心理应激对小鼠脂肪组织黄嘌呤氧化酶表达、活性及相关指标的影响*

目的:探讨心理应激对小鼠脂肪组织黄嘌呤氧化酶表达、活性及相关指标的作用。方法:雄性无特定病原体(SPF)级20只昆明小鼠随机分2组(每组10只),即慢性束缚应激(Stress)组和正常对照(Control)组。Stress组小鼠每天在自制式束缚器中限制活动2 h,其余时间两组小鼠在相同环境中自由饮水摄食,实验持续14 d,取血和白色脂肪组织(WAT);观察脂肪组织病理学改变,检测WAT中黄嘌呤氧化酶(XO)和烟酰胺腺嘌呤二核苷酸磷酸氧化酶4(Nox-4)的蛋白水平,检测WAT组织中XO、Nox-4、超氧化物歧化酶(Mn SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)、脂联素(ADPN)、单核细胞趋化蛋白1(MCP-1)、白介素6(IL-6)、肿瘤坏死因子α(TNF-α)、胰岛素受体底物1(IRS-1)、葡萄糖转运蛋白4(GLUT-4)、组织因子(TF)、纤溶酶原激活物抑制物1(PAI-1)的mRNA表达,检测血清和WAT组织中XO酶活性以及血清甘油三酯(TG)、总胆固醇(T-Cho)、游离脂肪酸(FFA)、尿酸(UA)的含量。结果:与control组比较,stress小鼠腹股沟WAT组织中XO免疫染色阳性着色细胞黄褐色沉淀深且丰富,WAT中出现大量的单核细胞、中性粒细胞、嗜酸性粒细胞及浆细胞浸润反应和炎症性的改变;血清XO浓度、WAT组织中XO mRNA水平和XO的酶活性显著升高(P＜0.01),血清游离脂肪酸(FFA)和尿酸(UA)的含量显著增高(P＜0.01),WAT组织中Nox-4蛋白、MCP-1、IL-6、TNF-α、TF、PAI-1mRNA的表达水平显著增高(P＜0.01),而Mn-SOD、GSH-Px、CAT、ADPN、IRS-1和GLUT-4的mRNA水平则显著降低(P＜0.01)。结论:心理应激可诱发脂肪XO过量表达及其活性增高,进而引起脂肪炎症、糖代谢及凝血酶原异常等反应。     

不同寄主对牧草盲蝽生长发育的影响

在人工气候条件下对牧草盲蝽若虫在9种不同寄主植物上的发育历期、存活率等进行研究,以探讨牧草盲蝽对不同寄主植物适合度,明确不同寄主对牧草盲蝽生长发育的影响。结果表明,牧草盲蝽若虫在花椰菜和四季豆上发育历期最短,分别为16.56 d和17.60 d,存活率最高,分别为76%和74%。田旋花上牧草盲蝽若虫历期最长为22.12 d,存活率最低仅35%。用花椰菜、四季豆喂养牧草盲蝽成虫体重最大,分别为0.083 g和0.069 g。用9种不同寄主对牧草盲蝽进行室内饲养,仅在花椰菜、四季豆上孵出若虫。由此可见,花椰菜、四季豆是牧草盲蝽生长发育最适寄主植物,田旋花适合度最低。     

Molecular characterization of a novel gene encoding an 8-kDa-subunit of antigen B from Echinococcus granulosus genotypes 1 and 6

Antigen B in hydatid cyst fluid of Echinococcus granulosus is a polymeric lipoprotein of 160 kDa, and is an aggregate of several different but homologous small proteins with approximately 8 kDa which are encoded by a multigene family. Four genes encoding 8-kDa-subunit monomers of the antigen B have been identified from E. granulosus. Recently, we have isolated another novel gene from Echinococcus multilocularis encoding a fifth 8-kDa-subunit of AgB (named EmAgB8/5), predominantly transcribed in the adult worm, but not in vesicles of metacestodes. In this study, we cloned and characterized two EmAgB8/5 homologue genes from E. granulosus genotypes 1 and 6 by PCR, and named as EgG1AgB8/5 and EgG6AgB8/5, respectively. The phylogenetic relationship of these genes with other genes encoding the antigen B 8-kDa-subunit monomers was also discussed.     

Dynamics of the intestinal bacterial community in black soldier fly larval guts and its influence on insect growth and development

Black soldier fly (BSF), Hermetia illucens (Diptera: Stratiomyidae), is a prominent insect for the bioconversion of various organic wastes. As a saprotrophic insect, the BSF inhabits microbe-rich environments. However, the influences of the intestinal microorganisms on BSF growth and development are not very clear. In this study, the dynamics of the intestinal bacterial community of BSF larvae (BSFL) were analyzed using pyrosequencing. Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria were the most prevalent bacterial phyla in the intestines of all larval instars. The dynamic changes in bacterial community compositions among different larval instars were striking at the genus level. Klebsiella, Clostridium, Providencia, and Dysgonomonas were the relatively most abundant bacteria in the 1st- to 4th-instar BSFL, respectively. Dysgonomonas and Providencia also dominated the 5th- and 6th-instar larvae, at ratios of 31.1% and 47.2%, respectively. In total, 148 bacterial strains affiliated with 20 genera were isolated on different media under aerobic and anaerobic conditions. Among them, 6 bacteria, BSF1–BSF6, were selected for further study. The inoculation of the 6 isolates independently into germ-free BSFL feeding on an artificial diet showed that all the bacteria, except BSF4, significantly promoted BSF growth and development compared with the germ-free control. Citrobacter, Dysgonomonas, Klebsiella, Ochrobactrum, and Providencia promoted BSF development significantly by increasing the weight gains of larvae and pupae, as well as increasing the prepupae and eclosion rates. In addition, Citrobacter, Klebsiella and Providencia shortened the BSF life cycle significantly. The results illustrate the promotive effects of intestinal bacteria on BSF growth and development.     

Echinococcus multilocularis: developmental stage-specific expression of Antigen B 8-kDa-subunits

Antigen B (AgB) initially found in hydatid cyst fluid of Echinococcus granulosus is a polymeric lipoprotein of 160 kDa, and is an aggregate of several different but homologous small proteins with approximately 8 kDa. Four genes encoding these 8-kDa-subunits have been identified from E. granulosus. In this study we isolated five genes encoding 8-kDa-subunits of AgB from Echinococcus multilocularis. Sequence comparison of isolated cDNA clones demonstrated that one of these five clones was completely identical to EmAgB8/1 which had been isolated previously by our group, and three of them were 94.5, 90.8, and 91.9% homologous to E. granulosus antigen B 8-kDa subunit genes, EgAgB8/2, EgAgB8/3, and EgAgB8/4, respectively. The remaining clone shared 51-58% homology with the nucleotide sequences of AgB genes. Gene-specific RT-PCR and Western blot analyses revealed that these genes were expressed in a developmentally regulated manner in E. multilocularis vesicles, protoscoleces, and immature adult worms. Possible functions of different expression manners are also discussed.     

入侵植物黄花刺茄在新疆不同生境中的繁殖特性

外来植物的入侵与其繁殖特性密切相关,比较外来植物在不同生境中的繁殖特性将为揭示其入侵的最适生境及其入侵机制并制定合理的管理策略提供理论依据。黄花刺茄(Solanum rostratum)是一种原产新热带区和美国西南部、仅进行有性繁殖的一年生杂草,已在中国新疆等7个省/市成功入侵。本文对黄花刺茄在新疆绿洲、荒漠草原和砾质荒漠中的有性繁殖特性进行了研究,旨在比较该物种在不同生境中的繁殖能力,明确其在新疆入侵的最适生境。结果表明:(1)黄花刺茄单花开放持续时间为27–47 h。3种生境中植株每天开花时间和单花开放持续时间基本相同,但开花数/株表现为绿洲>荒漠草原>砾石荒漠,生境间存在极显著差异(P<0.01)。(2)3种生境中黄花刺茄的传粉昆虫均为四条隧蜂(Halictus quadricinctus)、隧蜂(Halictus sp.)和扁柄木蜂(Xylocopa latipes),且均为蜂振传粉。其中,扁柄木蜂的访花次数极少。(3)3种生境中传粉昆虫的总访花频率表现为绿洲>荒漠草原>砾石荒漠,彼此间均存在显著差异(P<0.05)。四条隧蜂喜好低温高湿环境,而隧蜂偏好高温低湿环境,四条隧蜂的日访花高峰期早于隧蜂。(4)3种生境中黄花刺茄的结实数/株、结籽数/果实、结籽数/株及种子千粒重表现为绿洲>荒漠草原>砾石荒漠,且结实数/株与开花数/株及传粉昆虫的总访花频率均呈极显著正相关,结籽数/果实和结籽数/株与总访花频率均呈显著正相关。这些结果说明:在新疆干旱区,绿洲是黄花刺茄入侵的最适生境。黄花刺茄在绿洲中可获得较多的资源,形成较多的花以吸引更多的传粉昆虫,并产生较多且千粒重较大的种子。     

核桃仁内隔膜中总黄酮最佳提取工艺的研究

目的:从核桃仁内隔膜中提取并测定总黄酮含量,选择最佳提取工艺条件.方法:以芦丁为对照品,用分光光度法在最大吸收波长510nm对其含量进行测定.结果:测得样品中总黄酮含量C=6.430%,最佳提取工艺:乙醇浓度为75%、料液比为1:40、超声提取时间为60min、超声提取温度为80℃.结论:选用芦丁为对照品应用于紫外分光光度法测定核桃仁内隔膜总黄酮含量准确度较高,方法简单,可作为测定核桃仁内隔膜中黄酮含量的一种手段.