾蕨、细弱凤尾蕨、线羽凤尾蕨、栗柄凤尾蕨、单叶凤尾蕨、细羽凤尾蕨、三叉凤尾蕨和鸡冠凤尾蕨。并证实凤仪凤尾蕨Pteris dalhousiae Hook.没有分布至中国。     

Isolation of intact chains of polyphosphate from "Propionibacterium shermanii" grown on glucose or lactate

A procedure is presented for the isolation of intact polyphosphate (poly P) from "Propionibacterium shermanii." It is demonstrated, by including [32P]poly P during the extraction, that this procedure does not hydrolyze the poly P, and it is shown that two other widely used procedures do cause breakdown of the poly P. The procedure presented allows isolation of three fractions, short-chain poly P which is soluble in trichloroacetic acid, long-chain poly P which is soluble at neutral pH, and long-chain poly P which is present in volutin granules. Cells which had been grown on lactate did not contain short-chain poly P but did contain a high amount of long-chain poly P, which accumulated to 3% of the cell dry weight. At least 70% of this poly P was present in volutin granules. The poly P ranged in length from 250 to 725 phosphate residues and was the same average size as that synthesized in vitro by the poly P kinase from "P. shermanii". This indicates that the poly P kinase is responsible for catalyzing the synthesis of the poly P. In contrast to cells grown on lactate, those which had been grown on glucose did not contain volutin granules, did contain short-chain poly P and had 100-fold less long-chain poly P than lactate-grown cells. We propose that during the fermentation of glucose, the amount of poly P is lower than during growth on lactate because it is continuously utilized as a substrate in the phosphorylation of glucose.     

中国古蚤属分类研究(蚤目,栉眼蚤科)

通过对我国现有古蚤属标本和有关资料进行全面整理和系统分类研究,认为目前我国已知古蚤属共有27种,它们隶属于4个种团,分别为钝刺古蚤种团obtuspina group(1种)、鼩鼱古蚤种团soricis group(2种)、偏远古蚤种团remota group(16种)和短额古蚤种团brevifrontata group(8种),其数量已近该属世界已知种的一半.文中分别对我国已知各种古蚤的鉴别特征、生物学和地理分布状况作了介绍,并编制了各种团、种及亚种检索表.根据它们的分布特征认为我国西南部横断山区可能是古蚤属的分布中心.文中对偏远古蚤种团目前存在的问题进行了讨论.     

Characterization of interaction sites in the Saccharomyces cerevisiae ribosomal stalk components

The interactions among the yeast stalk components (P0, P1alpha, P1beta, P2alpha and P2beta) and with EF-2 have been explored using immunoprecipitation, affinity chromatography and the two-hybrid system. No stable association was detected between acidic proteins of the same type. In contrast, P1alpha and P1beta were found to interact with P2beta and P2alpha respectively. An interaction of P0 with P1 proteins, but not with P2 proteins, was also detected. This interaction is strongly increased with the P0 carboxyl end, which is able to form a pentameric complex with the four acidic proteins. The P1/P2 binding site has been located between residues 212 and 262 using different C-terminal P0 fragments. Immunoprecipitation shows the association of EF-2 with protein P0. However, the interaction is stronger with the P1/P2 proteins than with P0 in the two-hybrid assay. This interaction improves using the 100-amino-acid-long C-end of P0 and is even higher with the last 50 amino acids. The data indicate a specific association of P1alpha with P2beta and of P1beta with P2alpha rather than the dimerization of the acidic proteins found in prokaryotes. In addition, they suggest that stalk assembly begins by the interaction of the P1 proteins with P0. Moreover, as functional interactions of the complete P0 were found to increase using protein fragments, the data suggest that some active sites are exposed in the ribosome as a result of conformational changes that take place during stalk assembly and function.     

中国塔蚁属系统分类研究(膜翅目,蚁科)

记述中国塔蚁属Pyramica Roger昆虫26种,其中描述3新种,提出1个新组合Pyramica dayui(Xu).提供了各个种的地理分布,编制了25种工蚁分种检索表,台湾塔蚁P.formosa(Terayama,Lin & Wu)仅知蚁后.26个中国已知种是:多氏塔蚁P.doherti(Emery),平岛塔蚁P.hirashimai (Ogata),命运塔蚁P.1achesis Bolton,王氏塔蚁P.emeswangiBolton,节膜塔蚁P.membranifera(Emery),高作塔蚁P.takasago(Terayama,Lin＆Wu),弄巴塔蚁P.nongba sp.nov.,威氏塔蚁P.wilsoni Wang,日本塔蚁P.japonica(Ito),山地塔蚁P.formosimonticola(Terayama,Lin & Wu),典剑塔蚁P.benten(Terayama,Lin&Wu),细毛塔蚁P.leptothrix (Wheeler),高雅塔蚁P.elegantula(Terayama ＆ Kubota),哀牢山塔蚁P.ailaoshana sp.nov.,玛祖塔蚁P.mazu(Terayama,Lin & Wu),吉上塔蚁P.kichijo(Terayama,Lin & Wu),杨氏塔蚁P.yangi sp.nov.,中华塔蚁P.sinensis Wang,六节塔蚁P.hexamera(Brown),提西塔蚁P.tisiphone Bolton,大禹塔蚁P.dayui(Xu),犬齿塔蚁P.canina(Brown & Boisvert),邵氏塔蚁P.sauteri(Forel),温和塔蚁P.mitis Brown,截头塔蚁P.mutica(Brown),台湾塔蚁P.formosa (Terayama,Lin＆Wu).     

Printed in Great Britain The genus Phyllhermannia (Acari: Cryptostigmata)

The genus Phyllhermannia Berlese, 1916 is redefined. Two main groups of species are postulated within the genus, each being further divided into two subgroups. Known species reviewed completely or in part are: P. dentata, P. bimaculata, P. mollis and P. pulcher . New distribution records are given for the New Zealand species P. foliata, P. forsteri, P. mollis, P. phyllophora and P. rubra , together with a distribution map of all species. Some biogeographical comments are included for the genus. P. africana Balogh, 1958 is redescribed and a new species, P. collofi sp.n., is established. A key to the species of the world is provided.     

Role of phosphorylated aminoacyl residues in generating atypical consensus sequences which are recognized by casein kinase-2 but not by casein kinase-1.

Casein kinase-2 (CK-2) is a ubiquitous Ser/Thr specific protein kinase that recognizes phosphorylatable residues located upstream of acidic determinants, its consensus sequence being Ser(Thr)-Xaa-Xaa-Acidic. Here we show that the phosphotetrapeptide AcSer(P)-Ser(P)-Ser-Ser(P), which is devoid of the canonical consensus sequence, is nevertheless phosphorylated by CK-2 with rates comparable to that of typical peptide substrates Ser-Glu-Glu-Glu-Glu-Glu and Arg-Arg-Arg-Glu-Glu-Glu-Thr-Glu-Glu-Glu routinely employed for assaying CK-2 activity. The phosphopeptide AcSer(P)-Ser-Ser(P) [but not Ac-Ser-Ser(P)-Ser(P) or AcSer(P)-Ser(P)-Ser] is also phosphorylated albeit less efficiently than AcSer(P)-Ser(P)-Ser-Ser(P). Further N-terminal elongation with additional phosphoseryl residues to give the peptides AcSer(P)-Ser(P)-Ser(P)-Ser-Ser(P) and AcSer(P)-Ser(P)-Ser(P)-Ser(P)-Ser-Ser(P) does not improve but rather slightly decreases the phosphorylation efficiency by CK-2. These two peptides are conversely excellent substrates for CK-1, which does not appreciably phosphorylate either AcSer(P)-Ser-Ser(P) or AcSer-(P)-Ser(P)-Ser-Ser(P). Either individual or multiple replacement of the phosphorylated residues with glutamic acid in the peptide AcSer(P)-Ser(P)-Ser-Ser(P) drastically reduces the phosphorylation efficiency by CK-2, the phosphoseryl residue at position -2 playing an especially crucial role which cannot be surrogated by glutamyl residues.(ABSTRACT TRUNCATED AT 250 WORDS)     

Chemical-shift-perturbation mapping of the phosphotransfer and catalytic domain interaction in the histidine autokinase CheA from Thermotoga maritima

Regulating the activity of the histidine autokinase CheA is a central step in bacterial chemotaxis. The CheA autophosphorylation reaction minimally involves two CheA domains, denoted P1 and P4. The kinase domain (P4) binds adenosine triphosphate (ATP) and orients the gamma phosphate for phosphotransfer to a reactive histidine on the phosphoacceptor domain (P1). Three-dimensional triple-resonance experiments allowed sequential assignments of backbone nuclei from P1 and P4 domains as well as the P4 assignments within a larger construct, P3P4, which includes the dimerization domain P3. We have used nuclear magnetic resonance chemical-shift-perturbation mapping to define the interaction of P1 and P3P4 from the hyperthermophile Thermotoga maritima. The observed chemical-shift changes in P1 upon binding suggest that the P1 domain is bound by interactions on the side opposite the histidine that is phosphorylated. The observed shifts in P3P4 upon P1 binding suggest that P1 is bound at a site distinct from the catalytic site on P4. These results argue that the P1 domain is not bound in a mode that leads to productive phosphate transfer from ATP at the catalytic site and imply the presence of multiple binding modes. The binding mode observed may be regulatory or it may reflect the binding mode needed for effective transfer of the histidyl phosphate of P1 to the substrate proteins CheY and CheB. In either case, this work describes the first direct observation of the interaction between P1 and P4 in CheA.     

Mutational Analysis of the Role of Nucleoside Triphosphatase P4 in the Assembly of the RNA Polymerase Complex of Bacteriophage φ6

Bacteriophage 6 is a complex enveloped double-stranded RNA virus with a segmented genome and replication strategy quite similar to that of the Reoviridae. An in vitro packaging and replication system using purified components is available. The positive-polarity genomic segments are translocated into a preformed polymerase complex (procapsid) particle. This particle is composed of four proteins: the shell-forming protein P1, the RNA polymerase P2, and two proteins active in packaging. Protein P7 is involved in stable packaging, and protein P4 is a homomultimeric potent nucleoside triphosphatase that provides the energy for the RNA translocation event. In this investigation, we used mutational analysis to study P4 multimerization and assembly. P4 is assembled onto a preformed particle containing proteins P2 and P7 in addition to P1. Only simultaneous production of P1 and P4 in the same cell leads to P4 assembly on P1 alone, whereas the P1 shell is incompetent for accepting P4 if produced separately. The C-terminal part of P4 is essential for particle assembly but not for multimerization or enzymatic activity. Altering the P4 nucleoside triphosphate binding site destroys the ability to form multimers.     

Bioavailability of different phosphorus forms in freshwater systems

The recent literature on the bioavailability of different forms of P in freshwater systems is reviewed. Bioavailable P is defined as the sum of immediately available P and the P that can be transformed into an available form by naturally occurring processes. Methods used to estimate the bioavailable P pool, which vary between studies largely depending on the time perspective applied, are critically evaluated. Most studies on particulate P aim to determine the potentially available P pool. Potential bioavailability of particulate P is normally analysed in bioassays with algal yield determinations and the available P fraction is characterized from interpretations of results of sequential chemical extractions. NaOH-extractable P is in most studies the most algal-available P fraction. For soil samples and tributary water particulate matter, NaOH-P has often been found to be equal to algal extractable P. In other studies depletions of NaOH-P have accounted for the algal P uptake, but only a minor proportion of the fraction has been utilized. Organic P in lake water particulate matter and bed sediments of eutrophic lakes can also be algal-available to a significant extent.Studies on the bioavailability of dissolved P have often been concerned with immediate availability, or the minimum amount of available P. Such studies need other types of experimental design and normally assays with radiotracers are used. Immediately available P is frequently found to be less than P chemically assessed as dissolved reactive P (DRP) at low (< 10 µg DRP·l^-1) concentrations. However, immediate availability may also approach or exceed DRP concentrations, especially at higher concentrations. Potential bioavailability, assayed as for particulate P, may generally render higher bioavailability than P assayed as immediately available. Large fractions of dissolved P remain unutilized and are primarily found in the high molecular weight fraction of dissolved P.     

Evolutionary origin of human and primate malarias: evidence from the circumsporozoite protein gene

We have analyzed the conserved regions of the gene coding for the circumsporozoite protein (CSP) in 12 species of Plasmodium, the malaria parasite. The closest evolutionary relative of P. falciparum, the agent of malignant human malaria, is P. reichenowi, a chimpanzee parasite. This is consistent with the hypothesis that P. falciparum is an ancient human parasite, associated with humans since the divergence of the hominids from their closest hominoid relatives. Three other human Plasmodium species are each genetically indistinguishable from species parasitic to nonhuman primates; that is, for the DNA sequences included in our analysis, the differences between species are not greater than the differences between strains of the human species. The human P. malariae is indistinguishable from P. brasilianum, and P. vivax is indistinguishable from P. simium; P. brasilianum and P. simium are parasitic to New World monkeys. The human P. vivax-like is indistinguishable from P. simiovale, a parasite of Old World macaques. We conjecture that P. malariae, P. vivax, and P. vivax-like are evolutionarily recent human parasites, the first two at least acquired only within the last several thousand years, and perhaps within the last few hundred years, after the expansion of human populations in South America following the European colonizations. We estimate the rate of evolution of the conserved regions of the CSP gene as 2.46 x 10(-9) per site per year. The divergence between the P. falciparum and P. reichenowi lineages is accordingly dated 8.9 Myr ago. The divergence between the three lineages leading to the human parasites is very ancient, about 100 Myr old between P. malariae and P. vivax (and P. vivax-like) and about 165 Myr old between P. falciparum and the other two.      

Revision of the cluster-flies of the Pollenia viatica species-group (Diptera: Calliphoridae)

Abstract. The Pollenia viatica species-group ( =pallida species-group) is defined and described. It consists of P.bicolor Robineau-Desvoidy, P.bulgarica Jacentkovsk, P.fulvipalpis Macquart, P.mediterranea Grunin, P.ruficrura Rondani, stat.rev., P.viatica Robineau-Desvoidy, stat.rev. (= P.pallida Rodendorf, syn.n.) and P.ponti sp.n. It is mono-phyletic, mainly on the basis of a synapomorphic ovipositor tip, and the vagabunda species-group is its sister group. A key to all species is provided, the terminalia of both sexes illustrated and all taxa redescribed. Lectotypes are designated for Pollenia bisulca Pandellé, P.ruficrura Rondani and P.viatica Robineau-Desvoidy. Pollenia ruficrura is removed from its current status as a nomen dubium. Pollenia bicolor and P.ponti are western Mediterranean species, the latter also occurs in Czechoslovakia. P.fulvipalpis is endemic to France and Channel Islands. P.ruficrura is known only from Corsica and Italy. P.mediterranea is an eastern Mediterranean species reaching east to Armenia. P.bulgarica is distributed from Hungary to Caucasus. P.viatica is widespread from France, Great Britain and Southern Scandinavia to Central Asia. All species are summer or autumn species, and seem to have only one generation each year. The immature stages and life-cycle of a species from Paris, France, named 'Pollenia rudis' by Keilin (1909, 1915) are tentatively assigned to P. viatica . It survives the winter as a first instar larva within the earthworm Allolobophora chlorotica Savigny.     

The lichen genus Physcia in Central and South America

Thirty-four species of the lichen genus Physcia (s. str.) in Central and South America are defined. Morphology, anatomy, chemistry, distribution, habitat, relation to other taxa and some evolutionary trends are discussed. A key to the species is presented. Eleven species are described as new; P. cinerea, P. convexella, P. coronifera, P. decorticata, P. kalbii, P. lobulata, P. lopezii, P. manuelii, P. rolfii, P. sinuosa , and P. tenuis. P. nubila is a new name for Heterodermia desertorum .     

The genus Panisea (Orchidaceae), a taxonomic revision

The genus Panisea is revised. A total of 13 taxa have previously been described. In the present revision 7 species are recognized: P. albiflora, P. apiculata, P. demissa, P. distelidia sp. nov., P. tricallosa, P. uniflora and P. yunnanensis. A new variety, P. tricallosa var. garrettii is proposed.