斜纹夜蛾核多角体病毒几丁质酶基因上游4.0kb的序列分析

本文报道了斜纹夜蛾核多角体病毒几丁质酶基因(chiA)上游约4.0 kb范围内的序列,它包括了六个读码框(ORF1～6),其长度分别为156 bp、297 bp、540 bp、369 bp、1281 bp和228 bp,可编码的氨基酸长度分别为51、98、179、122、426和75个,分子量分别为6.15?kD、11.46 kD、21.70 kD、14.69 kD、47.59 kD和9.09 kD。在ORF1、ORF2、ORF3起始密码前分别有一个、二个及一个杆状病毒早期启动子基序CAGT;在ORF4、ORF5起始密码前各有一个及二个杆状病毒晚期启动子基序TAAG。在ORF1、ORF4、ORF5终止密码下游有真核生物mRNA转录poly(A)加尾信号。ORF4为AcMNPVORF53、BmNPVORF42、OpMNPVORF56、LdMNPVORF54的同源基因。ORF1、ORF2、ORF6与已知的杆状病毒基因没有同源性,可能为三个新的基因。     

斜纹夜核多角体病毒DNA XbaⅠ4.0kb片段锌指蛋白基因及重复序列分析

测定了斜纹夜核多角体病毒（Spodoptera litura nucleopolyhedrovirus,SpltNPV)中山大学分离株基因DNA XbaI4.0片段全序列,该片段包括一个锌指蛋白基因及三个区域的DNA重复序列（SR1、SR2、SR3）。该锌指蛋白基因读码框为2196个核苷酸,编码731个氨基的蛋白质,分子量为83．09KD,该蛋白的等电点为4．61,在其5‘非编码区内有一个杆状病毒早期启动子基序GAGT5及一个TATA盒,在其终止密码的下游有5个真核生物转录mRNA时poly(A)加尾信号AATAAA。在223－241氨基酸残基之间有一个锌指蛋白基序,这一基序属于锌指蛋白基序中的C3HC4类,即环指（Ring finger)类基序,在323－340氨基酸残基区域为一个核定位信号,该蛋白可能为一个高度折叠的蛋白质。在该片段中存在三个DNA重复序列区域（SAR1、SR2、SR3）,其中SR1与SR3区或存在更大量的重复序列,SR1区域其中的一个重复序列长达41bp,SR1,SR3重复序列区域可能作为该病毒转录的增强子,或者作为DNA复制的起始点。     

棉铃虫核型多角体病毒基因组结构及p10基因

用BamHI、EcoRV、HindⅢ、KpnⅠ、PstⅠ和XbaⅠ六种限制性内切酶消化HaSNPV C1株基因组DNA,电泳后形成的大于400bp的片段数分别为11、31、13、6、7和25条。预计整个基因组长度为137.7kb左右。构建了HaJSNPV基因组6种限制性内切酶的物理图谱,并在图谱上定位了5个同源重复区hr1、hr2、hr3、hr4和hr5以及多角体蛋白(ph）基因、极早基因（ie1)、p10、几丁质酶（chitinase）基因、DNA聚合酶基因（DNApol）、解旋酶（helicase）基因、超氧化物歧化酶基因(sod）、碱性外切核酸酶基因（alk-exo）、蜕皮甾体尿苷二磷酸葡萄糖转移酶基因（egt）。HaSNPV的基因组结构与其他已知的病毒表现了很明显的差异。p10基因位于BamHI-Ⅰ片段（1.89kb)上,其转录方向与多角体蛋白基因（polh）相反。p10上游为p26基因,下游为p74基因,p26和p10基因转录方向一致,p74基因转录方向与前两者相反。p10基因编码区全长261bp,可编码分子量为9.3kD ,由87个氨基酸残基组成的多肽。编码区上游是一个富含AT区,在起始密码子ATG上游－52bp处有杆状病毒晚期基因启动子典型的转录起始位点元件TAAG,而在翻译终止密码子TGA下游20bp处有转录终止信号AATAAA。     

斜纹夜蛾核多角体病毒DNA XbaI 4.0 kb片段锌指蛋白基因及重复序列分析

测定了斜纹夜蛾核多角体病毒 (Spodopteralituranucleopolyhedrovirus,SpltNPV)中山大学分离株基因组DNAXbaI4.0kb片段全序列 ,该片段包括一个锌指蛋白基因及三个区域的DNA重复序列 (SR1、SR2、SR3)。该锌指蛋白基因读码框为 2 196个核苷酸 ,编码 731个氨基酸的蛋白质 ,分子量为 83 .0 9kD ,该蛋白的等电点为 4.6 1。在其 5′非编码区内有一个杆状病毒早期启动子基序GAGT及一个TATA盒 ,在其终止密码的下游有 5个真核生物转录mRNA时poly(A)加尾信号AATAAA。在 2 2 3～ 2 41氨基酸残基之间有一个锌指蛋白基序 ,这一基序属于锌指蛋白基序中的C3HC4类 ,即环指 (Ringfinger)类基序。在 32 3～ 340氨基酸残基区域为一个核定位信号。该蛋白可能为一个高度折叠的蛋白质。在该片段中存在三个DNA重复序列区域 (SR1、SR2、SR3) ,其中SR1与SR3区域存在更大量的重复序列 ,SR1区域其中的一个重复序列长达 41bp ,SR1、SR3重复序列区域可能作为该病毒转录的增强子 ,或者作为DNA复制的起始点。     

棉铃虫单核衣壳核多角体病毒囊膜蛋白odv—e66基因及其邻近区域的序列分析

杆状病毒ODV－E66蛋白是包涵体来源病毒（occlusion-derived virus,ODV）囊膜的结构蛋白,ODV囊膜对ODV的稳定性和感染性具有重要作用。本文报道了HaSNPV odv-e66基因及其邻近区域共4237bp的核苷酸序列及其分析结果。HaSNPV的odv-e66基因编码区全长2019bp,推测编码一个由672个氨基酸残基组成的,分子量为74.5kD的蛋白质。在起始密码子ATG上游具有杆状病毒晚期转录起始信号ATAAG。与其他杆状病毒ODV－E66的氨基酸序列比较分显示HaSNPV ODV-E66蛋白具有多个保守区域,包括N末端的强疏水功能区、序列中部的一个可能的核定位信号RKIW,两个Leu-xipper以及5个跨膜区。odv-e66基因上游的两个ORF分别与AcMNPV的orf108和orf109具有同源性,下游的ORF与LsNPV的p13基因具有同源性。     

斜纹夜蛾核多角体病毒 DNA XbaI 4.0 kb 片段锌指蛋白基因及重复序列分析

测定了斜纹夜蛾核多角体病毒(Spodopteralituranucleopolyhedrovirus,SpltNPV)中山大学分离株基因组DNAXbaI4.0kb片段全序列,该片段包括一个锌指蛋白基因及三个区域的DNA重复序列(SR1、SR2、SR3).该锌指蛋白基因读码框为2196个核苷酸,编码731个氨基酸的蛋白质,分子量为83.09kD,该蛋白的等电点为4.61.在其5′非编码区内有一个杆状病毒早期启动子基序GAGT及一个TATA盒,在其终止密码的下游有5个真核生物转录mRNA时poly(A)加尾信号AATAAA.在223～241氨基酸残基之间有一个锌指蛋白基序,这一基序属于锌指蛋白基序中的C3HC4类,即环指(Ringfinger)类基序.在323～340氨基酸残基区域为一个核定位信号.该蛋白可能为一个高度折叠的蛋白质.在该片段中存在三个DNA重复序列区域(SR1、SR2、SR3),其中SR1与SR3区域存在更大量的重复序列,SR1区域其中的一个重复序列长达41bp,SR1、SR3重复序列区域可能作为该病毒转录的增强子,或者作为DNA复制的起始点.     

球孢白僵菌tps2基因的克隆和生物信息学分析

运用SMART RACE RT-PCR技术与DNA步移技术,首次从球孢白僵菌中克隆出完整的海藻糖-6-磷酸磷酸酯酶TPS2的基因编码区序列及上游序列。该基因cDNA全长3219 bp,其中开放阅读框（ORF）2619 bp,编码872个氨基酸。成熟蛋白理论分子量为97.8 kD,理论等电点为6.32。编码框结构基因的全长为2821 bp,有两个长度分别为140 bp和62 bp的内含子。分析表明,上游序列中含有TATA-box、CAAT-box和GC-box,并且也存在GATA元件等启动子顺式调控元件。本文结果将为进一步研究海藻糖在虫生真菌中的生理合成以及抗逆调控机制奠定坚实的基础。     

拟南芥生长素受体基因TIR1启动子的初步分析

以野生型拟南芥（Arabidopsis Columbia）基因组DNA为模板,通过PCR扩增得到拟南芥生长素受体基因T1R1启动子的5个不同长度的系列缺失片段,将这些片断分别克隆到PGM—T载体上。序列分析表明,该启动子系列缺失片段的大小分别为2008bp、1524bp、939bp、532bp和321bp。与已报道的序列完全相同。将不同长度的启动子克隆片断分别与GUS基因融合,构建成表达载体后,在烟草叶片中作遗传转化。分析结果显示：不同长度的启动子片段已整合到烟草基因组中并有GUS酶活性存在,且不同长度启动子片段的表达活性有较明显差异。     

多粘类芽孢杆菌SC2 xynD和gluB的克隆及序列分析

β-1,4-木聚糖酶和β-1,3-1,4-葡聚糖酶活性检测结果表明,多粘类芽孢杆菌(Paenibacillus polymyxa)SC2能同时产生β-1,4-木聚糖酶和β-1,3-1,4-葡聚糖酶.以菌株SC2的基因组DNA为模板,通过TAIL-PCK方法克隆到4 807bp的DNA片段.DNAMAN软件分析,该DNA片段包含2个开放阅读框(ORF),ORF1长度为1 908 bp,编码含635个氨基酸、分子量为67.8kD的蛋白;ORF2长度为714 bp,编码含237个氨基酸、分子量为26.8kD的蛋白.BLAST分析结果表明,ORFI与已报道的P.polymyxa ATCC 842的xynD基因相似性为94%.ORF2与P.polymyxaWY110的gluB基因相似性为99%.基因序列的系统发育分析进一步说明.ORFI和ORF2分别为β-1,4-木聚糖酶基因xynD和β-1,3-1,4-葡聚糖酶基因gluB.     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Time of detection of recessive genes: effects of system of mating and number of examined individuals

Summary Anthers were cultured from two sets of seven lines of hexaploid wheat (Triticum aestivum L.) with different cytoplasms, the euplasmic nucleus donors, Siete Cerros 66 and Penjamo 62, as well as their six alloplasmic lines derived from wild relative species of the genera Triticum and Aegilops. Significant cytoplasmic and nuclear effects but no cytoplasmic-nuclear interaction were found for embryogenic anther response, with the best performance of Penjamo 62 in Ae. kotschyi cytoplasm. Plant regeneration was not affected significantly by the cytoplasmic background of the lines cultured. The possible genetic implications of the observed cytoplasmic and nuclear influences on the in vitro haploid induction of wheat are discussed.     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.