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<正> The dinosaurs of China are among the most exciting in the world. An appreciation of the anatomy of Chinese dinosaurs has become a central element in modern studies of dinosauriah evolution (Russell 1987), and the world's palaeontologists have paid a great deal of attention to China because of her abundant dinosaur resources. The Dinosaur Project, originally called the Canada-China Dinosaur Project (CCDP), was organized in 1985. In that year, the Ex Terra Foundation, Alberta, signed an agreement establishing the project with three core partners: The Tyrrell Museum of Palaeontology in Drumheller, The Natiolaal Mu-  相似文献   
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一种紫色水稻的遗传及其在光敏不育系育种中应用的研究   总被引:15,自引:0,他引:15  
研究表明,本院获得的一种紫色水稻的植株色遗传受控于C、 A、Pl3个独立基因座位上显性基因的互补作用,另有一独立的显性基因对Pl基因的表达起抑制作用。由于该抑制基因在籼稻中的高频率存在,因而,紫稻与一般绿稻品种杂交F1多表现为绿株。紫稻光敏不育(株)系的不育性表达和配合力表现,均可达到与普通光敏不育系相似的水平。本文还讨论了选育籼型紫稻光敏不育系设想的可行性。 Abstract:The inheritance of a purple rice in crosses to green rices was investigated.A group of dominant and interactive genes,C,A and Pl,was found to control the expression of the trait and the other independent inhibitor I-Pl-1 to inhibit the effect of the gene Pl.Because of the wide existence of the gene I-Pl-1 in indica rice,most of F1 plants of the crosses between purple rice and green cultivars were green.The primary study indicated that,for the purple photoperiod-sensitive genic male-sterile lines,the degrees of the sterility and its stability in the sterile stage,and of the fertility in the fertile stage,and the combining ability levels of the purple rice were as high as the degrees and levels for the green rice.A tentative idea on breeding purple photoperiod-sensitive male-sterile lines of indica rice was suggested and its feasibility and advantage was discussed.  相似文献   
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冰草属研究进展   总被引:2,自引:0,他引:2  
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One of the physiological functions of cellular prion protein(PrP C )is believed to work as a cellular resistance to oxidative stress,in which the octarepeats region within PrP plays an important role.However,the detailed mechanism is less clear.In this study,the expressing plasmids of wild-type PrP (PrP-PG5)and various PrP mutants containing 0(PrP-PG0),9(PrP-PG9)and 12(PrP-PG12)octarepeats were generated and PrP proteins were expressed both in E.coli and in mammalian cells.Protein aggregation and formation of carbonyl groups were clearly seen in the recombinant PrPs expressed from E.coli after treatment of H2O2.MTT and trypan blue staining assays revealed that the cells expressing the mutated PrPs within octarepeats are less viable than the cells expressing wild-type PrP.Statistically significant high levels of intracellular free radicals and low levels of glutathione peroxidase were observed in the cells transfected with plasmids containing deleted or inserted octarepeats.Remarkably more productions of carbonyl groups were detected in the cells expressing PrPs with deleted and inserted octarepeats after exposing to H2O2.Furthermore,cells expressing wild-type PrP showed stronger resistant activity to the challenge of H2O2 at certain extent than the mutated PrPs and mock. These data provided the evidences that the octarepeats number within PrP is critical for maintaining its activity of antioxidation.Loss of its protective function against oxidative stress may be one of the possible pathways for the mutated PrPs to involve in the pathogenesis of familial Creutzfeldt-Jacob diseases.  相似文献   
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研究了一类在两个不同斑块环境中的具时滞基于比率依赖的扩散捕食者-食饵系统,并利用重合度中的延拓定理得到了该系统周期解存在的充分条件.  相似文献   
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As an immediate-early protein of herpes simplex virus, infected-cell polypeptide 0 (ICP0) exhibits complicated interactions with host cells, and its regulatory function on gene expression is of great importance. Since the ICP0 encoding sequence contains many rare codons which are absent in E.coli, and ICP0 is highly unstable in prokaryotic cells, expression of entire ICP0 in prokaryotic cells has never been reported. In order to further investigate the function of ICP0, a recombinant plasmid was constructed by subcloning a cDNA fragment encoding an amino-terminal of 105 residues of the ICP0 protein into pGEX-5x-1 vector. The resulting GST-105 fusion antigen peptide was expressed with high efficiency in E.coli. Antibodies prepared after the immunization of mice with purified fusion protein can recognize not only the denatured ICP0 protein, but also the native ICP0 protein with normal biological conformation.  相似文献   
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低温诱导绿豆黄化幼苗乙烯产生过程中活性氧的作用   总被引:17,自引:0,他引:17  
低温明显诱导绿豆 (PhaseolusradiatusL .)黄化幼苗乙烯产生速率的升高 ,同时也诱导活性氧产生速率不同程度的提高 ,显示二者之间有密切的关系。乙烯合成抑制剂AVG (2 aminoethoxyvinlglycine)、AOA(aminooxyaceticacid)能明显减弱低温对绿豆黄化幼苗乙烯产生的诱导作用 ,但对活性氧的产生没有明显的影响 ,说明低温诱导的乙烯产生的增加并不是活性氧产生增加的原因。超氧阴离子自由基 (O- ·2 )的特异性清除剂SOD和DABCO(1,4 diazabicyclo 2 ,2 ,2 octane)能有效削弱低温对乙烯产生的诱导作用 ,外源O- ·2 产生系统明显促进经过低温处理的幼苗回到常温下生长初期乙烯产生的增加 ,说明O- ·2 产生的增加可能是低温诱导乙烯产生增加的原因之一。低温诱导的H2 O2 产生的增加则被证明与乙烯产生速率的升高没有直接关系。  相似文献   
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用绒毛组织微核评价母亲因素对人胚的致突变性   总被引:1,自引:0,他引:1  
崔应琦  董非文 《遗传学报》1990,17(3):238-242
对507对欲作人工流产的夫妇进行断面调查及绒毛组织微核的测定,以探讨父母吸烟、饮酒及采取避孕措施等因素对子代的致突变性。结果显示:微核的发生率与母亲年龄、孕次、孕龄、既往流产史等自身的因素无关;各种避孕措施及少量饮酒均不具有诱发绒毛微核细胞率增加的作用。然而,男方吸烟、女方被动吸烟其微核细胞率为0.7645±0.0561‰高于饮酒组(0.5667±0.2004‰)和非吸烟对照组(05522±0.0616‰),与对照组有显著性统计学意义(P<0.05)。男方配偶吸烟兼饮酒者其微核发生率最高(0.7944±0.0754‰),说明吸烟与饮酒对诱发绒毛微核的产生有协同作用的趋势。本文并对男方吸烟和/或女方被动吸烟可诱发胚胎绒毛组织细胞DNA和/或纺锤体装置的损伤,进行了探讨,提出应引起人们的高度重视,并建议利用人类绒毛组织微核测定法作为监测环境致突变因子对人类下一代影响的方法。  相似文献   
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