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排序方式: 共有577条查询结果,搜索用时 375 毫秒
191.
Karen Head Shiaoching Gong Sheldon Joseph Cuidong Wang Tania Burkhardt Michael R. Rossi Jeffrey LaDuca Sei-Ichi Matsui Mary Vaughan David G. Hicks Nathaniel Heintz John K. Cowell 《Mammalian genome》2007,18(5):328-337
The LGI1 gene has been implicated in the development of epilepsy and the invasion phenotype of glial cells. Controversy over the specific
tissue expression pattern of this gene has stemmed from conflicting reports generated using immunohistochemistry and the polymerase
chain reaction. LGI1 is one of a four-member family of secreted proteins with high homology and here we demonstrate, using
GFP-tagged constructs from the four LGI1family members, that commonly used antibodies against LGI1 cross-react with different
family members. With the uncertainty surrounding the use of commercially available antibodies to truly establish the expression
pattern of LGI1, we generated transgenic mice carrying the LGI1-containing BAC, RP23-127G7, which had been modified to express
the GFP reporter gene under the control of the endogenous regulatory elements required for LGI1 expression. Three founder
mice were generated, and immunohistochemistry was used to determine the tissue-specific pattern of expression. In the brain,
distinct regions of glial and neuronal cell expression were identified, as well as the choriod plexus, which is largely pia-derived.
In addition, strong expression levels were identified in glandular regions of the prostate, individual tubules in the kidney,
sympathetic ganglia in the kidney, sebaceous glands in the skin, the islets of Langerhans, the endometrium, and the ovary
and testes. All other major organs analyzed were negative. The pattern of reporter gene expression was identical in three
individual founder mice, arguing against a position effect altering expression profile due to the integration site of the
BAC. 相似文献
192.
It is widely recognized that maternal phenotype can have important effects on offspring, but paternal phenotype is generally assumed to have no influence in animals lacking paternal care. Nonetheless, selection may favour the transfer of environmentally acquired condition to offspring from both parents. Using a split-brood, cross-generational laboratory design, we manipulated a key environmental determinant of condition - larval diet quality - of parents and their offspring in the fly Telostylinus angusticollis, in which there is no evidence of paternal provisioning. Parental diet did not affect offspring survival, but high-condition mothers produced larger eggs, and their offspring developed more rapidly when on a poor larval diet. Maternal condition had no effect on adult body size of offspring. By contrast, large, high-condition fathers produced larger offspring, and follow-up assays showed that this paternal effect can be sufficient to increase mating success of male offspring and fecundity of female offspring. Our findings suggest that both mothers and fathers transfer their condition to offspring, but with effects on different offspring traits. Moreover, our results suggest that paternal effects can be important even in species lacking conventional forms of paternal care. In such species, the transfer of paternal condition to offspring could contribute to indirect selection on female mate preferences. 相似文献
193.
Behavioral plasticity and G × E of reproductive tactics in Nicrophorus vespilloides burying beetles
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Mauricio J. Carter Megan L. Head Allen J. Moore Nick J. Royle 《Evolution; international journal of organic evolution》2015,69(4):969-978
Phenotypic plasticity is important in the evolution of traits and facilitates adaptation to rapid environmental changes. However, variation in plasticity at the individual level, and the heritable basis underlying this plasticity is rarely quantified for behavioral traits. Alternative behavioral reproductive tactics are key components of mating systems but are not often considered within a phenotypic plasticity framework (i.e., as reaction norms). Here, using lines artificially selected for repeated mating rate, we test for genetic (G × E) sources of variation in reproductive behavior of male Nicrophorus vespilloides burying beetles (including signaling behavior), as well as the role of individual body size, in responsiveness to changes in social environment. The results show that body size influences the response of individuals’ signaling behavior to changes in the social environment. Moreover, there was G × E underlying the responses of males to variation in the quality of social environment experienced (relative size of focal male compared to his rival). This shows that individual variation in plasticity and social sensitivity of signaling behavior can evolve in response to selection on investment in mating behavior, with males selected for high mating investment having greater social sensitivity. 相似文献
194.
According to classical parental care theory males are expected to provide less parental care when offspring in a brood are less likely to be their own, but empirical evidence in support of this relationship is equivocal. Recent work predicts that social interactions between the sexes can modify co‐evolution between traits involved in mating and parental care as a result of costs associated with these social interactions (i.e. sexual conflict). In burying beetles (Nicrophorus vespilloides), we use artificial selection on a paternity assurance trait, and crosses within and between selection lines, to show that selection acting on females, not males, can drive the co‐evolution of paternity assurance traits and parental care. Males do not care more in response to selection on mating rate. Instead, patterns of parental care change as an indirect response to costs of mating for females. 相似文献
195.
Ellenor Mittendorfer-Rutz Linnea Kjeldg?rd Bo Runeson Aleksander Perski Maria Melchior Jenny Head Kristina Alexanderson 《PloS one》2012,7(9)
Background
Despite the magnitude and increase of sickness absence due to mental diagnoses, little is known regarding long-term health outcomes. The aim of this nationwide population-based, prospective cohort study was to investigate the association between sickness absence due to specific mental diagnoses and the risk of all-cause and cause-specific mortality.Methods
A cohort of all 4 857 943 individuals living in Sweden on 31.12.2004 (aged 16–64 years, not sickness absent, or on retirement or disability pension), was followed from 01.01.2005 through 31.12.2008 for all-cause and cause-specific mortality (suicide, cancer, circulatory disease) through linkage of individual register data. Individuals with at least one new sick-leave spell with a mental diagnosis in 2005 were compared to individuals with no sickness absence. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated by Cox regression, adjusting for age, sex, education, country of birth, family situation, area of residence, and pre-existing morbidity (diagnosis-specific hospital inpatient (2000–2005) and outpatient (2001–2005) care).Results
In the multivariate analyses, mental sickness absence in 2005 was associated with an increased risk for all-cause mortality: HR: 1.65, 95% CI: 1.47–1.86 in women and in men: 1.73, 1.57–1.91; for suicide, cancer (both smoking and non-smoking related) as well as mortality due to circulatory disease only in men. Estimates for cause-specific mortality ranged from 1.48 to 3.37. Associations with all-cause mortality were found for all mental sickness absence diagnostic groups studied.Conclusions
Knowledge about the prognosis of patients sickness absent with specific mental diagnoses is of crucial clinical importance in health care. Sickness absence due to specific mental diagnoses may here be used as a risk indictor for subsequent mortality. 相似文献196.
Since initial launch of insect protected transgenic crops, the most effective strategy to manage the potential for target pests to evolve resistance has been the use of a single mode of action with "high dose" and structured refuge. However, the effectiveness of this strategy is limited if mortality of certain pests does not reach "high dose" criteria, inconsistent implementation of refuges and non-rare resistance alleles. More recently, several pyramided trait products, which include multiple modes of action against key target pests, have been developed. These products offer the potential for dramatically improved resistance management with smaller refuges and less dependence on high mortality of susceptible and heterozygous insects and rare resistance alleles. We show that products such as SmartStax and PowerCore offer compelling resistance management benefits compared with single mode of action products and allow for the option of products containing refuge seed mixtures rather than structured refuges to effectively delay resistance. We conclude that all stakeholders, including technology developers, growers, crop advisors, extensions services and regulatory authorities should continue to encourage the development, deployment and adoption of pyramided trait products for improved pest management and improved resistance management. 相似文献
197.
Jessica Junker Stephen Blake Christophe Boesch Geneviève Campbell Louwrens du Toit Chris Duvall Atanga Ekobo Gilles Etoga Anh Galat‐Luong Joel Gamys Jessica Ganas‐Swaray Sylvain Gatti Andrea Ghiurghi Nicolas Granier John Hart Josephine Head Ilka Herbinger Thurston Cleveland Hicks Bas Huijbregts Inaoyom S. Imong Noëlle Kuempel Sally Lahm Jeremy Lindsell Fiona Maisels Matthew McLennan Laura Martinez Bethan Morgan David Morgan Felix Mulindahabi Roger Mundry Kouamé Paul N'Goran Emmanuelle Normand Anne Ntongho David Tiku Okon Charles‐Albert Petre Andrew Plumptre Hugo Rainey Sébastien Regnaut Crickette Sanz Emma Stokes Adama Tondossama Sandra Tranquilli Jacqueline Sunderland‐Groves Peter Walsh Elizabeth A. Williamson Hjalmar S. Kuehl 《Diversity & distributions》2012,18(11):1077-1091
198.
Inhibition of prion-protein conversion: a therapeutic tool? 总被引:2,自引:0,他引:2
199.
Agreement between Theory and Measurement in Quantification of Ammonia-Oxidizing Bacteria 总被引:2,自引:0,他引:2
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Gulnur Coskuner Stuart J. Ballinger Russell J. Davenport Rheanne L. Pickering Rosario Solera Ian M. Head Thomas P. Curtis 《Applied microbiology》2005,71(10):6325-6334
Autotrophic ammonia-oxidizing bacteria (AOB) are of vital importance to wastewater treatment plants (WWTP), as well as being an intriguing group of microorganisms in their own right. To date, corroboration of quantitative measurements of AOB by fluorescence in situ hybridization (FISH) has relied on assessment of the ammonia oxidation rate per cell, relative to published values for cultured AOB. Validation of cell counts on the basis of substrate transformation rates is problematic, however, because published cell-specific ammonia oxidation rates vary by over two orders of magnitude. We present a method that uses FISH in conjunction with confocal scanning laser microscopy to quantify AOB in WWTP, where AOB are typically observed as microcolonies. The method is comparatively simple, requiring neither detailed cell counts or image analysis, and yet it can give estimates of either cell numbers or biomass. Microcolony volume and diameter were found to have a log-normal distribution. We were able to show that virtually all (>96%) of the AOB biomass occurred as microcolonies. Counts of microcolony abundance and measurement of their diameter coupled with a calibration of microcolony dimensions against cell numbers or AOB biomass were used to determine AOB cell numbers and biomass in WWTP. Cell-specific ammonia oxidation rates varied between plants by over three orders of magnitude, suggesting that cell-specific ammonia oxidation is an important process variable. Moreover, when measured AOB biomass was compared with process-based estimates of AOB biomass, the two values were in agreement. 相似文献
200.
Wang H Head J Kosma P Brade H Müller-Loennies S Sheikh S McDonald B Smith K Cafarella T Seaton B Crouch E 《Biochemistry》2008,47(2):710-720
Lipopolysaccharides (LPS) of Gram-negative bacteria are important mediators of bacterial virulence that can elicit potent endotoxic effects. Surfactant protein D (SP-D) shows specific interactions with LPS, both in vitro and in vivo. These interactions involve binding of the carbohydrate recognition domain (CRD) to LPS oligosaccharides (OS); however, little is known about the mechanisms of LPS recognition. Recombinant neck+CRDs (NCRDs) provide an opportunity to directly correlate binding interactions with a crystallographic analysis of the binding mechanism. In these studies, we examined the interactions of wild-type and mutant trimeric NCRDs with rough LPS (R-LPS). Although rat NCRDs bound more efficiently than human NCRDs to Escherichia coli J-5 LPS, both proteins exhibited efficient binding to solid-phase Rd2-LPS and to Rd2-LPS aggregates presented in the solution phase. Involvement of residues flanking calcium at the sugar binding site was demonstrated by reciprocal exchange of lysine and arginine at position 343 of rat and human CRDs. The lectin activity of hNCRDs was inhibited by specific heptoses, including l-glycero-alpha-d-manno-heptose (l,d-heptose), but not by 3-deoxy-alpha-d-manno-oct-2-ulosonic acid (Kdo). Crystallographic analysis of the hNCRD demonstrated a novel binding orientation for l,d-heptose, involving the hydroxyl groups of the side chain. Similar binding was observed for a synthetic alpha1-->3-linked heptose disaccharide corresponding to heptoses I and II of the inner core region in many LPS. 7-O-Carbamoyl-l,d-heptose and d-glycero-alpha-d-manno-heptose were bound via ring hydroxyl groups. Interactions with the side chain of inner core heptoses provide a potential mechanism for the recognition of diverse types of LPS by SP-D. 相似文献