重铬酸钾对蚕豆根尖细胞致畸效应的研究

以蚕豆根尖为材料,研究重铬酸钾对蚕豆根尖细胞的致畸效应。采用蚕豆根尖细胞的微核试验和染色体畸变试验方法,以不同浓度的重铬酸钾为诱变剂,测定蚕豆根尖细胞的微核率和染色体畸变率。结果表明：重铬酸钾能诱发较高频率的微核率,即在一定浓度范围内,其微核率随重铬酸钾处理浓度的升高而增加,但高于一定浓度后反而呈下降趋势;不同浓度的重铬酸钾均使蚕豆根尖细胞有丝分裂指数增大;重铬酸钾还能诱导蚕豆根尖细胞产生较高频率的染色体畸变,且产生多种类型的染色体畸变。结论是重铬酸钾对蚕豆根尖细胞具有明显的致畸效应。Abstract：We studied the aberrant effects of different concentrations of potassium dichromate on Vicia Faba root tip cells. The micronucleus and chromosome aberration assay was conducted to determine the micronucleus rate and chromosome aberration rate of Vicia faba root tip cells induced by potassium dichromate. The result indicated that potassium dichromate could increase the micronucleus rate of Vicia faba root tip cells. Within certain range of concentration the rate of micronucleus was found to be increased with the increase of potassium dichromate concentration,but beyond this range the rate of micronucleus decreased with further increase of potassium dichromate concentration. The potassium dichromate at different concentrations could increase the cell mitosis index. Besides,it also caused various types of chromosome aberration,and the rates of chromosome aberration were always higher than that of the control group. The conclusion of this study was that potassium dichromate has obvious teratogenic effect on vicia faba root tip cells.     

NaCl胁迫对大麦细胞分裂及染色体行为的影响

NaCl溶液培养导致大麦幼苗根尖细胞有丝分裂指数下降,细胞姐妹染色单体交换(SCE)频率增高,且诱发包括染色体断片、后期染色体桥、不均等分裂及间期细胞微核等的染色体行为异常。细胞平均SCE频率及异常分裂细胞的比率与NaCl浓度和作用时间呈正相关。结果提示：NaCl浓度高或作用时间较长时对大麦细胞具有遗传学毒性。 Abstract：The effects of NaCl solution on chromosome behavior and sister chromatid exchanges(SCE)of barley were studied.Abnormal chromosome behavior including chromosome fragmentation,micronuclei,anaphase bridges and unequal split was found in root tip cells of Hordeum vulgare seedlings.Mitotic index decreased but SCE frequency increased significantly when barley incubated with NaCl solution.The effects of NaCl solution depended on its concentration and treatment duration.The higher the treated concentration was,the higher the ratio of chromosomal aberration was.The longer the treatment duration was,the higher the degree of the effects was.The results showed that NaCl solution was genotoxic when the concentration was higher and the treated time was longer.     

60Co事故受照人员远期细胞遗传学效应观察

对三例钴源事故受照人员照后6(7)年和11(12)年两次细胞遗传学随访结果表明,两次随访受照者染色体畸变率分别为4.29%和3.63%,均显著高于对照组(P<0.01),但两次随访间未见显著差异(P>0.05),而且第一次随访染色体畸变是以双+环和无着丝粒断片为主,第二次随访是以易位、缺失和倒位为主;两次随访受照者微核率分别为4.17‰和1.17‰,第二次随访微核率明显下降(P<0.01)。提示随着照后时间推移, 非稳定性染色体畸变逐渐丢失,稳定性染色体畸变仍保持在较高水平。 Abstract：　The analyses of chromosome aberrations and micronuclei in peripheral blood lymphocyte were performed in 3 cases exposed to 60Co radiation accident in 6(7) years and 11(12) years after irradiation. The results show that the frequencies of chromosome aberrations in exposed cases were 4.29% in 6(7) years and 3.63% in 11(12) years after irradiation, respectively, and the difference was not significant in the two times follow-up study. Most of the chromosome aberrations were acentric and dicentric chromosomes in first time follow-up study, and translocation, deletion and inversion chromosomes in second time follow-up one. The frequencies of micronuclei in exposed group were 4.17‰ and 1.17‰ in the two times follow-up study, respectively, and the rates of micronuclei in second time follow-up study were much lower than that in first one. The results indicated that the unstable type aberrations were gradually lost as time goes on ,and the level of stable type aberration was of high degree.     

Physical mapping of three fruit ripening genes：Endopolygalacturonase,ACC oxidase and ACC synthase from apple（Malus x domestica） in an apple rootstock A106（Malus sieboldii

The apple rootstock,A106(Malus sieboldii),had 17 bivalents in pollen mother cells at meiotic metaphase 1,and 17 chromosomes in a haploid pollen cell.Karyotypes were prepared from root-tip cells with 2n=34 chromosomes,Seven out of 82 karyotypes(8.5%) showed one pari of satellites at the end of the short arm of chromosome 3.C-bands were shown on 6 pairs of chromosomes 2,4,6,8,14,and 16 near the telomeric regions of short arms.Probes for three ripening-related genes from Malus x domestica:endopolygalacturonase(EPG,0.6kb),ACC oxidase(1.2kb),and ACC synthase(2kb)were hybridized in situ to metaphase chromosomes of A106.Hybridization sites for the EPG gene were observed on the long arm of chromosome 14 in 15 out of 16 replicate spreads and proximal to the centromere of chromosomes 6 and 11.For the ACC oxidase gene,hylridization sites were observed in the telomeric region of the short arm of chromosomes 5 and 11 in 87% and 81% of 16 spreads respectively,proxiaml to the centromere of chromosome 1 in 81% of the spreads,and on the long arm of chromosome 13 in 50% of the spreads. Physical mapping of three fruit ripening genes in an apple rootstock A106.Twenty five spreads were studied for the ACC synthase gene and hybridization sites were observed in the telomeric region of the short arm of chromosome 12 in 96% of the spreads.chromosomes 9 and 10 in 76% of the spreads,and chromosome 17 in 56% of the spreads.     

Molecular Cytogenetic Characterization of a Wheat - Leymus mollis 3D（3Ns） Substitution Line with Resistance to Leaf Rust

Leymus mollis （Trin.） Pilger （NsNsXmXm, 2n = 28）, a wild relative of common wheat, possesses many potentially valuable traits that could be transferred to common wheat during breeding programs. In this study, the karyotypic constitution of a wheat - L. mollis 3D（3Ns#1） disomic substitution line isolated from the F5 progeny of octoploid Tritileymus M842-16 x Triticum durum cv. D4286, which was designated as 10DM57, was determined using genomic in situ hybridization （GISH）, fluorescent in situ hybridization （FISH）, SSR markers, and EST- STS markers. Screening of mitosis and meiosis showed that 10DM57 had a chromosome karyotype of 2n = 42 =21Ⅱ. GISH indicated that 10DM57 was a line with 40 chromosomes from wheat and two of the Ns chromosomes from L. mollis, which formed a ring bivalent in pollen mother cells at metaphase I. FISH analysis showed that the chromosome 3D may be replaced by 3Ns#1 in 10DM57. DNA markers, including SSR and EST-STS primers, showed that the pair of wheat chromosome 3D in 10DM57 was substituted by the pair of chromosome 3Ns#t from L. mollis. Evaluation of the agronomic traits showed that, compared with its common wheat relative 7182, 10DM57 was resistant to leaf rust while the spike length and number of spikes per plant were improved significantly, which correlated with a higher wheat yield. The new germplasm, 10DM57, could be exploited as an intermediate material in wheat genetic and breeding programs.     

绒毛细胞与新生儿脐带血和成人外周血染色体断裂和裂隙的比较

绒毛用直接法制片,新生儿脐带血和成人外周血用半微量全血法制片。对绒毛、脐带血和外周血染色体的断裂和裂隙进行比较。结果表明,绒毛细胞的染色体断裂和裂隙比新生儿脐带血和成人外周血的显著增高,而新生儿脐带血和成人外周血之间则无明显差异。 Abstract:Chromosome breaks and gaps in chorionic villus cells and lymphocytes from newborn and abult were compared.The number of chromosome breaks and gaps in chorionic villus cells was higher than that in newborn and adult lymphocytes,This might be one of the reasons for higher chromosome aberration rate in chorionic villus.     

三氧化二砷（As2O3）对蚕豆根尖毒性效应的细胞遗传学研究

本文以蚕豆根尖为材料,研究不同浓度As2O3在不同的处理时间内对蚕豆胚根根尖的细胞遗传学毒性效应。结果表明：不同浓度的As2O3在不同处理时间内均能诱发较高的微核率和染色体畸变率,并能有效地积累中期分裂相,阻止其进入后期与末期。结论是As2O3对蚕豆根尖细胞具有明显的细胞遗传学毒性效应,并具有积累有丝分裂中期细胞的效应。 Abstract:The cytogenetic toxic effects of different concentration of As2O3 within different time on the cell of Vicia Faba root tip were studied.The results indicate that the different concentrations of As2O3 can induce high frequency of micronucleus and chromosome aberration.Besides,it can accumulate the metaphases in mitosis efficiently and prevent the cells from continuing their cell cycle.It shows that As2O3 has marked cytogenetic toxic effect on the root tip cells of Vicia Faba,and effect of accumulating the metaphases in mitosis.     

应用荧光原位杂交(FISH)技术研究 黑叶猴染色体易位

本文应用染色体荧光原位杂交(FISH)技术,利用人9号和14号染色体特异探针,对深低温冻存和长期传代的黑叶猴细胞株染色体畸变进行了分析。确定在长期冻存和传代过程中,一些黑叶猴细胞在No.12和No.17染色体之间发生了易位,一条 No.17染色体发生断裂,断裂点在17q13,断裂片段17q13-17qter易位到一条 No.12染色体长臂末端,形成一条小的中着丝粒的和一条具较长长臂的衍生染色体即 der(17) 和 der(12)。结果表明,荧光原位杂交技术用人染色体特异探针不仅能检测出人类染色体畸变,也能有效地检测灵长类动物染色体畸变。 Abstract　In this paper,the chromosome aberration of long-term cryopreserved and subcultured Francois' monkey (Semnopithecus francoisi) cell line(KCB 92008) was analyzed by fluoresence in situ hybridizaton (FISH) using human 9 and 14 chromosome DNA probes. After compared the hybridization pattern with the G-banding pattern on the same metaphase,a translocation between Nos.12 and 17 chromosomes was identified. In some Francois'monkey cells,one of chromosome No.17 was broken into two at the breakpoint 17q13,the segment(17q13-17qter) without centromere transfered to the long arm terminal of one chromosome No.12. Thus,two derivant chromosomes der(12) and der(17) were formed,the long arm of der(12) was longer than the normal partner,while the long arm of der(17) was shorter than the normal one. The result indicated that the technique of FISH using human whole chromosome probes was not only a powerful tool to detect human chromosome rearrangements,but also a usefulmethod to study the primate chromosome aberration.     

Arabidopsis PTD Is Required for Type I Crossover Formation and Affects Recombination Frequency in Two Different Chromosomal Regions

In eukaryotes, crossovers together with sister chromatid cohesion maintain physical association between homologous chromosomes, ensuring accurate chromosome segregation during meiosis I and resulting in exchange of genetic information between homologues. The Arabidopsis PTD （Parting Dancers） gene affects the level of meiotic crossover formation, but its functional relationships with other core meiotic genes, such as AtSP011-1, AtRAD51, and AtMSH4, are unclear; whether PTD has other functions in meiosis is also unknown. To further analyze PTD function and to test for epistatic relationships, we compared the meiotic chromosome behaviors ofAtspoll-1 ptd and Atrad51 ptd double mutants with the relevant single mutants. The results suggest that PTD functions downstream of AtSP011-1 and AtRAD51 in the meiotic recombination pathway. Furthermore, we found that meiotic defects in rck pM and Atmsh4 ptd double mutants showed similar meiotic phenotypes to those of the relevant single mutants, providing genetic evidences for roles of PTD and RCK in the type I crossovers pathway. Moreover, we employed a pollen tetrad-based fluorescence method and found that the meiotic crossover frequencies in two genetic intervals were significantly reduced from 6.63% and 22.26% in wild-type to 1.14% and 6.36%, respectively, in the ptd~2 mutant. These results revealed new aspects of PTD function in meiotic crossover formation.     

Trichlorfon exposure, spindle aberrations and nondisjunction in mammalian oocytes

Consumption of trichlorfon-poisoned fish by women in a small Hungarian village has been associated with trisomy resulting from an error of meiosis II in oogenesis. We therefore examined mouse oocytes exposed for 3 h during fertilization to 50 μg/ml trichlorfon. Spindle morphology was not visibly altered by the pesticide. Chromosomes segregated normally at anaphase II with no induction of aneuploidy. However, formation of a spindle was disturbed in many oocytes resuming meiosis I in the presence of trichlorfon. In spite of the spindle aberrations and the failure of bivalents to align properly at the equator, oocytes did not become meiotically arrested but progressed to metaphase II. At this stage, spindles were highly abnormal, and chromosomes were often totally unaligned, unattached or dispersed on the elongated and disorganized spindle. By causing spindle aberrations and influencing chromosome congression, trichlorfon appears, therefore, to predispose mammalian oocytes to random chromosome segregation, especially when they undergo a first division and develop to metaphase II during exposure. This is the first case in which environmentally induced human trisomy can be correlated with spindle aberrations induced by chemical exposure. Our observations suggest that oocytes may not possess a checkpoint sensing displacement of chromosomes from the equator at meiosis I and may therefore be prone to nondisjunction. Received: 2 August 1998; in revised form: 12 September 1998 / Accepted: 13 September 1998     

被孢霉W_（A－90）发酵生产γ－亚麻酸的研究

本文研究了由被抱霉变株ＭＡ－９０生产了γ－亚麻酸的发酵条件．确定了最适碳源、复源及Ｃ／Ｎ．初步建立了生产γ－亚麻酸的工艺条件。葡萄糖、蔗糖及天冬酰胺和尿素为最适碳、氮源。在Ｃ／Ｎ为２０／１,葡萄糖浓度为８０ｇ／Ｌ的条件下．油脂产量和油脂中γ－亚麻酸的含量分别为８．２ｇ／Ｌ和１４．１３％,γ－亚麻酸产量及生物量分别为１．１５７ｇ／Ｌ和３１．２ｇ／Ｌ。后期适当降低培养温度和良好的通气条件均有利于γ－亚麻酸的积累。     

CHAPS对M_(412)的动力学和共振拉曼光谱的影响

研究了表面活性剂CHAPS对紫膜中菌紫质在光循环过程中M_(412)的衰减速率及质子泵功能的影响.光循环中间体M_(412)快、慢衰减组分的衰减速率及质子衰减速率均受到CHAPS的影响,综合激光拉曼光谱对M_(412)和其它光循环中间体相对含量的测定,表明CHAPS对紫膜的影响是通过影响其膜脂完整的液晶结构,而使紫膜光循环动力学过程及质子泵功能发生变化的.     

蜂毒对菌紫质(bR)光循环中间体M_(412)和质子泵的影响

蜂毒对菌紫质(bR)光循环中间体M_(412)及质子泵的动力学过程有较大影响.表现在M_(412)慢衰减组分(M_(412~S))和质子的半衰期增大及产出量的减小,说明蜂毒分子的介入抑制了M_(412)的生成和衰减过程,同时也阻碍了紫膜的质子泵功能.但似乎对M_(412)快衰减组分影响不大.以上结果支持了M_(412~S)与质子泵功能有关的说法.实验结果同时反映出蜂毒除与膜脂分子存在强烈作用外还与bR本身直接作用.因此,蜂毒是一种研究膜脂蛋白相互作用及膜蛋白功能的较好材料.     

番茄种子经激光和咖啡因处理后其当代生物效应的研究

咖啡因具有抑制一些酶的活性,可减弱或消除生物体自身对激光引起的生物效应的修复作用。试验证明咖啡因对番茄种子萌发有强烈的抑制作用,咖啡因和激光复合处理生物效应显著,可降低番茄种子的发芽,并促进番茄果实增大和生长前期速率加快。     

小麦辐射二代性状的数量遗传分析

本文采用生物统计和数量遗传学方法、分析了辐照剂量为0（对照）、15、25、35KR的铯─137γ射线对二个小麦品种的诱变效应及其选择效果;估算了七个数量性状的分布特征数和遗传方差、遗传变异系数、遗传力、遗传进度、相对遗传进度等遗传参数。辐射二代的变异较大,有大粒、大穗、早熟突变体出现;株粒重、穗粒重、穗长、穗粒数、抽穗期的遗传变异系数和相对遗传进度都较大,选择效果较好;铯-137γ射线能有效地应用于小麦辐射育种,且适宜辐照剂量为35KR。     

EMS诱变甘蓝型油菜M_2代群体的表型突变研究

利用4种浓度EMS处理甘蓝型油菜NJ7982种子,选取其中诱变效果好的处理(0.4%EMS),研究其后代突变型和突变频率。对4.8万株的M2代群体鉴定结果表明,6种器官性状在群体中均出现了突变。子叶突变性状包括3子叶、子叶黄化等,占群体的0.22%;叶片突变性状包括黄化叶、白化叶、紫色叶、上卷叶、下卷叶等,占0.74%;花器突变性状包括紫色花蕾、死蕾、3花瓣、6花瓣、白色瓣、花瓣黄白镶嵌、花瓣皱缩、完全不育、部分可育等,占9.38%;株型突变性状包括矮秆、紫茎等,占4.98%;角果突变性状包括粗角、长角、紫角等,占2.79%;种皮黄色,占0.40%;总的表型突变频率为18.51%。这些遗传多样性的突变材料,为甘蓝型油菜种质创新及品种遗传改良提供基础性材料。     

灵芝发酵菌丝体中灵芝酸的分离纯化及生物活性检测

灵芝深层发酵菌丝体经甲醇提取得到粗灵芝酸,以甲苯:乙酸乙酯:乙酸(12:4:0.5)为展开剂,通过硅胶薄层层析法分离得到三种灵芝酸,命名为M_1,M_2和M_3,其R_f值分别为0.56,0.49,0.17.在优化的硅胶柱层析条件下,即以CH_3OH:CHCl_3=3:97,5:95,1:9为洗脱剂,进行分段洗脱;进样量:硅胶量=1:60;在30m×500mm的层析柱上纯化得到三种灵芝酸.抗菌实验显示,三种四环三萜酸具有抑制大肠杆菌、产气杆菌、肠炎杆菌、金黄色葡萄球菌和枯草芽孢杆菌生长的活性.     

~(12)C~(6 )注入小麦种子胚乳引起M_1代的变化

通过控制单核能大小 ,将 1 2 C离子注入小麦种子胚乳 ,结果引起 M1 代植株的较大变化。这些变化包括 :生物学性状的变异 ;根尖细胞染色体畸变率和微核率的显著提高 ;POD酶活性显著提高和 CAT酶活性、MDA含量和蛋白质含量的较大程度的下降等。本文也讨论了诱变胚乳对胚作用的可能机理     

航天与60 Co-γ射线辐射诱变对光温敏核不育水稻M1代农艺性状的影响研究

研究航天搭载、~(60)Co-γ射线及其复合处理光温敏核不育水稻干种子M_1代的发芽率、幼苗生长、植株生长发育及其农艺性状变化.结果表明,对M_1代的生物学效应(抑制或刺激),因不同性状和不同的处理方式而不同;两种光温敏核不育水稻在当代对三种不同诱变处理的辐射敏感性表现一致,而两种光温敏核不育水稻各自对三种不同诱变处理的敏感性不一致.