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181.
Insect γ‐aminobutyric acid receptors (GABARs) are important molecular targets of cyclodiene and phenylpyrazole insecticides. Previously GABARs encoding rdl (resistant to dieldrin) genes responsible for dieldrin and fipronil resistance were identified in various economically important insect pests. In this study, we cloned the open reading frame cDNA sequence of rdl gene from fipronil‐susceptible and fipronil‐resistant strains of Laodelphax striatellus (Lsrdl). Sequence analysis confirmed the presence of a previously identified resistance‐conferring mutation. Different alternative splicing variants of Lsrdl were noted. Injection of dsLsrdl reduced the mRNA abundance of Lsrdl by 27–82%, and greatly decreased fipronil‐induced mortality of individuals from both susceptible and resistant strains. These data indicate that Lsrdl encodes a functional RDL subunit that mediates susceptibility to fipronil. Additionally, temporal and spatial expression analysis showed that Lsrdl was expressed at higher levels in eggs, fifth‐instar nymphs, and female adults than in third‐instar and fourth‐instar nymphs. Lsrdl was predominantly expressed in the heads of 2‐day‐old female adults. All these results provide useful background knowledge for better understanding of fipronil resistance related ionotropic GABA receptor rdl gene expressed variants and potential functional differences in insects.  相似文献   
182.
巴西橡胶树(Hevea brasiliensis)的黄色体在胶乳凝固和保护植株过程中有重要作用。本文比较使用三氯醋酸/丙酮(TCA/ ACE)、Tris缓冲液、磷酸缓冲液提取橡胶树胶乳黄色体总蛋白的双向电泳效果。确定一种适合双向电泳的蛋白提取方法。结果表明Tris缓冲液提取法得到的双向电泳图谱可以达到300个,尤其是低丰度蛋白呈现性较好,适合提取黄色体蛋白以进行双向电泳。  相似文献   
183.
海堤对广西沿海红树林的数量,群落特征和恢复的影响   总被引:19,自引:1,他引:19  
广西大陆海岸线的 63%为海堤 ,海堤数量达 498个 .海堤建立毁灭了原生红树林 ,现余 5654hm2 ,其中约 85%为堤前红树林 .海堤阻截了红树林滩涂的自然海岸地貌 ,结果是红海榄和木榄已很少 ,榄李濒危 ,角果木已消失 ,海漆和陆岸种类只能沿海堤坡面生长 ,而先锋红树植物白骨壤和桐花树成为现有红树林的优势种 .堤前红树林的恢复受到海堤维护时强烈的人为干扰 .堤前滩涂相对于平均海平面的高程较低 ,不是红树林繁盛的理想滩涂 .红树林人工造林的成活率和次生林恢复的速率在很大程度上取决于生境的沉积率 .  相似文献   
184.
人CD34~ 造血细胞是具有高度自我更新、多向分化及重建长期造血与免疫学功能的独特体细胞。为系统探索CD34~ 造血细胞的形态、细胞化学及超微结构特征,新近我们设计组合并建立了CIMS-100-FACS 440无菌二次分选术,可使所获CD34~ 造血细胞的纯度达100%。在此基础上,本研究采用Cambri-dge Quantimet 970全自动图像分析仪对光学显微镜、扫描电镜及透射电镜下的CD34~ 造血细胞进行了体视学方面的某些探讨,进一步从三维结构信息中深刻揭示CD34~ 造血细胞的形态计量学特征。经扫描→模数转换←阴影校正→图像暂存←统计分析等检测,结果表明:CD34~ 造血细胞的直径3.490—6.741μm,周长11.776—26.240μm,面积9.565—35.686μm~2,形状因子1.048—1.840,核浆比0.58—0.72,平均光密度0.17675—0.65100,积分光密度2717.217—9870.643。由此可见CD34~ 造血细胞的确为非均一细胞群,这可能与CD34~ 造血细胞的功能亚群与分化阶段密切相关。据我们所知,这是国际上首次有关人CD34~ 造血细胞体视学特征的报道。  相似文献   
185.
以北京地区油松(Pinus tabuliformis)人工林不同演替类型林分为研究对象,研究油松纯林、油松-栓皮栎(Quercus variabilis)混交林和栓皮栎纯林三种不同演替类型林分的空间结构、林下植被和土壤水分的变化规律及其相互作用关系。结果表明:(1)林分水平及垂直空间结构、草本层物种多样性、更新幼树生长、土壤持水和透气性能等指标在三种不同演替类型林分间差异显著(P<0.05),林分空间结构参数中的角尺度、林层指数和开敞度显著影响了各类型林分的灌草多样性,混交度、林层指数和大小比数显著影响了更新幼树的生长,混交度和林层指数显著影响了土壤水分的变化(P<0.05)。(2)松栎混交林灌草生物量、天然更新幼树的生长以及土壤水分物理状况均好于纯林,并主要受林分混交度和林层指数的共同作用。(3)各演替类型林分内均存在栓皮栎更新幼树,混交林栓皮栎更新幼树数量最多、长势最好,对林地资源的竞争最为激烈。因此,可以通过调整林分空间结构实现种间关系及林地资源的调控,以充分发挥森林生态系统的各项功能与价值。  相似文献   
186.
187.
Atherosclerosis is a kind of chronic cardiovascular disease, characterized by oxidized low-density lipoprotein (ox-LDL) accumulation in macrophage. Tanshinone IIA (Tan), a lipophilic pharmacologically activate compound from Salvia miltiorrhiza Bunge, has been indicated to exert cardioprotective roles. Nevertheless, the biological role of Tan and regulatory mechanism in atherosclerosis are not fully established. In present study, atherosclerosis model was established in THP-1-derived macrophages by treatment of ox-LDL. The adipogenesis was measured by Nile red staining. The expressions of inflammatory factors, microRNA-130b (miR-130b) and WNT5A were measured by quantitative real-time polymerase chain reaction or Western blot. The target association between miR-130b and WNT5A was explored via luciferase activity and RNA immunoprecipitation assay. The results showed that exposure of Tan inhibited ox-LDL-induced adipogenesis and expressions of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-alpha in THP-1-derived macrophages. miR-130b expression was decreased in THP-1-derived macrophages treated by ox-LDL and its overexpression attenuated adipogenesis as well as inflammatory response. miR-130b knockdown reversed the regulatory effect of Tan on adipogenesis and inflammatory response in THP-1-derived macrophages stimulated by ox-LDL. In addition, WNT5A acted as a functional target of miR-130b and inhibited by Tan and miR-130b. As a conclusion, Tan decreased the adipogenesis and inflammatory response by mediating miR-130b and WNT5A, providing a novel theoretical foundation for treatment of atherosclerosis.  相似文献   
188.
Recent evidence has verified the cardioprotective actions of irisin in different diseases models. However, the beneficial action of irisin on hypoxia-reoxygenation (HR) injury under high glucose stress has not been described. Herein our research investigated the influence of irisin on HR-triggered cardiomyocyte death under high glucose stress. HR model was established in vitro under high glucose treatment. The results illuminated that HR injury augmented apoptotic ratio of cardiomyocyte under high glucose stress; this effect could be abolished by irisin via modulating mitochondrial function. Irisin treatment attenuated cellular redox stress, improved cellular ATP biogenetics, sustained mitochondria potential, and impaired mitochondrion-related cell death. At the molecular levels, irisin treatment activated the 5′-adenosine monophosphate-activated protein kinase (AMPK) pathway and the latter protected cardiomyocyte and mitochondria against HR injury under high glucose stress. Altogether, our results indicated a novel role of irisin in HR-treated cardiomyocyte under high glucose stress. Irisin-activated AMPK pathway and the latter sustained cardiomyocyte viability and mitochondrial function.  相似文献   
189.
In eukaryotes, autophagy helps maintain cellular homeostasis by degrading and recycling cytoplasmic materials via a tightly regulated pathway.Over the past few decades, significant progress has been made towards understanding the physiological functions and molecular regulation of autophagy in plant cells. Increasing evidence indicates that autophagy is essential for plant responses to several developmental and environmental cues, functioning in diverse processes such as senescence, male fertility, root meristem maintenance, responses to nutrient starvation,and biotic and abiotic stress. Recent studies have demonstrated that, similar to nonplant systems,the modulation of core proteins in the plant autophagy machinery by posttranslational modifications such as phosphorylation, ubiquitination,lipidation, S-sulfhydration, S-nitrosylation, and acetylation is widely involved in the initiation and progression of autophagy. Here, we provide an overview of the physiological roles and posttranslational regulation of autophagy in plants.  相似文献   
190.
Joint capsule fibrosis caused by excessive inflammation results in post-traumatic joint contracture (PTJC). Transforming growth factor (TGF)-β1 plays a key role in PTJC by regulating fibroblast functions, however, cytokine-induced TGF-β1 expression in specific cell types remains poorly characterized. Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine involved in inflammation- and fibrosis-associated pathophysiology. In this study, we investigated whether MIF can facilitate TGF-β1 production from fibroblasts and regulate joint capsule fibrosis following PTJC. Our data demonstrated that MIF and TGF-β1 significantly increased in fibroblasts of injured rat posterior joint capsules. Treatment the lesion sites with MIF inhibitor 4-Iodo-6-phenylpyrimidine (4-IPP) reduced TGF-β1 production and relieved joint capsule inflammation and fibrosis. In vitro, MIF facilitated TGF-β1 expression in primary joint capsule fibroblasts by activating mitogen-activated protein kinase (MAPK) (P38, ERK) signaling through coupling with membrane surface receptor CD74, which in turn affected fibroblast functions and promoted MIF production. Our results reveal a novel function of trauma-induced MIF in the occurrence and development of joint capsule fibrosis. Further investigation of the underlying mechanism may provide potential therapeutic targets for PTJC.  相似文献   
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