m6A去甲基化酶ALKBH5对大鼠S1PR3基因3′-非编码区双荧光素酶活性的影响

[目的]明确m⁶A去甲基化酶ALKBH5对含S1PR3基因3′-非编码区(3′-UTR)双荧光素酶报告基因的调控作用。[方法]以大鼠前额叶皮层脑区cDNA为模板，利用聚合酶链式反应(PCR)扩增S1PR3基因3′-UTR中含有m⁶A修饰位点的目的片段。利用重叠延伸PCR方法将三个靶序列GGACT、GGACT、AGACT中的第三位A突变为C,并将野生型S1PR3-3′-UTR片段和突变型S1PR3-mut-3′-UTR片段分别正向插入到pmiR-RB-Report^TM vector载体中。将pcDNA3.1-ALKBH5或空载体pcDNA3.1与野生型和突变型双荧光素酶报告载体分别共转染PC12细胞，并检测荧光素酶活性。[结果]成功构建了包含S1PR3基因3′-UTR野生型双荧光素酶报告载体pmiR-S1PR3-3′-UTR和突变型双荧光素酶报告载体pmiR-S1PR3-mut-3′-UTR。荧光素酶活性分析表明与空载体pcDNA3.1组相比，ALKBH5可显著降低野生型及突变型C1和C2报告载体荧光素酶的活性(P<...     

沙棘hrh-miRn458靶向转录因子WRI1调控油脂合成

转录因子WRI1 (WRINKLED 1)在油脂合成过程中发挥重要调控作用, 其转录和翻译水平调控机理以及下游的靶基因现已基本明确, 但尚未见其转录后调控的报道。为探讨沙棘(Hippophae rhamnoides) hrh-miRn458与转录因子WRI1之间的靶向关系, 并阐明其在果肉和种子发育过程中的表达模式, 通过生物信息学方法预测hrh-miRn458成熟体序列及其与候选靶基因WRI1的结合位点, 采用双荧光素酶报告基因检测和RNA pull down技术相结合的方法验证hrh-miRn458与WRI1基因之间的靶向关系, 并应用qRT-PCR方法分析hrh-miRn458与WRI1在沙棘不同发育期果肉和种子油脂合成过程中的表达变化。结果表明, 生物信息学预测WRI1基因的CDS区第309-327位与hrh-miRn458成熟体序列的15个碱基互补; 荧光检测显示pmirGLO-WRI1-WT+hrh-miRn458 mimics显著抑制荧光素酶活性(P<0.001); RNA pull down实验证实hrh-miRn458与WRI1存在互作关系; 不同发育期果肉和种子中hrh-miRn458的表达量总体呈先下降后上升趋势, 其靶基因WRI1的表达量则呈先上升后降低趋势; 同一时期, 果肉中hrh-miRn458的表达量明显低于种子, 而果肉中的WRI1表达量则明显高于种子。综上, 沙棘hrh-miRn458靶向转录因子WRI1, 且二者在果肉和种子油脂合成过程中存在负调控关系。研究结果为深入理解沙棘种子油脂合成机制及培育高油品种提供了参考依据。     

家蚕Bmyan基因的克隆表达和作为microRNA 7靶基因的验证

microRNAs(miRNAs)是一类长约22 nt的非编码RNA,通过与其靶基因3′端非翻译区(3′-UTR)的结合来调节各项生命活动。克隆表达家蚕Bmyan基因,验证其是否是bmo-miR-7的靶基因对于深入研究家蚕变态发育机制有重要意义。基于同源性检索和PCR扩增,克隆了家蚕Bmyan基因CDS全长,编码476个氨基酸。序列分析表明,家蚕YAN蛋白的氨基酸序列保守,含SAM-PNT和ETs结构域。芯片数据、RT-PCR和定量PCR的检测结果表明,Bmyan在五龄3 d的家蚕头部、体壁、卵巢中高量表达,在其余组织中低量表达或不表达。在幼虫期,Bmyan表达水平相对较低,但在上蔟期和蛹期前4 d高量表达。通过3′RACE克隆了Bmyan基因的3′-UTR。RNAhybrid在线软件预测了其3'-UTR上bmo-miR-7的两个靶位点。构建了含有Bmyan基因3′-UTR和荧光素酶报告基因的转染载体,将该载体与bmo-miR-7的mimics序列共转染到家蚕胚胎细胞系BmE中,通过测定荧光素酶的活性,证明了Bmyan基因是bmo-miR-7的靶基因。本研究为进一步揭示bmo-miR-7和Bmyan在家蚕体内的生物学功能奠定了基础。     

靶向性甲基化酶真核表达载体pcDNA3.1-myc-3a的构建

目的:在pcDNA3.1真核表达载体中构建表达融合myc-6his标签的靶向性甲基化酶pcDNA3.1-myc-3a并进行鉴定。方法:以含有myc全长基因的pcDNA3.1-myc-Luc质粒为模板,通过PCR方法扩增获得myc(DBD),再以含有靶向性甲基化酶的pcDNA4.0-GBD-3a-myc-6his质粒为模板,通过PCR的方法扩增获得融合有myc-6his标签序列的目的区段3a,然后将两者克隆入表达载体pcDNA3.1;以双酶切和PCR方法对构建的载体进行鉴定。结果:通过PCR方法获得了靶向性甲基化载体pcDNA3.1-myc-3a,并通过免疫印记方法验证了抗myc标签抗体可以特异性识别目的蛋白。结论:正确构建了靶向性甲基化酶pcDNA3.1-myc-3a的真核表达载体。     

家蚕miR-301对化学感受蛋白基因csp9表达的调控

【目的】探索家蚕Bombyx mori miRNAs对化学感受蛋白基因表达的调控作用,以进一步研究miRNAs及其靶基因在昆虫化学识别中的作用。【方法】利用生物信息学方法预测和筛选可能作用于家蚕化学感受蛋白CSPs基因家族成员的miRNAs;实时荧光定量PCR分析预测获得的候选miR-301和其作用的靶基因在家蚕成虫不同组织中的表达变化;构建miR-301预测靶基因3′-UTR的双荧光素酶报告载体,与合成的miR-301 mimics或阴性对照转染人胚肾细胞HEK293,通过双荧光素酶报告基因检测系统中荧光素酶活性变化检测miR-301对其靶基因表达的调控作用。【结果】生物信息学分析结果发现,家蚕化学感受蛋白基因csp9是miR-301的预测靶基因,二者的结合位点位于csp9的3′-UTR区。实时荧光定量PCR检测结果表明,miR-301在交配后家蚕雌雄成虫触角和雄成虫头部都显著上调表达,靶基因csp9在对应组织中表达则显著下调。二者共转染HEK293细胞后,双荧光素酶检测结果表明,miR-301可以通过与csp9 3′-UTR的互作,显著抑制上游荧光素酶报告基因的表达。【结论】家蚕化学感受蛋白基因csp9是miR-301的靶基因,miR-301通过与靶基因3′-UTR的结合,在翻译水平上抑制csp9的表达。     

麻竹miR172a靶基因DlAP2的克隆及其表达

为了解开花麻竹(Dendrocalamus latiflorus)的Dl AP2基因功能,采用RT-PCR和RACE技术克隆了mi R172a靶基因AP2同源序列c DNA全长,命名为Dl AP2。结果表明,Dl AP2基因c DNA全长为1729 bp,包含5′端非编码区81 bp、开放阅读框1464 bp、3′端非编码区160 bp和24个碱基的Poly A尾巴,在编码框靠近3′端130 bp处有1个高度匹配mi R172a的结合位点(CTGCAGCATCATCAGGATTCT)。Dl AP2编码487个氨基酸的蛋白,具有两个AP2结构域,属于AP2/ERF家族AP2亚家族的AP2组,与来自其它单子叶植物的AP2蛋白均有较高同源性。RLM-5′RACE分析表明,mi R172a主要在靶序列的第11~12个碱基之间剪切靶基因Dl AP2的mi RNA。q RT-PCR结果表明,麻竹花芽中Dl AP2基因的表达规律与mi R172a表达变化正好相反,证明mi R172a对Dl AP2基因的表达具有调控作用。     

簸箕柳AP3同源基因SsMADS的克隆与特性分析

用cDNA末端快速扩增(rapid-amplification of cDNA ends,RACE)方法从簸箕柳雄花序中克隆了一个AP3同源基因的cDNA,长826 bp,包括完整的编码区、5′-UTR和3′-UTR,并将其相应的基因命名为SsMADS。该基因由7个外显子和6个内含子组成,编码区长723 bp,编码241个氨基酸,其N-端具有典型的MADS保守结构域。序列分析表明,SsMADS编码的氨基酸序列与毛果杨(Populus trichocarp)AP3同源蛋白有95.7%相似性,与其他几种柳属植物的AP3同源蛋白相似性达96.1%～99.6%。实时定量RT-PCR表明,SsMADS在叶、茎和根中表达量极低,在花序中表达量较高,并且其表达量在花器官的早中期发育阶段逐步提高,说明该基因在簸箕柳花器官的发育中起作用。     

小麦甲基转移酶基因TaDnMT2的克隆及特性分析

依赖于DNA甲基化的基因表达调控在植物生长发育过程中发挥重要功能,而DNA甲基转移酶是调节DNA甲基化模式的功能蛋白之一。本研究采用RACE技术克隆了小麦甲基转移酶基因TaDnMT2的包含完整编码区的cDNA序列,并系统分析了该基因的结构特征及其在小麦生长发育过程中的表达特性。结果表明,TaDnMT2的cDNA序列为1321bp（GenBank登录号：JN642641）,其中5′-和3′-UTR（非翻译区）分别为84和115bp、ORF（开放阅读框）1122bp;TaDnMT2编码的氨基酸序列包含2个S-腺苷甲硫氨酸结合域（I和X）、甲基转移酶活性位点（IV）、靶胞嘧啶结合位点（VI）、中和DNA骨架负电荷域（VIII）和靶位点识别区（IX）6个高度保守域,属于DNA甲基转移酶家族的DnMT2亚类;三维结构预测显示,TaDnMT2蛋白可以形成包括7个β-折叠和4个α-螺旋的特定空间结构。表达特性分析的结果表明,TaDnMT2基因在‘京841’小麦不同发育时期的叶中表达量均较高,且其在三叶龄期和五叶龄期的表达量受春化处理的影响;在种子发育过程中,该基因在授粉后5d的种子中表达量较高,随着种子发育进程的推进其表达水平呈逐渐下降趋势;在不同发育时期的根系中,TaDnMT2基因均具有较高水平的表达,且在分蘖期根系中的表达量最高。推断TaDnMT2基因可能在小麦生长发育过程中发挥重要功能。     

MiR-27靶基因的分析及鉴定

MicroRNAs(miRNAs)是一类约20～25nt的小分子核苷酸,在细胞内的多种生物学过程,如细胞增殖、凋亡、生长、分化和代谢等过程中具有重要的功能。已知miR-27在脂肪细胞和肌肉细胞的发育过程中起了重要作用,其在神经细胞中的表达调节至今仍不清楚。在本研究中,通过miRBase和TargetScan数据库分析了miR-27的靶基因,构建了miR-27的真核表达载体,改造了萤火虫荧光素酶和海肾荧光素酶报告载体,将miR-27的靶基因Bmi1的3′-UTR融合到报告载体中,转染神经胶质瘤细胞,利用双荧光素酶检测系统分析荧光素酶的活性。研究发现miR-27a和miR-27b共同的靶基因主要调节发育过程。MiR-27真核表达载体能产生成熟态的miR-27。MiR-27a、miR-27b或miR-27a和miR-27b联合与Bmi1的3′-UTR的正义序列共转染U343细胞能明显降低萤火虫荧光素酶的活性(分别P0.05,P0.05,P0.01),这提示了Bmi1可能为miR-27的靶基因。     

从HFRS患者的PBMC建立BLCL及其意义

体外研究汉滩病毒(Hantaan virus,HTNV)S基因及其5'端、3'端在BLCL(EBV-transformed Blymphoblastoidcellline,BLCL)内稳定表达的意义,为核蛋白T细胞表位的研究奠定基础.本研究从肾综合征出血热(HFRS)患者的外周血单个核细胞(PBMC)建立与HTNV特异性CTL同源的患者自身的EB病毒转化的B淋巴母细胞系,将含有不同HTNV S基因片段的重组真核表达载体转染入BLCL,获得长期稳定表达,作为靶细胞系,为下一步进行CTL杀伤试验提供靶细胞系.设计4条引物,用PCR方法从PBV220-S22原核质粒中扩增出S基因全读码框(37-1326bp)及S基因5'端(37-501bp),S基因3'端(502-1326bp),用TA克隆将其克隆入pcDNA3.1/V5-His-TOPO载体中,成功构建pcDNA3.1-S及pcDNA3.1-S-N、pcDNA3.1-S-C真核表达载体,并通过脂质体转染至BLCL细胞中,进行了稳定表达.间接免疫荧光成功检测到pcDNA3.1-S及pcDNA3.1-S-N、pcDNA3.1-S-C在BLCL细胞中的表达.pcDNA3.1-S及pcDNA3.1-S-N、pcDNA3.1-S-C真核表达载体有较高的转染效率,目的基因能在宿主细胞中长期稳定表达,有利于研究HTNV-S基因在T细胞表位研究中的意义.建立的特异性CTL克隆对表达完整NP、NP羧基和氨基端肽段的靶细胞均有比较明显的杀伤效应,平均杀伤率分别为50.2%、39.0%和25.4%.HTNV-NP优势T细胞表位可能主要位于病毒核蛋白的羧基端.     

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.     

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.     

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.     

A molecular phylogeny of Hebeloma species from Europe

In order to widen the scope of existing phylogenies of the ectomycorrhizal agaric genus Hebeloma a total of 53 new rDNA ITS sequences from that genus was generated, augmented by sequences retrieved from GenBank, and analysed using Bayesian, strict consensus and neighbour joining methods. The lignicolous Hebelomina neerlandica, Gymnopilus penetrans, and two species of Galerina served as outgroup taxa. Anamika indica, as well as representatives of the genera Hymenogaster and Naucoria, were included to test the monophyly of Hebeloma, which is confirmed by the results. Hebeloma, Naucoria, Hymenogaster and Anamika indica cluster in a strongly supported monophyletic hebelomatoid clade. All trees largely reflect the current infrageneric classification within Hebeloma, and divide the genus into mostly well-supported monophyletic groups surrounding H. crustuliniforme, H. velutipes, H. sacchariolens, H. sinapizans, and H. radicosum, with H. sarcophyllum being shown at an independent position; however this is not well supported. The section Indusiata divides with strong support into three groups, the position of the pleurocystidiate Hebeloma cistophilum suggests the possible existence of a third subsection within sect. Indusiata. Subsection Sacchariolentia is raised to the rank of section.     

Die GattungKarschia — Bindeglied zwischen bitunicaten Ascomyceten und lecanoralen Flechtenpilzen?

The genusKarschia, in the earlier sense, including saprophytes and parasites on lichens, has been thought to be a non-lichenized parallel genus of the lichen genusBuellia. Modern workers included it on the one hand inBuellia, on the other hand combined it with bitunicate ascomycetes. It is now proved thatKarschia is heterogeneous and contains but superficially similar members both of the genusBuellia of theLecanorales and of typical or masked bitunicateAscomycetes. Therefore, it can not be regarded as a link betweenLecanorales andDothideales. The type species ofKarschia belongs to theDothideales.

     

Demographic characteristics of an intertidal bay goby (Lepidogobius lepidus)

Synopsis In a fourteen month study (May 1976 – June 1977) I examined the following characteristics of an intertidal bay goby (Lepidogobius lepidus) in Morro Bay, California, U.S.A.: annual and seasonal patterns of abundance, age composition and growth rates, survivorship and mortality patterns, and the reproductive cycle for female gobies. Fishes were collected with the aid of quinaldine and otoliths and ovaries removed. Age and growth rates were estimated from otolith annuli using a back calculation formula and a Brody-Bertalanffy growth curve. Mortality rates were derived using the methods of Heincke (1913), Robson & Chapman (1960), mean age, and a catch curve (Ricker 1975). A gonad index was used to describe the annual reproductive cycle. Results indicated that abundance fluctuated seasonally and that these fluctuations appeared to be caused by reproductive emigrations. Bay gobies reached an age of 7+ and a standard length of 87 mm. Growth was relatively constant (6 mm yr⁻¹) until age 5, at which point it began to decline. The mean rates of survivorship, mortality, and instantaneous mortality were 0.75, 0.25, and 0.29 respectively. Mortality rates for individual age classes ranged from 0.13 to 0.51 and increased with age. This stock appears to reproduce mainly during the winter.     

Systematic significance of mature embryo of bamboos

The mature embryo of seven species belonging to five genera of Indian bamboos is described. In all these the basic pattern of embryo organisation is same: the scutellar and coleoptilar bundles are not separated by an internode, the epiblast is absent, the lower portion of the scutellum and the coleorhiza are separated by a cleft and the margins of embryonic leaves overlap. The features unique to fleshy fruited bamboos are: presence of a massive scutellum, the juxtaposition of plumule and radicle and the occurrence of a bud in the axil of the coleoptile. The fleshy fruit bearing bamboos should be classified into one group, the tribeMelocanneae. Evidence is provided to recognise additional groups in the subfamilyBambusoideae.