美洲大蠊等五种蜚蠊酯酶同工酶的比较研究

用聚丙烯酰胺凝胶等电聚焦电泳技术对美洲大蠊的不同发育期和不同器官的酯酶同工酶及五种蜚蠊成虫的酯酶同工酶进行了比较研究。结果表明，美洲大蠊７—８龄若虫的酶带数多于其它虫态，７—１０龄若虫多出一条ＰＩ５．８的酶带。除美洲大蠊外，各种蜚蠊雌成虫的酶带数均多于雄成虫，并与雄成虫共有其所有的酶带数。五种蜚蠊间具有四条共带，相似性高于７０％。美洲大蠊与不同属的德国小蠊问酯酶同工酶的相似性高于与之同属的黑胸大蠊间的相似性．表现出与形态分类的差异。     

南方小花蝽对烟蚜的捕食作用

为评价南方小花蝽对烟蚜的控制潜能,在25℃的条件下研究了南方小花蝽3龄若虫、4龄若虫、5龄若虫、雌成虫和雄成虫分别对烟蚜3龄若蚜、4龄若蚜和成蚜在烟草叶片上的捕食作用.结果表明:南方小花蝽不同龄期若虫与雌、雄成虫对不同虫龄及虫态烟蚜的捕食功能反应均符合Holling-II圆盘方程.南方小花蝽各虫态均对3龄若蚜的捕食量最大,对成蚜的捕食量最小.南方小花蝽雌成虫对3龄烟蚜的瞬时攻击率最高达0.5000,寻找效应最强为0.4766.研究表明南方小花蝽对烟蚜捕食量大,捕食能力强,是烟蚜的有效天敌.     

去除共生菌对德国小蠊生物适合度的影响

本研究利用抗生素处理德国小蠊,比较共生菌去除前后德国小蠊卵荚脱落率、幼虫孵化率、羽化率、雄雌虫比例(雄/雌)、成虫寿命以及平均生长历期等方面的差异,并计算其相对适合度.结果表明,无共生菌德国小蠊卵荚脱落率升高20%,幼虫孵化率降低23.3%,正常羽化率减少8.8%,成虫寿命缩短(雄虫5.6 d,雌虫6.5 d),生长历期延长3 d,雄虫/雌虫比例无明显变化;与对照组相比,无共生菌德国小蠊相对生物适合度为0.61,显示出明显的适合度劣势,表明共生菌对德国小蠊的繁殖及生长发育均具有重要作用.该研究将为进一步揭示共生菌影响德国小蠊生物适合度的机制奠定基础,并为开发以昆虫共生菌为靶标的新型害虫防治策略提供理论依据.     

黑胸大蠊水提取物对H22荷瘤小鼠肿瘤的抑制作用

为探讨黑胸大蠊水提取物对H₂₂荷瘤小鼠肿瘤的抑制作用及其对及免疫器官的影响,构建H₂₂细胞腹水瘤模型,将昆明小鼠皮下接种H₂₂细胞,随机分为模型组,环磷酰胺组,黑胸大蠊水提取物高、中、低剂量组,另设正常组.通过瘤块体积、瘤块质量、抑瘤率、脏器指数、肿瘤组织HE染色等指标,观察黑胸大蠊水提取物对H₂₂荷瘤小鼠的肿瘤抑制作用及免疫器官的影响.实验结果表明：高剂量组的瘤块体积和瘤块质量与模型组相比,具有显著性差异（P<0.05）,黑胸大蠊水提取物低、中、高剂量组对H₂₂荷瘤小鼠的抑瘤率分别为20.72%,29.24%,43.16%;与正常组相比,各剂量组脾脏指数均有所增加,高、中剂量组具有显著性差异（P<0.05）;各剂量组胸腺指数均有所降低,但与模型组相比无统计学意义（P>0.05）.肿瘤组织切片HE染色显示黑胸大蠊水提取物高、中、低剂量组与模型组相比,肿瘤组织均有不同程度的坏死.黑胸大蠊水提取物具有抑制H₂₂荷瘤小鼠肿瘤生长的作用,且对免疫器官无明显损害作用.     

褐飞虱可溶性蛋白SDS-PAGE电泳分析

采用SDS-PAGE电泳分析褐飞虱成虫和各龄期若虫的可溶性蛋白,结果表明,成虫各类样品中,条带数量基本相同,只发现一条雌性成虫所特有的蛋白条带,而多数条带在不同翅型或性别样品中存在着含量差异。如有4条条带在长翅型中的含量明显高于短翅型中的含量;在雌、雄成虫样品的比较中则发现2条条带在雄虫中含量高于雌虫,而另有3条条带在雌虫中含量高于雄虫。若虫样品随着龄期升高,条带逐渐增多,发现有4条条带在各个龄期中均有表达,1条条带只在5龄若虫样品中出现,另有1条条带从4龄期开始出现。此外,还发现有2条条带在长翅芽若虫样品中的含量(9.029,9.563 ng/μL)明显高于短翅芽若虫样品中的含量(5.133,3.111 ng/μL)。并讨论了这些差异条带与翅型或性别分化方面的关系。     

探讨不同因素对白背飞虱在稻苗间传播南方水稻黑条矮缩病毒效率的影响

结果表明,白背飞虱(5龄若虫、长翅型和短翅型成虫)在18~34℃的温度区间内均能在不同生育期的水稻上传毒,传毒率在3.3%~41.2%间.介体发育阶段、环境温度和水稻生育期均能显著影响该虫的传毒能力(P0.01),不同发育阶段白背飞虱的传毒能力依次是5龄若虫短翅型成虫长翅型成虫;26℃时该虫传毒率最高,其次是22℃,最后依次是28℃、18℃和34℃;苗龄越低传毒率越高.这三者中任意2因素间都有极显著的互作效应(P0.01),它们对该虫传毒的影响顺序依次是温度水稻生育期介体发育阶段环境温度×介体发育阶段环境温度×水稻生育期介体发育阶段×水稻生育期.不同品种的感染率不同,5个品种感染率从高到低的顺序分别是陵两优268(41.7%)、金优899(37.6%)、金优284(36.2%)、培两优981(32.1%)和威优644(29.3%).其中,陵两优268的感染率显著高于其它品种(P0.05),金优898和金优284之间感染率差异不显著(P0.05),威优644的感染率显著低于其它品种(P0.05).禁食时间在12 h以上时,该虫传毒能力显著降低(P0.05).白背飞虱在稻苗间的传毒效率与水稻品种、环境温度、该虫发育阶段、水稻品种及生育期、该虫禁食时间长短密切相关,其中水稻生育期、温度和白背飞虱的发育阶段间还存在极显著的互作效应.     

犬钩虫(Ancylostoma caninum)不同发育时期蛋白质组分分析

为了解犬钩虫在不同发育时期蛋白质的表达情况,我们运用SDS-PAGE凝胶电泳对犬钩虫不同发育时期L3、L4和雌、雄虫的可溶性蛋白组分进行了分析,结果发现,L3期幼虫有22条蛋白带,L4期有17条蛋白带,雄虫有22条,雌虫有22条,各期既有共同的蛋白条带也有期特异性的蛋白条带.其中L3期蛋白条带较多,L3、L4期幼虫的蛋白条带和成虫的蛋白质条带有较大差别,而雄虫和雌虫之间差别很小.这可能与L3是感染期幼虫,需要分泌更多酶穿透宿主皮肤.对犬钩虫不同发育时期表达的蛋白进行分析,为进一步开展钩虫致病和期特异性抗原的免疫保护机制以及以抗原为基础的免疫学诊断研究奠定了基础.     

蠋蝽对桃蛀螟幼虫捕食功能反应

为明确蠋蝽(Arma chinensis)对桃蛀螟(Conogethes punctiferalis)幼虫的生物防控潜能,在室内条件下测定蠋蝽5龄若虫、雌成虫和雄成虫对桃蛀螟3龄、5龄幼虫的捕食能力。结果显示：蠋蝽5龄若虫、雌成虫和雄成虫对不同龄期桃蛀螟幼虫的捕食功能反应均符合HollingⅡ模型。蠋蝽对桃蛀螟3龄、5龄幼虫的控害能力由强到弱的排序均为：雌成虫,雄成虫,5龄若虫;随着猎物密度的增加,蠋蝽对桃蛀螟3龄、5龄幼虫的搜寻效应均逐渐降低,雌成虫的搜寻效应大于5龄若虫和雄成虫。蠋蝽5龄若虫、雌雄成虫均对桃蛀螟具有较好的控害潜能,且蠋蝽雌成虫的控害潜能大于雄成虫和5龄若虫。     

东方田鼠抗日本血吸虫病机制研究

本文报道了在东方田鼠抗日本血吸虫机制研究方面的研究成果。经多次重复感染试验 ,证实来源于血吸虫疫区 (洞庭湖 )和非疫区 (宁夏青铜峡 )的东方田鼠均具有抗日本血吸虫病能力 ,这种能力是可遗传的 ,与获得性免疫关系不大 ;体内外的检测与杀伤试验显示东方田鼠体内存在的抗日本血吸虫童虫和成虫抗原的天然抗体IgG3和补体可能在其抗血吸虫病方面具有很重要的作用 ;东方田鼠和腹腔巨噬细胞 (Mф)、嗜酸细胞 (Eos)对血吸虫童虫具有天然的黏附能力 ;用东方田鼠血清筛选日本血吸虫成虫cDNA文库 ,获得了 5个阳性克隆 ,其中 4个克隆为新基因 ,…     

中华稻蝗山西晋源种群乙酰胆碱酯酶生化特性研究

对中华稻蝗山西晋源种群五龄若虫和成虫进行了马拉硫磷敏感性的生物测定，同时对若虫和成虫的乙酰胆碱酯酶（ACHE）特性进行了比较研究，生物测定结果表明，晋源种群若虫的LD50值（4．94μg／g虫重）是成虫（2．44μg/g虫重）的2．02倍；有机磷抑制剂对该种群若虫和成虫的AChE的体外抑制研究表明，晋源成虫AChE对氧化毒死蜱、对氧磷、甲基内吸磷的敏感性比晋源若虫分别高1．39、1．34和1．24倍．乙酰胆碱酯酶动力学研究结果表明，若虫动力学参数Km值和Vmax值均较成虫为高；用乙酰硫代胆碱（ATC）做底物测定AChE活性，若虫AChE活性是成虫的1．22倍．中华稻蝗晋源种群若虫对有机磷抑制剂敏感性下降可能与其AChE活性的增高有关，而成虫与若虫之间AChE活性的差异可能与不同阶段虫体对马拉硫磷选择压力的差异有关。     

长角血蜱不同龄期虫体免疫原性研究

用酶联免疫吸附技术,用长角血蜱三个龄期的虫体蛋白检测其幼虫、若虫和成虫多次叮咬后的兔血清效价.结果表明不同生活阶段的虫体之间存在免疫交叉反应.用SDS-PAGE方法分析了几种蜱类的蛋白质,结果表明长角血蜱不同发育期虫体共有的主要蛋白质有5种,分子量分别为97.4、94、63、37和32kDa;越南血蜱幼虫和微小牛蜱幼虫与长角血蜱不同发育期虫体共有的蛋白质有2种,分子量为97.4、94kDa.用酶联免疫印渍技术研究发现:长角血蜱三个龄期虫体分别叮咬兔产生的抗血清与长角血蜱不同发育期虫体蛋白质印渍,显示出共同蛋白质带,分子量为94kDa.三种抗血清与越南血蜱幼虫印渍显示出的蛋白质,其分子量为97.4、94kDa;与微小牛蜱幼虫蛋白反应显示的蛋白质带,分子量为83、63kDa.实验结果表明不仅长角血蜱三个龄期虫体之间存在免疫交叉反应,而且与微小牛蜱幼虫和越南血蜱幼虫之间也存在免疫交叉反应.     

松突圆蚧发育起点温度和有效积温的测定及其应用

采用恒温培养与林间观察相结合的方法对松突圆蚧发育的起点温度和有效积温进行测定,结果表明:松突圆蚧各虫期的发育起点温度分别为1龄若虫(6.99±0.23)℃,2龄若虫(8.74±1.06)℃,蛹期(13.08±1.56)℃,雌成虫期(9.44±1.22)℃,整个生活史(10.47±1.03)℃;有效积温分别为1龄若虫208.30℃.d,2龄若虫200.23℃.d,蛹期77.61℃.d,雌成虫期477.80℃.d,整个生活史810.87℃.d。用有效积温法估测松突圆蚧在福建省各县(市、区)和广东部分地区可能发生的世代数,估测值与实际年发生世代数基本相符,可作为松突圆蚧监测预警和防治决策的依据。     

黑胸大蠊浓核病毒的病理学研究

应用组织化学方法以及电镜超薄切片技术对黑胸大蠊浓核病毒感染蜚蠊的病理学作了初步研究．经孚尔根—亮绿染色、甲基绿—派洛宁染色、吖啶橙染色,发现蜚蠊中肠柱状上皮、盲囊、马氏管和砂囊组织不被蜚蠊浓核病毒感染外,其它几乎所有蜚蠊组织都被病毒感染,并在细胞核内形成孚尔根反应强阳性,派洛宁和吖啶橙好染的均匀物质团．电镜下发现,感染细胞核明显膨大,核内异染色质浓缩并被推向核的边缘,核仁分离并最后消失．核内病毒粒子从发生基质形成、释放,最后使核膜破裂而进入细胞质中．在少量细胞中可见到大片晶格排列的病毒颗粒．感染细胞内线粒体、内质网均退化,空泡化     

褐斑大蠊减数分裂观察

探讨褐斑大蠊减数分裂规律，运用空气干燥法对褐斑对褐斑大蠊精原细胞第一次减数分裂染色体形态进行观察，细胞分裂过程中细线期，偶线期，粗线期，双线期，终变期染色体形态学特征，结果表明褐斑大蠊减数分裂过程与蜚蠊属其他种相似，符合一般规律。     

Comparative analysis of the three-dimensional structure of Periplaneta fuliginosa densovirus

The three-dimensional structure of Periplaneta fuliginosa densovirus(pfDNV)is determined at 2.3nm resolution using the techniques of cryo-electron microscopy and image reconstruction.The pfDNV contains five structural proteins and 60 protein subunits arranged on a T=1 icosahedral shell with a relatively smooth surface.Its reconstruction reveals its distinct capsid structure from those observed in CPV and GmDNV.As in GmDNV,spike-like protrusions are not present in pfDNV at the threefold axes; while two small thorn-like protrusions are identified there However,different from CPV and GmDNV,cylindrical channels along the fivefold axes are closed in pfDNV;while a small thorn-like protrusions,which have not been reported in other parvovirus,are observed there in pfDNV although their function is yet to be investigated.The pfDNV has dimple-like depressions at the icosahedral twofold axes;but has no canyon-like regions encircling the fivefold axes.The icosahedrally well-ordered nucleic acid has also been observed in pfDNV,suggesting that the protein and nucleic acid probably form closed interaction.     

Evidence for immunological cross-reaction between sporozoites and blood stages of a human malaria parasite

Malaria parasites (Plasmodium spp.) show a complex pattern of development in the mammalian host and many studies support the view that the surface of the sporozoite, injected by the mosquito, has no antigens in common with the erythrocytic stage of development. For example, immunization with the erythrocytic parasites generates antisera with negligible titre by indirect immunofluorescence to the sporozoite surface. Although monoclonal antibodies prepared against erythrocytic stages were reported to show cross-reaction to the sporozoite stage, this appeared to be due to cytoplasmic antigens exposed by the method of sporozoite preparation, and in Plasmodium knowlesi, a cDNA clone coding for the circumsporozoite antigen, the major protein of the sporozoite surface, showed no hydridization to mRNA isolated from the erythrocytic stages. Here, however, we present evidence for an antigenic determinant shared by the sporozoite surface and the erythrocytic stages of the human malaria parasite, P. falciparum. Moreover, our studies show that the antigen(s) elicit a strong immune response in man.     

The origins of insect metamorphosis.

Insect metamorphosis is a fascinating and highly successful biological adaptation, but there is much uncertainty as to how it evolved. Ancestral insect species did not undergo metamorphosis and there are still some existing species that lack metamorphosis or undergo only partial metamorphosis. Based on endocrine studies and morphological comparisons of the development of insect species with and without metamorphosis, a novel hypothesis for the evolution of metamorphosis is proposed. Changes in the endocrinology of development are central to this hypothesis. The three stages of the ancestral insect species-pronymph, nymph and adult-are proposed to be equivalent to the larva, pupa and adult stages of insects with complete metamorphosis. This proposal has general implications for insect developmental biology.     

Determination of the genus-specific antigens in outer membrane proteins from the strains of Leptospira interrogans and Leptospira biflexa with different virulence

Objective:To determine the existence of genus-specific antigens in outer membrane proteins (OMPs) of leptospira with different virulence. Methods: Microscope agglutination test (MAT) was applied to detect the agglutination between commercial rabbit antiserum against leptospiral genus-specific TR/Patoc I antigen and 17 strains of Leptospira interrongans belonging to 15 serogroups and 2 strains of Leptospira biflexa belonging to 2 serogroups.The outer envelopes (OEs) of L.interrogans serogroup Icterohaemorrhagiae serovar lai strain lai (56601) with strong virulence and serogroup Pomona serovar pomona strain Luo (56608) with low virulence,and L.biflexa serogroup Semaranga serovar patoc strain Patoc I without virulence were prepared by using the method reported in Auran et al.(1972).OMPs in the OEs were obtained by treatment with sodium deoxycholate. SDS-PAGE and western blot were used for analyzing the features of the OMPs on electrophoretic pattern and the immunoreactivity to the antiserum against TR/Patoc I antigen, respectively. Results:All the tested strains belonging to different leptospiral serogroups agglutinated to the antiserum against leptospiral genus-specific TR/Patoc I antigen with agglutination titers ranging from 1:256-1:512. A similar SDS-PAGE pattern of the OMPs from the three strains of leptospira with different virulence was shown and the molecular weight of a major protein fragment in the OMPs was found to be approximately 60 KDa.A positive protein fragment with approximately 32 KDa confirmed by Western blot,was able to react with the antiserum against leptospiral genus-specific TR/Patoc I antigen, and was found in each the OMPs of the three stains of leptospira.Conclusion: There are genus-specific antigens on the surface of L.interrogans and L.biflexa. The OMP with molecular weight of 32 KDa may be one of the genus-specific protein antigens of leptospira.