bluuebunny/crossref_metadata_2025 huggingface dataset:
BOTERO1 is required for normal orientation of cortical microtubules and anisotropic cell expansion in Arabidopsis
Authors: Bichet Adeline , Desnos Thierry , Turner Simon , Grandjean Olivier , Höfte Herman
Published: August 2010

Mutants at the BOTERO1 locus are affected in anisotropic growth in all non‐tip‐growing cell types examined. Mutant cells are shorter and broader than those of the wild type. Mutant inflorescence stems show a dramatically reduced bending modulus and maximum stress at yield. Our observations of root epidermis cells show that the cell expansion defect in bot1 is correlated with a defect in the orientation of the cortical microtubules. We found that in cells within the apical portion of the root, which roughly corresponds to the meristem, microtubules were loosely organized and became much more highly aligned in transverse arrays with increasing distance from the tip. Such a transition was not observed in bot1. No defect in microtubule organization was observed in kor‐1, another mutant with a radial cell expansion defect. We also found that in wild‐type root epidermal cells, cessation of radial expansion precedes the increased alignment of cortical microtubules into transverse arrays. Bot1 roots still show a gravitropic response, which indicates that ordered cortical microtubules are not required for differential growth during gravitropism. Interestingly, the fact that in the mutant, these major changes in microtubule organization cause relatively subtle changes in cell morphology, suggest that other levels of control of growth anisotropy remain to be discovered. Together, these observations suggest that BOT1 is required for organizing cortical microtubules into transverse arrays in interphase cells, and that this organization is required for consolidating, rather than initiating, changes in the direction of cell expansion.
Identification of symbiosis‐regulated genes in Eucalyptus globulus–Pisolithus tinctorius ectomycorrhiza by differential hybridization of arrayed cDNAs
Authors: Voiblet Catherine , Duplessis Sébastien , Encelot Nathalie , Martin Francis
Published: August 2010

Ectomycorrhiza development alters gene expression in the fungal and plant symbionts. The identification of a large number of genes expressed exclusively or predominantly in the symbiosis will contribute greatly to the understanding of the development of the ectomycorrhizal symbiosis. We have constructed a cDNA library of 4‐day‐old Eucalyptus globulus–Pisolithus tinctorius ectomycorrhiza and sequenced 850 cDNAs cloned randomly or obtained through suppression subtractive hybridization (SSH). Based on the absence of a database match, 43% of the ectomycorrhiza ESTs are coding for novel genes. At the developmental stage analysed (fungal sheath formation), the majority of the identified sequences represented ‘housekeeping’ proteins, i.e. proteins involved in gene/protein expression, cell‐wall proteins, metabolic enzymes, and components of signalling systems. We screened arrayed cDNAs to identify symbiosis‐regulated genes by using differential hybridization. Comparisons of signals from free‐living partners and symbiotic tissues revealed significant differences in expression levels (differential expression ratio >2.5) for 17% of the genes analysed. No ectomycorrhiza‐specific gene was detected. The results successfully demonstrate the use of the cDNA array and SSH systems as general approaches for dissecting symbiosis development, and provide the first global picture of the cellular functions operating in ectomycorrhiza.
THERMOPHILIC AMINOPEPTIDASES FROM BACILLUS STEAROTHERMOPHILUS. I. ISOLATION, SPECIFICITY, AND GENERAL PROPERTIES OF THE THERMOSTABLE AMINOPEPTIDASE I *
Authors: Roncari G. , Zuber H.
Published: August 2010

A thermostable aminopeptidase (AP 1) from homogenates of B. stearothermo‐philus was purified by filtration on Sephadex G‐150, by heat treatment, by chromatography on DEAE Sephadex and Sephadex G‐200, and by preparative polyacrylamide gel electrophoresis. The enzyme shows one band in polyacrylamide gel electrophoresis and has a pH optimum between 7.5 and 8 for LNA and between 9.2 and 9.4 for Gly‐Leu‐Tyr. One striking feature in the amino‐acid composition of AP I in comparison with the data of leucinaminopeptidase is the larger proportion of hydrophobic amino‐acid residues and of glycine. As regards its specificity, AP I differs from other amino‐peptidases in certain important respects. The activation energy for the hydrolysis of Leu‐Gly was calculated to be 16,300 cal/M‐1. The enzyme remains stable for several hours at 80 C; after 30 min at this temperature the activity increases by about 20 per cent (Vm increases, while Km remains the same). The stability of the enzyme in urea, dodecyl sulphate, and various alcohols was studied. The activity of the enzyme even increases in 10 per cent tertiary butanol, in the same way as after heat treatment (Vm increases, while Km remains the same). The kinetics of the increase in activity following heat treatment or in 10 per cent tertiary butanol are discussed. At 20°C, AP I exhibits a sigmoidal dependence of reaction velocity on the concentration of LNA whereas at 40°C or 80°C the curves show a hyperbolic behaviour. In the metal‐enzyme complex of AP I the Co2+ ions are strongly bound at pH 8 (up to 10‐2MEDTA). At a pH lower than 6 the stable apo‐enzyme is formed in 10‐2M EDTA. The apo‐enzyme can be reactivated to the holo‐enzyme by adding Co‐2. The metal‐enzyme complexes of various metals show different substrate specificities.
STUDIES ON HUMAN SOMATOTROPIN. PREPARATION AND SOME PHYSICO‐CHEMICAL PROPERTIES
Authors: Fønss‐Bech P. , Schmidt Knud D.
Published: August 2010

A method for the preparation of human STH* was developed on the basis of Wilhelm's technique from 1961 which was simplified, by for example, introducing gel filtration. The purity of the preparation was established by a large number of purity criteria: zone electrophoresis on starch, zone electrophoresis in a density gradient, determination of N‐ and C‐terminal end groups, determination of the N‐terminal amino acid sequence, quantitative amino‐acid analysis, determination of molecular weight by gel filtration (mol. wt.: 2.2×104), etc. Oxidation of human STH causes polymerization. The alteration of the degree of polymerization of the oxidized product was studied at varying pH levels. The molecular weight of the preparation at the highest degree of polymerization was found to be 45×104.
THE REDUCTION OF PROTEIN DISULFIDE BONDS IN THE ABSENCE OF DENATURANTS *
Authors: Bewley Thomas A. , Li Choh Hao
Published: August 2010

The ability of dithiothreitol to effect the reduction of the disulfide bonds in five proteins (lysozyme, ribonuclease, bovine serum albumin, insulin, and ovine prolactin) under mild conditions and in the absence of denaturant has been examined. In general, reduction was carried out for one hour at room temperature in 0.1 M KCl, pH 8.1, using dithiothreitol in a twenty molar excess over protein disulfide content. The extent of reduction was evaluated both by alkylation of the reduced protein with iodoacetamide followed by amino‐acid analysis and by direct assay of the sulfhydryl content of the reduced protein using 5,5′‐dithiobis‐(2‐nitrobenzoic acid). Lysozyme, prolactin, and insulin appeared to be quantitatively reduced. Fourteen of the eighteen disulfide bonds in bovine serum albumin were cleaved, whereas ribonuclease was not reduced to any significant extent under these conditions.
ISOLATION OF A SINGLE COMPONENT OF FISH INSULIN FROM A BONITO‐TUNA‐SWORDFISH INSULIN MIXTURE AND ITS COMPLETE AMINO‐ACID SEQUENCE
Authors: Neumann P. , Humbel R. E.
Published: August 2010

A single insulin component has been isolated by ion‐exchange chromatography on CM‐cellulose from a commercially available mixture of tuna, bonito, and swordfish insulin. The biological activity of this component is in the range of 17 i.u./mg as determined with the rat adipose tissue assay.

This fish insulin ha s been reduced and aminoethylated. The two chain derivatives were separated by column chromatography on IRC‐50.

The A and B chain derivatives contain 21 and 30 amino acids, respectively. The two chain derivatives were digested with trypsin and the resulting peptides separated by high voltage paper electrophoresis, paper chromatography, and, in some cases, by ion‐exchange chromatography and gel filtration. Certain tryptic peptides were further digested with chymotrypsin.

The amino‐acid sequences of the resulting peptides were determined by a modified “dansyl”‐Edman technique and by the use of aminopeptidase M, carboxypeptidase A and B, and citrus carboxypeptidase.

The complete amino‐acid sequence of chains A and B is given.
THE EXTRACTION AND SOME PROPERTIES OF MEMBRANE‐BOUND PROTEINS FROM OX CEREBRAL CORTEX MICROSOMES
Authors: Brackenridge C. J. , Bachelard H. S.
Published: August 2010

1. The effects of various treatments on the extraction of acidic proteins and on enzymic activities in microsomal preparations of bovine cerebral cortex have been examined. After ultrasonic irradiation, density‐gradient centrifugation demonstrated the association of proteins and the enzymes (Na+, K+)‐ATPase and K+ ‐NPPase with particles of lower density than in the original membrane fraction. However, experiments involving ammonium sulphate precipitation, exclusion chromatography, and acrylamide‐gel electrophoresis suggested that the material was still particulate. 2. Non‐ionic detergents comprising homologous polyoxyethylene ethers (Lubrols) and Triton X‐100, a cholate‐deoxycho‐late‐dodecylsulphate mixture, and cetyltrimethylammonium bromide were selected for studies of surface‐active agents. The anionic system released the most protein and K+ ‐NPPase activity after dialysis. 3. Despite the low recovery of enzymic activity, pentanol was found to release more acidic proteins than treatment with butanol, sodium iodide, or detergents. 4. Regardless of the method of preparation, extracted proteins had only a limited solubility at I – 0.1 below pH 5.5. Electrophoresis demonstrated the predominance of negatively‐charged proteins in unprecipitated material after lowering the pH. 5. To elucidate the best conditions for the extraction with pentanol, the effects of the following variables were examined: pentanol concentration, pH and ionic strength of the medium, microsomal protein content, and time and type of mixing.
THE CONFORMATION OF THE HIGH‐SULPHUR PROTEINS OF WOOL. II. DIFFERENCE SPECTRA OF KERATEINE‐B
Authors: Bhatnagar G. M. , Crewther W. G.
Published: August 2010

A high‐sulphur metakeratin fraction obtained from wool was reduced electrolytically to the thiol form in the presence of minimal amounts of 2‐mercaptoethanol.

Incorporation of urea in solutions at pH 9.2 of the kerateine obtained in this manner gave rise to a large negative difference spectrum at a wavelength of about 240 nm with two small negative spectral peaks at wavelengths near 280 nm.

Studies on model compounds showed that the major peak at 240 nm was due largely to an increase in the pKa; values of thiol groups in the protein. The peaks near 280 nm cannot be accounted for on a similar basis and indicate that the kerateine assumes an ordered state which is disordered on the addition of urea.
X‐RAY STUDIES ON CYTOCHROME C PEROXIDASE
Authors: Hagman Lars‐Ove , Larsson Lars Olof , Kierkegaard Peder
Published: August 2010

An X‐ray crystallographic investigation of the enzyme cytochromecperoxidase is in progress. This report describes experimental methods for the X‐ray diffraction work. The crystals of the enzyme are orthorhombic with cell dimensionsa ‐108.0 Å, b –77.8 Å, and c =51.4 Å. The space group is P212121. Projection data of the native enzyme have been recorded using Ni‐filtered and graphite‐monochromatized Cu K radiation. The ratioI graphite/Iniof about 0.8 was obtained for the diffracted beams. With graphite monochromatized radiation the disintegration of the crystals decreased and the accuracy of the intensity measurements increased due to the improved peak‐to‐background ratios.
STUDIES ON THE CONFORMATION OF AMINO ACIDS
Authors: Ponnuswamy P. K. , Sasisekharan V.
Published: August 2010

Potential energy calculations were carried out to determine the possible conformations of N‐ and C‐terminal glycyl and alanyl residues. Non‐bonded and electrostatic contributions to the conformational energies were obtained and their role in predicting the favourable conformations has been assessed. It is shown that in the case of glycyl and alanyl N‐terminal residues, a conformation in which the plane of the amide group is nearly coplanar with the plane through the backbone atoms N, C, and C is the most favourable one and this conformation is mainly stabilized by the electrostatic interactions. The results also indicate that the backbone conformation of all the N‐terminal residues with various side chains are nearly the same and could be shown to be that of glycyl and alanyl N‐terminal residues. The importance of the coplanarity of the amide and the carboxyl groups and so also their perpendicular orientation in the C‐terminal residues is stressed.
SYNTHESIS and PROPERTIES OF ARGININE OLIGOPEPTIDES
Authors: Ito Hisashi , Ichikizaki Iwao , Ando Toshio
Published: August 2010

Di‐, tri‐, and tetra‐arginine were prepared from carbobenzoxy‐nitro‐L‐arginine via carbobenzoxy‐nitro‐L‐arginyl‐nitro‐L‐arginine methyl ester, carbobenzoxy‐nitro‐L‐arginyl‐nitro‐L‐arginyl‐nitro‐L‐arginine methyl ester, and carbobenzoxy‐nitro‐L‐argi‐nyl‐nitro‐L‐arginyl‐nitro‐L‐arginyl‐nitro‐L‐arginine methyl ester, respectively, by mixed anhydride and dicyclohexyl‐carbodiimide (DCC) methods. Measurement of the optical rotation of the peptide hydrolysates at 224 mμ showed that no racemization has occurred during the syntheses. Mean residue rotations at 224 mμ of these peptides have some relationship with the chain length. Color values of the Sakaguchi reaction per residue of these peptides decreased as the peptide chain became longer.
HEMOGLOBIN NAGASAKI (αA/2 β17/2Glu) A NEW ABNORMAL HUMAN HEMOGLOBIN FOUND IN ONE FAMILY IN NAGASAKI
Authors: Maekawa Masayuki , Maekawa Tomoyuki , Fujiwara Naoko , Tabara Kunio , Matsuda Genji
Published: August 2010

An abnormal human hemoglobin was found in one family living in Nagasaki and was designated Hb‐Nagasaki. It migrated faster than the normal human hemoglobin towards the anode in thin‐layer starch gel electrophoresis with tris‐EDTA‐borate buffer, pH 8.6. The observation suggested that the abnormality occurred in the (S chain. This abnormal ft chain was isolated and digested with trypsin and pepsin, respectively. The abnormal tryptic peptide and the abnormal peptic peptide thus obtained were isolated and purified by high voltage paper electrophoresis and paper chromatography, and the amino acid compositions of these peptides were determined. As a result, it was found that in Hb‐Nagasaki, a glutamic acid was substituted for the lysine residue at β 17 in the normal hemoglobin.
CYSTINE IN SILK FIBROIN, BOMBYX MORI
Authors: Robson A. , Woodhouse J. M. , Zaidi Z. H.
Published: August 2010

Silkworms of Bombyx mori in their fifth instar were fed mulberry leaves coated with 35S cysteine and the fibroin extracted from their glands. The 35S fibroin was oxidized and a sample, analysed, when the 35S was found exclusively in 35S cysteic acid. The oxidized 35S fibroin yielded a soluble fraction on digestion with trypsin: that which remained insoluble was then treated with chymotrypsin which solubilized part of it. Peptides containing 35S cysteic acid were separated from these two soluble fractions by a combination of the techniques of resin chromatography, Sephadex chromatography, and paper electrophoresis. The sequences of four peptides were examined and were shown to form part of a ‘parent sequence’, Gly‐Ala‐Gly‐Ala‐Gly‐Cya‐Asx‐Ser‐Ala‐Val‐Cya(Pro, Leu), which accounted for approximately three‐quarters of the cysteic acid in silk fibroin. It is suggested that the fibroin molecule is a single chain of molecular weight 103,000 with an intrachain disulphide bond between the two half‐cystine residues indicated in the above sequence.
CHARACTERIZATION OF A HUMAN PATHOLOGICAL IMMUNOGLOBULIN FRAGMENTING DURING PURIFICATION
Authors: Brackenridge C. J.
Published: August 2010

A pathological immunoglobulin GI (Po), briefly characterized in plasma before purification, was found to fragment during salt precipitation to material resembling the Fab and Fc components of papain proteolysis. Termed (Fab)s and (Fc)s fragments, they were studied by a variety of physicochemical and immunological procedures as a pseudoglobulin mixture and after isolation by ion‐exchange chromatography.

The (Fab)s fragment was almost identical in composition to the analogous IgC products arising from papain, plasmin, and trypsin attack. Except for a low half‐eystine content, comparative amino acid analyses and tryptic peptide mapping indicated that the (Fc)s fragment was closely related to the proteins elaborated in heavy chain disease. Experiments with papain digests showed that the Fab fragment possessed more antigenic determinants than (Fab)s whereas the Fc and (Fc)s fragments were immunologically indistinguishable.

Quantitative end‐group determinations revealed that each Po fragment contained a single free N‐terminal residue. A tridecapeptide sequence was established for the (Fab)s fragment and a hexapeptide sequence for (Fc)s at their N‐termini. Comparisons with known structural data suggested that the (Fab)s sequence was due to I chains. The location of the hexapeptide was tentatively assigned to the N‐terminal section of the Fc component of tryptic proteolysis.
STUDIES ON THE CONFORMATION OF AMINO ACIDS
Authors: Ponnuswamy P. K. , Sasisekharan V.
Published: August 2010

Preferred conformations of the backbone and side‐chain of the amino acids, norvaline, leucine, phenylalanine, tyrosine, tryptophan, and histidine obtained by calculating the energies of conformations are reported. The conformations of non‐aromatic side groups are restricted to only certain values of χ1 and χ2, and the backbone conformation is the same as shown for aminobutyric acid having a single γ ‐methyl group. The aromatic side groups prefer a perpendicular orientation about the bond Cβ‐Cγ and deviations from this orientation are characteristic of the position of the γ ‐atom. The experimentally observed conformations of amino acids with S‐atoms and aromatic groups in the side‐chain are compared with the theoretical predictions and the agreement is found to be excellent.
EVIDENCE ON ERYTHROCYTE AMINOPEPTIDASE B
Authors: Mäkinen Kauko K. , Mäkinen Pirkko‐Liisa
Published: August 2010

Purified rat liver aminopeptidase B preparations were found to contain two molecular forms of the enzyme which can be separated by preparative electrophoresis on poly‐acrylamide columns. The one with higher electrophoretic mobility represents the actual liver enzyme and the one with lower electrophoretic mobility was seen to be derived most likely from hemolyzed red blood cells constantly present in liver homo‐genates. This was proved by purifying aminopeptidase B directly from isolated rat erythrocytes with the same procedure earlier used for the liver enzyme. The enzymic properties of the three enzymes (two derived from livers and one derived from erythrocytes) were seen to be largely the same. The similarity was especially considerable in the kinetics of the enzyme‐catalyzed reactions, where substrate inhibition was seen to be the most characteristic feature.
DISSOCIATION CONSTANTS OF LANTHIONINE AND ITS STRUCTURE IN AQUEOUS SOLUTION
Authors: Stapleton I. W. , Weber O. A.
Published: August 2010

L‐ and meso‐isomers of lanthionine (3,3’‐thiodialanine) have been studied by poten‐tiometric, IR, NMR, and ORD techniques. Proton dissociation constants and thermodynamic values valid at 20° andμ‐0.37 (NaN03) are given. Unusually low values for all dissociation constants as well as the significant difference between the corresponding pK, and pKt values of both isomers have been recorded and attributed to the presence of two asymmetric centres in the molecule and to the bridging sulphur. atom. Marked differences between the L‐ and me so‐crystal structures have also been revealed, whereas no difference has been observed by NMR in acid solution. From temperature variation studies in acid, basic, and neutral aqueous solutions, the thioether group has been found to behave as a dissymmetric chromophore with a marked Kauzman‐Eyring effect. A cyclic structure stabilized by endo‐cyclic ionic or carboxylic interactions has been proposed as a possible model which would allow for rotational isomerism around the sulphur atom.
Fibromyalgia and bipolar disorder: a potential problem?
Authors: Wilke William S , Gota Carmen E , Muzina David J
Published: August 2010

Wilke WS, Gota CE, Muzina DJ. Fibromyalgia and bipolar disorder: a potential problem? Bipolar Disord 2010: 12: 514–520. © 2010 The Authors. Journal compilation © 2010 John Wiley & Sons A/S.

Objective:  To screen patients with fibromyalgia for bipolar disorder and to determine if there were any clinical clues, other than the Mood Disorders Questionnaire (MDQ), which might suggest a diagnosis of comorbid bipolar disorder.

Methods:  A total of 128 consecutive new fibromyalgia patients referred to a tertiary care center rheumatology practice were enrolled and assessed using a standard clinical protocol that included the completion of four screening questionnaires: (i) MDQ for bipolar disorder, (ii) Beck Depression Inventory (BDI) for depression, (iii) Epworth Sleepiness Scale (ESS) for daytime sleepiness, and (iv) Fibromyalgia Impact Questionnaire Disability Index (FIQ‐DI) to assess for functional capacity.

Results:  A quarter of the fibromyalgia subjects, 25.19%, had a positive screen for bipolar disorder (MDQ ≥ 7); 78.12% were clinically depressed (BDI ≥ 10); and 52.13% reported daytime sleepiness (ESS ≥ 10). Fibromyalgia subjects who screened positive for bipolar disorder had more severe depression than those with a negative screen [median BDI: 26.0 (19.0, 32.0) versus 15.0 (9.0, 24.0), p < 0.001].

Conclusions:  We report a high prevalence of positive testing for bipolar disorder in this fibromyalgia cohort. Clinical data and questionnaire instruments other than nonspecific high depression severity failed to identify these patients. Since the norepinephrine serotonin reuptake inhibitors duloxetine and milnacipran have been recently approved by the U.S. Food and Drug Administration for the treatment of fibromyalgia, and because patients with bipolar disorder may experience destabilization of mood when treated with such agents, patients with fibromyalgia should be systematically screened for bipolar disorder prior to treatment.
An update on the ABCC transporter family in plants: many genes, many proteins, but how many functions?
Authors: Wanke D. , Üner Kolukisaoglu H.
Published: August 2010

The ABCC subfamily of the ATP binding cassette (ABC) transporters, which were formerly known as multidrug resistance‐related proteins (MRPs), consists of closely related members found in all eukaryotic organisms. Although more than a decade of intensive research has elapsed since the first MRP protein was functionally characterised in Arabidopsis thaliana, knowledge of this particular transporter family is still limited in plants. Although ABCC proteins were originally defined as vacuolar pumps of glutathione‐S (GS) conjugates, evidence, as well as speculation, on their endogenous functions inside the cell ranges from detoxification and heavy metal sequestration, to chlorophyll catabolite transport and ion channel regulation. The characterisation of knockout mutants in Arabidopsis has been pivotal for elucidation of different roles of ABCC transporters. However, a functional annotation for the majority of these transport proteins is still lacking, even in this model plant. On the one hand, this problem seems to be caused by functional redundancy between family members, which might lead to physiological complementation by a highly homologous gene in the mutant lines. On the other hand, there is growing evidence that the functional diversity of ABCC genes in Arabidopsis and other plants is far greater than previously assumed. For example, analysis of microarray expression data supports involvement of ABCC transporters in the response to biotic stress: particular changes in ABCC transcript levels are found, which are pathogen‐specific and evoke distinct signalling cascades. Current knowledge about plant ABCC transporters indicates that novel and unexpected functions and substrates of these proteins are still waiting to be elucidated.
Expression, localisation and phylogeny of a novel family of plant‐specific membrane proteins
Authors: Kasaras A. , Kunze R.
Published: August 2010

In a screen for senescence‐associated genes in Arabidopsis thaliana, a novel, highly up‐regulated membrane protein was identified. It is a member of an uncharacterised, strictly plant‐specific gene family and was named AtDMP1 (Arabidopsis thaliana DUF679 domain membrane protein 1). The AtDMP proteins are predicted to have four transmembrane spans, with cytosolic amino‐ and carboxy‐termini. In this study, we investigated the phylogenetic distribution of DMP proteins, their tissue‐specific expression and subcellular localisation in A. thaliana. The Chlamydomonas reinhardtii and Physcomitrella patens genomes in dicots contain only a single DMP gene copy, whereas there are five to 13 DMP genes and 11–16 in monocots, many of which supposedly result from recent gene duplications. The ubiquitous occurrence of DMP proteins in green plants and their absence from other kingdoms suggest a role in plant‐specific processes. In A. thaliana, expression of nine out of ten DMP genes was detected. The expression patterns were found to be markedly tissue‐ and development‐specific; thus, functional redundancy of most proteins is unlikely. The occurrence of several AtDMPs in tissues undergoing senescence (AtDMP1, ‐3, ‐4), dehiscence (AtDMP7) or abscission (AtDMP2, ‐4, ‐7) suggests involvement of DMPs in different types of programmed cell death. AtDMP‐eGFP fusion proteins were found to localise either to the endoplasmic reticulum, the tonoplast or, under certain conditions, to both membrane systems. Further investigations are in progress to elucidate functions of the AtDMP proteins.
The Arabidopsis sugar transporter (AtSTP) family: an update
Authors: Büttner M.
Published: August 2010

The Arabidopsis sugar transporter (AtSTP) family is one of the best characterised families within the monosaccharide transporter (MST)‐like genes. However, several aspects are still poorly investigated or not yet addressed experimentally, such as post‐translational modifications and other factors affecting transport activity. This mini‐review summarises recent advances in the AtSTP family as well as objectives for future studies.
High‐Speed Video Analysis Reveals Individual Variability in the Courtship Displays of Male Golden‐Collared Manakins
Authors: Fusani Leonida , Giordano Marta , Day Lainy B. , Schlinger Barney A.
Published: August 2010

The males of the Golden‐collared manakin (Manacus vitellinus), a passerine bird of the Neotropical region, perform elaborate courtship displays that are among the most spectacular in the animal kingdom. During a 7‐mo long breeding season, male manakins aggregate in leks of up to 12 individuals, and each male clears a small ‘court’ on the forest floor where he spends several hours per day performing his displays either with or without the presence of a female. Like males of other manakin species, males of M. vitellinus produce loud mechanical sounds with their wings during the displays. The elaborate displays of the manakins are thought to be the result of sexual selection, which is particularly intense in lekking species in which females choose their mate mainly on the basis of behavioural and morphological features. However, we know little about differences in display between male manakins which may be related to individual differences in reproductive success. A quantitative, detailed analysis of the courtship displays has been difficult because the birds’ movements are too fast to be studied with standard video recording techniques. For the first time, we recorded the displays of male Golden‐collared manakins in the forest of Panama with a high‐speed camera that allows a time resolution 5–40 times higher than that of a standard video camera. We found that several elements of the displays differed significantly between individuals. In addition, the slow‐motion analysis revealed the features of the displays that had not been described in previous studies. Individually different features of the displays may form the basis for female choice and will allow testing hypotheses about the evolution of the manakin displays by sexual selection and their importance for speciation mechanisms in the genus Manacus.
Thermal Behaviour of Honeybees During Aggressive Interactions
Authors: Stabentheiner Anton , Kovac Helmut , Schmaranzer Sigurd
Published: August 2010

We report here on the interrelationship of aggressive behaviour and thermoregulation in honeybees. Body temperature measurements were carried out without behavioural disturbance by infrared thermography. Guard bees, foragers, drones, and queens involved in aggressive interactions were always endothermic, i.e. had their flight muscles activated. Guards made differential use of their endothermic capacity. Mean thorax temperature was 34.2–35.1°C during examination of bees but higher during fights with wasps (37°C) or attack of humans (38.6°C). They usually cooled down when examining bees whereas examinees often heated up during prolonged interceptions (maximum >47°C). Guards neither adjusted their thorax temperature (and thus flight muscle function and agility) to that of examined workers, nor to that of drones, which were 2–7°C warmer. Guards examined cool bees (<33°C) longer than warmer ones, supporting the hypothesis that heating of examinees facilitates odour identification by guards, probably because of vapour pressure increase of semiochemicals with temperature. Guards in the core of aggressive balls clinged to the attacked insects to fix them and kill them by heat (maximum 46.5°C). Bees in the outer cluster layers resembled normal guards behaviourally and thermally. They served as active core insulators by heating up to 43.9°C. While balled wasps were cooler (maximum 42.5°C) than clinging guards balled bees behaved like examinees with maximum temperatures of 46.6°C, which further supports the hypothesis that the examinees heat up to facilitate odour identification.
Repeatability of Male Mate Choice in the Mosquitofish, Gambusia holbrooki
Authors: Hoysak Drew J. , Godin Jean‐Guy J.
Published: August 2010

Male mate choice has evolved in many species in which female fecundity increases with body size. In these species, males are thought to have been selected to favour mating with large females over smaller ones, thereby potentially increasing their reproductive success. While male mate choice is known to occur, it is less well studied than female mate choice and little is known about variation in mating preference among individual males. Here, we presented individual male eastern mosquitofish (Gambusia holbrooki) with paired females that differed in body size, and we quantified their mate preference on two consecutive days, allowing us to assess repeatability of preferences expressed. When males were allowed to view paired stimulus females, but not to acquire chemical or tactile cues from them, they exhibited a strong preference for large females over smaller ones. However, individual males were not consistent in the strength of their preference and repeatability was not significant. When individual males were allowed to fully interact with pairs of females, the males again exhibited a preference for large females over smaller ones, as revealed by a greater number of attempted copulations with large females than with smaller ones. In the latter social context, individual male preference was significantly repeatable. These results indicate that male eastern mosquitofish from our Florida study population possess, on average, a mating preference for larger females and that this preference is repeatable when males socially interact freely with females. The significant repeatability for mating preference, based on female body size, obtained for male mosquitofish in the current study is consistent with the presence of additive genetic variation for such preferences in our study population and thus with the opportunity for the further evolution of large body size in female mosquitofish through male mate choice.
Factors Affecting Mating Tactics in the Fiddler Crab, Uca vocans hesperiae
Authors: Dyson Miranda L.
Published: August 2010

The mating strategies of male fiddler crabs are variable and highly flexible within species. In this study I examine three types of mating strategy used by individual male Uca vocans hesperaie. The most common strategy, termed a ‘standard gambit’, where males approached females at their burrow entrance and initiated courtship, accounted for 63% of mating attempts and 75% of successful matings. The rarest strategy (4% of mating attempts) was the ‘dig out’, where males attempted to mate with females whose burrows they had excavated. This strategy accounted for 19% of successful matings. ‘Herding’ behaviour which involved a male attempting to herd a female into a burrow and mate, contributed 33% of mating attempts but were generally unsuccessful, accounting for only 2.6% of successful matings. Males used more than one strategy during the study period. Smaller males used the standard gambit strategy more often than herding or dig outs while larger males used the herding strategy more often. There was no relationship between male size and mating success and males did not preferentially mate with females of a certain size. The predominant strategy adopted by males over the lunar cycle depended on female behaviour. Herding behaviour was induced by female wandering which escalated at full moon. Standard gambits were the commonest strategy adopted at and around new moon. The low success rate of male mating attempts (16%) indicates a reluctance by females to mate multiply. This may lead to conflict between the sexes because in fiddler crabs there is last male sperm precedence.
Mating Behaviour of the Sperm Trading Sea Slug Chelidonura hirundinina: Repeated Sex Role Alternation Balances Reciprocity
Authors: Putz Annika , Michiels Nico K. , Anthes Nils
Published: August 2010

In animals with separate sexes, male fitness usually increases with the number of matings, whereas female fitness more directly depends on the amount of accessible reproductive resources. In simultaneous hermaphrodites, such differences in fitness pay‐offs between male and female sexual function can result in a preference to copulate in one particular sex role, generating conflicts over mating roles if mates share the same preference. Sperm trading, i.e. the conditional exchange of sperm between mates as found in some hermaphrodites, is often considered a possible solution for the conflict over mating roles. Conditional sperm exchange has recently been demonstrated in Chelidonura hirundinina (Opisthobranchia, Aglajidae), but its functional causes remain obscure. Based on a detailed characterization of mating in this species, we here assess two potential benefits of sperm trading, the balancing of sperm exchange between partners, and the acquisition of information about the partner’s fecundity. We found that the number of sperm droplets exchanged between partners varied more between than within pairs, supporting the first hypothesis. Moreover, larger individuals donated more sperm droplets and are known to produce more eggs. As body size is tightly linked to fecundity, a sperm recipient may use the number of received sperm droplets as an honest signal of the female quality of the sperm donor. Our findings thus help to elucidate how sperm trading may contribute to optimizing the investment of costly sperm in response to partner quality.
Interspecific Differences in Responses to Predation Risk May Confer Competitive Advantages to Invasive Freshwater Turtle Species
Authors: Polo‐Cavia Nuria , López Pilar , Martín José
Published: August 2010

The nature of competitive interactions between native and introduced invasive species is unclear. In the Iberian Peninsula, the introduced red‐eared slider (Trachemys scripta elegans) is an invasive species that is competing and displacing the endangered native Spanish terrapin (Mauremys leprosa). We hypothesized that interspecific differences in antipredatory behavior might confer competitive advantages to introduced T. scripta. We examined whether interspecific differences in responses to predation risk affect the time that turtles remained hidden in the shell before using an active escape to water. Both turtle species adjusted hiding times by balancing predation threat, microhabitat conditions and the costs of remaining hidden. However, introduced T. scripta showed longer hiding times before escaping than native M. Leprosa, which, in contrast, switched from waiting hidden in the shell to escape to deep water as soon as possible. These interspecific differences might result from the risk of facing different types of predators in different microhabitats (land vs. water) in their original habitats. However, in anthropogenically altered habitats where predators have been greatly reduced, T. scripta may avoid potential costs of unnecessary repeated escape responses to water (e.g. interruption of basking). These behavioral asymmetries could contribute to the greater competitive ability of introduced T. scripta within anthropogenically disturbed environments.
Canine Reconciliation and Third‐Party‐Initiated Postconflict Affiliation: Do Peacemaking Social Mechanisms in Dogs Rival Those of Higher Primates?
Authors: Cools Annemieke K.A. , Van Hout Alain J.‐M. , Nelissen Mark H. J.
Published: August 2010

Conflicts over food, access to mates, or other limited resources can sometimes escalate into aggression. In species that form social groups, these aggressive conflicts can jeopardize the benefits of group living, such as enhanced access to valued resources, necessitating the development of behavioural mechanisms that either mitigate conflicts, prevent aggressive escalation or resolve disputes. Two important mechanisms for managing the effects of disputes involve postconflict (PC) affiliative behaviour, either between the former opponents (called ‘reconciliation’) or between one opponent and a third party. Even though numerous studies have tested reconciliatory and third‐party affiliation tendencies in primates, for non‐primate animals little systematic data are available. We performed behavioural observations on three groups of captive domestic dogs (Canis familiaris) and used a PC/MC method to test the existence of reconciliation and third‐party affiliation in this species. The results of this study clearly indicate that both reconciliation and third‐party PC interactions are present in the domestic dog, and form important social mechanisms of the domestic dog. Furthermore, familiar individuals showed a significantly higher proportion of reconciled conflicts than did unfamiliar individuals, and also displayed fewer conflicts. Finally, we show that most of the third‐party affiliations involve the victim of a conflict and that victim‐directed affiliation outweighs victim‐initiated third‐party affiliation in these PC interactions.
Why Do Male Tree Weta Aggressively Evict Females from Galleries After Mating?
Authors: Kelly Clint D.
Published: August 2010

The sexually dimorphic Wellington tree weta (Hemideina crassidens Blanchard) (Orthoptera: Anostostomatidae) is a harem‐defending polygynous insect in which males use their enormous mandibles to fight conspecifics for access to harems residing in tree cavities (gallery). Tree weta ejaculates (spermatophores) do not include a nuptial meal (spermatophylax) to delay removal by females as in some ensiferan Orthoptera. Consequently, male tree weta are predicted to remain with their mates post‐copula to ensure complete sperm transfer. Contrary to prediction, however, males forcibly eject females from the mating site (gallery) soon after copulation. Results suggest that forcible ejection occurs apparently because females consume the previous spermatophore if either the resident male or a rival initiates a subsequent copulation attempt. Thus, ejection appears to reduce the resident male’s risk that his ejaculate will be eaten and his mate will copulate with another male.
Peroxidase Activity During Susceptible and Resistant Interactions Between Cassava (Manihot esculenta) and Xanthomonas axonopodis pv. manihotis and Xanthomonas cassavae
Authors: Pereira L. F. , Goodwin P. H. , Erickson L.
Published: August 2010

Phenolic compounds have been implicated in the resistance of cassava (Manihot esculenta) to xanthomonads. Cassava cultivars MCOL 22 and CM 523–7 were inoculated with Xanthomonas axonopodis pv. manihotis and Xanthomonas cassavae. CM523–7 was susceptible to both pathogens, whereas MCOL 22 was susceptible to X. a. pv. manihotis and resistant to X. cassavae. In the resistant interaction, no disease symptoms were observed in the leaf, bacterial growth was greatly reduced, and there was a twofold increase in cell wall‐bound peroxidase activity, which may be related to lignin deposition.
Dual Role for Ethylene in Susceptibility of Tomato to Verticillium Wilt
Authors: Robison M. M. , Griffith M. , Pauls K. P. , Glick B. R.
Published: August 2010

Ethylene has been observed to both inhibit and promote the symptoms of Verticillium wilt (caused by Verticillium dahliae) in tomato. To test the hypothesis that ethylene has different effects at different stages in the infection process, ethylene levels were manipulated in V. dahliae‐infected tomato plants by the application of an ethylene synthesis inhibitor aminoethoxyvinylglycine (AVG) and/or ethylene's biosynthetic precursor 1‐aminocyclopropane‐1‐carboxylate (ACC) and the effects on disease severity were examined. Statistically significant reductions in disease severity were consistently obtained for AVG‐treated plants that had ACC added at the time of inoculation. A model is therefore proposed in which post‐infection ethylene enhances Verticillium wilt development in tomato whereas its presence at the time of infection inhibits disease development.
Bean Anthracnose: Inoculation Methods and Influence of Plant Stage on Resistance of Phaseolus vulgaris Cultivars
Authors: Bigirimana J. , Höfte M.
Published: August 2010

Bean anthracnose, caused by Colletotrichum lindemuthianum, severely reduces bean production world‐wide and rapid methods are required to investigate bean‐C. lindemuthianum interactions. In this study, bean cvs Boterkoning, Saxa and Admires were inoculated with C. lindemuthianum race 69 using three different methods: germinated seed inoculation, seedling inoculation and detached leaf inoculation. Although the methods gave similar results, inoculation of detached leaves was the best method. In order to compare the susceptibility of bean at different developmental stages, cvs Prelude, Boterkoning, Saxa and Admires were used. Leaves harvested from 6‐, 8‐, 10‐, 12‐ and 14‐day‐old plants were inoculated with C. lindemuthianum races 9, 69, 385, and 401. Race 9 was virulent to the four bean cultivars at all the tested stages; cvs Admires and Saxa were resistant to races 69, 385 and 401, whereas cv. Boterkoning was susceptible. Plants of cv. Prelude were sensitive at 8 days of age, but resistant when 12 and 14 days old. The present results suggest that the resistance of certain bean cultivars is not equally expressed at all the developmental stages.
Light‐Dependent Accumulation of Tryptamine in the Rice Sekiguchi Lesion Mutant Infected with Magnaporthe grisea
Authors: Arase S. , Ueno M. , Toko M. , Honda Y. , Itoh K. , Ozoe Y.
Published: August 2010

An antifungal compound with an infection‐inhibiting activity was isolated from a rice Sekiguchi lesion (sl) mutant and identified as the indole alkaloid tryptamine. Tryptamine inhibited not only spore germination and appressorium formation of Magnaporthe grisea at high concentrations (> 600 μ g/ml) but also the infection hypha formation in onion cells at low concentrations (150‐300 μ g/ml). Tryptamine is a normal compound of the rice sl‐mutant but accumulates further in rice with a mutant‐type response (Sekiguchi lesion formation) to inoculation with M. grisea spores. A mutant type of response is involved in light‐enhanced resistance. The accumulation of tryptamine was not induced, however, in rice with a wild‐type response (blast lesion formation). This study strongly suggests that tryptamine plays an important role as a possible factor in light‐enhanced resistance in the rice sl‐mutants.
Reservoir and Non‐reservoir Hosts of Bean‐Wilt Pathogen, Fusarium oxysporum f. sp. phaseoli
Authors: Dhingra O. D. , Netto R. A. Coelho
Published: August 2010

The capacity of Fusarium oxysporum f. sp. phaseoli to multiply in the roots of 12 non‐host plant species was determined with the objective of selecting potential candidates for crop rotation and/or green manuring in infested bean fields. The plants were inoculated at the seedling stage by a benomyl‐resistant mutant of the pathogen using the root‐dip technique and transplanted to natural soil. The number of colony forming units/g dry root tissue (CFU/g) was determined at the full bloom stage. Quantitatively, the root colonization differed greatly among the plant species. The roots and lower stem of Dolichos lablab, Phaseolus lunatus, Mucuna aterrima, Canavalia ensiforme and Vigna unguiculata were the most compatible with the pathogen and those of Sorghum bicolor, Crotalaria juncea, Oryza sativa and Zea mays were least compatible. No disease symptoms developed on any plant species. Chlamydospore germination in the rhizosphere also differed significantly among the plant species. There was no correlation between percentage chlamydospore germination in the rhizosphere and extent of root colonization. Most plant species recommended for green manuring in bean fields allowed extensive root and stem colonization by F. o. f. sp. phaseoli and were considered as reservoir hosts. All three of the gramineous species tested and C. juncea were classed as non‐reservoir host, because the pathogen did not colonize the stem and its multiplication in the roots was very low. These plant species appear to be good candidates for long‐term field evaluation to determine their usefulness in an integrated management of Fusarium bean‐wilt.
Root Rot and Wilt of Kangaroo Paw (Anigozanthos manglesii) Caused by Pythium myriotylum (Drechs.) in Israel
Authors: Tsror (Lahkim) L. , Hazanovsky M. , Mordechai‐Lebiush S. , Ben‐David T. , Dori I. , Matan E.
Published: August 2010

A root rot and wilt disease of Anigozanthos manglesii (Kangaroo Paw) grown in greenhouses in Israel, for exporting as cut flowers to Europe, was characterized. Pythium myriotylum (Drechs.) and Rhizoctonia solani (Kühn) were the prevalent pathogens in diseased plants collected from commercial greenhouses. Fusarium oxysporum, Fusarium spp. and Myrothecium sp. were also isolated, but P. myriotylum or R. solani were not detected in samples from symptomless plants in tissue cultures (Australian origin) or plants at different stages in the nursery; non‐pathogenic F. oxysporum and Fusarium spp. were detected in several samples. In pathogenicity tests carried out in pots, plant mortality occurred 7 days after inoculation with P. myriotylum. In a field experiment carried out in methyl bromide‐fumigated soil, the incidence of dead plants following inoculation with P. myriotylum alone was 22% 10 days after inoculation, increasing to 78% after an additional 25 days. The incidence of dead plants following inoculation with R. solani alone was only 5% and in plants inoculated simultaneously with both pathogens, disease incidence was 88% 35 days after inoculation. Mortality reached 90–100% in plants inoculated with P. myriotylum, either singly or combined with R. solani 60 days after inoculation, whereas in plants inoculated with R. solani it was 5%. The maximum mortality in plants inoculated with R. solani was 25%, 76 days after inoculation. These results clearly demonstrate that P. myriotylum was the dominant pathogen in the root rot and wilt of A. manglesii.