Preparing protein microarrays by soft-landing of mass-selected ions     

Ouyang Z  Takáts Z  Blake TA  Gologan B  Guymon AJ  Wiseman JM  Oliver JC  Davisson VJ  Cooks RG 《Science (New York, N.Y.)》2003,301(5638):1351-1354

Intact, multiply protonated proteins of particular mass and charge were selected from ionized protein mixtures and gently landed at different positions on a surface to form a microarray. An array of cytochrome c, lysozyme, insulin, and apomyoglobin was generated, and the deposited proteins showed electrospray ionization mass spectra that matched those of the authentic compounds. Deposited lysozyme and trypsin retained their biological activity. Multiply charged ions of protein kinase A catalytic subunit and hexokinase were also soft-landed into glycerol-based liquid surfaces. These soft-landed kinases phosphorylated LRRASLG oligopeptide and D-fructose, respectively.  相似文献   

Optimization of virulence functions through glucosylation of Shigella LPS     

West NP  Sansonetti P  Mounier J  Exley RM  Parsot C  Guadagnini S  Prévost MC  Prochnicka-Chalufour A  Delepierre M  Tanguy M  Tang CM 《Science (New York, N.Y.)》2005,307(5713):1313-1317

Shigella, the leading cause of bacillary dysentery, uses a type III secretion system (TTSS) to inject proteins into human cells, leading to bacterial invasion and a vigorous inflammatory response. The bacterium is protected against the response by the O antigen of lipopolysaccharide (LPS) on its surface. We show that bacteriophage-encoded glucosylation of Shigella O antigen, the basis of different serotypes, shortens the LPS molecule by around half. This enhances TTSS function without compromising the protective properties of the LPS. Thus, LPS glucosylation promotes bacterial invasion and evasion of innate immunity, which may have contributed to the emergence of serotype diversity in Shigella.  相似文献   

Glutamate receptor-like genes form Ca2+ channels in pollen tubes and are regulated by pistil D-serine   总被引：1，自引：0，他引：1  

Michard E  Lima PT  Borges F  Silva AC  Portes MT  Carvalho JE  Gilliham M  Liu LH  Obermeyer G  Feijó JA 《Science (New York, N.Y.)》2011,332(6028):434-437

Elevations in cytosolic free calcium concentration ([Ca(2+)](cyt)) constitute a fundamental signal transduction mechanism in eukaryotic cells, but the molecular identity of Ca(2+) channels initiating this signal in plants is still under debate. Here, we show by pharmacology and loss-of-function mutants that in tobacco and Arabidopsis, glutamate receptor-like channels (GLRs) facilitate Ca(2+) influx across the plasma membrane, modulate apical [Ca(2+)](cyt) gradient, and consequently affect pollen tube growth and morphogenesis. Additionally, wild-type pollen tubes grown in pistils of knock-out mutants for serine-racemase (SR1) displayed growth defects consistent with a decrease in GLR activity. Our findings reveal a novel plant signaling mechanism between male gametophyte and pistil tissue similar to amino acid-mediated communication commonly observed in animal nervous systems.  相似文献   

Experimental evolution of reduced sex ratio adjustment under local mate competition     

Macke E  Magalhães S  Bach F  Olivieri I 《Science (New York, N.Y.)》2011,334(6059):1127-1129

Theory predicts that local mate competition (LMC) favors the evolution of female-biased sex ratios. Empirical support of this prediction is indirect and comes from comparative studies or from studies showing that individuals can adjust their offspring sex ratio in response to varying LMC intensities. Replicate lines from a population of the spider mite Tetranychus urticae were selected under three LMC intensities for up to 54 generations. Within each selection regime, the final sex ratio matched theoretical predictions. Furthermore, the ability of individuals to adjust their offspring sex ratio diminished in females evolving under strict LMC, but not in females evolving under relaxed LMC levels. These results provide direct experimental evidence for the evolutionary process by which LMC modifies sex-allocation strategies and suggest that evolution under strict and constant LMC may lead to a loss of phenotypic plasticity.  相似文献   

The mutational landscape of head and neck squamous cell carcinoma     

Stransky N  Egloff AM  Tward AD  Kostic AD  Cibulskis K  Sivachenko A  Kryukov GV  Lawrence MS  Sougnez C  McKenna A  Shefler E  Ramos AH  Stojanov P  Carter SL  Voet D  Cortés ML  Auclair D  Berger MF  Saksena G  Guiducci C  Onofrio RC  Parkin M  Romkes M  Weissfeld JL  Seethala RR  Wang L  Rangel-Escareño C  Fernandez-Lopez JC  Hidalgo-Miranda A  Melendez-Zajgla J  Winckler W  Ardlie K  Gabriel SB  Meyerson M  Lander ES  Getz G  Golub TR  Garraway LA  Grandis JR 《Science (New York, N.Y.)》2011,333(6046):1157-1160

Head and neck squamous cell carcinoma (HNSCC) is a common, morbid, and frequently lethal malignancy. To uncover its mutational spectrum, we analyzed whole-exome sequencing data from 74 tumor-normal pairs. The majority exhibited a mutational profile consistent with tobacco exposure; human papillomavirus was detectable by sequencing DNA from infected tumors. In addition to identifying previously known HNSCC genes (TP53, CDKN2A, PTEN, PIK3CA, and HRAS), our analysis revealed many genes not previously implicated in this malignancy. At least 30% of cases harbored mutations in genes that regulate squamous differentiation (for example, NOTCH1, IRF6, and TP63), implicating its dysregulation as a major driver of HNSCC carcinogenesis. More generally, the results indicate the ability of large-scale sequencing to reveal fundamental tumorigenic mechanisms.  相似文献   

Effects of glucocorticoids and norepinephrine on the excitability in the hippocampus   总被引：13，自引：0，他引：13  

M Jo?ls  E R de Kloet 《Science (New York, N.Y.)》1989,245(4925):1502-1505

The CA1 pyramidal neurons in the hippocampus contain a high density of adrenal corticosteroid receptors. By intracellular recording, CA1 neurons in slices from adrenalectomized rats have been found to display a markedly reduced afterhyperpolarization (that is, the hyperpolarizing phase after a brief depolarizing current pulse) when compared with their sham controls. No differences were found for other tested membrane properties. Brief exposure of hippocampal slices from adrenalectomized rats to glucocorticoid agonists, 30 to 90 minutes before recording, greatly enhanced the afterhyperpolarization. In addition, glucocorticoids attenuated the norepinephrine-induced blockade of action potential accommodation in CA1 neurons. The findings indicate that glucocorticoids can reduce transmitter-evoked excitability in the hippocampus, presumably via a receptor-mediated genomic action.  相似文献   

Computed tomographic and gross anatomy of the head of the blue-fronted Amazon parrot (Amazona aestiva)     

Ana Carolina Lourenço Faillace  Kássia Regina Aguiar Vieira  Marcelo Ismar Silva Santana 《Anatomia, histologia, embryologia》2021,50(1):192-205

  相似文献   

Partially replacing sorghum silage with cactus (Opuntia stricta) cladodes in a soybean oil-supplemented diet markedly increases trans-11 18:1, cis-9, trans-11 CLA and 18:2 n-6 contents in cow milk     

Marco A. S. Gama  Talita A. de Paula  Antônia S. C. Véras  Sebastião I. Guido  Cristiano A. V. Borges  Rosemar Antoniassi  Fernando C. F. Lopes  Maria L. M. W. Neves  Marcelo de A. Ferreira 《Journal of animal physiology and animal nutrition》2021,105(2):232-246

Based on low 18:0 contents observed in milk fat of cows fed cactus cladodes (CC), we hypothesized that including Opuntia stricta cladodes in a soybean oil (SO)-supplemented diet would promote incomplete rumen biohydrogenation of supplemental PUFA, leading to increased trans-11 18:1 and cis-9, trans-11 CLA contents in milk. Twelve Holstein cows were used in a two-period study: (a) Baseline: all cows received a total mixed ration (TMR) composed of sorghum silage (SS) and a concentrate containing no SO for 14 days; (b) Treatment: cows received one of the following SO-supplemented diets for 21 days: (1) SS-TMR: a TMR composed of SS and a SO-enriched concentrate, (2) CC-TMR: a TMR containing CC as a partial substitute for SS plus the SO-enriched concentrate, and (3) CC-PMR: same diet as in treatment 2, but CC were mixed with the SO-enriched concentrate and fed as a partial mixed ration (PMR). Both CC diets increased relative abundances of trans-11 18:1, cis-9, trans-11 CLA, and 18:2 n-6 in milk fat, whereas opposite effects were observed on 18:0 and cis-9 18:1. Proportion of 18:2 n-6 increased, and cis-9, trans-11 CLA tended to increase with CC-PMR as compared to CC-TMR, whereas 18:3 n-3 was higher with CC-PMR than with SS-TMR. Proportions of several odd- and branched-chain fatty acids, certain 18:1 isomers, and trans-9, cis-11 CLA changed with CC diets, notably with CC-PMR. Milk yield and intake of most nutrients (except fibre) increased or tended to increase with the CC diets, whereas gross milk composition was unaltered. Stearoyl-CoA desaturase-1 index for C18 (SCD₁₈) was higher with CC-PMR than with SS-TMR, and milk n-6:n-3 FA ratio and apparent transfer of 18:2 n-6 to milk increased with CC diets. These results indicate that Opuntia stricta cladodes can be a valuable feed ingredient for improving the nutraceutical value of milk fat.  相似文献   

Effect of dietary inclusion of Spirulina on production performance,nutrient digestibility and meat quality traits in post-weaning piglets     

Cátia Falcão Martins  José Pestana Assunção  David M. Ribeiro Santos  Marta Sofia Morgado dos S. Madeira  Cristina Maria Riscado Pereira Mateus Alfaia  Paula Alexandra Antunes Brás Lopes  Diogo Francisco Maurício Coelho  José Pedro Cardoso Lemos  André M. de Almeida  José António Mestre Prates  João Pedro Bengala Freire 《Journal of animal physiology and animal nutrition》2021,105(2):247-259

The effect of Spirulina (Arthrospira platensis), individually or in combination with two commercial carbohydrases, in piglet diets was assessed on growth performance, nutrient digestibility and meat quality traits. Forty post-weaned male piglets from Large White × Landrace sows crossed with Pietrain boars with an initial live weight of 12.0 ± 0.89 kg were used. Piglets were assigned to one of four dietary treatments (n = 10): cereal and soya bean meal base diet (control), base diet with 10% Spirulina (SP), SP diet supplemented with 0.005% Rovabio^® Excel AP (SP + R) and SP diet supplemented with 0.01% lysozyme (SP + L). Animals were slaughtered after a 4-week experimental period. Growth performance was negatively affected by the incorporation of Spirulina in the diets, with an average decrease of 9.1% on final weight, in comparison with control animals. Total tract apparent digestibility (TTAD) of crude protein was higher (p < .05) in the control group than in other groups. In addition, lysozyme increased TTAD of crude fat and acid detergent fibre, relative to the SP and control groups, respectively. In addition, the incorporation of Spirulina, individually and supplemented with enzymes, did not impair meat quality traits. Surprisingly, no protective effect against lipid oxidation was observed with the inclusion of Spirulina in pork after 7 days of storage. This study indicates that growth performance of post-weaning piglets was impaired by the incorporation of 10% Spirulina in the diets, which is mediated by an increase in digesta viscosity and a lower protein digestibility, as a consequence of the resistance of microalga proteins to the action of endogenous peptidases. In addition, it also indicates that lysozyme, in contrast to Rovabio^® Excel AP, is efficient in the degradation of Spirulina cell wall in piglet's intestine. However, the digestion of proteins liberated by Spirulina cell wall disruption is still a challenge.  相似文献   

Influence of seminal plasma during different stages of bovine sperm cryopreservation     

Gabriela Bertaiolli Zoca  Eneiva Carla Carvalho Celeghini  Guilherme Pugliesi  Carla Patricia Teodoro de Carvalho  Mayra Elena Ortiz D'Avila Assumpção  Adriano Felipe Perez Siqueira  Leticia Zoccolaro Oliveira  Renata Lançoni  Rubens Paes de Arruda 《Reproduction in domestic animals》2021,56(6):872-883

This study aimed to evaluate the effect of seminal plasma on bovine sperm cryopreservation and to assess the integrity of plasma and acrosomal membranes, mitochondrial potential, remodelling of F-actin cytoskeleton and sperm chromatin fragmentation during the cooling, equilibrium and freezing/thawing stages. Six ejaculates collected from seven Nelore bulls (n = 42) were used in this study. Each ejaculate was divided into two aliquots (with seminal plasma = SP group; without seminal plasma = NSP group) and packed to a final concentration of 50 × 10⁶ sperm per straw. Statistical analyses were performed using SAS software (version 9.3), and p ≤ .05 was considered significant. A time effect was observed for all sperm characteristics (p < .05), except for chromatin fragmentation (p > .05). The presence of seminal plasma better preserved the acrosomal integrity (SP = 75.2% and NSP = 71.7%; p < .05) and also provided lower F-actin remodelling during cryopreservation process (SP = 29.9% and NSP = 32.4%; p < .05). Regarding to the cryopreservation stages, it was observed that cooling step induced higher remodelling of F-actin than the equilibrium and freezing/thawing stages (56.3%, 32.2% and 23.9%, respectively; p < .05). The equilibrium step had minor influence on overall sperm characteristics while the freezing/thawing stage was responsible for the highest percentage of damage in plasma membrane (−65.2%), acrosomal membrane (−34.0%) and mitochondrial potential (−48.1%). On the other hand, none of the cryopreservation stages affected chromatin integrity. It was concluded that the presence of seminal plasma provides increased acrosomal integrity and reduced remodelling of F-actin cytoskeleton. Higher F-actin remodelling is observed after the cooling step while the freezing/thawing step is most damaging to sperm membranes and mitochondrial potential during bovine sperm cryopreservation.  相似文献