黄曲条跳甲室内饲养方法的改进

介绍一种饲养黄曲条跳甲Phyllotreta striolata(Fabricius)的改进新方法,采用分隔式养虫笼饲养成虫和萝卜"凹"型孔饲养幼虫,结果表明,使用该方法进行饲养,卵的成活率可达89.3%,1~3龄幼虫的存活率为65.0%~70.0%,蛹的存活率达80.0%,可以有效实现黄曲条跳甲的室内饲养。     

黄曲条跳甲人工饲养技术改进

通过室内人工饲养建立实验种群,是开展黄曲条跳甲Phyllotreta striolata(Fabricius)各种研究的基础,解决其幼虫阶段的人工饲养技术是建立其实验种群的关键。介绍经改进后的黄曲条跳甲室内人工饲养技术,该方法简单易行,可以方便地获取试虫的不同虫态;采用"小菜苗法"和"萝卜薄片堆叠法"室内饲养黄曲条跳甲幼虫,最高存活率可达90%以上。     

植物提取物对黄曲条跳甲成虫毒作用的研究

研究24种植物提取物对黄曲条跳甲成虫的毒杀活性.结果表明处理后72h,供试植物提取物中的7种对黄曲条跳甲成虫有毒作用,但毒杀活性较低,其中烟碱对黄曲条跳甲成虫的毒杀效果最好,累积死亡率为3.33%;假莲翘Duranta repens 乙醇得取物对黄曲条跳甲成虫的毒杀效果最差,累积死亡率为1.12%;其余提取物对黄曲条跳甲成虫的毒杀效果居中,累积死亡率为1.67%-2.78%.因此,毒杀作用并不是供试植物提取物对黄曲条跳甲成虫的主要控制机理.     

植物提取物对黄曲条跳甲成虫毒杀作用的研究

研究24种植物提取物对黄曲条跳甲成虫的毒杀活性。结果表明：处理后72h,供试植物提取物中的7种对黄曲条跳甲成虫有毒杀作用,但毒杀活性较低,其中烟碱对黄曲条跳甲成虫的毒杀效果最好,累积死亡率为3．33％;假莲翘Duranta repeens乙醇提取物对黄曲条跳甲成虫的毒杀效果最差,累积死亡率为1．21％;其余提取物对黄曲条跳甲成虫的毒杀效果居中,累积死亡率为1．67％-2．78％。因此,毒杀作用并不是供试植物提取物对黄曲条跳甲成虫的主要控制机理。     

秋季菜心田主要害虫生态位

对福州郊区菜心田害虫种群的生态位进行了初步研究。结果表明,黄曲条跳甲、小菜蛾和蚜虫为秋季菜心田最主要的害虫。不同害虫的生态位上存在明显分化,黄曲条跳甲在时间生态位上占有较多资源,小菜蛾则在空间生态位上占有相当多资源。并分析探讨了田间不同害虫种群混合发生的竞争机制及相应的害虫控制策略。     

黄曲条跳甲种群分化的RAPD分析

采用RAPD方法,对福建省19个不同菜区黄曲条跳甲地理种群的分化进行了研究。结果表明：相同种群采用相同引物进行扩增的重复性较好,不同种群采用相同引物进行扩增的差异性较高;19个不同菜区的黄曲条跳甲主要分为4个类群：闽东南沿海地区类群、闽西北地区类群、泉州类群和东山岛类群,黄曲条跳甲不同地理种群的遗传距离与地理距离有关。东山岛和泉州2个特异性类群的出现,说明地形、蔬菜种植以及农药使用等人为因子会影响其地理种群的分化。     

环境因素对黄曲条跳甲种群扩散的影响

应用标记回收技术,研究了寄主及气象因素对黄曲条跳甲种群扩散的影响.结果表明,黄曲条跳甲的自然扩散是由环境引起(τ≈1),温度、风速与之有一定的相关性(P<0.05),高温不利于黄曲条跳甲的扩散,其扩散主要沿逆风或与风向垂直方向进行,而湿度与黄曲条跳甲成虫扩散无显著相关(P>0.05).寄主是影响黄曲条跳甲扩散的重要因子,在几种寄主植物中,菜心上收集的标记成虫数最多,其次为芥菜,再次为白菜,芥蓝上基本没有.     

虫害诱导的植株对小菜蛾取食和生长发育的影响

本文从菜田生态系统的角度出发,就黄曲条跳甲Phyllotreta striolata(Fabricius)取食诱导对小菜蛾Plutella xylostella(L.)造成的影响进行了研究。黄曲条跳甲取食诱导对小菜蛾取食的影响比较明显,一般来说,黄曲条跳甲少量或短时间的取食会刺激小菜蛾幼虫在相应叶片上的取食,反之则会抑制;而且不同的寄主,不同完整度的叶片(即是否被黄曲条跳甲取食过)上的承载能力不同,芥菜、白菜、菜心和萝卜的承载力弱于甘蓝和芥蓝,黄曲条跳甲取食过的叶片弱于未被黄曲条跳甲取食过的叶片;不同数量的黄曲条跳甲取食对小菜蛾的产卵量影响显著,对其余生物学参数影响不显著,少量的黄曲条跳甲取食会刺激小菜蛾的产卵,多数则会抑制。     

黄曲条跳甲对毒死蜱敏感性差异的生化机制

采用生物测定方法测定黄曲条跳甲Phyllotreta striolata(F.)2个室内试验种群(蔊菜试验种群、上海青试验种群)和1个田间自然种群对毒死蜱的LC50值。结果表明,蔊菜试验种群对毒死蜱的LC50值最低,为30.3459mg.L-1;田间自然种群对毒死蜱的LC50值最高,为77.8448mg.L-1,与蔊菜试验种群相比的敏感性指数为0.39。对不同种群黄曲条跳甲乙酰胆碱酯酶(AChE)、羧酸酯酶(CarE)、谷胱甘肽-S-转移酶(GSTs)的活性测定结果表明,黄曲条跳甲田间自然种群AChE活性最低,与菜试验种群、上海青试验种群相比,差异极显著(P>0.01);田间自然种群GSTs活性最高,与蔊菜试验种群、上海青试验种群相比,差异极显著(P>0.01);黄曲条跳甲蔊菜试验种群CarE活性最低,田间自然种群CarE活性最高,二者差异极显著(P>0.01);说明黄曲条跳甲对毒死蜱的敏感性下降可能与AChE活性的降低,与CarE、GSTs的活性提高有一定的关系。     

苏云金芽胞杆菌HA和HD对黄曲条跳甲成虫的毒力分析

黄曲条跳甲Phyllotreta striolata (Fabricius)是为害十字花科蔬菜的世界性害虫之一.为了探究苏云金芽胞杆菌HA和HD对黄曲条跳甲成虫的防治潜力,本研究测定了苏云金芽胞杆菌HA和HD菌株对黄曲条跳甲成虫的毒力,以及对其谷胱甘肽-S-转移酶(GST)活性和中肠组织形态的影响.结果 表明:Bt-HA和Bt-HD均对黄曲条跳甲成虫有杀虫活性,LC50分别为4.01×108 CFU/mL和1.17×108 CFU/mL.菌株Bt-HD处理组的GST酶活性高于对照组和菌株Bt-HA处理组.菌株Bt-HA处理黄曲条跳甲成虫14 d后,中肠微绒毛肿胀脱落;菌株Bt-HD处理黄曲条跳甲成虫4d后中肠微绒毛开始疏松脱落,14 d后中肠柱状细胞底膜变形脱落.综上所述,苏云金芽胞杆菌HD对黄曲条跳甲成虫的毒力更强,是防治黄曲条跳甲成虫的优势菌株,其杀虫机理值得深入研究.     

Different degree of ileal colonization by segmented, filamentous bacteria in two strains of mice.

Segmented, filamentous bacteria (SFBs) are autochthonous, apathogenic inhabitants of the ileum of various animal species. Outbred Swiss (Cpb:SE) mice have significantly higher degrees of SFB colonization than do inbred BALB/c mice. The present studies were carried out to identify determinants of this strain difference. In a cross-fostering experiment it was shown that SFB colonization of the pups is determined by the strain of the pups themselves rather than by the strain of the nursing dam. Thus, maternal effects may not be involved in SFB colonization. In a cross-infecting experiment using germ-free and SFB-positive animals of the two mouse strains, it was found that ileal SFB colonization is determined by host characteristics rather than by origin of the SFBs. Thus, SFBs that are specific for a given mouse strain may not exist in the two strains of mice. It is concluded that the mouse strain difference in SFB colonization is determined by host characteristics, which probably have a genetic basis.     

Effects of fluid shear stress on adventitial fibroblast migration: implications for flow-mediated mechanisms of arterialization and intimal hyperplasia

The involvement of vascular fibroblasts (FBs) and smooth muscle (SM)-like cells in physiological and pathological processes in large vessels (intimal hyperplasia) and microvessels (capillary arterialization), and the realization that these cells are exposed to interstitial flow shear stress (SS), motivate this study of SS on FB migratory activity. Rat adventitial FBs were grown to either 30-50% confluence (subconfluent FBs; SFBs) or full confluence (confluent FBs; CFBs) in culture. Immunofluorescence and Western blotting assays were conducted to evaluate the expression of two phenotype markers: SM alpha-actin and SM myosin heavy chain (MHC). Both assays indicated a significant increase in SM alpha-actin expression in CFBs compared with SFBs, suggesting a phenotype difference between the two cell populations. SFBs and CFBs both expressed minimal SM MHC. Both cell populations were seeded on Matrigel-coated cell culture inserts and exposed to 4 h of either 1 or 20 dyn/cm(2) SS via a rotating disk apparatus in the presence of the chemoattractant platelet-derived growth factor-BB to quantify the effect of SS on SFB and CFB migration. Four hours of 20 dyn/cm(2) SS significantly enhanced SFB migration while it suppressed CFB migratory activity. Four hours of 1 dyn/cm(2) SS did not significantly alter either SFB or CFB migration levels. Because of the distinct migratory responses of SFBs and CFBs in response to SS, phenotype modulation appears to be one way to regulate their involvement in both physiological and pathological remodeling processes.     

A Long Lifetime Aqueous Organic Solar Flow Battery

Monolithically integrated solar flow batteries (SFBs) hold promise as compact stand‐alone energy systems for off‐grid solar electrification. Although considerable research is devoted to studying and improving the round‐trip efficiency of SFBs, little attention is paid to the device lifetime. Herein, a neutral pH aqueous electrolyte SFB with robust organic redox couples and inexpensive silicon‐based photoelectrodes is demonstrated. Enabled by the excellent stability of both electrolytes and protected photoelectrodes, this SFB device exhibits not only unprecedented stable continuous cycling performance over 200 h but also a capacity utilization rate higher than 80%. Moreover, through comprehensive study on the working mechanisms of SFBs, a new theory based on instantaneous solar‐to‐output electricity efficiency toward more optimized device design is developed and a significantly improved solar‐to‐output electricity efficiency of 5.4% from single‐junction silicon photoelectrodes is realized. The design principles presented in this work for extending device lifetime and boosting round trip energy efficiency will make SFBs more competitive for off‐grid applications.     

The Lifestyle of the Segmented Filamentous Bacterium: A Non-Culturable Gut-Associated Immunostimulating Microbe Inferred by Whole-Genome Sequencing

Numerous microbes inhabit the mammalian intestinal track and strongly impact host physiology; however, our understanding of this ecosystem remains limited owing to the high complexity of the microbial community and the presence of numerous non-culturable microbes. Segmented filamentous bacteria (SFBs), which are clostridia-related Gram-positive bacteria, are among such non-culturable populations and are well known for their unique morphology and tight attachment to intestinal epithelial cells. Recent studies have revealed that SFBs play crucial roles in the post-natal maturation of gut immune function, especially the induction of Th17 lymphocytes. Here, we report the complete genome sequence of mouse SFBs. The genome, which comprises a single circular chromosome of 1 620 005 bp, lacks genes for the biosynthesis of almost all amino acids, vitamins/cofactors and nucleotides, but contains a full set of genes for sporulation/germination and, unexpectedly, for chemotaxis/flagella-based motility. These findings suggest a triphasic lifestyle of the SFB, which comprises two types of vegetative (swimming and epicellular parasitic) phases and a dormant (spore) phase. Furthermore, SFBs encode four types of flagellin, three of which are recognized by Toll-like receptor 5 and could elicit the innate immune response. Our results reveal the non-culturability, lifestyle and immunostimulation mechanisms of SFBs and provide a genetic basis for the future development of the SFB cultivation and gene-manipulation techniques.     

Intestinal, segmented, filamentous bacteria

Abstract Segmented, filamentous bacteria (SFBs) are autochthonous, apathogenic bacteria, occuring in the ileum of mice and rats. Although the application of formal taxonomic criteria is imposible due to the lack of an in vitro technique to culture SFBs, microbes with a similar morphology, found in the intestine of a wide range of vertebrate and invertebrate host species, are considered to be related. SFBs are firmly attached to the epithelial cells of the distal ileal mucosa, their preferential ecological niche being the epithelium covering the Peyer's patches. Electron microscopic studies have demonstrated a considerable morphological diversity of SFBs, which may relate to different stages of a life cycle. Determinants of SFB colonization in vivo are host species, genotypical and phenotypical characteristics of the host, diet composition, environmental stress and antimicrobial drugs. SFBs can survive in vitro incubation, but do not multiply. On the basis of their apathogenic character and intimate relationship with the host, it is suggested that SFBs contribute to development and/or maintenance of host resistance to enteropathogens.     

Intestinal, segmented, filamentous bacteria.

Segmented, filamentous bacteria (SFBs) are autochthonous, apathogenic bacteria, occurring in the ileum of mice and rats. Although the application of formal taxonomic criteria is impossible due to the lack of an in vitro technique to culture SFBs, microbes with a similar morphology, found in the intestine of a wide range of vertebrate and invertebrate host species, are considered to be related. SFBs are firmly attached to the epithelial cells of the distal ileal mucosa, their preferential ecological niche being the epithelium covering the Peyer's patches. Electron microscopic studies have demonstrated a considerable morphological diversity of SFBs, which may relate to different stages of a life cycle. Determinants of SFB colonization in vivo are host species, genotypical and phenotypical characteristics of the host, diet composition, environmental stress and antimicrobial drugs. SFBs can survive in vitro incubation, but do not multiply. On the basis of their apathogenic character and intimate relationship with the host, it is suggested that SFBs contribute to development and/or maintenance of host resistance to enteropathogens.     

Constitutive upregulation of the transforming growth factor-beta pathway in rheumatoid arthritis synovial fibroblasts

Genome-wide gene expression was comparatively investigated in early-passage rheumatoid arthritis (RA) and osteoarthritis (OA) synovial fibroblasts (SFBs; n = 6 each) using oligonucleotide microarrays; mRNA/protein data were validated by quantitative PCR (qPCR) and western blotting and immunohistochemistry, respectively. Gene set enrichment analysis (GSEA) of the microarray data suggested constitutive upregulation of components of the transforming growth factor (TGF)-beta pathway in RA SFBs, with 2 hits in the top 30 regulated pathways. The growth factor TGF-beta1, its receptor TGFBR1, the TGF-beta binding proteins LTBP1/2, the TGF-beta-releasing thrombospondin 1 (THBS1), the negative effector SkiL, and the smad-associated molecule SARA were upregulated in RA SFBs compared to OA SFBs, whereas TGF-beta2 was downregulated. Upregulation of TGF-beta1 and THBS1 mRNA (both positively correlated with clinical markers of disease activity/severity) and downregulation of TGF-beta2 mRNA in RA SFBs were confirmed by qPCR. TGFBR1 mRNA (only numerically upregulated in RA SFBs) and SkiL mRNA were not differentially expressed. At the protein level, TGF-beta1 showed a slightly higher expression, and the signal-transducing TGFBR1 and the TGF-beta-activating THBS1 a significantly higher expression in RA SFBs than in OA SFBs. Consistent with the upregulated TGF-beta pathway in RA SFBs, stimulation with TGF-beta1 resulted in a significantly enhanced expression of matrix-metalloproteinase (MMP)-11 mRNA and protein in RA SFBs, but not in OA SFBs. In conclusion, RA SFBs show broad, constitutive alterations of the TGF-beta pathway. The abundance of TGF-beta, in conjunction with an augmented mRNA and/or protein expression of TGF-beta-releasing THBS1 and TGFBR1, suggests a pathogenetic role of TGF-beta-induced effects on SFBs in RA, for example, the augmentation of MMP-mediated matrix degradation/remodeling.