Molecular

Distribution by Scientific Domains
Distribution within Life Sciences

Kinds of Molecular

  • high molecular
  • recent molecular

  • Terms modified by Molecular

  • molecular aberration
  • molecular abnormality
  • molecular action
  • molecular activity
  • molecular adsorbent
  • molecular adsorbent Recirculat system
  • molecular adsorbent recirculating system
  • molecular adsorption
  • molecular aggregate
  • molecular aggregation
  • molecular alteration
  • molecular analysis
  • molecular and cell biology
  • molecular approach
  • molecular architecture
  • molecular arrangement
  • molecular aspect
  • molecular assembly
  • molecular assessment
  • molecular association
  • molecular background
  • molecular base
  • molecular basis
  • molecular basis underlying
  • molecular beam
  • molecular beam epitaxy
  • molecular binding
  • molecular biological
  • molecular biological approach
  • molecular biological methods
  • molecular biological studies
  • molecular biological techniques
  • molecular biologist
  • molecular biology
  • molecular biology approach
  • molecular biology techniques
  • molecular biomarker
  • molecular breeding
  • molecular brush
  • molecular building block
  • molecular calculation
  • molecular capsule
  • molecular cascade
  • molecular cause
  • molecular chain
  • molecular change
  • molecular chaperone
  • molecular character
  • molecular characterisation
  • molecular characteristic
  • molecular characterization
  • molecular chirality
  • molecular classification
  • molecular clock
  • molecular clock analysis
  • molecular clone
  • molecular cloning
  • molecular cloud
  • molecular cluster
  • molecular column
  • molecular complex
  • molecular complexity
  • molecular component
  • molecular composite
  • molecular composition
  • molecular compound
  • molecular configuration
  • molecular conformation
  • molecular connectivity
  • molecular connectivity index
  • molecular consequence
  • molecular constituent
  • molecular control
  • molecular correlate
  • molecular crowding
  • molecular crystal
  • molecular cue
  • molecular cytogenetic analysis
  • molecular cytogenetic techniques
  • molecular cytogenetics
  • molecular data
  • molecular data set
  • molecular data.
  • molecular dating
  • molecular defect
  • molecular descriptor
  • molecular design
  • molecular detail
  • molecular detection
  • molecular determinant
  • molecular device
  • molecular diagnosis
  • molecular diagnostic
  • molecular diagnostic techniques
  • molecular diagnostic tool
  • molecular diagnostics
  • molecular difference
  • molecular differentiation
  • molecular diffusion
  • molecular dimension
  • molecular dipole
  • molecular dipole moment
  • molecular dissection
  • molecular distance
  • molecular distribution
  • molecular divergence
  • molecular diversity
  • molecular docking
  • molecular dynamic simulation
  • molecular dynamics
  • molecular dynamics approach
  • molecular dynamics calculation
  • molecular dynamics computer simulation
  • molecular dynamics method
  • molecular dynamics methods
  • molecular dynamics simulation
  • molecular dynamics simulation study
  • molecular dynamics studies
  • molecular dynamics study
  • molecular dynamics trajectory
  • molecular ecology
  • molecular effects
  • molecular electron density
  • molecular electronics
  • molecular electrostatic potential
  • molecular energy
  • molecular engineering
  • molecular ensembles
  • molecular entity
  • molecular envelope
  • molecular environment
  • molecular epidemiology
  • molecular etiology
  • molecular evaluation
  • molecular event
  • molecular event underlying
  • molecular evidence
  • molecular evolution
  • molecular evolutionary rate
  • molecular examination
  • molecular explanation
  • molecular expression
  • molecular factor
  • molecular feature
  • molecular field
  • molecular field analysis
  • molecular film
  • molecular finding
  • molecular fingerprint
  • molecular fingerprinting
  • molecular flexibility
  • molecular form
  • molecular formula
  • molecular fragment
  • molecular framework
  • molecular function
  • molecular gas
  • molecular genetic
  • molecular genetic analysis
  • molecular genetic approach
  • molecular genetic basis
  • molecular genetic data
  • molecular genetic investigation
  • molecular genetic marker
  • molecular genetic methods
  • molecular genetic studies
  • molecular genetic study
  • molecular genetic techniques
  • molecular genetic testing
  • molecular genetics
  • molecular geometry
  • molecular glasses
  • molecular graphics
  • molecular groups
  • molecular heterogeneity
  • molecular hybridization
  • molecular hydrogen
  • molecular identification
  • molecular identity
  • molecular imaging
  • molecular imaging technology
  • molecular imprinting
  • molecular information
  • molecular inhibition
  • molecular insight
  • molecular integral
  • molecular interaction
  • molecular interaction field
  • molecular investigation
  • molecular iodine
  • molecular ion
  • molecular junction
  • molecular knot
  • molecular ladder
  • molecular layer
  • molecular length
  • molecular level
  • molecular link
  • molecular locus
  • molecular logic gate
  • molecular machine
  • molecular machinery
  • molecular machines
  • molecular mapping
  • molecular marker
  • molecular marker analysis
  • molecular marker data
  • molecular mass
  • molecular mass determination
  • molecular mass distribution
  • molecular mass value
  • molecular material
  • molecular mechanic
  • molecular mechanic calculation
  • molecular mechanical
  • molecular mechanical methods
  • molecular mechanism
  • molecular mechanism leading
  • molecular mechanism underlying
  • molecular mediator
  • molecular medicine
  • molecular method
  • molecular methods
  • molecular microbiology
  • molecular mimicry
  • molecular mobility
  • molecular model
  • molecular modeling
  • molecular modeling approach
  • molecular modeling calculation
  • molecular modeling studies
  • molecular modeling study
  • molecular modeling techniques
  • molecular modelling
  • molecular modelling studies
  • molecular models
  • molecular monitoring
  • molecular motion
  • molecular motor
  • molecular movement
  • molecular nature
  • molecular network
  • molecular nitrogen
  • molecular nutrition
  • molecular orbital
  • molecular orbital calculation
  • molecular orbital energy
  • molecular orbital energy level
  • molecular orbital theory
  • molecular order
  • molecular ordering
  • molecular organization
  • molecular orientation
  • molecular origin
  • molecular oxygen
  • molecular packing
  • molecular packing density
  • molecular parameter
  • molecular partner
  • molecular pathogenesis
  • molecular pathology
  • molecular pathway
  • molecular pattern
  • molecular perspective
  • molecular phenotype
  • molecular phylogenetic
  • molecular phylogenetic analysis
  • molecular phylogenetic studies
  • molecular phylogeny
  • molecular phylogeography
  • molecular physiology
  • molecular planarity
  • molecular plane
  • molecular player
  • molecular polarizability
  • molecular precursor
  • molecular prenatal diagnosis
  • molecular probe
  • molecular process
  • molecular profile
  • molecular profiling
  • molecular property
  • molecular radius
  • molecular ratio
  • molecular rearrangement
  • molecular recognition
  • molecular recognition ability
  • molecular recognition event
  • molecular recognition process
  • molecular recognition property
  • molecular regulation
  • molecular regulator
  • molecular relaxation
  • molecular replacement
  • molecular representation
  • molecular requirement
  • molecular research
  • molecular response
  • molecular result
  • molecular ring
  • molecular scaffold
  • molecular scale
  • molecular screening
  • molecular self-assembly
  • molecular sequence
  • molecular sequence data
  • molecular shape
  • molecular shuttle
  • molecular sieve
  • molecular signal
  • molecular signaling
  • molecular signaling pathway
  • molecular signature
  • molecular similarity
  • molecular simulation
  • molecular size
  • molecular skeleton
  • molecular solvent
  • molecular species
  • molecular spectroscopy
  • molecular stability
  • molecular step
  • molecular strategy
  • molecular structure
  • molecular structure determination
  • molecular studies
  • molecular study
  • molecular subgroup
  • molecular subtype
  • molecular surface
  • molecular surface area
  • molecular surface electrostatic potential
  • molecular survey
  • molecular switch
  • molecular switching
  • molecular symmetry
  • molecular system
  • molecular systematic studies
  • molecular systematics
  • molecular tagging
  • molecular target
  • molecular targeted therapy
  • molecular taxonomy
  • molecular technique
  • molecular techniques
  • molecular technology
  • molecular test
  • molecular testing
  • molecular therapeutics
  • molecular therapy
  • molecular thermodynamic model
  • molecular tool
  • molecular topology
  • molecular transport
  • molecular transporter
  • molecular tweezers
  • molecular type
  • molecular typing methods
  • molecular underpinning
  • molecular understanding
  • molecular unit
  • molecular variability
  • molecular variance
  • molecular variants
  • molecular variation
  • molecular vibration
  • molecular volume
  • molecular water
  • molecular weight
  • molecular weight average
  • molecular weight bands
  • molecular weight complex
  • molecular weight compound
  • molecular weight control
  • molecular weight cut-off
  • molecular weight determination
  • molecular weight development
  • molecular weight distribution
  • molecular weight dna
  • molecular weight fraction
  • molecular weight heparin
  • molecular weight increase
  • molecular weight measurement
  • molecular weight molecular weight
  • molecular weight organic acid
  • molecular weight poly
  • molecular weight polyethylene
  • molecular weight polymer
  • molecular weight protein
  • molecular weight range
  • molecular weight substance
  • molecular wire

  • Selected Abstracts


    DO RECENT FINDINGS IN PLANT MITOCHONDRIAL MOLECULAR AND POPULATION GENETICS HAVE IMPLICATIONS FOR THE STUDY OF GYNODIOECY AND CYTONUCLEAR CONFLICT?

    EVOLUTION, Issue 5 2008
    David E. McCauley
    The coexistence of females and hermaphrodites in plant populations, or gynodioecy, is a puzzle recognized by Darwin. Correns identified cytoplasmic inheritance of one component of sex expression, now known as cytoplasmic male sterility (CMS). Lewis established cytonuclear inheritance of gynodioecy as an example of genetic conflict. Although biologists have since developed an understanding of the mechanisms allowing the joint maintenance of CMS and nuclear male fertility restorer genes, puzzles remain concerning the inheritance of sex expression and mechanisms governing the origination of CMS. Much of the theory of gynodioecy rests on the assumption of maternal inheritance of the mitochondrial genome. Here we review recent studies of the genetics of plant mitochondria, and their implications for the evolution and transmission of CMS. New studies of intragenomic recombination provide a plausible origin for the chimeric ORFs that characterize CMS. Moreover, evidence suggests that nonmaternal inheritance of mitochondria may be more common than once believed. These findings may have consequences for the maintenance of cytonuclear polymorphism, mitochondrial recombination, generation of gynomonoecious phenotypes, and interpretation of experimental crosses. Finally we point out that CMS can alter the nature of the cytonuclear conflict that may have originally selected for uniparental inheritance. [source]


    STATISTICAL METHODS IN (MOLECULAR) EVOLUTION1

    EVOLUTION, Issue 2 2006
    Peter Beerli
    No abstract is available for this article. [source]


    MOLECULAR AND PHYLOGENETIC CHARACTERIZATION OF PHORMIDIUM SPECIES (CYANOPROKARYOTA) USING THE CPCB-IGS-CPCA LOCUS,

    JOURNAL OF PHYCOLOGY, Issue 1 2005
    Ivanka Teneva
    The accurate determination of species of Cyanoprokaryota/Cyanophyceae has many important applications. These include the assessment of risk with regard to blooms in water reservoirs as well as the identification of species capable of producing valuable bioactive compounds. Commonly, Cyanoprokaryota are classified based on their morphology. However, morphological criteria are not always reliable because they may change, for example, due to environmental factors. Thus, genetic and molecular analyses are a promising additional approach, but their application has so far been limited to relatively few genera. In light of this, we present here the first characterization of species and strains of the genus Phormidium Kütz. based on the cpcB-IGS-cpcA locus of the phycocyanin operon. In phylogenetic analyses using deduced amino acid sequences of the cpcB-cpcA regions, Phormidium was found to be polyphyletic. This analysis appeared to be dominated by the cpcB region, which is characterized by a relatively high percentage of informative substitutions. The percentage of variable positions within the cpcB-IGS-cpcA locus overall was 16.5%, thereby indicating a level of divergence remarkably higher than that reported for Nodularia and Arthrospira in previous studies relying on cpcB-IGS-cpcA. Further, alignment of informative nucleotide substitutions in the cpcB-IGS-cpcA sequences revealed a mosaic distribution, which may be indicative of genetic recombination events. Finally, the length and sequences of the IGS region alone proved useful as markers to differentiate the cyanobacterial genus Phormidium. However, whether the IGS region per se is sufficiently discriminatory to differentiate between Phormidium species or even strains requires further investigation using newly identified Phormidium sequence data. [source]


    MOLECULAR AND MORPHOLOGICAL DATA IDENTIFY A CRYPTIC SPECIES COMPLEX IN ENDOPHYTIC MEMBERS OF THE GENUS COLEOCHAETE BRÉB. (CHAROPHYTA: COLEOCHAETACEAE),

    JOURNAL OF PHYCOLOGY, Issue 6 2002
    Matthew T. Cimino
    The genus Coleochaete Bréb. is a relatively small group of freshwater microscopic green algae with about 15 recognized species. Although Coleochaete has long been considered to be a close relative of embryophytes, a comprehensive study of the genus has not been published since Pringsheim's 1860 monograph. As part of a systematic study of Coleochaete, we investigated four accessions of the genus that are morphologically similar to the endophytic species C. nitellarum Jost. Each of the four cultures was determined to be capable of endophytic growth in Nitella C. A. Agardh, a member of the closely related order Charales. Maximum likelihood and maximum parsimony analyses were performed on nucleotide data from the chloroplast genes atpB and rbcL that were sequenced from 16 members of the Coleochaetales and from other members of the Charophyceae, embryophytes, and outgroup taxa. These analyses indicate that the Coleochaetales are monophyletic and that the endophytic accessions are members of the scutata group of species. In addition, cell size and nucleotide data suggest that at least three different endophytic species may be represented. Herbivory, nutritional benefits, and substrate competition are three hypotheses that could explain the evolution and maintenance of the endophytic habit in Coleochaete. These data also imply that diversity in the genus may be markedly underestimated. [source]


    A SYSTEMATIC STUDY OF GIGAR-TINACEAE FROM PACIFIC NORTH AMERICA BASED ON MOLECULAR AND MORPHOLOGICAL EVIDENCE

    JOURNAL OF PHYCOLOGY, Issue 2000
    J.R. Hughey
    Greater than 50 species of Gigartinaceae have been described from Pacific North America, about half of which are currently recognized. Although the family is treated extensively in the taxonomic literature, many of the species are still confused and a comprehensive revision is required. We sequenced the rbcL (RuBisCO) gene and ITS (Internal Transcribed Spacer) 1, 2, and 5.8S regions from a large number of recent collections and identified a discrete of number data sets. These were analysed in comparison with the morphological evidence for each of the taxa. Uncertain of the possibility that our operational taxonomic units may not correspond to the types, we developed a protocol for isolating PCR-friendly DNA from herbarium specimens, some reaching back as far as 1670. The DNA profiles of types and historically important specimens were compared to those for recently collected silica gel-dried and formalin-fixed material and assigned correct names. Species studied ranged from Alaska to Mexico and the Gulf of California and were compared to outgroup taxa from Pacific South America and the Southern Ocean. Particular attention was paid to variations in morphology as they relate to habitat with emphasis on the presence or absence of different morphological forms among sympatric and allopatric populations. We recognize 10 species in Chondracanthus (including one new combination and one new species) and 16 species in Mazzaella (including two new combinations and two new species). Finally, we tested a phylogenetic hypothesis inferred for the Gigartinaceae from rbcL sequences for congruence with one generated from ITS sequences. [source]


    Molecular and morphological characterization of the association between bacterial endosymbionts and the marine nematode Astomonema sp. from the Bahamas

    ENVIRONMENTAL MICROBIOLOGY, Issue 5 2007
    Niculina Musat
    Summary Marine nematode worms without a mouth or functional gut are found worldwide in intertidal sandflats, deep-sea muds and methane-rich pock marks, and morphological studies show that they are associated with endosymbiotic bacteria. While it has been hypothesized that the symbionts are chemoautotrophic sulfur oxidizers, to date nothing is known about the phylogeny or function of endosymbionts from marine nematodes. In this study, we characterized the association between bacterial endosymbionts and the marine nematode Astomonema sp. from coral reef sediments in the Bahamas. Phylogenetic analysis of the host based on its 18S rRNA gene showed that Astomonema sp. is most closely related to non-symbiotic nematodes of the families Linhomoeidae and Axonolaimidae and is not closely related to marine stilbonematinid nematodes with ectosymbiotic sulfur-oxidizing bacteria. In contrast, phylogenetic analyses of the symbionts of Astomonema sp. using comparative 16S rRNA gene sequence analysis revealed that these are closely related to the stilbonematinid ectosymbionts (95,96% sequence similarity) as well as to the sulfur-oxidizing endosymbionts from gutless marine oligochaetes. The closest free-living relatives of these gammaproteobacterial symbionts are sulfur-oxidizing bacteria from the family Chromatiaceae. Transmission electron microscopy and fluorescence in situ hybridization showed that the bacterial symbionts completely fill the gut lumen of Astomonema sp., suggesting that these are their main source of nutrition. The close phylogenetic relationship of the Astomonema sp. symbionts to known sulfur-oxidizing bacteria as well as the presence of the aprA gene, typically found in sulfur-oxidizing bacteria, indicates that the Astomonema sp. symbionts use reduced sulfur compounds as an energy source to provide their hosts with nutrition. [source]


    Molecular and diffusion tensor imaging of epileptic networks

    EPILEPSIA, Issue 2008
    Aimee F. Luat
    Summary Several studies have shown that seizure-induced cellular and molecular changes associated with chronic epilepsy can lead to functional and structural alterations in the brain. Chronic epilepsy, when medically refractory, may be associated with an expansion of the epileptic circuitry to involve complex interactions between cortical and subcortical neuroanatomical substrates. Progress in neuroimaging has led not only to successful identification of epileptic foci for surgical resection, but also to an improved understanding of the functional and microstructural changes in long-standing epilepsy. Positron emission tomography (PET), functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) are all promising tools that can assist in elucidating the underlying pathophysiology in chronic epilepsy. Studies using PET scanning have demonstrated dynamic changes associated with the evolution from acute to chronic intractable epilepsy. Among these changes are data to support the existence of secondary epileptogenesis in humans. MRI with DTI is a powerful tool which has the ability to characterize microstructural abnormalities in epileptic foci, and to demonstrate the white matter fibers and tracts participating in the epileptic network. In this review, we illustrate how PET and DTI can be applied to depict the functional and microstructural alterations associated with chronic epilepsy. [source]


    Identification of economically important Liriomyza species by PCR-RFLP analysis,

    EPPO BULLETIN, Issue 1 2005
    L. F. F. Kox
    Only adult males of Liriomyza bryoniae, L. huidobrensis, L. sativae and L. trifolii can be identified with certainty on basis of their genitalia. Female adults, pupae and larvae can only be identified on the level of groups of species (L. bryoniae and L. huidobrensis vs. L. sativae and L. trifolii). Species identification in all developmental stages is possible using molecular biological techniques. Our method is a PCR amplification of a 790-bp fragment of mitochondrial cytochrome oxidase II (COII) DNA followed by RFLP analysis. The method was tested on single larvae, pupae and adults and proved to be applicable to these three life stages. The specificity of the assay was assessed by comparing the results of the PCR-RFLP analysis with those of morphological analysis using 60 Liriomyza specimens. Molecular and morphological identification agreed for all specimens analysed. PCR-RFLP is a powerful diagnostic tool for rapid and reliable identification of all life stages of economically important Liriomyza species. [source]


    Complexes of Yb3+ with EDTA and CDTA , Molecular and Electronic Structure

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 19 2008
    Janicki
    Abstract Two Yb3+ compounds, [C(NH2)3]2[Yb(EDTA)(H2O)2]ClO4·6H2O and [C(NH2)3][Yb(CDTA)(H2O)2]·4H2O, where EDTA is the ethylenediaminetetraacetate anion and CDTA is the trans -1,2-diaminecyclohexane- N,N,N,,N, -tetraacetate anion, were obtained and their crystal structures and spectroscopic properties were determined. In both compounds, the coordination geometries of the eight-coordinate Yb3+ ion are very similar. In each case, the inner sphere of the metal ion consists of four carboxyl oxygen atoms, two nitrogen atoms and two water molecules. The complexes were characterized by UV/Vis/NIR absorption at different temperatures and IR spectroscopy. The spectroscopic results revealed high sensitivity of the electronic 4f13 configuration upon minor changes in the coordination geometry around the Yb3+ ion. These data also demonstrate that species present in solutions of Yb3+,EDTA are similar to those found in the crystal, whereas in solutions of Yb3+,CDTA an equilibrium between at least two different forms exists. For the Yb3+,EDTA complex in solution and in the crystalline state, a charge-transfer transition was detected. Theoretical calculations revealed its complicated (Yb , ligand and ligand , Yb) character.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]


    Binuclear Mixed Valence Oxovanadium(IV/V) Complexes Containing a [OVIV(,-Ooxo)(,-Ophen)VVO]2+ Core: Synthesis, EPR Spectra, Molecular and Electronic Structure

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 9 2006
    Amrita Mondal
    Abstract Binuclear mixed valence oxovanadium(IV/v) complexes of general formula [V2O3L] containing a [OVIV(,-Ooxo)(,-Ophen)VVO]2+ core have been synthesised using conformationally labile N4O3 -coordinating heptadentate ligands (H3L). The X-ray structure of one complex has been examined. Solution EPR spectra revealed that the unpaired electron of the complexes is delocalised between the two vanadium centres. The simulated EPR spectrum of one complex confirms this experimental observation. DFT studies have been performed using crystallographic coordinates in order to obtain further insight into the electronic structure of this type of molecule. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source]


    Polymeric, Molecular, and Cation/Anion Arrangements in Chloro-, Bromo-, and Iododiruthenium(II,III) Carboxylate Compounds

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 12 2003
    M. Carmen Barral
    Abstract The synthesis and characterization of the anhydrous compounds [Ru2X(,-O2CR)4] [R = CH2CH2OPh, X = Cl (1a), Br (2a), I (3a); R = CMePh2, X = Br (5a), I (6a)] and of the solvated complexes [Ru2X(,-O2CR)4(H2O)] [R = CH2CH2OPh, X = Cl (1b), I (3b); R = CMePh2, X = Cl (4b), Br (5b), I (6b)] are described. Thermogravimetric analyses have been used to confirm the anhydrous or solvated natures of the complexes. The crystal structures of 1b·2MeOH, 3b·0.5H2O, and 4b have been investigated by X-ray diffraction and none of them shows the usual polymeric arrangement reported for tetracarboxylatodiruthenium(II,III) compounds. The structure of 3b·0.5H2O consists of cationic and anionic units, [Ru2(,-O2CCH2CH2OPh)4(H2O)2][Ru2I2(,-O2CCH2CH2OPh)4], and represents the first reported crystal structure of a tetracarboxylato(iodo)diruthenium(II,III) derivative. The structures 1b·2MeOH and 4b each show the presence of discrete dinuclear molecules. The crystal structure of [Ru2Cl(,-O2CCMePh2)4(H2O)] demonstrates that diruthenium compounds with the same halide and carboxylate ligands may adopt polymeric or discrete molecular dispositions. Magnetic susceptibility measurements of the complexes in the 2,300 K range have been carried out. Complex 2a shows a strong antiferromagnetic coupling, consistent with the existence of linear chains in the solid state. The complexes [Ru2X(,-O2CR)4(H2O)] show weak through-space antiferromagnetic coupling, in accordance with non-polymeric structures. The magnetic behaviour of 1a, 3a, 5a, and 6a suggests a mixture of arrangements. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]


    Deuterostome evolution: early development in the enteropneust hemichordate, Ptychodera flava

    EVOLUTION AND DEVELOPMENT, Issue 6 2001
    Jonathan Q. Henry
    SUMMARY Molecular and morphological comparisons indicate that the Echinodermata and Hemichordata represent closely related sister-phyla within the Deuterostomia. Much less is known about the development of the hemichordates compared to other deuterostomes. For the first time, cell lineage analyses have been carried out for an indirect-developing representative of the enteropneust hemichordates, Pty- chodera flava. Single blastomeres were iontophoretically labeled with DiI at the 2- through 16-cell stages, and their fates followed through development to the tornaria larval stage. The early cleavage pattern of P. flava is similar to that of the direct-developing hemichordate, Saccoglossus kowalevskii, as well as that displayed by indirect-developing echinoids. The 16-celled embryo contains eight animal "mesomeres," four slightly larger "macromeres," and four somewhat smaller vegetal "micromeres." The first cleavage plane was not found to bear one specific relationship relative to the larval dorsoventral axis. Although individual blastomeres generate discrete clones of cells, the appearance and exact locations of these clones are variable with respect to the embryonic dorsoventral and bilateral axes. The eight animal mesomeres generate anterior (animal) ectoderm of the larva, which includes the apical organ; however, contributions to the apical organ were found to be variable as only a subset of the animal blastomeres end up contributing to its formation and this varies from embryo to embryo. The macromeres generate posterior larval ectoderm, and the vegetal micromeres form all the internal, endomesodermal tissues. These blastomere contributions are similar to those found during development of the only other hemichordate studied, the direct-developing enteropneust, S. kowalevskii. Finally, isolated blastomeres prepared at either the two- or the four-cell stage are capable of forming normal-appearing, miniature tornaria larvae. These findings indicate that the fates of these cells and embryonic dorsoventral axial properties are not committed at these early stages of development. Comparisons with the developmental programs of other deuterostome phyla allow one to speculate on the conservation of some key developmental events/mechanisms and propose basal character states shared by the ancestor of echinoderms and hemichordates. [source]


    Molecular and cellular mechanisms of tissue repair

    EXPERIMENTAL DERMATOLOGY, Issue 10 2005
    Sabine Werner PhD
    No abstract is available for this article. [source]


    Myotendinous plasticity to ageing and resistance exercise in humans

    EXPERIMENTAL PHYSIOLOGY, Issue 3 2006
    N. D. Reeves
    The age-related loss of muscle mass known as senile sarcopenia is one of the main determinants of frailty in old age. Molecular, cellular, nutritional and hormonal mechanisms are at the basis of sarcopenia and are responsible for a progressive deterioration in skeletal muscle size and function. Both at single-fibre and at whole-muscle level, the loss of force exceeds that predicted by the decrease in muscle size. For single fibres, the loss of intrinsic force is mostly due to a loss in myofibrillar protein content. For whole muscle, in addition to changes in neural drive, alterations in muscle architecture and in tendon mechanical properties, exemplified by a reduction in tendon stiffness, have recently been shown to contribute to this phenomenon. Resistance training can, however, cause substantial gains in muscle mass and strength and provides a protective effect against several of the cellular and molecular changes associated with muscle wasting and weakness. In old age, not only muscles but also tendons are highly responsive to training, since an increase in tendon stiffness has been observed after a period of increased loading. Many of the myotendinous factors characterizing ageing can be at least partly reversed by resistance training. [source]


    Molecular and functional characterization of a novel splice variant of ANKHD1 that lacks the KH domain and its role in cell survival and apoptosisc

    FEBS JOURNAL, Issue 16 2005
    Melissa C. Miles
    Multiple ankyrin repeat motif-containing proteins play an important role in protein,protein interactions. ANKHD1 proteins are known to possess multiple ankyrin repeat domains and a single KH domain with no known function. Using yeast two-hybrid system analysis, we identified a novel splice variant of ANKHD1. This splice variant of ANKHD1, which we designated as HIV-1 Vpr-binding ankyrin repeat protein (VBARP), does not contain the signature KH domain, and codes for only a single ankyrin repeat motif. We characterized VBARP by molecular and functional analysis, revealing that VBARP is ubiquitously expressed in different tissues as well as cell lines of different lineage. In addition, blast searches indicated that orthologs and homologs to VBARP exist in different phyla, suggesting that VBARP might be evolutionarily conserved, and thus may be involved in basic cellular function(s). Furthermore, biochemical analysis revealed the presence of two VBARP isoforms coding for 69 and 49 kDa polypeptides, respectively, that are primarily localized in the cytoplasm. Functional analysis using short interfering RNA approaches indicate that this gene product is essential for cell survival through its regulation of caspases. Taken together, these results indicate that VBARP is a novel splice variant of ANKHD1 and may play a role in cellular apoptosis (antiapoptotic) and cell survival pathway(s). [source]


    Molecular and functional characterization of novel CRFR1 isoforms from the skin

    FEBS JOURNAL, Issue 13 2004
    Alexander Pisarchik
    In our continued studies on corticotropin releasing factor receptor (CRFR1) signaling in the skin, we tested functional activity of CRFR1,, e, f, g and h isoforms after transfection to COS cells. Both membrane-bound and soluble variants are translated in vivo into final protein products that undergo further post-translational modifications. CRFR1, was the only isoform coupled directly to adenylate cyclase with the exception of an artificial isoform (CRFR1h2) with the insertion of 37 amino acids between the ligand binding domain and the first extracellular loop that was capable of producing detectable levels of cyclic AMP (cAMP). Soluble isoforms could modulate cell response with CRFR1e attenuating and CRFR1h amplifying CRFR1,-coupled cAMP production stimulated by urocortin. Testing with plasmids containing the luciferase reporter gene, and inducible cis -elements (CRE, CaRE, SRE, AP1 or NF-,B) demonstrated that only CRFR1, was involved directly in the transcriptional regulation, while CRFR1g inhibited CRE activity. Significantly higher reporter gene expression by CRF was observed than that mediated by 4,-phorbol 12-myristate 13-acetate and forskolin alone, being compatible with the concomitant treatment by phorbol 12-myristate 13-acetate and forskolin. This suggests that both protein kinase A and C can be involved in CRF-dependent signal transduction. [source]


    Molecular and infection biology of the horse pathogen Rhodococcus equi

    FEMS MICROBIOLOGY REVIEWS, Issue 5 2009
    Kristine Von Bargen
    Abstract The soil actinomycete Rhodococcus equi is a pulmonary pathogen of young horses and AIDS patients. As a facultative intracellular bacterium, R. equi survives and multiplies in macrophages and establishes its specific niche inside the host cell. Recent research into chromosomal virulence factors and into the role of virulence plasmids in infection and host tropism has presented novel aspects of R. equi infection biology and pathogenicity. This review will focus on new findings in R. equi biology, the trafficking of R. equi -containing vacuoles inside host cells, factors involved in virulence and host resistance and on host,pathogen interaction on organismal and cellular levels. [source]


    Chytrid infections of Daphnia pulicaria: development, ecology, pathology and phylogeny of Polycaryum laeve

    FRESHWATER BIOLOGY, Issue 4 2006
    PIETER T. J. JOHNSON
    Summary 1. We combined ecological surveys, life table studies, microscopy and molecular sequencing to determine the development, ecology, pathology and phylogeny of Polycaryum laeve, an endoparasite of cladocerans. We report the first records of P. laeve from North America, where we have used a polymerase chain reaction primer and microscopic examination to confirm infections in 14 lakes. Infections are highly pathogenic and caused increased mortality, reduced growth, and reproductive castration in Daphnia pulicaria during life table studies. 2. Biweekly data from Allequash Lake (Wisconsin, U.S.A.) throughout 2003 indicated that fecundity and infection prevalence were inversely correlated. Infection prevalence was highest in late winter and early spring (up to 80%) and lowest during late summer. Epidemics were generally followed by sharp declines in host population density (up to 99%). 3. Within the haemocoel of its host, P. laeve forms thick-walled sporangia, which occur systemically in later stages of infection. Fungal thalli associate closely with muscle fibres and connective tissue, leading to degeneration as the infection becomes advanced. Following death of the host, flagellated zoospores are released through an exit papilla on the sporangium. Based on the infection-induced castration of the host and increases in infection prevalence with Daphnia size, we postulate that transmission is horizontal, but may be indirect through an additional host or free-living stage. 4. Molecular and morphological data clearly indicate that P. laeve belongs in the fungal phylum Chytriodiomycota, order Blastocladiales. Based on ribosomal RNA gene sequences and morphological features, we transfer the genus Polycaryum from the Haplosporidia to the Chytridiomycota, and designate a lectotype and epitype for P. laeve. Considering the high prevalence of P. laeve infection within Daphnia populations, the frequency with which we detected infections among lakes, and the keystone importance of large-bodied Daphnia in aquatic food webs, we suggest that P. laeve may exert a regulatory influence on Daphnia populations in lake ecosystems. [source]


    Resonant Tunneling Processes along Conjugated Molecular Wires: A Quantum-Chemical Description

    ADVANCED FUNCTIONAL MATERIALS, Issue 11-12 2002
    Y. Karzazi
    Abstract Molecular electronics research is a very active area in the field of nanotechnology. It is now well established that individual or self-assembled molecules can behave as nanoscopic switches in transistor and diode configurations. Molecular wires inserted into nanopores and contacted by two metallic electrodes can also be used as active elements for the fabrication of resonant tunneling diodes (RTDs). The RTD current/voltage (I/V) characteristics can display a negative differential resistance (NDR) behavior (i.e., a negative slope in the I/V curve) for reasons that are not yet fully understood. Here we describe a possible mechanism at the quantum-chemical level that is based on conformational effects and accounts for the experimental observation of strong NDR signatures in substituted phenylene ethynylene oligomers. The occurrence of a peak current in the I/V curves is rationalized by analyzing the evolution of the one-electron structure of the molecular wires upon application of a static electric field aligned along the molecular axis (the field simulates the driving voltage applied between the two electrodes in the RTD devices). The results of our calculations provide a general basis to develop strategies for the design of molecular wires displaying an NDR behavior. [source]


    Molecular and clinical heterogeneity in CLCN7-dependent osteopetrosis: report of 20 novel mutations,

    HUMAN MUTATION, Issue 1 2010
    Alessandra Pangrazio
    Abstract The "Osteopetroses" are genetic diseases whose clinical picture is caused by a defect in bone resorption by osteoclasts. Three main forms can be distinguished on the basis of severity, age of onset and means of inheritance: the dominant benign, the intermediate and the recessive severe form. While several genes have been involved in the pathogenesis of the different types of osteopetroses, the CLCN7 gene has drawn the attention of many researchers, as mutations within this gene are associated with very different phenotypes. We report here the characterization of 25 unpublished patients which has resulted in the identification of 20 novel mutations, including 11 missense mutations, 6 causing premature termination, 1 small deletion and 2 putative splice site defects. Careful analysis of clinical and molecular data led us to several conclusions. First, intermediate osteopetrosis is not homogeneous, since it can comprise both severe dominant forms with an early onset and recessive ones without central nervous system involvement. Second, the appropriateness of haematopoietic stem cell transplantation in CLCN7-dependent ARO patients has to be carefully evaluated and exhaustive CNS examination is strongly suggested, as transplantation can almost completely cure the disease in situations where no primary neurological symptoms are present. Finally, the analysis of this largest cohort of CLCN7-dependent ARO patients together with some ADO II families allowed us to draw preliminary genotype-phenotype correlations suggesting that haploinsufficiency is not the mechanism causing ADO II. The availability of biochemical assays to characterize ClC-7 function will help to confirm this hypothesis. © 2009 Wiley-Liss, Inc. [source]


    Molecular and muscle pathology in a series of caveolinopathy patients,

    HUMAN MUTATION, Issue 1 2005
    Luigi Fulizio
    Abstract Mutations in the caveolin-3 gene (CAV3) cause limb girdle muscular dystrophy (LGMD) type 1C (LGMD1C) and other muscle phenotypes. We screened 663 patients with various phenotypes of unknown etiology, for caveolin-3 protein deficiency, and we identified eight unreported caveolin-deficient patients (from seven families) in whom four CAV3 mutations had been detected (two are unreported). Following our wide screening, we estimated that caveolinopathies are 1% of both unclassified LGMD and other phenotypes, and demonstrated that caveolin-3 protein deficiency is a highly sensitive and specific marker of primary caveolinopathy. This is the largest series of caveolinopathy families in whom the effect of gene mutations has been analyzed for protein level and phenotype. We showed that the same mutation could lead to heterogeneous clinical phenotypes and muscle histopathological changes. To study the role of the Golgi complex in the pathological pathway of misfolded caveolin-3 oligomers, we performed a histopathological study on muscle biopsies from caveolinopathy patients. We documented normal caveolin-3 immunolabeling at the plasmalemma in some regenerating fibers showing a proliferation of the Golgi complex. It is likely that caveolin-3 overexpression occurring in regenerating fibers (compared with caveolin-deficient adult fibers) may lead to an accumulation of misfolded oligomers in the Golgi and to its consequent proliferation. Hum Mutat 25:82,89, 2005. © 2004 Wiley-Liss, Inc. [source]


    Serotonin and Sleep: Molecular, Functional and Clinical Aspects.

    HUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 6 2008
    B. L. Jacobs, D. J. Nutt., Edited by J. M. Monti, S. R. Pandi-Perumal
    No abstract is available for this article. [source]


    Molecular and cellular pathogenesis of X-linked lymphoproliferative disease

    IMMUNOLOGICAL REVIEWS, Issue 1 2005
    Kim E. Nichols
    Summary:, X-linked lymphoproliferative disease (XLP) is an inherited immune defect caused by mutations in the Src homology 2 domain-containing gene 1A, which encodes the adapter protein, signaling lymphocytic activation molecule (SLAM)-associated protein (SAP). SAP is expressed in T cells, natural killer (NK) cells, and NKT cells, where it binds to the cytoplasmic domain of the surface receptor SLAM (CD150) and the related receptors, 2B4 (CD244), CD84, Ly9 (CD229), NK-T-B-antigen, and CD2-like receptor-activating cytotoxic T cells. SAP also binds to the Src family tyrosine kinase Fyn and recruits it to SLAM, which leads to the generation of downstream phosphotyrosine signals. While the roles of the SLAM family receptors are only beginning to be understood, experiments suggest that these molecules regulate important aspects of lymphocyte function, such as proliferation, cytokine secretion, cytotoxicity, and antibody production. Thus, in XLP patients who lack functional SAP, the SLAM family receptors may not signal properly. This property likely contributes to the phenotypes of XLP, including fulminant infectious mononucleosis, lymphoma, and hypogammaglobulinemia. Further studies of SAP and the SLAM family receptors will provide insights into XLP and elucidate the signaling events regulating lymphocyte ontogeny and function. [source]


    Comment on "Molecular Transport Junctions: Clearing Mists"

    ADVANCED MATERIALS, Issue 16 2009
    Massimiliano Di Ventra
    No abstract is available for this article. [source]


    Using molecular and quantitative variation for assessing genetic impacts on Nucella lapillus populations after local extinction and recolonization

    INTEGRATIVE ZOOLOGY (ELECTRONIC), Issue 2 2006
    Isabelle Colson
    Abstract The dogwhelk Nucella lapillus is a predatory marine gastropod living on rocky shores in the North Atlantic. As with many other gastropod species, Nucella was affected by tributyltin (TBT) pollution during the 1970s and 1980s, and local populations underwent extinction. After a partial ban on TBT in the UK in 1987, vacant sites have been recolonized. Levels of genetic diversity and quantitative genetic variation in shell form were compared between recolonized sites and sites that showed continuous population at three localities across the British Isles. Overall, estimates of genetic diversity were only slightly lower in recolonized populations, suggesting that populations have recovered from previous impacts due to the relatively high levels of migration from non-impacted sites. Molecular and quantitative analyses are broadly concordant and a positive correlation was observed (although not statistically significant) between molecular and quantitative estimates of genetic diversity, indicating the potential usefulness of quantitative methods to complement molecular population genetics analyses. [source]


    Polyphenylene-Based Materials: Control of the Electronic Function by Molecular and Supramolecular Complexity

    ADVANCED MATERIALS, Issue 10-11 2009
    Bruno Schmaltz
    Abstract Organic electronics is one of the hottest and most exciting research topics today. However, its performance still lags behind that of inorganic-based electronics. This Progress Report demonstrates that by controlling the complexity of organic molecules at the molecular and at the supramolecular level as well as by choosing suitable processing techniques, the desired function for applications in electronics can be achieved. Our main focus is on polyphenylene-based nanomaterials, versatile organic molecules that allow access to novel intricate materials. We emphasize the molecular complexity as well as the supramolecular organization and the interfacing of novel organic materials as key guidelines. [source]


    Polystannanes: Polymers of a Molecular, Jacketed Metal,Wire Structure,

    ADVANCED MATERIALS, Issue 11 2008
    Fabien Choffat
    Abstract Organometallic polymers comprising a backbone of covalently connected metal atoms can be regarded as molecular metal wires surrounded by a jacket of organic matter. Such polymers are rare and their materials properties are largely unexplored. Here, we report on polystannanes, (SnR2)n, that is, polymers with a backbone of tin atoms, which are synthesized by dehydropolymerization of dialkylstannanes (H2SnR2) with the catalyst [RhCl(PPh3)3]. The polystannanes feature reversible phase transitions into liquid-crystalline states, remarkably, even below room temperature, and, interestingly, oriented either parallel or perpendicular to external driving forces, depending on the length of the alkyl substituents. [source]


    Comment on "Memory Effect and Negative Differential Resistance by Electrode-Induced Two-Dimensional Single-Electron Tunneling in Molecular and Organic Electronic Devices"

    ADVANCED MATERIALS, Issue 21 2006
    S. Majumdar
    No abstract is available for this article. [source]


    High-Mobility C60 Field-Effect Transistors Fabricated on Molecular- Wetting Controlled Substrates,

    ADVANCED MATERIALS, Issue 13 2006
    K. Itaka
    An atomically flat pentacene monomolecular layer remarkably improved the crystallinity of C60 films, thus enhancing the field-effect mobilities in C60 transistors (FETs) (see figure). They showed a four to five times better performance over devices with C60 films grown without a pentacene buffer. Molecular-wetting-controlled substrates can thus offer a general solution to the fabrication of high-performance crystalline organic devices. [source]


    Past, Present and Future Insights into the Understanding and Treatment of Osteoarthritis: Molecular and Mechanical Approaches

    INTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 1 2009
    Article first published online: 19 JAN 200
    First page of article [source]