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1.
本研究旨在探讨黄芩素抗猪丁型冠状病毒(porcine deltacoronavirus,PDCoV)感染的作用机制。通过Pharmmapper、Pubchem、STITCH、TCMSP和Swiss Targer Prediction数据库获得黄芩素的作用靶点。根据前期蛋白组学结果获得PDCoV感染的相关靶点,获取黄芩素与PDCoV感染的共同靶点,并利用STRING数据库和Cytoscape 3.8.2软件构建“药物-疾病-靶点”网络和靶蛋白相互作用网络,利用CytoNCA插件进行网络拓扑分析和核心网络构建,使用Metascape数据库对核心网络基因进行GO和KEGG分析。通过细胞试验对富集得到的信号通路下游基因表达水平进行检测。通过筛选,共获得黄芩素的潜在靶基因268个,黄芩素-PDCoV的共同靶点75个,GO富集结果表明黄芩素主要参与细胞周期、细胞膜筏形成、线粒体膜形成、纺锤体形成和MAPK信号级联传导过程;KEGG富集筛选得到277条信号通路(P<0.01),主要涉及PI3K-Akt信号通路、Ras信号通路和MAPK信号通路等。细胞试验结果表明,与正常细胞对照组相对,病毒感染后PI3K、AKTNF-κB mRNA表达显著升高;与病毒感染组相比,黄芩素处理组PI3KAKTNF-κB mRNA的表达显著降低(P<0.05)。黄芩素对PDCoV感染的作用具有多靶点、多通路的特点,可能是通过作用于AKT1、HSP90AA1、SRCEGFRCASP3、MAPKSTAT3等核心基因调控PI3K-Akt、Ras和MAPK信号通路、细胞凋亡、病毒感染等通路发挥作用,可以作为抗PDCoV感染的潜在治疗药物进一步研究。  相似文献   
2.
Exudative epidermitis (EE) is an acute, often fatal skin disease of piglets caused by Staphylococcus hyicus. Clinical and histopathological manifestations of EE are similar to those of staphylococcal scalded skin syndrome (SSSS), a human blistering skin disease, in which exfoliative toxins produced by Staphylococcus aureus digest the extracellular domains of desmoglein (Dsg) 1 and cause loss of epidermal cell-cell adhesion. The aims of this study were to isolate and characterize cDNA for full length of swine Dsg1, and to determine whether the extracellular domains of swine Dsg1 produced by baculovirus (sDsg1-His) could be digested by four isoforms of exfoliative toxin produced by S. hyicus (ExhA, ExhB, ExhC and ExhD). Nucleotide sequencing revealed that swine Dsg1 cDNA consisted of an open reading frame of 3138 bp, encoding a precursor protein of 1045 amino acids. Deduced amino acid sequence of the swine Dsg1 precursor were highly homologous to corresponding bovine, canine, human and murine sequences. Immunoadsorption assay with a secreted form of sDsg1-His revealed that sDsg1-His specifically absorbs the immunoreactivity of 10 human pemphigus foliaceus sera against swine keratinocyte cell surfaces, suggesting its proper conformation. When sDsg1-His was incubated in vitro with Exhs, all four isoforms of Exh directly digested sDsg1-His into smaller peptides, whereas removal of calcium from sDsg1-His completely inhibited its proteolysis by these four Exhs. Recognition and digestion of calcium-stabilized structure on the extracellular domains of swine Dsg1 by Exhs indicated that EE shares similar molecular pathophysiological mechanisms of intra-epidermal splitting with SSSS in humans.  相似文献   
3.
Microsatellite loci were developed for Gynochthodes boninensis, an endemic climbing plant in the Bonin Islands. Using a Roche 454 GS Junior next-generation sequencer, 158 microsatellite loci were designed. Of the 48 microsatellite loci tested, 37 were successfully amplified and 25 were polymorphic in two populations of G. boninensis. For the 25 polymorphic loci, the mean expected heterozygosities per locus were 0.303 in the Chichijima Island population and 0.310 in the Hahajima Island population, respectively. There was no evidence of linkage disequilibrium in either population, but one locus showed significant deviation from Hardy–Weinberg equilibrium in one population. The microsatellite loci developed in this study will be useful for future studies of population genetics of G. boninensis. In particular, because this species is androdioecious (males and hermaphrodites coexist), characterizing the species gene flow is crucial to understanding the evolution and maintenance of this rare sexual system.  相似文献   
4.
A six‐week growth trial was performed to estimate the dietary protein requirements for maximum growth of juvenile Brazilian sardine (Sardinella brasiliensis) based on growth performance, feed utilization, body composition and digestive enzyme activity. Six isoenergetic diets were formulated to contain protein levels that increased from 250 to 500 g/kg. Each diet was randomly assigned to triplicate groups of 160 fish with mean initial body weight of 0.93 ± 0.13 g, which were fed four times a day to apparent satiation. Growth tended to increase with the increase in the dietary protein level up to 400 g/kg. Total protein intake was indirectly correlated to apparent protein utilization. No significant differences in whole‐body composition were found between fish fed the different protein levels. Acid protease and neutral lipase activities did not show significant differences among the different protein dietary groups. Alkaline protease activity increased in fish fed up to 350 g/kg of protein and amylase activity in fish fed up to 400 g/kg. Using polynomial regression, 367 g/kg was estimated to be the optimum dietary protein requirement for maximum weight gain of juvenile Brazilian sardines.  相似文献   
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The limited availability of live bait for capturing skipjack tuna, Katsuwonus pelamis, is a bottleneck to increasing tuna production in many parts of the world. Therefore, a nutrition trial was performed to contribute to the production of the Brazilian sardine, Sardinella brasiliensis, for use as live bait. This study determined the best dietary carbohydrate to lipid ratio (CHO:L) for juvenile Brazilian sardines based on growth performance, feed utilisation, body composition, blood metabolites and digestive enzyme activity. Six isoenergetic and isonitrogenous diets were formulated with increased CHO:L ratios (2.05, 3.41, 4.15, 5.11, 5.80 and 6.72). Each diet was randomly assigned to triplicate groups of 100 fish with mean initial body weight of 2.97 ± 0.51 g, which were fed four times a day to apparent satiation. Survival was not affected by differences in diet, however, a low CHO:L ratio stimulated growth. Juveniles fed with a rich‐carbohydrate diet inhibit feed intake and protein intake. Body lipid increased as dietary lipid increased and was inversely correlated to body moisture. The diets did not affect the juvenile's blood metabolites. Alkaline and acid protease activities were not significantly different, but lipase and amylase responded positively to the dietary lipids and carbohydrates. Using segmented regression, the optimum CHO:L ratio for maximum weight gain of juvenile Brazilian sardines was estimated to be 3.41, which contain approximately 300 g kg?1 carbohydrate and 88 g kg?1 lipid.  相似文献   
8.
In saffron cod, Eleginus gracilis, the antifreeze glycoprotein (AFGP) is present during the winter. The effects of salmon prolactin (sPRL) and growth hormone (sGH) on plasma osmolality, sodium concentration and protein content of the saffron cod were investigated. In the winter, plasma osmolality and protein content decreased following the intraperitoneal injection of sPRL (20 µg kg-1 day-1 × 3) but injection of the same dose of sGH had no effect on either plasma osmolality or protein content. In similar experiments performed during the summer, sPRL and sGH had no effect on these parameters. The results suggest that PRL may act on the kidney, possibly clearing antifreeze glycoprotein (AFGP) by increasing glomerular filtration. The possible role of PRL and GH in the disappearance of AFGP during the summer are discussed.  相似文献   
9.
Although the use of stable transformants is indispensable to elucidate mechanisms underlying molecular plant–pathogen interactions, this approach remains difficult to apply to crops. Alternatively, biolistic transformation has often been used as a transient expression method in various plants. In this study, we developed a method for in situ biolistic transformation without separating leaves from barley seedlings by using a hand-held particle bombardment system because unwounded leaves are preferable for analyzing interactions between barley and Blumeria graminis f. sp. hordei which requires healthy living cells. As a result, we found that the infection rate in intact leaves was higher than in separated leaves and that the transformation efficiencies in leaves were higher when plants were grown in vermiculite rather than in culture soil. Furthermore, we determined the appropriate inoculation time after bombardment to analyze the incompatible interaction and successfully monitored the gradual occurrence of cell death over time. Our system was suitable for relatively long-term follow-up analysis of the fate of each single cell during plant–pathogen interactions.  相似文献   
10.
When fungal germlings, after forming haustoria of Blumeria graminis f. sp. hordei (B. graminis), were removed from the surfaces of barley coleoptiles by cellulose acetate, followed by challenge inoculation with the non-pathogen Erysiphe pisi, they infected the nonhost barley coleoptile cells. This phenomenon was not observed on the coleoptile surface when the fungal germlings of B. graminis were removed before the formation of haustoria. Also, when the surface was inoculated with the pathogen of barley B. graminis as a challenger, after removing the fungal germlings of inducer post haustorial formation, the penetration efficiency of the fungi increased significantly compared with that of the control. Furthermore, when we extracted the crude-susceptibility inducing factor (suppressor) from coleoptiles before and after the formation of haustoria of B. graminis, suppressor activity against infection with E. pisi was observed only in the extract of barley coleoptiles that included haustoria of B. graminis about 18 h or later after inoculation. Surprisingly, however, the extract did not increase the penetration efficiency of B. graminis significantly. Thus, we hypothesize that the suppressor extracted from barley coleoptiles in which B. graminis had formed haustoria has no effect on increasing the penetration efficiency of the primary infection from the appressorium of B. graminis but has an effect on the infection with non-pathogen E. pisi.  相似文献   
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