D-3-Dodecanoyltetradecanoic acid as a constituent of lipid A from the lipopolysaccharide ofYersinia pseudotuberculosis

Summary D-3-Dodecanoyltetradecanoic acid has been separated from the lipid A ofYersinia pseudotuberculosis and its structure has been established by chromato-mass-spectrometry and¹³C NMR spectroscopy, by comparison with authentic samples.     

Multiple roles of the DSCR1 (Adapt78 or RCAN1) gene and its protein product Calcipressin 1 (or RCAN1) in disease

The DSCR1 (Adapt78) gene¹ is transiently induced by stresses to temporarily protect cells against further potentially lethal challenges. However, chronic expression of the DSCR1 (Adapt78) gene has now been implicated in several pathological conditions including Alzheimer’s disease, Down syndrome and cardiac hypertrophy. Calcipressin 1 has been shown to function through direct binding and inhibition of the serine threonine protein phosphatase Calcineurin. Pharmacological inhibition of calcineurin, by the immunosuppressive drugs cyclosporin A and FK506, affects a wide variety of diseases. It is, therefore, likely that this endogenous calcineurin inhibitor, calcipressin 1, may also play a role in a variety of human diseases. ¹Please note that the mammalian DSCR1 gene is also called Adapt78 or RCAN1, and its protein products have been named Calcipressin1, MCIP1 and RCAN1. A proposal to adopt a single gene name of RCAN1 and a protein name RCAN1 (for Regulator of Calcineurin) has been endorsed by the HUGO Gene Nomenclature Committee, but final approval must await agreement from a majority of researchers in the field. Received 2 March 2005; received after revision 27 May 2005; accepted 19 July 2005     

Gonyauline: A novel endogenous substance shortening the period of the circadian clock of a unicellular alga

Summary The circadian clock in the unicellular algaGonyaulax polyedra is accelerated by a substance in extracts from the cells themselves. The extracts have been fractionated using the circadian rhythm of bioluminescence as bioassay. The active substance, termed gonyauline, has been isolated and characterized as a novel low molecular weight cyclopropanecarboxylic acid (S-methyl-cis-2-(methylthio) cyclopropanecarboxylic acid). Synthetic gonyauline has a similar shortening effect on the period of the circadian clock.     

Psilocybin,ein psychotroper Wirkstoff aus dem mexikanischen RauschpilzPsilocybe mexicana Heim

Summary The active principle ofPsilocybe mexicana Heim, a mexican mushroom with hallucinogenic properties, has been isolated in crystalline form. The compound has been given the namePsilocybin; it possesses indole characteristics and contains phosphorus. A second substance, closely related toPsilocybin but found only in traces, has been calledPsilocin.     

La formule chromosomique deSorex minutus L. (Mammalia-Insectivora)

Summary The chromosome complement ofSorex minutus L. has been determined. The caryotype is characterized by a diploid number of 42 and by aNF (fundamental number) of 56. The sex-chromosomes are of theX−Y type usual in mammals. The origin and the evolution of the chromosome set ofS. minutus, S. unguiculatus, andS. araneus have been discussed.      

The genetics of phytotoxin production by plant pathogenic fungi

Little is known about the genetic control of phytotoxin production by plant pathogenic fungi. The production of host-selective toxins known to play a role in disease development has been genetically analyzed in three species ofCochliobolus. InC. heterostrophus, a single genetic locus with two alleles has been identified controlling the production of HMT-toxin. This locus appears to be at or near the breakpoint of a chromosome rearrangement. Single genetic loci have also been identified controlling the production of HC-toxin byC. carbonum and HV-toxin byC. victoriae. The locus inC. carbonum may be a cluster of tightly linked genes.     

Histochemical localization of carbonic anhydrase in Malpighian tubules ofCulex pipiens

Summary Carbonic anhydrase (CA) activity has been localized histochemically by Hansson's method in Malpighian tubules ofCulex pipiens. The enzyme has been observed on membranes of the cytoplasmic inclusions of Malpighian cells; no CA activity has been found in other cytoplasmic structures. The possible meaning of the localization of the enzyme is discussed.     

Occurrence of a blood group A-like substance in eggs of the prosobranch snailPomacea canaliculata

Summary In the eggs of the prosobranch snailsPomacea canaliculata andPomacea insularum a blood group A-like substance has been detected by anti-A from the snailsHelix pomatia, Helix aspersa andCepaea nemoralis.     

Sauerstoff-Heteroringe. Die Konfiguration und Synthese desd,l-Homopterocarpins

Summary The racemic form of homopterocarpin (V), a constituent of red sandal-wood, has been synthesized by a method which has previously been proposed by the authors. N. M. R. spectral studies in conjunction with the examination of models have enabled the assignment of thecis configuration (V) to homopterocarpin.

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V. Mitteilung. IV. Mitteilung sieheH. Suginome, Exper.18, 161 (1962).     

Proposition 10, Book 2, in the <Emphasis Type="Italic">Principia</Emphasis>, revisited

In Proposition 10, Book 2 of the Principia, Newton applied his geometrical calculus and power series expansion to calculate motion in a resistive medium under the action of gravity. In the first edition of the Principia, however, he made an error in his treatment which lead to a faulty solution that was noticed by Johann Bernoulli and communicated to him while the second edition was already at the printer. This episode has been discussed in the past, and the source of Newton’s initial error, which Bernoulli was unable to find, has been clarified by Lagrange and is reviewed here. But there are also problems in Newton’s corrected version in the second edition of the Principia that have been ignored in the past, which are discussed in detail here.     

Selectable genetic markers for nematode transgenesis

The nematode Caenorhabditis elegans has been used to study genetics and development since the mid-1970s. Over the years, the arsenal of techniques employed in this field has grown steadily in parallel with the number of researchers using this model. Since the introduction of C. elegans transgenesis, nearly 20 years ago, this system has been extensively used in areas such as rescue experiments, gene expression studies, and protein localization. The completion of the C. elegans genome sequence paved the way for genome-wide studies requiring higher throughput and improved scalability than provided by traditional genetic markers. The development of antibiotic selection systems for nematode transgenesis addresses these requirements and opens the possibility to apply transgenesis to investigate biological functions in other nematode species for which no genetic markers had been developed to date.     

Genetic studies on gynandromorphism (sgm,gm) inCulex pipiens fatigans

Summary Individuals showing anterior-posterior gynandromorphism or somatic mosaicism of palpi respectively have been found in a laboratory strain ofCulex pipiens fatigans. The origin of the gynanders on the basis of binucleated eggs bearing anm factor and independently fertilized by male gemetes ofM andm genotype respectively has been suggested.This study was supported by the grant (No. 7/112/919/81 EMR-1), Council of Scientific and Industrial Research Govt., of India.     

Mapping of restriction enzyme cuts by a new two-dimensional procedure

Summary A new procedure has been worked out to establish restriction maps. The method is fast, does not in general require labeled DNA and has been applied to map the linear palindromic rDNA ofPhysarum with the restriction enzymeBstEII.Acknowledgment. This work was supported by grants from the NIH (GM-30338), the NSF (PCM 8116391) and the Swiss National Science Foundation (3.075.81).     

Biotransformation of a dietary sesterterpenoid in the Mediterranean nudibranchHypselodoris orsini

The metabolic relationship between the marine molluscHypselodoris orsini and the spongeCacospongia mollior has been reinvestigated. The predator-prey association has been confirmed even though the metabolic patterns of the two invertebrates are substantially different. Most probably the nudibranch converts the main sponge metabolite, the sesterterpenoid scalaradial (1), into a less oxygenated related metabolite, deoxoscalarin (4), followed by a second chemical transformation leading to a new sesterterpenoid, 6-keto-deoxoscalarin (5) which is selectively compartmentalized into some dorsal glands, mantle dermal formations (MDFs), strategically distributed near the gills. 6-keto-deoxoscalarin (5) has been characterized by 1D and 2D NMR methods. Finally, the unusual association of some Chromodorididae molluscs with sponges containing sesterterpenoids suggests a further analysis of their taxonomical collocation is required.     

Zur Kenntnis des lamellaren Musters in ausgewachsenen und der Kristallgitterstruktur in jungen Chloroplasten

Summary (1) It is shown that in the chloroplasts ofChlamydomonas andAnthoceros thick, dense lamellae and thin, less dense lamellae alternate. (2) In the chloroplasts of many phanerogame plants with grana, thin less dense lamellae limit the parcel of thick grana-lamellae above and below. Since the differentiations 1 and 2 are present in the photographs of many publications (although not mentioned), it is suggested that this kind of lamellarmodel has often been overlooked until now. — The « Kristallgitterstruktur » has been found in a cryptogamous plant,Selaginella, in young chloroplasts, for the first time. The connection between the elementary particles of the crystal-lattice and the young lamellae has been verified again. — The possibility of formation of double lamellae by fusion of blastulae or tubuli is discussed in detail.     

A role for <Emphasis Type="Italic">N</Emphasis>-acetylglucosamine as a nutrient sensor and mediator of insulin resistance

The ability to regulate energy balance at both the cellular and whole body level is an essential process of life. As western society has shifted to a higher caloric diet and more sedentary lifestyle, the incidence of type 2 diabetes (non-insulin-dependent diabetes mellitus) has increased to epidemic proportions. Thus, type 2 diabetes has been described as a disease of 'chronic overnutrition'. There are abundant data to support the relationship between nutrient availability and insulin action. However, there have been multiple hypotheses and debates as to the mechanism by which nutrient availability modulates insulin signaling and how excess nutrients lead to insulin resistance. One well-established pathway for nutrient sensing is the hexosamine biosynthetic pathway (HSP), which produces the acetylated aminosugar nucleotide uridine 5′-diphospho-N-acetylglucosamine (UDP-GlcNAc) as its end product. Since UDP-GlcNAc is the donor substrate for modification of nucleocytoplasmic proteins at serine and threonine residues with N-acetylglucosamine (O-GlcNAc), the possibility of this posttranslational modification serving as the nutrient sensor has been proposed. We have recently directly tested this model in adipocytes by examining the effect of elevated levels of O-GlcNAc on insulin-stimulated glucose uptake. In this review, we summarize the existing work that implicates the HSP and O-GlcNAc modification as nutrient sensors and regulators of insulin signaling. RID="*" ID="*"Corresponding author.     

Étude cytochimique des groupes sulfhydriles au cours des modifications de la détermination embryonnaire chez l'œuf de l'oursinParacentrotus lividus

Summary A cytochemical study of the distribution of sulfhydryl groups in animalized and vegetalized embryos of the sea-urchinParacentrotus lividus has been made by use of the Bennett's reagent. The distribution of the sulfhydryl groups appears homogeneous in these embryos. No gradient has been observed in the experimental conditions used.     

Variations de la différence de potentiel électrochimique des chlorures chezNitella en présence de benzène sulphonate

Summary The chloride electrochemical potential difference between the inside of cells ofNitella translucens and some external solutions, where Cl has been progressively replaced by benzenesulphonate, has been measured by means of Ag-AgCl electrodes. It appears that benzenesulphonate moves into the cell by an electrogenic pump and that the uptake of Cl byNitella is not in contradiction with a carrier hypothesis.

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This work was supported by grants from the F.N.R.S. and was carried out in the Biophysics Section of the Edinburgh University. We are indebted to Dr. E. J.Williams and Dr.Hogg for having sponsored this research and kindly provided the material.     

The perspectives of studying multi-domain protein folding

Most of fundamental studies on protein folding have been performed with small globular proteins consisting of a single domain. In vitro many of these proteins are well characterized by a reversible two-state folding scheme. However, the majority of proteins in the cell belong to the class of larger multi-domain proteins that often unfold irreversibly under in vitro conditions. This makes folding studies difficult or even impossible. In spite of these problems for many multi-domain proteins, folding has been investigated by classical refolding. Co-translational folding of nascent polypeptide chains when synthesized by ribosomes has also been studied. Single molecule techniques represent a promising approach for future studies on the folding of multi-domain proteins, and tremendous advances have been made in these techniques in recent years. In particular, fluorescence-based methods can contribute significantly to an understanding of the fundamental principles of multi-domain protein folding. Received 3 December 2008; accepted 23 December 2008