Residual influences on fecundity in drosophilid species

Summary A residual influence of males and females on oviposition has been examined in 7 drosophilids. There was evidence for oviposition deterrence inDrosophila funebris, with males as well as females producing the inhibitory effect. In contrast, male residues stimulated oviposition inZaprionus tuberculatus. Male residues also stimulated oviposition and appeared to serve as an aggregation cue inD. melanogaster.     

On the specific attraction of the males of the six-toothed spruce bark beetle,Pityogenes chalcographus (L.) to a mixture of synthetic pheromones of the eight-toothed spruce bark beetle,Ips typographus (L.) (Coleoptera,Scolytidae)

Summary Traps containing a mixture of attractants forIps typographus also caught other species of bark beetles. The numbers ofPityogenes chalcographus, Pityogenes conjunctus, andTrypodendron lineatum were too high to be interpreted as accidental captures. The males of the polygamousP. chalcographus were specifically attracted, indicating that theI. typographus pheromone or one of its components acts as a kairomone and primary attractant for the pioneering males ofP. chalcographus.     

Growth inhibitory,insecticidal and antifeedant effects of some antileukemic and cytotoxic quassinoids on two species of agricultural pests

Summary Several quassinoids, obtained by isolation and derivatization fromSimaba multiflora andSoulamea soulameoides, were evaluated for growth inhibitory and insecticidal effects against the tobacco budworm (Heliothis virescens) and for antifeedant effects againstH. virescens and the fall armyworm (Spodoptera frugiperda). The relative activity of the quassinoids as insect growth inhibitors generally paralleled their known relative potency as antileukemic and cytotoxic agents.Phytochemical aspects of this work were supported by Contract CM-97295 with the Division of Cancer Treatment, National Cancer Institute, National Institutes of Health, Bethesda, Md. Insects were kindly supplied by the agency of the United States Department of Agriculture at Brownsville, TX.     

Antioxidant survey to assess antagonism to redox stress using a prokaryotic and an eukaryotic system

Using a prokaryote (Escherichia coli) and a metazoa-resembling eukaryote (Ochromonas danica), we surveyed antioxidants which might overcome redox stress imposed by menadione sodium bisulphite (MD) and buthionine sulphoximine (BSO). BSO oxidant stress was evident only inO. danica; MD oxidant stress was evident in both organisms. Glutathione, its precursors, e.g. cysteine, homocysteine, and 2-oxo-4-thiazolidine carboxylic acid, and red blood cells, emerged as prime antioxidants for relieving BSO and MD oxidant stress. BSO and MD oxidant activity and antioxidant-annulling effect inO. danica were judged comparable to those found in animal cells whereas the resultsE. coli were not entirely equivalent. TheO. danica system emerged as a practical, rapid, and useful system for pinpointing oxidant stressors and antioxidants, and shows promise for studies with mammalian systems.     

Occurrence and biosynthesis of 11 (R)-hydroxy-eicosatetraenoic acid (11-R-HETE) in the Caribbean soft coralPlexaurella dichotoma

Gorgonian soft corals from the Caribbean Sea are known to contain prostaglandin-like compounds as well as other products of arachidonic acid lipoxygenation, and the formation of the latter has been suggested to represent the first step in prostaglandin biosynthesis. Here we present evidence for the presence of 11-R-hydroxy-5Z, 8Z, 12E, 14Z-eicosatetraenoic acid (11-R-HETE), as well as of the enzyme responsible for its biosynthesis, in the Caribbean gorgonianPlexaurella dichotoma. Lipid extracts fromP. dichotoma were purified by conventional SiO₂ column chromatography followed by reversed phase high-pressure liquid chromatography (HPLC). These yielded a component having chromatographic and spectroscopic properties identical to synthetic 11-HETE. Electron impact mass spectrometric analysis of the acetoxy-, methyl ester derivative of the compound confirmed its identity as 11-HETE, while chiral phase HPLC of the methyl ester derivative showed that the stereochemistry of the alcoholic carbon atom wasR. Enzymatically active homogenates fromP. dichotoma were able to convert both unlabelled and [³H] arachidonic acid into 11-HETE. In vitro biosynthesis of the latter metabolite was also observed with homogenates of the Mediterranean gorgonianParamuricea clavata, another non-prostaglandin-containing soft coral, thus suggesting that 11-R-HETE production is not necessarily accompanied by prostaglandin formation in gorgonian corals.     

Highly irritant ingenane type diterpene esters fromEuphorbia cyparissias L.

Summary From the roots ofEuphorbia cyparissias L. a highly irritant diterpene ester fraction was isolated and further resolved into its constituents. Together with some less active and some inactive isomers, the pure Euphorbia factors were characterized as new diesters of 13-hydroxyingenol and as triesters of the new 13,19-dihydroxyingenol. The Euphorbia factorsCy ₆,Cy ₁₁ andCy ₁₄ are the strongest irritants of the ingenane ester type hitherto known,Cy ₁₁ being at least as active as the standard diterpene ester type irritant 12-O-tetradecanoylphorbol-13-acetate (TPA).Acknowledgments. We are greatly indebted to the Wilhelm and Maria Meyenburg Foundation for financial support for the supply of plant material required for this investigation.The results were partially presented by H.H.O. at the 17. Hauptversammlung der Gesellschaft Deutscher Chemiker. München, 12.–16.9.1977. PhD-thesis. University of Heidelberg, 1978.     

Biochemical variation in theRana esculenta complex: A new hybrid form related toRana perezi andRana ridibunda

Summary Investigations of the green frogs from western Europe for electrophoretic variations at 4 enzyme loci demonstrated a new form which must be considered as a hybrid betweenRana ridibunda andR. perezi. Biochemical evidence supports the hypothesis that its reproduction is hybridogenetic, as it is forR. esculenta.     

Antimalarial drugs: recent advances in molecular determinants of resistance and their clinical significance

Molecular determinants of antimalarial drug resistance are useful and informative tools that complement phenotypic assays for drug resistance. They also guide the design of strategies to circumvent such resistance once it has reached levels of clinical significance. Established resistance to arylaminoalcohols such as mefloquine and lumefantrine in SE Asia is mediated primarily by gene amplification of the P. falciparum drug transporter, pfmdr1. Single nucleotide polymorphisms in pfmdr1, whether assessed in field isolates or transfection experiments, are associated with changes in IC₅₀ values (to arylaminoalcohols and chloroquine), but not of such magnitude as to influence clinical treatment outcomes. Recently described emerging in vitro resistance to artemisinins in certain areas correlates with mutations in the SERCA-like sequence PfATP6 and supports PfATP6 as a key target for artemisinins. Received 13 February 2006; revised after revision 7 March 2006; accepted 29 March 2006     

RNA editing in plant organelles: machinery, physiological function and evolution

In plants, RNA editing is a process for converting a specific nucleotide of RNA from C to U and less frequently from U to C in mitochondria and plastids. To specify the site of editing, the cis-element adjacent to the editing site functions as a binding site for the trans-acting factor. Genetic approaches using Arabidopsis thaliana have clarified that a member of the protein family with pentatricopeptide repeat (PPR) motifs is essential for RNA editing to generate a translational initiation codon of the chloroplast ndhD gene. The PPR motif is a highly degenerate unit of 35 amino acids and appears as tandem repeats in proteins that are involved in RNA maturation steps in mitochondria and plastids. The Arabidopsis genome encodes approximately 450 members of the PPR family, some of which possibly function as trans-acting factors binding the cis-elements of the RNA editing sites to facilitate access of an unidentified RNA editing enzyme. Based on this breakthrough in the research on plant RNA editing, I would like to discuss the possible steps of co-evolution of RNA editing events and PPR proteins. Received 30 September 2005; received after revision 5 November 2005; accepted 28 November 2005     

Biomedicine and diseases: the Klippel-Trenaunay syndrome, vascular anomalies and vascular morphogenesis

Vascular morphogenesis is a vital process for embryonic development, normal physiologic conditions (e.g. wound healing) and pathological processes (e.g. atherosclerosis, cancer). Genetic studies of vascular anomalies have led to identification of critical genes involved in vascular morphogenesis. A susceptibility gene, VG5Q (formally named AGGF1), was cloned for Klippel-Trenaunay syndrome (KTS). AGGF1 encodes a potent angiogenic factor, and KTS-associated mutations enhance angiogenic activity of AGGF1, defining ‘increased angiogenesis’ as one molecular mechanism for the pathogenesis of KTS. Similar studies have identified other genes involved in vascular anomalies as important genes for vascular morphogenesis, including TIE2, VEGFR-3, RASA1, KRIT1, MGC4607, PDCD10, glomulin, FOXC2, NEMO, SOX18, ENG, ACVRLK1, MADH4, NDP, TIMP3, Notch3, COL3A1 and PTEN. Future studies of vascular anomaly genes will provide insights into the molecular mechanisms for vascular morphogenesis, and may lead to the development of therapeutic strategies for treating these and other angiogenesis-related diseases, including coronary artery disease and cancer.Received 24 November 2004; received after revision 21 January 2005; accepted 2 March 2005     

Genetics of early mammalian folliculogenesis

Early ovarian folliculogenesis begins with the breakdown of germ cell clusters and formation of primordial follicles. Primordial follicles are the smallest ovarian follicle units continuously recruited to grow into primary and more advanced ovarian follicles. Genes expressed in the germ cells such as Figla, Nobox, Kit and Ntrk2, as well as genes expressed in the surrounding somatic cells such as Foxl2, Kitl and Ngf, play critical functions during early folliculogenesis. Transgenic mice continue to provide important insights into the genetic pathways that regulate early mammalian folliculogenesis. Genes critical in early folliculogenesis are important determinants of reproductive life span and represent candidate genes for human ovarian failure. Received 25 August 2005; received after revision 18 October 2005; accepted 21 November 2005     

Novel diterpenoid diacylglycerols from marine molluscs: potent morphogens and protein kinase C activators

Five novel 1,2-sn-diacylglycerols with diterpenoid acyl moieties in thesn-1 position were isolated and characterized, together with the corresponding 1,3-sn-diacylglycerols, from three species of dorid nudibranchs molluscs. Their potent activity as morphogens in vivo in theHydra tentacle regeneration assay and their parallel activity as activators of rat brain protein kinase C (PKC) in vitro are reported here. Our findings promote the use of these compounds as useful molecular probes for both in vivo and in vitro studies on the participation of PKC in cell development.     

Chemical and tactile communication between the root aphid parasitoidParalipsis enervis and trophobiotic ants: consequences for parasitoid survival

Females of the aphid parasitoidParalipsis enervis received liquid food by regurgitation (trophallaxis) from workers of the ant speciesLasius niger, but were not fed by workers ofMyrmica laevinodis andTetramorium caespitum. WhileP. enervis was not treated aggressively by workers of any of these species,Lasius flavus workers killed the parasitoid. This different ant behaviour resulted in a different parasitoid longevity. WhileP. enervis survived for only 10 min in the presence ofL. flavus (due to ant aggression) or for approximately one day in the presence ofT. caespitum andM. laevinodis (due to lack of trophallaxis), survival increased significantly to more than five days in the presence ofL. niger, which provided food regularly to the parasitoids. Our study suggests thatP. enervis mimics behavioural signals ofL. niger, as well as odor cues of its host aphidAnoecia corni, to avoid aggression byL. niger.     

Green leaf volatiles interrupt aggregation pheromone response in bark beetles infesting southern pines

Summary Green leaf volatiles were shown to interrupt responses to aggregation pheromones of three species of bark beetles (Coleoptera: Scolytidae) which infest pines in the southern United States [the southern pine beetle,Dendroctonus frontalis Zimm.; the four-spined engraver,Ips avulsus (Eichhoff); and the five-spined engraver,Ips grandicollis (Eichhoff)]. The order of effectiveness of the compounds tested for each species was hexanal>hexanal+hexan-1-ol>hexan-1-ol. Neither hexanal, hexan-1-ol nor hexanal+hexan-1-ol was as effective in interrupting pheromone responses ofD. frontalis as verbenone, a known inhibitor of this species. Other than interspecific chemical signals, this is the first report of an interruptant forIps species, and the only report of a pheromone interruptant active for bothIps andDendroctonus species.     

Urochordates carry multiple genes for goose-type lysozyme and no genes for chicken- or invertebrate-type lysozymes

Genome clones and expressed sequence tags (ESTs) from the ascidian Ciona intestinalis and from the larvacean Oikopleura dioica were analysed for the presence of lysozyme-encoding genes. Two genes were found to potentially code for goose-type lysozymes in Oikopleura, while three or possibly more g-type proteins form the lysozyme complement of C. intestinalis, and at least one of these genes from each species is expressed based on EST data. No genes for chicken- or invertebrate-type lysozymes were found in either urochordate species. Consistent with this finding, extracts of Oikopleura animals possessed hydrolysing activity on bacterial cell walls, and this activity was not inhibited in the presence of a known inhibitor of chicken-type lysozyme. A wide range of isoelectric points for the predicted lysozymes from Ciona (pI 4.4, 6.4 and 9.9) and from Oikopleura (pI 5.0 and 8.0) suggests tissue-specific adaptations as well as specific functional roles of the lysozymes. Comparisons of gene structures, encoded sequences, cysteine residue content and their positions in the proteins indicate that the g-type lysozymes of Ciona intestinalis are more closely related to those of vertebrates than are the g-type lysozymes of Oikopleura. Multiple genes from each species may result from separate and lineage-specific duplications followed by functional specialisation.Received 29 June 2003; received after revision 24 July 2003; accepted 29 July 2003     

Enzymes of arginine biosynthesis in methanogenic bacteria

Summary Methanobacterium thermoautotrophicum, Methanococcus vannielii andMethanobrevibacter arboriphilus, the 3 methanogenic bacteria tested, possessed an ornithine acetyltransferase and an arginine-sensitiveN-acetylglutamate 5-phopshtransferase. These 2 enzymes, as well as acetylornithinase and ornithine carbamoyltransferase, were insensitive to oxygen and were present at activity levels comparable to the levels observed in eubacteria.Acknowledgments. This work was supported by the Swiss National Foundation for Scientific Research (project No. 3.287.82). We thank A. Kiener for valuable discussions.     

Protein-O-mannosyltransferases in virulence and development

Protein-O-mannosyltransferases (Pmt proteins) catalyse the addition of mannose to serine or threonine residues of secretory proteins. This modification was described first for yeast and later for other fungi, mammals, insects and recently also for bacteria. O-mannosylation depends on specific isoforms of the three Pmt1, 2 and 4 subfamilies. In fungi, O-mannosylation determines the structure and integrity of cell walls, as well as cellular differentiation and virulence. O-mannosylation of specific secretory proteins of the human fungal pathogen Candida albicans and of the bacterial pathogen Mycobacterium tuberculosis contributes significantly to virulence. In mammals and insects, Pmt proteins are essential for cellular differentiation and development, while lack of Pmt activity causes Walker-Warburg syndrome (muscular dystrophy) in humans. The susceptibility of human cells to certain viruses may also depend on O-mannosyl chains. This review focuses on the various roles of Pmt proteins in cellular differentiation, development and virulence. Received 6 September 2007; received after revision 3 October 2007; accepted 5 October 2007     

Molecular characterization of the p83/100 proteins of variousBorrelia burgdorferi sensu lato strains

Conclusions As in OspA-serotyping experiments, theB garinii group (OspA-sterotype 3–7) showed highest diversity within this internal fragment of p83/100, whereas theB. afzelii group (OspA-type 2) and theB. burgdorferi sensu stricto group (OspA-type 1) were nearly identical. Determination of the size of the PCR products as well as restriction fragment length polymorphism analysis (DraI) can be used for classification into the three species ofB. burgdorferi sensu lato. Since p83/100 is chromosomally encoded, this protein might be a more stable marker for classification than the plasmid-encoded OspA. In contrast to the flagellin gene a subclassification of theB. garinii group is possible due to the diversity of the p83/100 internal fragment.     

<Emphasis Type="Italic">O</Emphasis>-fucose modifications of epidermal growth factor-like repeats and thrombospondin type 1 repeats: unusual modifications in unusual places

Recent discoveries revealing that carbohydrate modifications play critical roles in a wide variety of biological processes have brought wide recognition to the field of glycobiology. Growing attention has focused on the function of unusual O-linked carbohydrate modifications such as O-fucose. O-fucose modifications have been described in several different protein contexts, including epidermal growth factor-like repeats and thrombospondin type 1 repeats. The O-fucose modifications on thrombospondin type 1 repeats have only recently been described, but the site of modification occurs in a region proposed to play a role in cell adhesion. O-fucose modifications on epidermal growth factor-like repeats have been described as important players in several signal transduction systems. For instance, Notch, a cell-surface signaling receptor required for many developmental events, bears multiple O-fucose saccharides on the epidermal growth factor-like repeat of its extracellular domain. The O-fucose moieties serve as a substrate for the β1,3 N-acetylglucosaminyltransferase activity of Fringe, a known modifier of Notch function. The alteration of O-fucose structures by Fringe influences the ability of Notch ligands to activate the receptor and provides a means to regulate Notch signaling. Thus, O-fucose and Fringe provide a clear example of how carbohydrate modifications can have direct functional consequences on the proteins they modify. RID="*" ID="*"Corresponding author.     

Pierre-Joseph Macquer an Eighteenth-Century Artisanal-Scientific Expert

Summary

Pierre-Joseph Macquer (1718–1784) is well known as one of the major chemists in the eighteenth century as a theoretician and a teacher. He is also known for his works on dyeing. This paper presents a new face of Macquer. He proposed a theory on mordants in dyeing as early as 1775. Besides his activity at the Académie des sciences, he played an important role in Government as the commissioner of dyeing from 1766 where he established close links with artisan inventors. Académicien chimiste at the royal Manufactory of Sèvres from 1757, he was also the inventor of French porcelain. His notebooks show his organization, method, courage, passion and obstinacy in the search for the paste for hard porcelain. He also proposed an interpretation of its formation. Macquer was both a theoretician and a practical expert in dyeing as well as in porcelain making. He managed to bridge the gap between science and art.