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421.
422.
The aim of this study was to analyze the morphological variation of brown trout (Salmo trutta) in the Duero basin, an Atlantic river basin in the Iberian Peninsula, where a spatial segregation of two divergent lineages was previously reported, based on isozyme, microsatellite and mtDNA data. In these studies, two divergent pure regions (Pisuerga and Lower-course) and several hybrid populations between them were identified. Morphological variation was evaluated in 11 populations representative of the genetic differentiation previously observed in the Duero basin, using multivariate analysis on 12 morphometric and 4 meristic traits. A large differentiation between populations was observed (interpopulation component of variance: 41.8%), similar to that previously detected with allozymes and microsatellites. Morphometric differentiation was also reflected by the high classification success of pure and hybrid individuals to their respective populations, using multivariate discriminant functions (94.1% and 79.0%, respectively). All multivariate and clustering analyses performed demonstrated a strong differentiation between the pure regions. The hybrid populations, though showing large differentiation among them, evidenced an intermediate position between the pure samples. Head and body shape traits were the most discriminant among the morphometric characters, while pectoral rays and gillrakers were the most discriminant among the meristic traits. These results confirmed the high divergence of the brown trout from the Duero basin and suggest some traits on which selection could be acting to explain the spatial segregation observed. 相似文献
423.
424.
Luís Jaime Mota Amy E. Ramsden Mei Liu J. David Castle David W. Holden 《Cellular microbiology》2009,11(8):1236-1253
Salmonella enterica are facultative intracellular bacterial pathogens that proliferate within host cells in a membrane-bounded compartment, the Salmonella -containing vacuole (SCV). Intracellular replication of Salmonella is mediated by bacterial effectors translocated on to the cytoplasmic face of the SCV membrane by a type III secretion system. Some of these effectors manipulate the host endocytic pathway, resulting in the formation in epithelial cells of tubules enriched in late endosomal markers, known as Salmonella -induced filaments (SIFs). However, much less is known about possible interference of Salmonella with the secretory pathway. Here, a small-interference RNA screen revealed that secretory carrier membrane proteins (SCAMPs) 2 and 3 contribute to the maintenance of SCVs in the Golgi region of HeLa cells. This is likely to reflect a function of SCAMPs in vacuolar membrane dynamics. Moreover, SCAMP3, which accumulates on the trans -Golgi network in uninfected cells, marked tubules induced by Salmonella effectors that overlapped with SIFs but which also comprised distinct tubules lacking late endosomal proteins. We propose that SCAMP3 tubules reflect a manipulation of specific post-Golgi trafficking that might allow Salmonella to acquire nutrients and membrane, or to control host immune responses. 相似文献
425.
Kirk C. Hansen Lauren Kiemele Ori Maller Jenean O'Brien Aarthi Shankar Jaime Fornetti Pepper Schedin 《Molecular & cellular proteomics : MCP》2009,8(7):1648-1657
Epithelial cell behavior is coordinated by the composition of the surrounding
extracellular matrix (ECM); thus ECM protein identification is critical for
understanding normal biology and disease states. Proteomic analyses of ECM
proteins have been hindered by the insoluble and digestion-resistant nature of
ECM. Here we explore the utility of combining rapid ultrasonication- and
surfactant-assisted digestion for the detailed proteomics analysis of ECM
samples. When compared with traditional overnight digestion, this optimized
method dramatically improved the sequence coverage for collagen I, revealed the
presence of hundreds of previously unidentified proteins in Matrigel, and
identified a protein profile for ECM isolated from rat mammary glands that was
substantially different from that found in Matrigel. In a three-dimensional
culture assay to investigate epithelial cell-ECM interactions, mammary
epithelial cells were found to undergo extensive branching morphogenesis when
plated with mammary gland-derived matrix in comparison with Matrigel.
Cumulatively these data highlight the tissue-specific nature of ECM composition
and function and underscore the need for optimized techniques, such as those
described here, for the proteomics characterization of ECM samples.Extracellular matrix (ECM)1 is a critical component of the tissue microenvironment. ECM plays a pivotal role
in embryonic stem cell development and differentiation (1, 2) as well as many physiological (3) and pathological processes, including cancer
progression (4, 5). Cell regulation by ECM has been studied with high frequency in recent years
(7, 8).
However, our ability to globally characterize ECM composition both in
vitro and in vivo has been severely limited because of several
unique attributes of ECM proteins such as high molecular weight glycans and the presence
of covalent protein cross-links (6, 9, 10).
Traditional proteomics approaches have proven to be ineffective for the identification
of ECM proteins as demonstrated by the fact that collagens, despite being the most
abundant protein in mammals, are significantly underrepresented in tissue-based
proteomics data sets.Ultrasonication has long been used for the digestion of bioorganic materials to allow for
maximal and reproducible extraction and hence the accurate identification of small
molecule and inorganic analytes (11). More
recently, Capelo et al. (12)
have used ultrasonic energy to catalyze tryptic digestion of proteins for subsequent
mass spectrometry-based identification. Here we sought to determine whether this method
could be optimized to prepare ECM samples for mass spectrometry-based analysis. For
method development, we used rat tail collagen as a representative ECM protein for which
current proteomics approaches have proven relatively unsuccessful. Type I collagen is
defined as a right-handed triple helix heterotrimer comprising two identical
α1 chains and one α2 chain that form a fibrillar network (6). The physical properties of the triple helical
structure render the protein resistant to proteasch as trypsin (9). In this work, we focused our efforts on developing a digestion
approach that improves our ability to perform proteomics analysis on a type I collagen
preparation and then used this method to identify the protein composition of EHS murine
chondrosarcoma matrix (10), herein referred to as
Matrigel, and a matrix preparation from rat mammary tissue.In this study, we developed a digestion approach suitable for a two-dimensional liquid
chromatography-tandem mass spectrometry-based analysis of ECM proteins. Our digestion
approach involves three cycles of ultrasonication for rapid initial trypsin digestion
followed by overnight digestion using an acid-labile surfactant. This approach resulted
in significant improvement in collagen peptide identification and the identification of
numerous ECM proteins previously uncharacterized in Matrigel and in mammary tissue. The
application of our ECM-optimized ultrasonic assisted trypsin digestion method is
anticipated to significantly advance the identification of tissue- and disease
state-specific ECM proteins. 相似文献
426.
We report on the isolation and evaluation of 11 microsatellites from a widespread eastern North American wetland sedge, Carex scoparia. Loci exhibit 3-9 alleles over five populations and significant F(IS) (0.204-0.717) in most populations. All primers cross-amplify in at least two other species, and 10 cross-amplify in the more distantly related C. stipata. These markers will be used to examine population genetics and patterns of chromosomal diversification in this ecologically important sedge species and its relatives. 相似文献
427.
Louis Tong Jaime Chew Henry Yang Leonard PK Ang Donald TH Tan Roger W Beuerman 《BMC medical genomics》2009,2(1):1-21
Background
Pterygium is a common ocular surface disease characterized by fibrovascular invasion of the cornea and is sight-threatening due to astigmatism, tear film disturbance, or occlusion of the visual axis. However, the mechanisms for formation and post-surgical recurrence of pterygium are not understood, and a valid animal model does not exist. Here, we investigated the possible mechanisms of pterygium pathogenesis and recurrence.Methods
First we performed a genome wide expression analysis (human Affymetrix Genechip, >22000 genes) with principal component analysis and clustering techniques, and validated expression of key molecules with PCR. The controls for this study were the un-involved conjunctival tissue of the same eye obtained during the surgical resection of the lesions. Interesting molecules were further investigated with immunohistochemistry, Western blots, and comparison with tear proteins from pterygium patients.Results
Principal component analysis in pterygium indicated a signature of matrix-related structural proteins, including fibronectin-1 (both splice-forms), collagen-1A2, keratin-12 and small proline rich protein-1. Immunofluorescence showed strong expression of keratin-6A in all layers, especially the superficial layers, of pterygium epithelium, but absent in the control, with up-regulation and nuclear accumulation of the cell adhesion molecule CD24 in the pterygium epithelium. Western blot shows increased protein expression of beta-microseminoprotein, a protein up-regulated in human cutaneous squamous cell carcinoma. Gene products of 22 up-regulated genes in pterygium have also been found by us in human tears using nano-electrospray-liquid chromatography/mass spectrometry after pterygium surgery. Recurrent disease was associated with up-regulation of sialophorin, a negative regulator of cell adhesion, and never in mitosis a-5, known to be involved in cell motility.Conclusion
Aberrant wound healing is therefore a key process in this disease, and strategies in wound remodeling may be appropriate in halting pterygium or its recurrence. For patients demonstrating a profile of 'recurrence', it may be necessary to manage as a poorer prognostic case and perhaps, more adjunctive treatment after resection of the primary lesion. 相似文献428.
Movement herkogamy in Kosteletzkya virginica: Effect on reproductive success and contribution to pollen receipt and reproductive assurance
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Herkogamy may act as a mechanism to reduce interference between the reproductive functions of female and male organs, but too great a distance between stigmas and anthers may also decrease the outcross pollen transfer and male and female fitness. Our goal was to quantify the effect of movement herkogamy in Kosteletzkya virginica on reproductive success and its contribution to pollen receipt and reproductive assurance. Field investigations and hand-pollination experiments were performed to test: (1) the relationship between herkogamy before curvature of un-pollinated lobes and reproductive success under pollinator exclusion; (2) the contribution of movement herkogamy to pollen receipt; and (3) the relationship between pollen load and seed set. We noted that variation in herkogamy before curvature of un-pollinated lobes did not affect the outcome of autogamous self-pollination measured by fruit set and mean number of seeds per fruit. Under natural conditions, 39% of pollen grains deposited per flower were from autogamous self-pollination via movement herkogamy resulting in contact between anthers and stigmas. The relationship between the amount of pollen grains and the number of seeds per capsule was highly significant. Flowers producing four or five seeds received more pollen grains than those producing only one seed. Our data provides experimental evidence that movement herkogamy, which decreases the separation between anthers and stigmas and results in delayed self-pollination, contributes to pollen receipt and further enhances seed set when pollinators are scarce or absent. 相似文献
429.
Susan B. Perlman James P. Morris Brent C. Vander Wyk Steven R. Green Jaime L. Doyle Kevin A. Pelphrey 《PloS one》2009,4(6)
Background
Determining the ways in which personality traits interact with contextual determinants to shape social behavior remains an important area of empirical investigation. The specific personality trait of neuroticism has been related to characteristic negative emotionality and associated with heightened attention to negative, emotionally arousing environmental signals. However, the mechanisms by which this personality trait may shape social behavior remain largely unspecified.Methodology/Principal Findings
We employed eye tracking to investigate the relationship between characteristics of visual scanpaths in response to emotional facial expressions and individual differences in personality. We discovered that the amount of time spent looking at the eyes of fearful faces was positively related to neuroticism.Conclusions/Significance
This finding is discussed in relation to previous behavioral research relating personality to selective attention for trait-congruent emotional information, neuroimaging studies relating differences in personality to amygdala reactivity to socially relevant stimuli, and genetic studies suggesting linkages between the serotonin transporter gene and neuroticism. We conclude that personality may be related to interpersonal interaction by shaping aspects of social cognition as basic as eye contact. In this way, eye gaze represents a possible behavioral link in a complex relationship between genes, brain function, and personality. 相似文献430.
Beatriz Santamaría Alberto Benito-Martin Alvaro Conrado Ucero Luiz Stark Aroeira Ana Reyero María Jesús Vicent Mar Orzáez Angel Celdrán Jaime Esteban Rafael Selgas Marta Ruíz-Ortega Manuel López Cabrera Jesús Egido Enrique Pérez-Payá Alberto Ortiz 《PloS one》2009,4(8)