枸杞果糖激酶基因LbFRK7的克隆及表达分析

该研究以‘宁杞1号’枸杞果实为材料,基于转录组测序TR28373|c0_g1序列,利用RT-PCR技术,克隆出枸杞果糖激酶基因LbFRK7的全长序列为1 060bp,其中,ORF开放阅读框为1 044bp,编码有348个氨基酸,蛋白质分子量为37.44kD,理论等电点5.05;LbFRK7编码的氨基酸序列包含有pfkB碳水化合物激酶家族高度保守的3个特异性区域,2个底物识别位点,4个ATP结合位点;LbFRK7与烟草和辣椒的FRP7基因序列相似性较高,达到90%;利用实时荧光定量技术分析发现,不同组织中LbFRK7基因均有表达,且果实中的表达量最高,根中最低;随着果实的发育,果实中LbFRK7基因的表达量呈先升后降的变化趋势,并于开花后15d达到最高。在果实发育前期,LbFRK7基因的表达量与果糖含量的变化趋势相同,但在果实发育中期和后期,LbFRK7基因的表达量与果糖含量的变化趋势相反。相关分析结果显示,LbFRK7表达量与果糖和蔗糖含量的相关系数分别为-0.326和-0.339,但均未达到显著水平。研究表明,LbFRK7基因在枸杞果实发育过程中对果糖转化起到一定作用,特别是在果实成熟过程中对果糖含量的升高具有重要的作用。该研究结果为进一步探讨枸杞LbFRK7的功能及果糖代谢奠定了基础。     

宁夏枸杞苯丙氨酸解氨酶基因的cDNA克隆及其表达分析

为探讨宁夏枸杞(Lycium barbarum)苯丙氨酸解氨酶基因(LbPAL)的表达特征,采用PCR法克隆了宁夏枸杞LbPAL基因的cDNA,并用实时定量PCR法分析了其表达特征。结果表明:宁夏枸杞的LbPAL基因的全长cDNA为2321 bp,包含2163 bp、编码720个氨基酸的开放阅读框;LbPAL与茄科其他物种的PAL氨基酸序列及三维结构具有较高保守性;与茄科物种的PAL聚类在同一个分支中。LbPAL在叶、花瓣、S1期果实的表达量较高,而在根及S2~S5期果实的表达水平较低。在NaCl胁迫处理下,LbPAL在根和茎中的表达量均有下调的趋势;而在叶片中,LbPAL表达量先急剧增加而后急剧下降并趋于稳定。这为解析宁夏枸杞中类黄酮化合物的生物合成调节及生理功能提供了参考。     

鲢鱼解偶联蛋白2全长cDNA序列的克隆及其组织表达

从淡水食毒藻鱼类鲢鱼(Hypophthalmichthysmolitrix)肝脏,通过简并引物克隆解偶联蛋白2(un-couplingprotein2,UCP2)cDNA核心序列,应用5′RACE和3′RACE技术分别扩增该序列的5′末端和3′末端序列,最后通过序列拼接获得鲢鱼肝脏UCP2cDNA全序列。序列分析结果表明,鲢鱼肝脏UCP2cDNA全长1452bp,其中5′-UTR长337bp,3′-UTR长182bp,编码区933bp,编码310个氨基酸,推测的氨基酸序列包含线粒体内膜载体蛋白3个特征结构及解偶联蛋白(UCPs)的特征序列。对鲢鱼不同组织UCP2的表达调控研究发现,鲢鱼组织UCP2基因在肠道、肝脏、肌肉、脂肪组织均大量表达,而在脑组织表达量较低,这与鲢鱼体内微囊藻毒素在这几个组织的分布完全一致,表明UCP2的功能可能与抑制微囊藻毒素引发过量活性氧(ROS)生成有关。     

草鱼AMBP基因cDNA的克隆与序列分析

α1-微球蛋白和Bikunin是由同一基因翻译表达出的两种功能不相关联的血浆蛋白。本文通过快速扩增cDNA末端的方法,首次从草鱼肝脏组织克隆了α1-微球蛋白和Bikunin前体蛋白(α1-microglobulin/Bulinin precursor, AMBP）基因全长cDNA。其cDNA全长1230bp,包含5′非翻译区23 bp,3′非翻译区160 bp和开放读码框1047 bp。开放读码框编码348个氨基酸,包含182个氨基酸的α1-微球蛋白和145个氨基酸的Bikunin。草鱼AMBP与其他物种的氨基酸序列分析结果表明,它们具有较高的同源性(44.7%－84.4%),其中草鱼与斑马鱼同源性最高(84.4%)。结果表明AMBP序列结构和α1-微球蛋白与Bikunin共翻译表达特点在动物机体中具有着重要的生理意义。     

中国桔梗PgF3′5′H基因的克隆及表达分析

利用RT-PCR结合RACE技术,从中国桔梗(Platycodon grandiflorus)花朵中分离克隆了1个类黄酮-3′,5′-羟基化酶(flavonoid-3′,5′-hydroxylase,F3′5′H)基因的全长cDNA序列,命名为PgF3′5′H(GenBank登录号JQ403611)。PgF3′5′H基因全长1 787bp,包含1个编码532个氨基酸长为1 599bp的开放阅读框。蛋白序列比对显示,PgF3′5′H基因蛋白与其他物种的F3′5′H蛋白有很高的相似性,包含有CYP基序、Ⅰ螺旋区和血红素结合区等保守性序列,以及一段类似于风铃草F3′5′H蛋白的9个氨基酸的特殊区。半定量RT-PCR结果显示,PgF3′5′H的表达量随着花朵发育和花色素的出现而呈递增趋势,在花发育第四阶段的蓝色花蕾中达到最高,而在叶中不表达。研究推测,PgF3′5′H基因可能在中国桔梗蓝色花色素的生化合成途径中起重要作用。     

雅致枝霉Δ6-脂肪酸脱氢酶基因的克隆及在酿酒酵母中的表达

根据真菌Δ6-脂肪酸脱氢酶基因保守的组氨酸Ⅱ区和Ⅲ区附近保守序列设计兼并引物进行RT-PCR,得到雅致枝霉(Thamnidium elegans)As3.2806Δ6-脂肪酸脱氢酶基因459bp部分cDNA序列,然后通过快速扩增cDNA末端技术(RACE)向两端延伸得到1504bp的Δ6-脂肪酸脱氢酶基因全长cDNA序列。序列分析表明有一个1377bp、编码459个氨基酸的开放阅读框TED6。推测的氨基酸序列与已知其他真菌的Δ6-脂肪酸脱氢酶基因的氨基酸序列比对,具有3个组氨酸保守区、2个疏水区及N末端细胞色素b5融合区。将此编码区序列亚克隆到酿酒酵母缺陷型菌株INVSc1的表达载体pYES2.0中,构建表达载体pYTED6,并在酿酒酵母INVSc1中异源表达。通过气相色谱(GC)和气相色谱/质谱(GC-MS)分析表明,该序列在酿酒酵母中获得表达,产生γ-亚麻酸(GLA)的含量占酵母总脂肪酸的7.5%。证明此序列编码的蛋白能将外加的亚油酸转化为γ-亚麻酸,是一个新的有功能的Δ6-脂肪酸脱氢酶基因(GenBank,AY941161)。     

少根根霉Δ6-脂肪酸脱氢酶基因的克隆和表达

根据真菌Δ6 脂肪酸脱氢酶保守的氨基酸序列设计简并引物进行RT PCR ,获得一个 5 93bp的cDNA片段 ,再根据获得的部分序列设计基因特异性引物 ,通过cDNA末端扩增技术 (RACE)获得该cDNA的 3′和 5′序列 ,从而得到全长为 14 82bp的cDNA序列。序列分析结果表明 ,该序列具有一个长度为 1377bp、编码 4 5 8个氨基酸的开放阅读框 ,所编码蛋白质的大小为 5 2kD。与报道的Δ6 脂肪酸脱氢酶一样 ,推测的氨基酸序列具有膜整合脂肪酸脱氢酶特异性的 3个组氨酸保守区和疏水结构 ,在其氨基酸序列的N 末端具有类似于细胞色素b5的血红素结合区。该序列为一个新的编码Δ6 脂肪酸脱氢酶的基因 ,为了验证其功能 ,把开放阅读框序列RAD6亚克隆到表达载体 pYES2 0 ,构建重组表达载体pYRAD6 ,并转化到酿酒酵母的缺陷型菌株INVScl进行表达。通过气相色谱(GC)和气相色谱 /质谱 (GC MS)分析表明 ,该序列在酿酒酵母中获得表达。所编码的酶具有Δ6 脂肪酸脱氢酶活性 ,能将外源性的底物亚油酸转化为γ 亚麻酸 ,γ 亚麻酸的含量占酵母总脂肪酸的 3 85 %。     

鲢鱼解偶联蛋白2全长cDNA序列的克隆及其组织表达

从淡水食毒藻鱼类鲢鱼(Hypophthalmichthys molitrix)肝脏，通过简并引物克隆解偶联蛋白2(uncoupling protein 2，UCP2) cDNA核心序列，应用5′RACE和3′RACE技术分别扩增该序列的5′末端和3′末端序列，最后通过序列拼接获得鲢鱼肝脏UCP2 cDNA全序列。序列分析结果表明，鲢鱼肝脏UCP2 cDNA全长1 452 bp，其中5′-UTR长337 bp，3′-UTR长182 bp，编码区933 bp，编码310个氨基酸，推测的氨基酸序列包含线粒体内膜载体蛋白3个特征结构及解偶联蛋白(UCPs)的特征序列。对鲢鱼不同组织UCP2的表达调控研究发现，鲢鱼组织UCP2基因在肠道、肝脏、肌肉、脂肪组织均大量表达，而在脑组织表达量较低，这与鲢鱼体内微囊藻毒素在这几个组织的分布完全一致，表明UCP2的功能可能与抑制微囊藻毒素引发过量活性氧(ROS)生成有关。     

枸杞蔗糖磷酸合成酶基因的克隆及组织表达分析

利用RT-PCR及RACE技术,从药用植物枸杞中克隆了1个编码蔗糖磷酸合成酶(SPS)基因的全长cDNA,命名为LbSPS(GenBank登录号KC834608)。序列分析表明:LbSPS基因长3 677bp,开放阅读框为3 165bp,编码1 033个氨基酸,分子量为118.457 5kD,理论等电点6.05。系统进化分析显示,LbSPS编码的氨基酸序列与甜瓜、马铃薯、番茄等蔗糖磷酸合成酶基因编码氨基酸序列一致性为66%~98%。qRT-PCR分析显示,LbSPS基因在枸杞花中表达量最高,叶中表达水平较低。该研究为进一步了解LbSPS在枸杞生长发育、逆境胁迫等过程中的生物学功能奠定了基础。     

火把梨谷胱甘肽S-转移酶基因的克隆与表达

依据火把梨编码谷胱甘肽S-转移酶(GST)的EST序列设计基因特异引物,采用快速扩增cDNA末端技术,从云南火把梨中克隆到一个新的GST基因的全长cDNA序列。该基因被命名为PpGST(GenBank登录号为HQ889136)。PpGST全长cDNA为1 177bp,具有130bp 5′-UTR、696bp ORF以及351bp 3′-UTR,编码含231个氨基酸的蛋白质。与已知植物GSTs家族成员间的氨基酸序列聚类分析将PpGST聚为zeta类GST。RT-PCR分析显示,PpGST在火把梨光照的果皮和没有光照的果皮中大量表达,并且表达强度不受光照时间的影响,而在幼嫩叶片中没有表达。研究结果暗示在果皮中大量表达的PpGST可能参与维持火把梨果实发育过程中的氧化还原平衡及应答逆境胁迫。     

Presence of Rhizobium Etli bv . Phaseoli and Rhizobium Gallicum bv . Gallicum in Egyptian Soils

Seven bean rhizobial strains EBRI 2, 3, 21, 24, 26, 27 and 29 identified as Rhizobium etli, and EBRI 32 identified as Rhizobium gallicum, isolated from Egyptian soils and which nodulated Phaseolus vulgaris efficiently, were subjected to hybridization with a nifH probe in order to estimate the copy number of this gene. Seven strains (EBRI 2, 3, 21, 24, 26, 27 and 29) which were only able to nodulate Phaseolus vulgaris, contained three copies of the nifH gene, consistent with their identification as Rhizobium etli bv. phaseoli. Only one strain (EBRI 32) which nodulated both Phaseolus vulgaris and Leucaena leucocephala, had one copy of nifH gene. This confirmed the classification of this strain as Rhizobium gallicum bv. gallicum.     

Effects of MULTIFOLIATE-PINNA, AFILA, TENDRIL-LESS and UNIFOLIATA genes on leafblade architecture in Pisum sativum

In order to dissect the genetic regulation of leafblade morphogenesis, 16 genotypes of pea, constructed by combining the wild-type and mutant alleles of MFP, AF, TL and UNI genes, were quantitatively phenotyped. The morphological features of the three domains of leafblades of four genotypes, unknown earlier, were described. All the genotypes were found to differ in leafblade morphology. It was evident that MFP and TL functions acted as repressor of pinna ramification, in the distal domain. These functions, with and without interaction with UNI, also repressed the ramification of proximal pinnae in the absence of AF function. The expression of MFP and TL required UNI function. AF function was found to control leafblade architecture multifariously. The earlier identified role of AF as a repressor of UNI in the proximal domain was confirmed. Negative control of AF on the UNI-dependent pinna ramification in the distal domain was revealed. It was found that AF establishes a boundary between proximal and distal domains and activates formation of leaflet pinnae in the proximal domain.     

Prosthecium species with Stegonsporium anamorphs on Acer

Data from microscopic morphology, single-spore cultures, and DNA analyses of teleomorphs and anamorphs support the recognition of five species of Prosthecium with Stegonsporium anamorphs on Acer: P. acerinum sp. nov., the teleomorph of S. acerinum; P. acerophilum comb. nov., formerly known as Dictyoporthe acerophila; P. galeatum comb. nov., originally described as Massaria galeata; P. opalus sp. nov.; and P. pyriforme sp. nov., the teleomorph of S. pyriforme s. str. The morphology of both type specimens and freshly collected material was investigated. The teleomorphs have brown ellipsoidal ascospores with five distosepta and often a longitudinal distoseptum. The anamorphs of all species described here belong to Stegonsporium; their connection to the Prosthecium teleomorphs was demonstrated by morphology and DNA sequences of single spore cultures derived from both ascospores and conidia. The anamorphs and teleomorphs of all five Prosthecium species are described and illustrated by LM images, and a key to these species is provided. As perceived from this work, S. pyriforme is restricted to Europe and does not occur in North America, whereas S. acerinum is restricted to North America, not found in Europe. The host associations given in the literature are revised and evidence is provided that only A. opalus, A. pseudoplatanus, and A. saccharum are confirmed hosts of Prosthecium with Stegonsporium anamorphs. Molecular phylogenetic analyses of tef1, ITS rDNA, and partial nuLSU rDNA sequences confirm that the species with Stegonsporium anamorphs are closely related to P. ellipsosporum, the generic type species. Stilbospora macrosperma is confirmed as the anamorph of P. ellipsosporum by DNA data of single spore isolates obtained from both ascospores and conidia.     

Characterisation of cell wall polysaccharides, arabinogalactans-proteins (AGPs) and phenolics of Cola nitida, Cola acuminata and Garcinia kola seeds

Many Cola plant species are endemic to West and Central Africa. Cola acuminata and Cola nitida are used as masticatory when fresh, while the dried nuts are used for beverages and pharmaceutical purposes in Europe and North America. Garcinia kola seeds, that serve as a substitute for the true kola nuts, are used in African traditional medicine for the treatment of various diseases, including colic, headache and liver cirrhosis. Seeds extracts of G. kola are also known for their anti-inflammatory, antimicrobial and antiviral properties. To gain information on the chemical properties of the kolas, we have isolated and analyzed cell wall polysaccharides, arabinogalactan-proteins and phenolic substances from the seeds of the three kola species. The sugar composition of cell wall material of C. acuminata, C. nitida and G. kola revealed that Gal (up to 30%), Ara, GalA and Glc as the predominant monosaccharides, representing approximately 90% by mol of the total hydrolysable sugar present in this material. In Ammonium oxalate cell wall fraction, GalA was found to be the major sugar present in all kola species. In the alkali-soluble fraction, there were significant differences in the level of Glc and Gal. The level of Glc was high in C. acuminata and C. nitida while the level of Gal and Xyl were high in C. nitida and G. cola. Isolation and quantification of arabinogalactan-proteins demonstrate that G. kola seeds contained four to eight times more of these proteoglycans than the seeds of the other two species. Finally, analysis of soluble phenolic substances shows that caffeine and catechin were largely represented in C. acumina and C. nitida seeds, with caffeine accounting for 50% of all soluble phenolics. These findings indicate that the three Kola seeds are highly enriched in pectins and proteoglycans and that C. acuminata and C. nitida can be used as a possible source of caffeine and catechin.     

中国黑粉菌属和利罗黑粉菌属

黑粉菌属是Roussel 1806年建立的,全世界记载有三百余种,主要寄生于禾本科,是经济作物及牧草的重要致病菌·长期以来,对黑粉菌的邢子使用过各种名称,如厚垣孢子,冬孢子及黑粉孢子等.本文采用黑粉孢子以区别锈菌的冬孢子. 芳’(1979)在《中国真菌总汇》中列出黑粉菌属五十种及一个变型.作者经过显微结构和超显微结构的研究,承认其中二十九种为正确名称,八种及一变型为异名,顶黑粉菌(Ustilago acrearus Berk.)由于错拼而被废弃.埃地黑粉菌(Ustilago emodensis Berk.)被转移至利罗粉菌属(Liroa).另有十一种黑粉菌因缺少标本留待今后订正.自1979年以后,杨信东(1983)增加黑粉菌属二种我国新纪录,K.范基和郭林(1986)描述一新种,四种新纪录.在本文中,作者描述一新种:鸢尾蒜黑粉(Ustilago ixiolirii Guo L) ,孢子堆生在蒴果内,不开裂,黑色,粉末状.黑粉孢子球形,近球形,稀椭圆形, 12.5-21×10-21μm,黑褐色,壁厚1-1.Sμm,纹饰脑状.是迄今生在石蒜科植物上唯一黑粉菌的种,其它几种黑粉菌均属条黑粉菌属.本文增加七种我国新纪录.共计四十九种,寄生于六科四十四属植物,主要是禾本科和蓼科.这仅是黑粉菌属研究的初步报告,在全国范围内大量采集黑粉菌标本后,作者相信会有更多新种和我国新纪录被发现.利罗黑粉菌属(Liroa)是从黑粉菌属(Ustaligo)分出的,此属为单种属.     

Comparative study of Bifidobacteriumanimalis, Escherichiacoli, Lactobacilluscasei and Saccharomycesboulardii probiotic properties

The present work investigates some probiotic properties of four different microorganisms (Bifidobacterium animalis var. lactis BB-12, Escherichia coli EMO, Lactobacillus casei and Saccharomyces boulardii). In vitro and in vivo tests were carried out to compare cell wall hydrophobicity, production of antagonistic substances, survival capacity in the gastrointestinal tract of germ-free mice without pathological consequence, and immune modulation by stimulation of Küpffer cells, intestinal sIgA and IL-10 levels. In vitro antagonism against pathogenic bacteria and yeast was only observed for the probiotic bacteria B. animalis and L. casei. The hydrophobic property of the cell wall was higher for B. animalis and E. coli EMO, and this property could be responsible for a better ability to colonize the gastrointestinal tract of germ-free mice. Higher levels of sIgA were observed mainly for S. boulardii, followed by E. coli EMO and B. animalis, and only S. boulardii induced a significant higher level of IL-10. In conclusion, for a probiotic use, S. boulardii presented better characteristics in terms of immunomodulation, and B. animalis and L. casei for antagonistic substance production. The knowledge of the different probiotic properties could be used to choice the better microorganism depending on the therapeutic or prophylactic application.     

Probing the Drosophila retinal determination gene network in Tribolium (II): The Pax6 genes eyeless and twin of eyeless

The Pax6 genes eyeless (ey) and twin of eyeless (toy) are upstream regulators in the retinal determination gene network (RDGN), which instructs the formation of the adult eye primordium in Drosophila. Most animals possess a singleton Pax6 ortholog, but the dependence of eye development on Pax6 is widely conserved. A rare exception is given by the larval eyes of Drosophila, which develop independently of ey and toy. To obtain insight into the origin of differential larval and adult eye regulation, we studied the function of toy and ey in the red flour beetle Tribolium castaneum. We find that single and combinatorial knockdown of toy and ey affect larval eye development strongly but adult eye development only mildly in this primitive hemimetabolous species. Compound eye-loss, however, was provoked when ey and toy were RNAi-silenced in combination with the early retinal gene dachshund (dac). We propose that these data reflect a role of Pax6 during regional specification in the developing head and that the subsequent maintenance and growth of the adult eye primordium is regulated partly by redundant and partly by specific functions of toy, ey and dac in Tribolium. The results from embryonic knockdown and comparative protein sequence analysis lead us further to conclude that Tribolium represents an ancestral state of redundant control by ey and toy.     

Doc and copia instability in an isogenic Drosophila melanogaster stock

A high degree of heterogeneity and an overall increase in number of insertion sites of the mobile elements Doc and copia were revealed in one substock of an isogenic Drosophila melanogaster stock, while in two other substocks the distribution of copia sites was highly homogenous, but that of Doc sites was again heterogenous. We therefore concluded that copia was unstable in one of the substocks and Doc was unstable in all. Doc instability presumably arose earlier than copia instability. Doc and copia transpositions were directly observed in experiments with one substock. An abundance of copia insertions was revealed in the X chromosome where insertions with deleterious effects are exposed to selection in hemizygous condition. The locations of many other mobile elements (mdg1, mdg2, mdg3, mdg4, 297, B104, H.M.S. Beagle, I, P, BS, FB) were found to be conserved in each substock and did not differ between them, indicating that these mobile elements were stable. This homogeneity is a strong argument against any possibility of inadvertent contamination.