鲈鱼生长激素在甲醇酵母中的胞内表达

甲醇酵母pichia pastoris是一种理想的真核蛋白高水平表达系统.将鲈鱼(Lateolabrax japonicus)生长激素基因克隆到酵母整合型质粒载体pHIL-D2,经转化his4缺陷型酵母GS115,用PCR方法筛选阳性转化子,并用斑点印迹法筛选多拷贝转化子,经甲醇诱导表达,SDS-PAGE和蛋白质印迹杂交结果证实了表达产物为重组的鲈鱼生长激素.     

甜茶的化学成分及其α-葡萄糖苷酶抑制活性研究

为探究甜茶(Rubus suavissimus)中具有α-葡萄糖苷酶抑制活性的次级代谢产物,该文利用多种现代色谱分离技术对其干燥叶进行提取分离纯化,综合运用质谱、核磁共振波谱分析方法确定了单体化合物的结构,并对分离得到的化合物进行了α-葡萄糖苷酶抑制活性的测试。结果表明:(1)从甜茶的干燥叶中分离鉴定出10个化合物,分别为甜茶苷(1)、山奈酚-3-O-洋槐糖苷(2)、没食子酸(3)、二聚松柏醇(4)、5-甲氧基二聚松柏醇(5)、云实酸(6)、斯替维单糖苷(7)、斯替维醇(8)、16α,17-二羟基对映贝壳杉烷(9)、槲皮素-3-O-β-D-吡喃半乳糖苷(10),其中化合物2、4、5、9均为首次从甜茶中分离得到。(2)α-葡萄糖苷酶抑制活性测试结果显示,化合物2、3、5、6、10具有较强的α-葡萄糖苷酶抑制活性。该研究结果丰富了甜茶中具有α-葡萄糖苷酶抑制活性的化合物,并为降血糖相关产品的开发提供了理论依据。     

肿瘤中neu基因的过量表达及其抑制

neu基因编码一种和表皮生长因子受体同源的磷酸蛋白,具有酪氨酸激酶的活性.近年来在多种人类肿瘤中发现neu基因的扩增和(或)过量表达.一些蛋白质因子或化学药物可以在转录水平阻遏neu基因的过量表达或者降低其产物p185^neu的酪氨酸激酶活性,抑制具有neu基因过量表达的癌细胞的转移和增殖.     

拟南芥AtNHX2启动子的克隆及表达模式分析(英)

AtNHX2基因是拟南芥NHX基因家族的一员,编码了一种液泡膜中的Na⁺/H⁺反向运输体并对拟南芥的耐盐能力起着重要的作用.采用PCR扩增的方法克隆了拟南芥AtNHX2基因启始密码子上游约2.8 kb的DNA片段,并将其克隆到植物表达载体pCAMBIA1301-1中,通过基因枪轰击洋葱表皮瞬时表达的方法,初步检测启动子的活性.将重组质粒pCAMBIA1301-1/AtNHX2 promoter转化拟南芥并筛选纯合子.AtNHX2 promoter-GUS分析显示AtNHX2在所有的组织中均有表达,包括根尖.在保卫细胞中检测到了强烈的GUS表达,这一结果表明,AtNHX2对特殊细胞的pH调控和K⁺自身稳定方面起着重要的作用.AtNHX2启动子的活性可被NaCl抑制,并且抑制的强度和NaCl的浓度成正相关. 300 mmol/L KCl处理可增强启动子的活性,说明NaCl和KCl是在转录水平上调控AtNHX2的表达.在老叶中GUS活性比在新叶中GUS活性强,这说明了AtNHX2优先将有毒的离子积累在老叶中,从而有利于植物的正常发育.在根毛细胞中也观测到了强烈的GUS活性,这就暗示了AtNHX2在扩大的液泡中储存Na⁺.     

以甘油为碳源发酵Pichia pastoris组成型表达人血管生成抑制素

在Pichia pastoris组成型表达外源蛋白中碳源起着重要的调控作用。分别以葡萄糖、甘油、甲醇和油酸为碳源研究它们对摇瓶发酵GS115（pGAP9K-AS）表达hAS的影响。结果如下：油酸（163mg/L）,甘油（83mg/L）,葡萄糖 （76mg/L）,甲醇（57mg/L）。 根据以上结果,以甘油为碳源在30L生物反应器中进行GS115（pGAP9K-AS）工程菌的高密度发酵。48h后测得hAS的产量为169mg/L。产物hAS具有免疫活性并能抑制bFGF 诱导的CAM血管生成和实验小鼠黑色素瘤的生长。治疗12d后,抑瘤率达到90%,统计学分析结果表明hAS治疗组和PBS治疗组小鼠的肿瘤体积呈现显著性差异(P<0.01)。     

以甘油为碳源发酵Pichia pastoris组成型表达人血管生成抑制素

在Pichia pastoris组成型表达外源蛋白中碳源起着重要的调控作用。分别以葡萄糖、甘油、甲醇和油酸为碳源研究它们对摇瓶发酵GS115（pGAP9K-AS）表达hAS的影响。结果如下：油酸（163mg/L）,甘油（83mg/L）,葡萄糖 （76mg/L）,甲醇（57mg/L）。 根据以上结果,以甘油为碳源在30L生物反应器中进行GS115（pGAP9K-AS）工程菌的高密度发酵。48h后测得hAS的产量为169mg/L。产物hAS具有免疫活性并能抑制bFGF 诱导的CAM血管生成和实验小鼠黑色素瘤的生长。治疗12d后,抑瘤率达到90%,统计学分析结果表明hAS治疗组和PBS治疗组小鼠的肿瘤体积呈现显著性差异(P<0.01)。     

里氏木霉内切葡萄糖苷酶Ⅳ在毕赤酵母中的表达*

进行了内切葡萄糖苷酶Ⅳ(EGⅣ)在毕赤酵母(Pichia pastoris)表达系统中的表达。采用RT-PCR的方法从里氏木霉(Trichoderma reesei)中分离到eg4基因。将eg4基因与毕赤酵母表达载体pPICZαA连接,得到重组质粒pPICZαA-eg4。将该重组质粒线性化后转化毕赤酵母GS115,eg4基因通过同源重组被整合到毕赤酵母的染色体上,并处于酵母α因子的下游,得到重组菌株P.pastoris-EGⅣ1。在甲醇     

人源抗HBsAg单链抗体在巴氏毕赤酵母中的表达

在P.pastoris中分泌表达非融合抗HBsAg单链抗体（HBscFv）。设计引物从pGEMHBscFv上扩增目的基因,亚克隆至P.pastoris表达载体pPICZαA中,线性化后转化P. pastorisGS115;转化子经菌落PCR、高浓度Zeocin抗性筛选鉴定后,甲醇诱导目的蛋白表达。结果发现,重组HBscFv可以在α因子的引导下,分泌至培养基中,产量为80mg/L;分泌至培养基中的HBscFv具有结合HBsAg活性,活性总量在诱导培养72h后达最高峰,在诱导培养后期,HBscFv活性下降;PAS糖显色结果表明,酵母表达HBscFv是一种低糖基化蛋白或非糖基化蛋白。     

Neuronatin基因研究进展

Neuronatin(Nnat)是最近克隆的脑特异表达的新基因,在大脑发育过程中被选择性地剪接.人Nnat基因全长3 973 bp,含有3个外显子和2个内含子.Nnat mRNA有α和β两种剪接形式,分别编码81个和54个氨基酸,两者具有同一相位的开放阅读框架,差别在于β形式中间的外显子被剪切掉.人Nnat是单拷贝基因,定位于染色体20q11.2～12.小鼠Nnat基因定位于2号染色体末端.该基因是印记基因(imprinted gene),仅在父本来源的等位基因表达,而母本来源的等位基因则被甲基化不能表达.该基因在胚胎期及出生后早期大量表达,而在成年和衰老动物大脑中表达明显降低,因此推测该基因与大脑的发育和分化密切相关.成年动物中垂体前叶是Nnat mRNA唯一强表达的地方.推测其蛋白质产物具有疏水N端和亲水C端,是跨膜蛋白,其确切功能尚属未知.     

虎纹镇痛活性肽在毕赤酵母中的分泌表达

虎纹镇痛活性肽HWAP-Ⅰ是从虎纹捕鸟蛛初毒中分离纯化,具有镇痛活性的多肽类神经毒素.为了在P.pastoris中高效分泌表达HWAP-Ⅰ,依照RT-PCR的结果,人工合成编码虎纹镇痛活性肽的基因片段,与酵母表达载体pPIC9K重组,构建表达质粒pPIC9K-HWAP-Ⅰ.转化GS115宿主菌后,筛选出整合型His⁺Mut^S表达菌株.经诱导培养后,SDS-聚丙烯酰胺凝胶电泳(PAGE)证明HWAP-Ⅰ在毕赤酵母中能有效分泌表达,产物的分子质量为4 ku左右,产量达80 mg/L.体外小鼠输精管阻断实验证实表达产物具有明显的生物活性.     

Foreign exploration for Scirtothrips perseae Nakahara (Thysanoptera: Thripidae) and associated natural enemies on avocado (Persea americana Miller)

Scirtothrips perseae Nakahara was discovered attacking avocados in California, USA, in 1996. Host plant surveys in California indicated that S. perseae has a highly restricted host range with larvae being found only on avocados, while adults were collected from 11 different plant species. As part of a management program for this pest, a “classical” biological control program was initiated and foreign exploration was conducted to delineate the home range of S. perseae, to survey for associated natural enemies and inventory other species of phytophagous thrips on avocados grown in Mexico, Guatemala, Costa Rica, the Dominican Republic, Trinidad, and Brazil. Foreign exploration efforts indicate that S. perseae occurs on avocados grown at high altitudes (>1500 m) from Uruapan in Mexico south to areas around Guatemala City in Guatemala. In Costa Rica, S. perseae is replaced by an undescribed congener as the dominant phytophagous thrips on avocados grown at high altitudes (>1300 m). No species of Scirtothrips were found on avocados in the Dominican Republic, Trinidad, or Brazil. In total, 2136 phytophagous thrips were collected and identified, representing over 47 identified species from at least 19 genera. The significance of these species records is discussed. Of collected material 4% were potential thrips biological control agents. Natural enemies were dominated by six genera of predatory thrips (Aeolothrips, Aleurodothrips, Franklinothrips, Leptothrips, Scolothrips, and Karnyothrips). One genus each of parasitoid (Ceranisus) and predatory mite (Balaustium) were found. Based on the results of our sampling techniques, prospects for the importation of thrips natural enemies for use in a “classical” biological control program in California against S. perseae are not promising.     

Phylogeny of cardinalfishes (Teleostei: Gobiiformes: Apogonidae) and the evolution of visceral bioluminescence

The cardinalfishes (Apogonidae) are a diverse clade of small, mostly reef-dwelling fishes, for which a variety of morphological data have not yielded a consistent phylogeny. We use DNA sequence to hypothesize phylogenetic relationships within Apogonidae and among apogonids and other acanthomorph families, to examine patterns of evolution including the distribution of a visceral bioluminescence system. In conformance with previous studies, Apogonidae is placed in a clade with Pempheridae, Kurtidae, Leiognathidae, and Gobioidei. The apogonid genus Pseudamia is recovered outside the remainder of the family, not as sister to the superficially similar genus Gymnapogon. Species sampled from the Caribbean and Western Atlantic (Phaeoptyx, Astrapogon, and some Apogon species) form a clade, as do the larger-bodied Glossamia and Cheilodipterus. Incidence of visceral bioluminescence is found scattered throughout the phylogeny, independently for each group in which it is present. Examination of the fine structure of the visceral bioluminescence system through histology shows that light organs exhibit a range of morphologies, with some composed of complex masses of tubules (Siphamia, Pempheris, Parapriacanthus) and others lacking tubules but containing chambers formed by folds of the visceral epithelium (Acropoma, Archamia, Jaydia, and Rhabdamia). Light organs in Siphamia, Acropoma, Pempheris and Parapriacanthus are distinct from but connected to the gut; those in Archamia, Jaydia, and Rhabdamia are simply portions of the intestinal tract, and are little differentiated from the surrounding tissues. The presence or absence of symbiotic luminescent bacteria does not correlate with light organ structure; the tubular light organs of Siphamia and chambered tubes of Acropoma house bacteria, those in Pempheridae and the other Apogonidae do not.     

Molecular phylogeny of Phebalium (Rutaceae: Boronieae) and related genera based on the nrDNA regions ITS 1+2

Parsimony analyses of the internal transcribed spacer regions of nuclear ribosomal DNA (ITS 1 & ITS 2) for 38 taxa sampled from the Phebalium group (Rutaceae: Boronieae) and two outgroups confirm that, with the exception of Phebalium sensu stricto and Rhadinothamnus, six of the currently recognised genera within the group are monophyletic. The data indicate that Phebaliums. str. is paraphyletic with respect to Microcybe, and Rhadinothamnus is paraphyletic with respect to Chorilaena. Rhadinothamnus and Chorilaena together are the sister group to Nematolepis. Drummondita, included as an outgroup taxon, clustered within the ingroup as sister to Muiriantha and related to Asterolasia.The phylogeny suggests that the evolution of major clades within a number of these genera (e.g. Phebalium) relates to vicariance events between eastern and south-western Australia. Leionema is an eastern genus, with the most basal taxon being the morphologically distinct Leionema ellipticum from northern Queensland. Leionema also includes one species from New Zealand, but this species (as with some others) proved difficult to sequence and its phylogenetic position remains unknown. Taxonomic changes at the generic level are recommended.The authors wish to thank Paul G.Wilson, PERTH, for advice and discussion, and Paul Forster, BRI, for collecting and providing material of Leionema ellipticum. The project was supported by a Melbourne University Postgraduate Award (to BM), the Australian Biological Resources Study (ABRS), Australian Systematic Botany Society and Wolf Den (Australia) Investments.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Biological control of three floating water weeds,<Emphasis Type="Italic">Eichhornia crassipes,Pistia stratiotes</Emphasis>, and <Emphasis Type="Italic">Salviniamolesta</Emphasis> in the Republic of Congo

Since 1999, four specific weevils (Coleoptera, Curculionidae) were released in the Republic of Congo against three exotic floating water weeds: Neochetina eichhorniae Warner and N. bruchi Hustache against water hyacinth, Neohydronomus affinis Hustache against water lettuce, and Cyrtobagous salviniae Calder and Sands against water fern. Recoveries of exotic weevils were made from all 24 release sites except one, and all four species have established and spread (up to 800 km for water hyacinth weevils). Within a few years of releases, control of water fern and water lettuce was such that fishing and navigation could be resumed, while reductions of water hyacinth populations were only beginning.     

New species and new combinations in Peruvian Orchidaceae

seventeen new species and combinations are proposed in the generaChondrorhyncha, Cischweinfia, Cochlioda, Eloyella, Encyclia, Kefersteinia, Koellensteinia, Macroclinium, Rodriguezia, Solenidiopsis, andStenia. All new species are illustrated. A key is provided for 2-flowered species ofMacroclinium, PeruvianSigmatostalix, and PeruvianStenia. Solenidium (Solenidiopsis) peruvianum Schltr. is lectotypified.     

安徽牯牛降的丝孢菌Ⅰ

本文报导作者采自安徽枯牛降自然保护区的18种丝孢菌,分属于5个属,其中有3个新种:牛皮冻生尾孢(Cercospora paederiicola),山鸡椒假尾饱(Pseudocercospora litseae-cubebae),鸡血藤生假尾孢(P. millettiicola)和2个中国新纪录。文中对新种进行了描述及绘图,新记录种作了简要说明。研究的标本保存在中国科学院微生物研究所真菌标本室(HMAS)。     

Changes of dung beetle communities from rainforests towards agroforestry systems and annual cultures in Sulawesi (Indonesia)

Little is known about how tropical land-use systems contribute to the conservation of functionally important insect groups, including dung beetles. In a study at the margin of Lore Lindu National Park (a biodiversity hotspot in Central Sulawesi, Indonesia) dung-beetle communities were sampled in natural forest, young secondary forest, agroforestry systems (cacao plantations with shade trees) and annual cultures (maize fields), each with four replicates (n = 16 sites). At each site we used 10 pitfall traps, baited with cattle dung, along a 100 m transect for six 3-day periods. The number of trapped specimens and species richness at the natural forest sites was higher than in all land-use systems, which did not significantly differ. Each land-use system contained, on average, 75% of the species richness of the natural forest, thereby indicating their importance for conservation. However, a two-dimensional scaling plot based on NESS indices (m = 6) indicated distinct dung beetle communities for both forest types, while agroforestry systems and annual cultures exhibited a pronounced overlap. Mean body size of dung beetles was not significantly influenced by land-use intensity. Five of the six most abundant dung beetle species were recorded in all habitats, whereas the abundance of five other species was significantly related to habitat type. Mean local abundance and number of occupied sites were closely correlated, further indicating little habitat specialisation. The low dung beetle diversity (total of 18 recorded species) may be due to the absence of larger mammals in Sulawesi during historical times, even though Sulawesi is the largest island of Wallacea. In conclusion, the dung beetle fauna of the lower montane forest zone in Central Sulawesi appears to be relatively robust to man-made habitat changes and the majority of species did not exhibit strong habitat preferences.     

Taxonomic status of the species of the green algal genusNeochloris

Komárek has recently reviewed the various species assigned to the green algal genusNeochloris Starr (Chlorococcales, Chlorococcaceae) and removed those with uninucleate vegetative cells to a new genus,Ettlia. Watanabe & Floyd, unaware ofKomárek's work, also reviewed the species ofNeochloris and distributed them among three genera—Neochloris, Chlorococcopsis gen. nov., andParietochloris gen. nov.—on the basis of details of the covering of the zoospore and the arrangement of the basal bodies of the flagellar apparatus. This paper reconciles these two treatments and makes additional recommendations at the ranks of genus, family, order, and class.