High Similarity (high + similarity)

Distribution by Scientific Domains
Distribution within Life Sciences

Selected Abstracts

The mitochondrial genome of the Korean hairstreak, Coreana raphaelis (Lepidoptera: Lycaenidae)

I. Kim
Abstract We determined the complete nucleotide sequences of the mitochondrial genome (mitogenome) of the Korean hairstreak, Coreana raphaelis (Lepidoptera: Lycaenidae). The entire mitochondrial DNA (mtDNA) molecule was 15 314 bp long. The C. raphaelis genes were in the same order and orientation as the completely sequenced mitogenomes of other lepidopteran species, except for the presence of an extra copy of tRNASer(AGN). High similarity in primary sequence and secondary structure between the two tandemly located copies of the tRNASer(AGN) suggest a recent duplication of an original single tRNASer(AGN). The DHU arm of the two copies of tRNASer(AGN) formed a simple loop as seen in many other metazoan mt tRNASer(AGN). The putative initiation codon for the C. raphaelis COI gene appears to be a tetranucleotide, TTAG, found commonly in the sequenced lepidopterans. ATPase8, ATPase6, ND4L and ND6 genes, which are next to another protein-coding gene at their 3, end all had the sequences potential to form a hairpin structure, suggesting the importance of such a structure for precise cleavage of the mature protein-coding genes. [source]

Localization and functional characterization of the human NKCC2 isoforms

I. Carota
Abstract Aim:, Salt reabsorption across the apical membrane of cells in the thick ascending limb (TAL) of Henle is primarily mediated by the bumetanide-sensitive Na+/K+/2Cl, cotransporter NKCC2. Three full-length splice variants of NKCC2 (NKCC2B, NKCC2A and NKCC2F) have been described. The NKCC2 isoforms have specific localizations and transport characteristics, as assessed for rabbit, rat and mouse. In the present study, we aimed to address the localization and transport characteristics of the human NKCC2 isoforms. Methods:, RT-PCR, in situ hybridization and uptake studies in Xenopus oocytes were performed to characterize human NKCC2 isoforms. Results:, All three classical NKCC2 isoforms were detected in the human kidney; in addition, we found splice variants with tandem duplicates of the variable exon 4. Contrary to rodents, in which NKCC2F is the most abundant NKCC2 isoform, NKCC2A was the dominant isoform in humans; similarly, isoform-specific in situ hybridization showed high expression levels of human NKCC2A along the TAL. Compared to NKCC2B and NKCC2F, human NKCC2A had the lowest Cl, affinity as determined by 86Rb+ uptake studies in oocytes. All NKCC2 isoforms were more efficiently inhibited by bumetanide than by furosemide. A sequence analysis of the amino acids encoded by exon 4 variants revealed high similarities between human and rodent NKCC2 isoforms, suggesting that differences in ion transport characteristics between species may be related to sequence variations outside the highly conserved sequence encoded by exon 4. Conclusion:, The human NKCC2 is an example of how differential splicing forms the basis for a diversification of transporter protein function. [source]

Hev b 9, an enolase and a new cross-reactive allergen from Hevea latex and molds

FEBS JOURNAL, Issue 24 2000
Purification, characterization, cloning, expression
Natural rubber latex allergy is an IgE-mediated disease that is caused by proteins that elute from commercial latex products. A complementary DNA (cDNA) coding for Hev b 9, an enolase (2-phospho- d -glycerate hydrolyase) and allergen from latex of the rubber tree Hevea brasiliensis, was amplified by PCR. The PCR primers were designed according to conserved regions of enolases from plants. The obtained cDNA amplification product consisted of 1651 bp and encoded a protein of 445 amino-acid residues with a calculated molecular mass of 47.6 kDa. Sequence comparisons revealed high similarities of the Hevea latex enolase to mold enolases that have been identified as important allergens. In addition, the crucial amino-acid residues that participate in the formation of the catalytic site and the Mg2+ binding site of enolases were also conserved. Hevea latex enolase was produced as a recombinant protein in Escherichia coli with an N-terminal hexahistidyl tag, and purified by affinity chromatography. The yield amounted to 110 mg of purified Hev b 9 per litre of bacterial culture. The recombinant allergen bound IgE from latex, as well as mold-allergic patients, in immunoblot and ELISA experiments. The natural enolase was isolated from Hevea latex by (NH4)2SO4 precipitation and ion exchange chromatography. The natural and the recombinant (r)Hev b 9 showed equivalent enzymatic activity. Patients' IgE-antibodies preincubated with rHev b 9 lost their ability to bind to natural (n) Hev b 9, indicating the identity of the B-cell epitopes on both molecules. Cross-reactivity with two enolases from Cladosporium herbarum and Alternaria alternata was determined by inhibition of IgE-binding to these enolases by rHev b 9. Therefore, enolases may represent another class of highly conserved enzymes with allergenic potentials. [source]

Bacillus subtilis contains a cyclodextrin-binding protein which is part of a putative ABC-transporter

Annette Kamionka
Abstract Bacillus subtilis is able to grow on ,-, ,- and ,-cyclodextrins as a carbon source via a yet unknown metabolizing system. Sequence analysis of the B. subtilis genome reveals that the putative yvfK-yvfO operon seems to be involved in cyclodextrin utilization, containing the open reading frame yvfK, now termed cycB. The amino acid sequence derived from the DNA sequence bears high similarities to solute-binding proteins from B. subtilis, as well as to cymE from Klebsiella oxytoca and malE from Escherichia coli, both encoding solute-binding proteins able to interact with cyclodextrins. A [His]6 -tagged variant of CycB from B. subtilis was constructed, overproduced in E. coli and purified. The modified protein has been used to study its substrate specificity by surface plasmon resonance and fluorescence spectroscopy. From these data, CycB can be classified as a cyclodextrin-binding protein which interacts with all three natural cyclodextrins: ,, , and ,, thereby showing the highest affinity to ,-cyclodextrin. [source]


INSECT SCIENCE, Issue 4 2003
Jiang-hong Li
Abstract A clone inserted with 1 104 bp fragment containing a 765bp Open Reading Frame(ORF), encoding a putative 2,3-bisphosphoglycerate(2,3BPG) dependent Phosphoglycerate mutase(dPGAM) that catalyzes the transfer of a phosphate group from the C3 carbon atom to the C2 carbon atom of phosphoglycerate, was screened by mass sequencing from the cDNA library of the venom glands of Apis cerana. The deduced amino acid sequence shared high similarities (39% - 88%)with the dPGAM of 7 other organisms, but the similarities with the iPGAM of 4 other organisms were low (10% - 12%). Moreover, the alignment of Ac-PGAM with the dPGAMs from 7 other organisms showed that all the active site amino acid residues were conserved. This result shows that Ac-PGAM is a typical dPGAM. Thus, this is the second PGAM gene reported in Insecta. Furthermore, phylogenetic analysis showed that the evolutionary tree of PGAMs reflects the systematic relationship of species. [source]

Expression of morphogenic genes in mature ovarian and testicular tissues: Potential stem-cell niche markers and patterning factors

Kristian R. von Schalburg
Abstract Morphogens are developmental regulators that modulate different tissue patterning, proliferation, differentiation, or remodeling processes in embryonic and adult tissues. Morphogens may also evoke specific regulatory programs in stem cells. Some of the morphogens involved in these processes have been characterized, while others remain unidentified. A microarray containing 3,557 salmonid cDNAs was used to compare the transcriptomes of rainbow trout precocious ovary at three different stages during second year (June, August, and October) with a reference (June normal ovary) transcriptome. During this study, we detected morphogen transcript hybridizations to salmonid elements and the study was enlarged to investigate these activities in various developmental stages of both ovary and testis. Genes from diverse development regulator families such as Anterior gradient-2, BMP, Epimorphin, Flightless, Frizzled, Notch, Tiarin, Twisted gastrulation, and Wnt were demonstrated to be expressed in the adult trout gonads. In mice or rats, expression of mammalian bmp-4, epimorphin, flightless, twisted gastrulation, and GW112 transcripts were localized to cell types isolated from the developed ovary and testis. Comparisons of salmonid and mammalian morphogens at the amino acid residue level show high similarities, suggesting functional conservation. This report provides evidence for local regulation by various morphogens and their potential to control distinct programs of gene expression in the gametes and their accessory cells during gametogenesis. Mol. Reprod. Dev. © 2005 Wiley-Liss, Inc. [source]

Determination of self-incompatible genotypes in sweet cherry (Prunus avium L.) accessions and cultivars of the German Fruit Gene Bank and from private collections

PLANT BREEDING, Issue 5 2007
M. Schuster
Abstract Sweet cherries are self-incompatible because of a gametophytic self-incompatibility system. S alleles in the style and pollen determine the crossing relationships. Knowledge of the S allele constitution of cultivars is very important for cherry growers and breeders, and recently, molecular methods have been developed to distinguish the S alleles in sweet cherries. The S allele genotypes of 149 sweet cherry cultivars and clones, including 126 not previously genotyped, were determined by using PCR analysis. Thirteen different S alleles in 40 combinations were distinguished and nine new incompatibility groups were documented. Two new S alleles were identified in five local sweet cherry processing cultivars from southwestern Germany using the second intron primers. The sequence of these alleles was determined and compared to all known sequences available in the NCBI database. The sequences obtained showed high similarities to the alleles S19 and S22, previously described only in wild cherries, Prunus avium L. [source]

Molecular cloning and sequence analysis of an ascidian egg ,-N-acetylhexosaminidase with a potential role in fertilization

Ryo Koyanagi
,-N-Acetylhexosaminidase, which is found almost ubiquitously in sperm of invertebrates and vertebrates, supposedly mediates a carbohydrate-based transient sperm,egg coat binding. In ascidians and mammals, ,-hexosaminidase released at fertilization from eggs has been proposed to modify sperm receptor glycoproteins of the egg envelope, thus setting up a block to polyspermy. Previously, it was shown that in potential sperm receptor glycoproteins of the ascidian Phallusia mammillata, N-acetylglucosamine is the prevailing glycoside residue and that the egg harbors three active molecular forms of ,-hexosaminidase. In the present study, P. mammillata,-hexosaminidase cDNA was isolated from an ovarian cDNA library and characterized. The deduced amino acid sequence showed a high similarity with other known ,-hexosaminidases; however, P. mammillata,-hexosaminidase had a unique potential N-glycosylation site. A phylogenetic analysis suggested that P. mammillata,-hexosaminidase developed independently after having branched off from the common ancestor gene of the chordate enzyme before two isoforms of the mammalian enzyme appeared. In situ hybridization revealed stage-specific expression of ,-hexosaminidase mRNA during oogenesis in the oocyte and in the accessory test and follicle cells. This suggests that the three egg ,-hexosaminidase forms are specific for the oocyte, test cells and follicle cells. [source]

Relative abundance and diversity of ammonia-oxidizing archaea and bacteria in the San Francisco Bay estuary

Annika C. Mosier
Summary Ammonia oxidation in marine and estuarine sediments plays a pivotal role in the cycling and removal of nitrogen. Recent reports have shown that the newly discovered ammonia-oxidizing archaea can be both abundant and diverse in aquatic and terrestrial ecosystems. In this study, we examined the abundance and diversity of ammonia-oxidizing archaea (AOA) and betaproteobacteria (,-AOB) across physicochemical gradients in San Francisco Bay , the largest estuary on the west coast of the USA. In contrast to reports that AOA are far more abundant than ,-AOB in both terrestrial and marine systems, our quantitative PCR estimates indicated that ,-AOB amoA (encoding ammonia monooxygenase subunit A) copy numbers were greater than AOA amoA in most of the estuary. Ammonia-oxidizing archaea were only more pervasive than ,-AOB in the low-salinity region of the estuary. Both AOA and ,-AOB communities exhibited distinct spatial structure within the estuary. AOA amoA sequences from the north part of the estuary formed a large and distinct low-salinity phylogenetic group. The majority of the ,-AOB sequences were closely related to other marine/estuarine Nitrosomonas -like and Nitrosospira -like sequences. Both ammonia-oxidizer community composition and abundance were strongly correlated with salinity. Ammonia-oxidizing enrichment cultures contained AOA and ,-AOB amoA sequences with high similarity to environmental sequences. Overall, this study significantly enhances our understanding of estuarine ammonia-oxidizing microbial communities and highlights the environmental conditions and niches under which different AOA and ,-AOB phylotypes may thrive. [source]

Cloning, expression and characterization of a gene encoding nitroalkane-oxidizing enzyme from Streptomyces ansochromogenes

FEBS JOURNAL, Issue 24 2002
Jihui Zhang
A nitroalkane-oxidizing enzyme gene (naoA) was cloned from a genomic DNA library of Streptomyces ansochromogenes 7100. The deduced protein (NaoA) of this gene contains 363 amino acids and has high similarity to several nitroalkane-oxidizing enzymes from various micro-organisms. The naoA gene was subcloned into an expression vector pET23b and overexpressed in Escherichia coli BL21(DE3). The protein was then purified, and its characteristics were studied. Experimental results showed that NaoA can convert 1-nitropropane, 2-nitropropane and nitroethane into the corresponding carbonyl compounds. The optimal pH and temperature for NaoA was found to be pH 7,8 and 48,56 °C, respectively. The Km of NaoA for nitroethane is ,,26.8 mm. NADH and nitro blue tetrazolium are strong inhibitors of NaoA, and thiol compounds and superoxide dismutase partially inhibit the enzyme activity. Therefore, superoxide may be an essential intermediate in the oxidation of nitroalkane by NaoA. [source]

Cloning and characterization of novel snake venom proteins that block smooth muscle contraction

FEBS JOURNAL, Issue 11 2002
Yasuo Yamazaki
In this study, we isolated a 25-kDa novel snake venom protein, designated ablomin, from the venom of the Japanese Mamushi snake (Agkistrodon blomhoffi). The amino-acid sequence of this protein was determined by peptide sequencing and cDNA cloning. The deduced sequence showed high similarity to helothermine from the Mexican beaded lizard (Heloderma horridum horridum), which blocks voltage-gated calcium and potassium channels, and ryanodine receptors. Ablomin blocked contraction of rat tail arterial smooth muscle elicited by high K+ -induced depolarization in the 0.1,1 µm range, but did not block caffeine-stimulated contraction. Furthermore, we isolated three other proteins from snake venoms that are homologous to ablomin and cloned the corresponding cDNAs. Two of these homologous proteins, triflin and latisemin, also inhibited high K+ -induced contraction of the artery. These results indicate that several snake venoms contain novel proteins with neurotoxin-like activity. [source]

Baltic Sea cyanobacterial bloom contains denitrification and nitrification genes, but has negligible denitrification activity

Jaana M Tuomainen
Abstract A cyanobacterial bloom in the Gulf of Finland, Baltic Sea, was sampled throughout the development and senescence of aggregates in August 1999. While conditions inside the aggregates were favourable for denitrification (rich in nitrogen and carbon, with anoxic microzones), essentially none was detected by a sensitive isotope pairing method. Polymerase chain reaction-based methods, targeting functional genes encoding the key enzymes of denitrification and nitrification processes (nirS, nirK, amoA), revealed that the non-aggregated filaments harboured amoA gene fragments with high similarity to Nitrosospira amoA sequences, as well as both types of nitrite reductase genes, nirS and nirK. Only the nirS -type nitrite reductase gene and no amoA was detected in aggregated filaments. Thus, despite optimal environmental conditions and genetic potential for denitrification, the blooms of filamentous nitrogen-fixing cyanobacteria must be seen solely as a source, and not as a sink of nitrogen in the Baltic Sea. [source]

Elevated zinc induces siderophore biosynthesis genes and a zntA -like gene in Pseudomonas fluorescens

Silvia Rossbach
Abstract Zinc-regulated genes were analyzed in Pseudomonas fluorescens employing mutagenesis with a reporter gene transposon. Six mutants responded with increased gene expression to elevated concentrations of zinc. Genetic and biochemical analysis revealed that in four of the six mutants the transposon had inserted into genes essential for the biosynthesis of the siderophore pyoverdine. The growth of one of the mutants was severely impaired in the presence of elevated concentrations of cadmium and zinc ions. In this mutant, the transposon had inserted in a gene with high similarity to P-type ATPases involved in zinc and cadmium ion transport. Four mutants reacted with reduced gene expression to elevated concentrations of zinc. One of these mutants was sensitive to zinc, cadmium and copper ions. The genetic region targeted in this mutant did not show similarity to any known gene. [source]

Chemical composition of the essential oils from Eriocephalus africanus L. var. africanus populations growing in Spain

Hugo Merle
Abstract Essential oils from the aerial parts of three Eriocephalus africanus L. var. africanus populations were analysed by means of GC,FID and GC,MS. Sixty-one constituents were identified, representing more than 96% of the total oil composition. Artemisia ketone (56.46,56.58%), intermedeol (9.19,11.63%) and , -eudesmol (4.26,5.64%) were the main compounds. Application of the Pearson correlation coefficient showed high similarity between the nine samples analysed. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Identification and characterization of antimicrobial peptide, defensin, in the taiga tick, Ixodes persulcatus

Y. Saito
Abstract Ixodes persulcatus is the primary vector for human tick-borne diseases in Japan. A cDNA library was constructed from whole body homogenates of fed nymphs of I. persulcatus. From this library, one cDNA encoding defensin-like antimicrobial peptide was identified. The amino-acid sequence showed high similarity to those of the defensins of other ticks and arthropods. I. persulcatus defensin mRNA transcripts were detected at all life cycle stages of fed ticks and found to be predominantly expressed in the midguts of adult female ticks, but not in the salivary glands, a finding corroborated by Western blotting analysis. To investigate the function of I. persulcatus defensin, we examined its antibacterial activity by evaluation of growth of several bacterial strains in the presence of the synthetic peptide. The defensin from I. persulcatus markedly inhibited the growth of Gram-positive bacteria including Staphylococcus aureus, Bacillus subtilis and Corynebacterium renale, but not Gram-negative bacteria except Escherichia coli O157. In conclusion, these results suggest that I. persulcatus defensin may be playing a significant role in the defence against microbes from bloodmeals. [source]

N-terminal tail of a viral histone H4 encoded in Cotesia plutellae bracovirus is essential to suppress gene expression of host histone H4

W. Gad
Abstract An endoparasitoid wasp, Cotesia plutellae, possesses a symbiotic bracovirus (CpBV), which facilitates parasitism of a specific host, such as larvae of the diamondback moth, Plutella xylostella. A viral histone H4 (CpBV-H4) has been found in the CpBV genome and its gene product plays a role in impairing the host insect cellular immune response. Based on its high similarity to histone H4 of P. xylostella apart from its extended N-terminal tail, it has been suspected to alter host gene expression. Histone subunits were purified from parasitized P. xylostella larvae and found to contain both host and viral H4s, confirming a previous report of a possible epigenetic mode of action. Moreover, this study showed that the host H4 levels in the parasitized larvae clearly decreased during the parasitization period, whereas CpBV-H4 levels maintained a significant level without significant changes. To understand the decrease of host H4 levels, transcription levels of host H4 were monitored by quantitative reverse-transcriptase PCR (RT-PCR) and showed a significant decrease in parasitized P. xylostella larvae, whereas no significant change of the mRNA level was detected in nonparasitized larvae. This transcriptional control of host H4 expression was also observed by inducing transient expression of CpBV-H4 in nonparasitized P. xylostella. Moreover, co-injection of CpBV-H4 and its specific double-stranded RNA recovered the host H4 expression level. To identify a functional domain of CpBV-H4 involved in the transcriptional control, the extended N-terminal tail of CpBV-H4 was removed by preparing a truncated viral H4 construct in an expression vector by deleting the N-terminal tail of 38 amino acid residues and inducing its expression in nonparasitized P. xylostella larvae. The truncated CpBV-H4 clearly lost its inhibitory effects on host H4 transcription. Moreover, the presence of CpBV-H4 affects the spreading of host haemocytes by an epigenetic effect, which is at least partly restored in larvae expressing the truncated version of CpBV-H4. This study suggests that the viral H4 encoded in CpBV can alter host gene expression with its extended N-terminal tail. [source]

Rapid and accurate identification of microorganisms contaminating cosmetic products based on DNA sequence homology

Y. Fujita
Synopsis The aim of this study was to develop rapid and accurate procedures to identify microorganisms contaminating cosmetic products, based on the identity of the nucleotide sequences of the internal transcribed spacer (ITS) region of the ribosomal RNA coding DNA (rDNA). Five types of microorganisms were isolated from the inner portion of lotion bottle caps, skin care lotions, and cleansing gels. The rDNA ITS region of microorganisms was amplified through the use of colony-direct PCR or ordinal PCR using DNA extracts as templates. The nucleotide sequences of the amplified DNA were determined and subjected to homology search of a publicly available DNA database. Thereby, we obtained DNA sequences possessing high similarity with the query sequences from the databases of all the five organisms analyzed. The traditional identification procedure requires expert skills, and a time period of approximately 1 month to identify the microorganisms. On the contrary, 3,7 days were sufficient to complete all the procedures employed in the current method, including isolation and cultivation of organisms, DNA sequencing, and the database homology search. Moreover, it was possible to develop the skills necessary to perform the molecular techniques required for the identification procedures within 1 week. Consequently, the current method is useful for rapid and accurate identification of microorganisms, contaminating cosmetics. Résumé Le but de cette étude est de développer une procédure rapide et fiable pour identifier les micro-organismes contaminant les produits cosmétiques. Cette procédure repose sur l'identification des séquences des nucléotides des espaceurs transcrits internes (Internal Transcribed Spacer ou région ITS), de l'ADN codant pour l'ARN ribosomique (rADN). Cinq types de micro-organismes sont isolés sur la partie intérieure des bouchons des flacons de lotions pour le soin de la peau et de gels lavants. Les régions ITS rADN des micro-organismes sont amplifiées grâce à l'utilisation de la méthode ,colony-direct PCR, ou ,ordinal PCR, en utilisant les extraits d'ADN comme matrices. Les séquences de nucléotides de l'ADN amplifiées sont évaluées et soumises à une recherche homologique dans une librairie d'ADN disponible au public. Ainsi, grâce aux bases de données, nous obtenons des séquences d'ADN qui possèdent une similaritéélevée avec les séquences recherchées des cinq organismes analysés. La procédure d'identification classique exige des compétences d'experts et une période d'environ un mois pour identifier les micro-organismes. D'autre part, il faut 3 à 7 jours pour terminer toutes les procédures utilisées dans la méthode ici décrite, y compris l'isolation et la culture des organismes, le séquençage de l'ADN et la recherche dermatologique dans les bases de données. De plus, il est possible en 1 semaine de développer les compétences nécessaires pour mettre en ,uvre les techniques moléculaires requises pour les procédures d'identification. Cette méthode est donc utile pour une identification rapide et fiable des micro-organismes qui contaminent les cosmétiques. [source]

An antifungal compound produced by Bacillus subtilis YM 10,20 inhibits germination of Penicillium roqueforti conidiospores

G.S. Chitarra
Abstract Aims: To identify and characterize an antifungal compound produced by Bacillus subtilis YM 10-20 which prevents spore germination of Penicillium roqueforti. Methods and Results: The antifungal compound was isolated by acid precipitation with HCl. This compound inhibited fungal germination and growth. Identification by HPLC and mass spectrometry analysis showed high similarity to iturin A. Permeabilization and morphological changes in P. roqueforti conidia in the presence of the inhibitor were revealed by fluorescence staining and SEM, respectively. Conclusions: The iturin-like compound produced by B. subtilis YM 10-20 permeabilizes fungal spores and blocks germination. Significance and Impact of the Study: Fluorescence staining in combination with flow cytometry and scanning electron microscopy are efficient tools for assessing the action of antifungal compounds against spores. Iturin-like compounds may permeabilize fungal spores and inhibit their germination. [source]

Novel stem/progenitor cells with neuronal differentiation potential reside in the leptomeningeal niche

Francesco Bifari
Abstract Stem cells capable of generating neural differentiated cells are recognized by the expression of nestin and reside in specific regions of the brain, namely, hippocampus, subventricular zone and olfactory bulb. For other brain structures, such as leptomeninges, which contribute to the correct cortex development and functions, there is no evidence so far that they may contain stem/precursor cells. In this work, we show for the first time that nestin-positive cells are present in rat leptomeninges during development up to adulthood. The newly identified nestin-positive cells can be extracted and expanded in vitro both as neurospheres, displaying high similarity with subventricular zone,derived neural stem cells, and as homogeneous cell population with stem cell features. In vitro expanded stem cell population can differentiate with high efficiency into excitable cells with neuronal phenotype and morphology. Once injected into the adult brain, these cells survive and differentiate into neurons, thus showing that their neuronal differentiation potential is operational also in vivo. In conclusion, our data provide evidence that a specific population of immature cells endowed of neuronal differentiation potential is resident in the leptomeninges throughout the life. As leptomeninges cover the entire central nervous system, these findings could have relevant implications for studies on cortical development and for regenerative medicine applied to neurological disorders. [source]

Molecular and Biochemical Evidence for Phenylpropanoid Synthesis and Presence of Wall-linked Phenolics in Cotton Fibers

Ling Fan
Abstract The mature cotton (Gossypium hirsutum L.) fiber is a single cell with a typically thickened secondary cell wall. The aim of this research was to use molecular, spectroscopic and chemical techniques to investigate the possible occurrence of previously overlooked accumulation of phenolics during secondary cell wall formation in cotton fibers. Relative quantitative reverse transcription-polymerase chain reaction analysis showed that GhCAD6 and GhCAD1 were predominantly expressed among seven gene homologs, only GhCAD6 was up-regulated during secondary wall formation in cotton fibers. Phylogenic analysis revealed that GhCAD6 belonged to Class I and was proposed to have a major role in monolignol biosynthesis, and GhCAD1 belonged to Class III and was proposed to have a compensatory mechanism for monolignol biosynthesis. Amino acid sequence comparison showed that the cofactor binding sites of GhCADs were highly conserved with high similarity and identity to bona fide cinnamyl alcohol dehydrogenases. The substrate binding site of GhCAD1 is different from GhCAD6. This difference was confirmed by the different catalytic activities observed with the enzymes. Cell wall auto-fluorescence, Fourier transform infrared spectroscopy (FTIR), high-performance liquid chromatography (HPLC) and chemical analyses confirmed that phenolic compounds were bound to the cell walls of mature cotton fibers. Our findings may suggest a potential for genetic manipulation of cotton fiber properties, which are of central importance to agricultural, cotton processing and textile industries. [source]

Genetic Diversity: Geographical Distribution and Toxin Profiles of Microcystis Strains (Cyanobacteria) in China

Zhong-Xing Wu
Abstract Twenty strains of Microcystis Kütz were isolated from different freshwater bodies in China to analyze the diversity, geographical distribution and toxin profiles. Based on whole-cell polymerase chain reaction of cpcBA-IGS nucleotide sequence, the derived neighbor-joining (NJ) and maximum parsimony (MP) trees indicate that these strains of Microcystis can be divided into four clusters. The strains from south, middle and north region of China formed distinct lineages, suggesting high diversity and a geographical distribution from south to north locations. Moreover, the results being indicating high variable genotypes of the strains of the Microcystis strains from the same lake show that there is high diversity of Microcystis within a water bloom population. Comparing the results of the present study with those reported for compared with 43 strains of Microcystis from other locations, also reveals Chinese strains have high similarity with those from regions in the North Hemispherical. This suggests that the Microcystis strains in the world might have a geographical distribution. Analysis of 30 strains using the primers MCF/TER and TOX2P/TOX2M showed that there was no correlation between the gene of cpcBA-IGS and the presence of mcy. Toxic strains were founded to be predominant in different water bodies throughout China. [source]

Neudesin, a novel secreted protein with a unique primary structure and neurotrophic activity

Ikuo Kimura
Abstract We identified a novel secreted protein and named it neudesin. Mouse neudesin of 171 amino acids is unique with no primary structural similarity to any known proteins. The neudesin protein produced in cultured cells was secreted efficiently into the culture medium. Mouse neudesin mRNA was expressed abundantly in the developing brain and spinal cord in embryos, but was expressed widely in postnatal tissues including brain, heart, lung, and kidney. Mouse neudesin mRNA was expressed in neurons but not glial cells of the brain. The protein exhibited significant neurotrophic activity in primary cultured mouse neurons but not mitogenic activity in primary cultured mouse astrocytes. Neudesin activated the mitogen-activated protein (MAP) and phosphatidylinositol-3 (PI-3) kinase pathways. The activity of neudesin was inhibited by the inhibitor pertussis toxin for Gi/Go-protein but not by inhibitors for receptor tyrosine kinases. These results indicated that the activity was mediated via the activation of the MAP and PI-3 kinase pathways, potentially by the activation of a Gi/Go-protein-coupled receptor. Human neudesin of 172 amino acids with high similarity (,91% identity) to mouse neudesin was also identified. The human neudesin gene was mapped to chromosome 1p33. The identification of neudesin, a novel secreted protein with a unique primary structure and neurotrophic activity, will provide new insights into the development and maintenance of neurons. © 2004 Wiley-Liss, Inc. [source]

Comparative Sequence Analysis of Coat Protein Gene of Iranian Citrus tristeza virus Isolates

A. Barzegar
Abstract Twenty-two isolates of Citrus tristeza virus (CTV) collected from two different geographical regions of Iran were characterized based on coat protein (CP) gene sequences. Thirteen virus isolates were collected from northern parts of Iran with high distribution of CTV infection and nine isolates were obtained from southern regions where the presence and aphid transmission of CTV was previously reported. All isolates were recovered from field trees showing varied CTV symptoms such as decline in most citrus varieties on sour orange rootstock, inverse pitting on some sour orange rootstocks below bud union, mild-to-moderate stem pitting on the trunk of some sweet orange. Isolates F, G, MB1, MB7, MB2, MB8, MB9, MB11 and MB17 were recovered from healthy looking Miyagawa Satsuma on trifoliate rootstock originally infected with CTV imported from Japan in late-1960s. The presence of virus in citrus samples was confirmed using polyclonal as well as monoclonal antibody. The CTV CP gene of all isolates was amplified by reverse transcriptase polymerase chain reaction (RT,PCR) using CP gene-specific primers yielding 672 bp amplicon. The restriction fragment length polymorphism (RFLP) profile, nucleotide and deduced amino acid sequences were analysed and compared with each other and also with some other exotic CP gene sequences of CTV isolates available in GenBank. Analysis of our data revealed that Iranian isolates have high similarity to California SY568 severe stem pitting and Japanese NUagA seedling yellows strains (up to 97%). The dendrogram generated from the deduced amino acid sequence could separate MB1, MB2, MB8, MB9, MB11 and MB17 isolates from others. However, no major dissociation between the isolates from northern and southern region could be obtained. [source]

Development of a sensitivity-improved immunoassay for the determination of carbaryl in food samples

Tingting Dong
Abstract BACKGROUND: With the aim of developing a highly sensitive immunoassay for carbaryl, a hapten which had high similarity to carbaryl was synthesised using a safer and more practical approach. After it was conjugated to horseradish peroxidase, direct competitive heterologous enzyme-linked immunosorbent assay (CD-ELISA) was optimised and characterised. The assay performance conditions were investigated in details. Enhanced chemiluminescence ELISA (ECL-ELISA) was also used in preliminary studies. RESULTS: The assay obtained an IC50 value (the concentration causing 50% inhibition) of 2 µg kg,1, which was 12-fold more sensitive than previous results of homologous CD-ELISA. In ECL-ELISA, the IC50 was further decreased 10-fold to 0.2 µg kg,1. The CD-ELISA developed was applicable for broad conditions, and could be applied on various food samples with a more convenient pre-treatment. Average recoveries were in a range of 88.3,101.7%. The results correlated well with those obtained using high-performance liquid chromatography (HPLC) analysis (R2 = 0.989). CONCLUSION: The ELISA developed was a great improvement in the determination of carbaryl, showing that the immunoassay developed was a simple, rapid and efficient method that was reliable for the detection of carbaryl and suitable for rapid quantitative or qualitative determination in food samples. Copyright © 2010 Society of Chemical Industry [source]

Propagule banks and regenerative strategies of aquatic plants

Isabelle C.S. Combroux
Lambinon et al. (1992); Wiegleb & Kaplan (1998) for Potamogeton species and Corillon (1975) for Characeae Abstract. The role of the propagule bank in aquatic plant maintenance was studied in two riverine wetlands. Four sites were selected, characterized respectively by flooding, drying up, both disturbances operating, and neither operating. Our hypothesis was that recolonization after drying up would mostly involve seeds and buds from the propagule bank, whereas recolonization after floods would mostly involve rhizomes. Dry sites were characterized by a high density of seeds, and a high similarity between seed species and established vegetation. Unspecialized fragments remaining in wet parts of the sediment probably also contribute to species maintenance. Species maintenance in sites subjected to flooding was highly dependent on deeply anchored rhizomes, as indicated by the strong floristic similarity between species that occur in the established vegetation and rhizomes in the bank. Regeneration of the community after scouring floods also involved seeds, some species being able to flower under water. When scouring flooding and drying up were superimposed, regenerative strategies exhibited in the bank did not simply result from the ,addition' of the two disturbance effects. When the disturbances did not occur too closely together in time, species were able to survive either by: (1) producing many propagules under aquatic conditions or (2) coping with the temporal variability by producing several types of propagules. [source]

Fish assemblages and rapid colonization after enlargement of an artificial reef off the Algarve coast (Southern Portugal)

MARINE ECOLOGY, Issue 4 2008
Francisco Leitão
Abstract Artificial reefs (ARs) have been deployed in Algarve (Southern Portugal) coastal waters to contribute to the sustainability of local nearshore fisheries. Herein, we describe the colonization process of the recently deployed Faro/Ancão AR, and assess the time until the fish assemblage reaches stability and their seasonal patterns. In addition, we compare the results from the present study with those previously reported for an older AR. The fish assemblages were monitored monthly over a 2-year period by means of visual census. A rapid increase in fish colonization occurred within the first 4 months. After this initial period the assemblage structure showed high similarity (> 73%). The high rate of colonization of the AR was related to the maturity already achieved by the nearby 14-year-old AR and to the fish migration from the Ria Formosa lagoon, a nearby nursery habitat. The reef fish assemblage structure showed a seasonal pattern, mainly associated with recruitment episodes of occasional demersal species (Boops boops, Trachurus trachurus and Pagellus spp.) in spring and summer. A total of 66% of the species found in AR are of commercial and recreational importance. The overall mean density and biomass were 2.8 ind·m,3 and 207 g·m,3. The occasional demersal species accounted for 42% of the fish density. The most important species in terms of biomass belong to the Sparidae family along with Dicentrarchus labrax. The fish assemblage of the new ARs showed higher mean number of species, diversity, density and biomass values than those reported for the older AR. This result was associated with enlargement of the AR area and with the fishing exploitation of the isolated, small and patchy old AR. Moreover, the high biomass values recorded in the new ARs were mainly due to the increased density of D. labrax after AR enlargement. The results of the present study are used to define guidelines for suitable management strategies for the AR areas that are exploited by the local commercial and recreational fisheries. [source]

Purification and characterization of natural Bet v 1 from birch pollen and related allergens from carrot and celery

Mirko A. Bollen
Abstract Birch pollen allergy is predominantly caused by the major allergen Bet v 1 and can lead to crossreactions with homologous proteins in food. Two major cross-reactive food allergens are Dau c 1 from carrot and Api g 1 from celery, which have never been purified from their natural source. Here, we describe a non-denaturing purification method for obtaining natural Bet v 1, Dau c 1 and Api g 1, comprising of ammonium sulfate precipitation, hydrophobic interaction chromatography and size exclusion chromatography. This method resulted in 98,99% pure isoform mixtures for each allergen. Characterization of these isoform mixtures with Q-TOF MS/MS clearly showed earlier reported isoforms of Bet v 1, Dau c 1 and Api g 1, but also new isoforms. The presence of secondary structure in the three purified allergens was demonstrated via circular dichroism and showed high similarity. The immune reactivity of the natural allergens was compared with recombinant proteins by Western blot and ELISA and showed similar reactivity. [source]

Characterization of a developmentally regulated amino acid transporter (AAT1p) of the rust fungus Uromyces fabae

Christine Struck
summary In the rust fungus Uromyces fabae, invasion of the host plant and haustorium formation are accompanied by the activation of many genes (PIGs =in planta induced genes). In addition to the previously described AAT2 (PIG2), AAT1 (PIG27) was found to encode a protein with a high similarity to fungal amino acid permeases. AAT1 transcripts are present in germinated hyphae and throughout the mycelium later in the infection process, but occur at the highest levels in haustoria. Expression of AAT1p in a histidine uptake-defective yeast mutant revealed energy-dependent transport of 14C-histidine, with a KM value of 25.8 µm. In addition, complementation analysis revealed AAT1 -dependent transport for lysine. Using Xenopus oocytes as expression system, AAT1p-dependent symport of protons with a broad spectrum of amino acids was observed, with the highest activities obtained with histidine and lysine. These results confirm that in rust fungi, the expression of amino acid transporters is developmentally regulated and occurs preferentially in the parasitic phase of development. [source]

Characterization of an Arabidopsis thaliana Homologue of the Nuclear Export Receptor CAS by its Interaction with Importin,

PLANT BIOLOGY, Issue 4 2002
D. Haasen
Abstract: We have previously described four genes encoding different Importin ,-like proteins from Arabidopsis thaliana. Here we describe the putative nuclear export receptor for Importin ,. Using protein interaction assays in the yeast two-hybrid system, we characterized an Arabidopsis protein showing high similarity to human CAS, the nuclear export receptor for Importin ,. Arabidopsis CAS specifically bound to four different plant Importin , proteins but not to proteins containing leucine-rich nuclear export signals (NESs) that are recognized by Exportin 1 (XPO1/CRM1). Like all members of the Importin , family, Arabidopsis CAS also interacted with the regulatory GTPase Ran. Deletion of 15 amino acid residues from the amino terminus of CAS abolished binding of Importin ,, but did not influence the interaction with the GTPase Ran. We found two regions of Importin ,1 that profoundly influence the binding to CAS: the amino terminal Importin beta-binding (IBB) domain and the carboxy terminus. Whereas the IBB domain did not directly bind to CAS, but might rather affect the interaction through conformational changes within the Importin , protein, the carboxy terminal domain strongly interacted with CAS. [source]

Ser/Thr/Tyr phosphoproteome analysis of pathogenic and non-pathogenic Pseudomonas species

Ayshwarya Ravichandran
Abstract Protein phosphorylation on serine, threonine, and tyrosine is well established as a crucial regulatory posttranslational modification in eukaryotes. With the recent whole-genome sequencing projects reporting the presence of serine/threonine kinases and two-component proteins both in prokaryotes and eukaryotes, the importance of protein phosphorylation in archaea and bacteria is gaining acceptance. While conventional biochemical methods failed to obtain a snapshot of the bacterial phosphoproteomes, advances in MS methods have paved the way for in-depth mapping of phosphorylation sites. Here, we present phosphoproteomes of two ecologically diverse non-enteric Gram-negative bacteria captured by a nanoLC-MS-based approach combined with a novel phosphoenrichment method. While the phosphoproteome data from the two species are not very similar, the results reflect high similarity to the previously published dataset in terms of the pathways the phosphoproteins belong to. This study additionally provides evidence to prior observations that protein phosphorylation is common in bacteria. Notably, phosphoproteins identified in Pseudomonas aeruginosa belong to motility, transport, and pathogenicity pathways that are critical for survival and virulence. We report, for the first time, that motility regulator A, probably acting via the novel secondary messenger cyclic diguanylate monophosphate, significantly affects protein phosphorylation in Pseudomonas putida. [source]