Pertussis toxin modulation of sodium channels in the central neurons of cyhalothrin-resistant and cyhalothrin-susceptible cotton bollworm, Helicoverpa armigera

Pertussis toxin （FIX） inhibits the activation of the α-subunit of the inhibitory heterotrimeric G-proteins （Cαi/o） and modulates voltage-gated sodium channels, which may be one of the primary targets of pyrethroids. To investigate the potential mechanisms of agricultural pests resistance to pyrethroid insecticides, we examined the modulations by PTX on sodium channels in the central neurons of the 3rd-4th instar larvae of cyhalothrin-resistant （Cy-R） and cyhaiothrin-susceptible （Cy-S） Helicoverpa armigera by the whole-cell patch-clamp technique. The isolated neurons were cultured for 12-16 h in an improved L15 insect culture medium with or without PTX （400 ng/mL）. The results showed that both the Cy-R and Cy-S sodium channels exhibited fast kinetics and tetrodotoxin （TTX） sensitivity. The Cy-R sodium channels exhibited not only altered gating properties, including a 8.88-mV right shift in voltage-dependent activation （V0.5act） and a 6.54-mV right shift in voltage-dependent inactivation （V0.5inact）, but also a reduced peak in sodium channel density （Ⅰdensity） （55.2% of that in Cy-S neurons）. Cy-R sodium channels also showed low excitability, as evidenced by right shift of activation potential （Ⅴacti） by 5-10 mV and peak potential （Ⅴpcak） by 20 mV. FIX exerted significant effects on Cy-S sodium channels, reducing sodium channel density by 70.04%, right shifting V0.5act by 14.41 mV and V0.5inact by 9. 38 mV. It did not cause any significant changes of the parameters mentioned above in the Cy-R sodium channels. The activation time （Tpeak） from latency to peak at peak voltage and the fast inactivation time constant （τinact） in both Cy-S and Cy-R neurons were not affected. The results suggest that cotton bollworm resistant to pyrethroid insecticides involves not only mutations and allosteric alterations of voltage-gated sodium channels, but also might implicate perturbation of PTX-sensitive Gαi/o-COupled signaling Wansduction pathways.     

温度和盐度对吉富品系尼罗罗非鱼幼鱼鳃Na+-K+-ATPase活力的联合效应

试验采用中心组合设计(central composite face-centered design,CCF)和响应曲面法(response surface methodology,RSM)研究了温度(12—34℃)和盐度(0—26)两因素对体长为(4.36±0.105)cm,体重为(2.45±0.153)g的吉富品系尼罗罗非鱼(GIFT Nile tilapia,Oreochromis niloticus;简称吉富罗非鱼)幼鱼鳃Na+-K+-ATPase活力的联合效应。结果表明:(1)温度和盐度的一次效应和二次效应对Na+-K+-ATPase活力影响极显著(P<0.01),温度和盐度的互作效应不显著(P>0.05);(2)经响应曲面法分析,随着温度和盐度的增大,Na+-K+-ATPase活力呈先减小后增大的趋势;(3)建立了Na+-K+-ATPase活力与温度、盐度间关系的模型方程(R2=0.9829,Pred.R2=0.8550,P<0.01),并可用于预测吉富罗非鱼幼鱼鳃Na+-K+-ATPase的活力;(4)优化结果显示,温度为24.15℃,盐度为11.75时,Na+-K+-ATPase活力最小为0.62μmol无机磷.mg-1蛋白.h-1,满意度函数值高达0.961。Na+-K+-ATPase活力可以作为检测罗非鱼生长性能的指标,其活力较低时,一般反映了鱼体生存环境适宜,生长代谢旺盛,消耗于渗透调节的能量较少。     

Detection of a common and persistent tet(L)-carrying plasmid in chicken-waste-impacted farm soil

The connection between farm-generated animal waste and the dissemination of antibiotic resistance in soil microbial communities, via mobile genetic elements, remains obscure. In this study, electromagnetic induction (EMI) surveying of a broiler chicken farm assisted soil sampling from a chicken-waste-impacted site and a marginally affected site. Consistent with the EMI survey, a disparity existed between the two sites with regard to soil pH, tetracycline resistance (Tc(r)) levels among culturable soil bacteria, and the incidence and prevalence of several tet and erm genes in the soils. No significant difference was observed in these aspects between the marginally affected site and several sites in a relatively pristine regional forest. When the farm was in operation, tet(L), tet(M), tet(O), erm(A), erm(B), and erm(C) genes were detected in the waste-affected soil. Two years after all waste was removed from the farm, tet(L), tet(M), tet(O), and erm(C) genes were still detected. The abundances of tet(L), tet(O), and erm(B) were measured using quantitative PCR, and the copy numbers of each were normalized to eubacterial 16S rRNA gene copy numbers. tet(L) was the most prevalent gene, whereas tet(O) was the most persistent, although all declined over the 2-year period. A mobilizable plasmid carrying tet(L) was identified in seven of 14 Tc(r) soil isolates. The plasmid's hosts were identified as species of Bhargavaea, Sporosarcina, and Bacillus. The plasmid's mobilization (mob) gene was quantified to estimate its prevalence in the soil, and the ratio of tet(L) to mob was shown to have changed from 34:1 to 1:1 over the 2-year sampling period.     

植物类受体蛋白参与植物生长与发育的研究进展

类受体蛋白(receptor-like protein,RLP)广泛存在于高等植物中,其家族在拟南芥中有57个成员。研究表明RLP蛋白参与了植物茎尖分生组织(shoot apical meristem,SAM)、根尖分生组织(root apical meristem,RAM)和维管分生组织等器官的生长与发育过程,例如CLV2(CLAVATA2)和FEA2(FASCINATED EAR2)参与了分生组织的维持与分化和其他器官的发育、TMM(TOO MANY MOUTHS)则介导了植物表皮细胞的分裂和气孔分布。另一方面,RLP蛋白在植物抗病中发挥着重要作用,包括番茄抗叶霉菌Cf类蛋白、番茄抗黑白轮枝菌Ve1和Ve2以及番茄应答非致病绿色木霉菌激发子的抗病蛋白LeEix等。同时,研究表明RLP蛋白在细胞间信号的接受与传递过程中起着极为重要的作用。本文综述了近年来对植物类受体蛋白参与植物生长与发育的功能、信号识别、传输与转导等方面的研究进展。     

降低UV-B辐射对烤烟株高影响的非自治Logistic模型

根据在低纬高海拔的云南烟区,对烤烟品种云烟87进行不同程度的降低UV-B辐射的试验结果,建立了描述紫外线辐射影响烤烟株高生长形态的非自治Logistic模型.模型分析结果表明,与自然UV-B辐射相比较,当辐射强度的适当降低时,有利于烟株的生长,然而,当辐射强度降低得过多时,反而又不利于其生长.     

黄粉虫防御性分泌物化学成分的GC/MS分析

用二氯甲烷为溶剂萃取黄粉虫成虫腹部防御性分泌物并经GC/MS法分析,检测出其中7种成分:2-甲基对苯醌、对甲酚、正二十三烷、正二十四烷、12-二十五烯、正二十五烷和正二十六烷。幼虫和蛹腹末端的体液与成虫防御性分泌物共有4种长链烷烃,幼虫另含有3种有机酸。幼虫和蛹均不含有毒性较强的2-甲基对苯醌和对甲酚,用作动物蛋白饲料较安全。对成虫分泌物中的2-甲基对苯醌和对甲酚进行了定量分析,并探讨了不同日龄和性别的成虫防御性分泌物的分泌规律及再生性特点。     

Preparation of the cellulose/silica hybrid containing cationic group by sol–gel crosslinking process and its dyeing properties

The cellulose/silica hybrid (CSH) was prepared by sol–gel crosslinking process. 2,4,6-tri [(2-epihydrin-3-bimethyl-ammonium)propyl]-1,3,5-triazine chloride (Tri-EBAC) was used as crosslinking agent in the sol–gel process. The dyeing properties of the cellulose/silica hybrid with the traditional reactive dyes were discussed by reflectance spectra, color yield (K/S) and the colorimetric data of CIELAB. SEM analysis was used to characterize surface structure of the cellulose/silica hybrid. The results show that the cellulose/silica hybrid could be dyed with traditional reactive dyes. The dyeing process for the cellulose/silica hybrid quickly reached equilibrium. K/S of three different color dyes on cellulose/silica hybrid was much higher than those of them on the traditional cellulose. Cellulose/silica hybrid imparted excellent fastness properties. After dyeing, the reflectance spectra curves and the minimum reflectance wavelengths of the dyed cellulose/silica hybrid and cellulose fabrics had not noticeable change.     

黄粉虫防御性分泌物抑菌活性的研究

目的:研究黄粉虫防御性分泌物的化学成分及其抑菌活性。方法:用二氯甲烷萃取分泌物并经GC/MS分析,后用牛津杯法和平板连续稀释法分别就该分泌物对大肠杆菌、金黄色葡萄球菌、白色假丝酵母、黑曲霉、桔青霉的抑菌作用及2-甲基对苯醌和对甲酚标准品对上述供试菌的最低抑菌浓度进行测定和比较。结果:分泌物含2-甲基对苯醌、对甲酚和正二十三烷等7种成分,抑菌强度:桔青霉>大肠杆菌和金黄色葡萄球菌>白色假丝酵母>黑曲霉。结论:该分泌物对这5种供试菌的抑制效果优于2-甲基对苯醌和对甲酚标准品。     

Dishevelled-DEP domain interacting protein (DDIP) inhibits Wnt signaling by promoting TCF4 degradation and disrupting the TCF4/β-catenin complex

The TCF4/β-catenin complex, the executor of canonical Wnt/β-catenin signaling, is regulated by a variety of factors. Among these, Dishevelled (Dvl) is a critical regulator that releases β-catenin from degradation and stabilizes TCF4/β-catenin complex. Here, we report that DDIP (Dishevelled-DEP domain Interacting Protein, also named as Spats1, spermatogenesis associated, serine-rich 1), a novel protein that interacts with Dvl, regulates Wnt signaling. We provide evidence that DDIP suppresses Lef-1 luciferase reporter activity stimulated by Wnt1, Dvl2 or β-catenin, interacts with the TCF4/β-catenin complex, and disrupts the interaction of TCF4 and β-catenin by promoting TCF4 degradation through the proteasome pathway. Our results indicate that DDIP is a negative regulator of the canonical Wnt signaling.     

基于ISSR标记的黄河下游区域鲁桑地方品种遗传关系分析

应用ISSR分子标记技术对来自黄河下游区域(山东省和河北省)的46个鲁桑[Morus alba var. multicaulis (Perrott. ) Loud. ]地方品种的遗传多样性进行了分析;并基于遗传相似系数、采用UPGMA法对这些地方品种的遗传关系进行了研究.结果表明,用15个ISSR引物从46个鲁桑地方品种的总DNA中共扩增出109条带,其中多态性条带81条,多态性条带百分率为74.31%,表明供试的鲁桑地方品种间存在丰富的遗传多样性;46个地方品种间的遗传相似系数为0.602～0.898,相对偏高.聚类分析结果显示,46个鲁桑地方品种被分为2类,其中,第1类包含来自河北的品种'冀丰'和'冀黄鲁选',第2类包含其余44个品种;后者还能进一步分成9个亚类,其中A、E、F、G、H和I亚类所包含的36个品种均来自山东,组成B、C和D亚类的品种分别来自河北和山东;此外,E亚类仅包含'白条擗桑'1个品种,是46个品种中惟一的三倍体品种.研究结果显示,基于ISSR标记分析的46个鲁桑地方品种的遗传关系与地理分布具有一定的相关性.