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81.
家兔选育性状典型相关分析 总被引:3,自引:0,他引:3
选择日本大耳白和新西兰两个品种家兔的生长、繁殖、以及体尺3组共17个性状,应用多元统计方法进行了典型相关分析,结果表明;日本大耳白兔的初生重、初生窝重、21日龄重、泌乳力、胸围等5个性状,新西兰兔的产活仔数、初生重、21日龄重、泌乳力、断奶窝重、母兔体重等6个性状为主要性状。 相似文献
82.
利用RT-PCR和Western-blotting技术分析了胆固醇侧链裂解酶(P450scc)、3β-羟甾脱氢酶(3β-HSD)、C17-20裂解酶(P450c17)、StAR mRNA和蛋白在成年昆明小白鼠心脏、脾、肝、肾中的表达.结果显示,StAR mRNA及其蛋白、P450scc mRNA在以上组织中均有表达;3β-HSD在肾中有较强的表达,在其他组织的表达较弱;P450c17在上述组织中无明显的表达,但在睾丸中有明显的表达.这表明,心脏、脾、肝、肾均具有合成类固醇的能力,但合成类固醇的类型存在一定的差异. 相似文献
83.
近20多年来,我国养殖业发展迅速,取得了可喜的业绩。我国肉类、蛋类总产量连续多年保持世界第一,养殖业为改善我国人民生活水平,调整人们膳食结构、提高农民收入做出了巨大的贡献。但它的发展不可避免地产生了大量的“畜产公害”,畜禽粪便、养殖污水任意堆弃、排放现象普遍存在。 相似文献
84.
本文用离子选择电极法测定了N,N—二甲基膦酸基甘氨酸(NBPG)与银、镉、汞的配合物组成和稳定常数。结果表明,NBPG与Ag~ 、Cd~(2 )、Hg~(2 )均生成组成为1:1的多齿质子型配合物。其lgK_稳值分别为:AgL5.28、CdH_3L3.63、CdH_2L5.16、CdHL7.30、CdL11.56、HgH_3L6.06、HgH_2L7.55、HgHL8.24、HgL12.58。 相似文献
85.
本文报道了寄生在雷林一号桉“[Eucalyptus leichou NO:1]”叶片上的一个国内新记录病原菌[Fairmaniella leprosa(Fairman)Petrak & Sydow.]的主要特征,并与已知种作了比较;文中讨论了国内外研究状况,寄主及分布。标本采集于广东省雷州林业局林科所人工桉树林。 相似文献
86.
A. Schots J. De Boer A. Schouten J. Roosien J. F. Zil Verentant H. Pomp L. Bouwman-Smits H. Overmars F. J. Gommers B. Visser W. J. Stiekema J. Bakker 《European journal of plant pathology / European Foundation for Plant Pathology》1992,98(2):183-191
Engineering resistance against various diseases and pests is hampered by the lack of suitable genes. To overcome this problem we started a research program aimed at obtaining resistance by transfecting plants with genes encoding monoclonal antibodies against pathogen specific proteins. The idea is that monoclonal antibodies will inhibit the biological activity of molecules that are essential for the pathogenesis. Potato cyst nematodes are chosen as a model and it is thought that monoclonal antibodies are able to block the function of the saliva proteins of this parasite. These proteins are, among others, responsible for the induction of multinucleate transfer cells upon which the nematode feeds. It is well documented that the ability of antibodies to bind molecules is sufficient to inactivate the function of an antigen and in view of the potential of animals to synthesize antibodies to almost any molecular structure, this strategy should be feasible for a wide range of diseases and pests.Antibodies have several desirable features with regard to protein engineering. The antibody (IgG) is a Y-shaped molecule, in which the domains forming the tips of the arms bind to antigen and those forming the stem are responsible for triggering effector functions (Fc fragments) that eliminate the antigen from the animal. Domains carrying the antigen-binding loops (Fv and Fab fragments) can be used separately from the Fc fragments without loss of affinity. The antigen-binding domains can also be endowed with new properties by fusing them to toxins or enzymes. Antibody engineering is also facilitated by the Polymerase Chain Reaction (PCR). A systematic comparison of the nucleotide sequence of more than 100 antibodies revealed that not only the 3′-ends, but also the 5′-ends of the antibody genes are relatively conserved. We were able to design a small set of primers with restriction sites for forced cloning, which allowed the amplification of genes encoding antibodies specific for the saliva proteins ofGlobodera rostochiensis. Complete heavy and light chain genes as well as single chain Fv fragments (scFv), in which the variable parts of the light (VL) and heavy chain (VH) are linked by a peptide, will be transferred to potato plants. A major challenge will be to establish a correct expression of the antibody genes with regard to three dimensional folding, assembly and intracellular location. 相似文献
87.
The present study was to investigate the feasibility and efficiency of the DNA vaccine to protect chickens against very virulent infectious bursal disease virus (vvIBDV) infection. A plasmid DNA carrying VP2‐4‐3 genes of vvIBDV SH95 and a plasmid DNA carrying chicken interleukin‐6 (ChIL‐6) genes were constructed and designated as pALTER‐MAX‐VP2‐4‐3 and pALTER‐MAX‐ChIL‐6 respectively. Several DNA vaccination experiments were performed: 1‐week‐old chickens were intramuscularly injected with only plasmid pcDNA3‐VP2, pALTER‐MAX‐VP2‐4‐3 or mixture with pALTER‐MAX‐ChIL‐6. The chickens at 4 weeks old were orally inoculated with vvIBDV SH95. The results showed that immunization with the mixture of pALTER‐MAX‐VP2‐4‐3 and pALTER‐MAX‐ChIL‐6 three times conferred protection for 90% of chickens. Enzyme‐linked immunosorbent assay (ELISA) antibody titres in chickens immunized together with pALTER‐MAX‐ChIL‐6 were higher than those immunized simply with plasmid pcDNA3‐VP2 or pALTER‐MAX‐VP2‐4‐3. IBDV was not detected in the bursa of the protected chickens at 8 days after challenge by RT‐PCR. The results indicate that protection against vvIBDV can be achieved by using the VP2‐4‐3 gene of vvIBDV as a DNA vaccine. Furthermore, the simultaneous injection of ChIL‐6 plasmid significantly increased the protection after challenge with the very virulent strain. 相似文献
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90.
桃果实絮败机理及减缓措施 总被引:5,自引:2,他引:5
桃果实在8℃以下的低温环境中贮藏2周以上极易受冷害,后熟过程中表现出果肉质地发绵、汁液减少等 絮败现象。絮败的产生主要是果胶甲酯酶(PE)和多聚半乳糖醛酸酶(PG)活性变化不平衡导致果胶质正常降解受 阻,形成凝胶所致。综述了近年来对于桃和油桃絮败机理方面的研究成果,从絮败发生的机理、絮败程度检测以及在 低温贮藏中如何减缓絮败发生的措施等方面进行了论述。认为影响桃果实絮败的主要因素是贮藏温度、品种、成熟 度等。絮败的评价主要用出汁率等方法,在贮藏中可以采用气调、中途加温、外源乙烯处理、延期贮藏等措施减缓絮 败发生。提出了需要近一步研究的内容。 相似文献