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81.
四川白三叶根瘤菌遗传多样性及系统发育研究 总被引:1,自引:0,他引:1
为阐明四川部分地区野生白三叶根瘤菌的遗传多样性及系统发育地位,对分离自四川雅安、康定、泸定、西昌、成都和乐山6个地区白三叶根瘤的69株菌进行系统研究。采用16S rDNA限制性片段长度多态性分析(restriction fragment length polymorphism, RFLP)和16S rDNA基因、持家基因(recA、atpD、glnII)、结瘤基因(nodC)、固氮基因(nifH)系统发育分析的方法进行了研究。结果表明,16S rDNA PCR-RFLP中所有供试菌株产生了4种酶切图谱类型,表现出较为丰富的遗传多样性。持家基因与16S rDNA基因系统发育分析结果基本一致,9株代表菌株主要分布在α-变形菌纲(Alpha-Proteobacteria)的根瘤菌属(Rhizobium),并与豌豆根瘤菌三叶草生物型(R. leguminosarum bv. trifolii) ATCC 14480T的亲缘关系较近。PCR可扩增出nodC和nifH基因片段,但从属于土壤杆菌属(Agrobacterium)的菌株LS1105中则扩增不出这两个基因。所有供试菌株被鉴定到了种的水平,证实了68株为白三叶根瘤菌,并通过不同采样地点菌株之间的比较,发现白三叶与根瘤菌的共生关系因地理分布不同而具有多样性,对于丰富白三叶根瘤菌资源及其开发利用具有重要意义。 相似文献
82.
应用鸡新城疫(ND)LaSota株和减蛋综合征(EDS-76)LA3株,分别接种鸡胚和鸭胚增殖病毒,血凝价分别达≥1:1280和≥1:10000时,收取病毒,经福尔马林灭活,按一定比例加入吐温-80、油佐剂制成ND-EDS-76二联疫苗,经无菌检验、安全性试验、剂量选择、保护性试验、免疫效果和免疫期测定及保存期观察,结果表明:该二联苗安全性好,于蛋鸡开产前1月皮下注射1mL/只,25d后ND和EDS-76抗体可先后达到高峰,免疫期1年。保存期4℃为1年,20℃为3个月。 相似文献
83.
为给我国新型兽医制度建设提供借鉴,对美国国家兽医认证计划(NVAP)及其主要制度进行了研究。研究表明,美国认证兽医是经美国动植物卫生监督局(APHIS)法定程序认证,代表联邦兽医(官)和州动物卫生官(SAHO)实施流通动物检疫监管,协助政府兽医(官)控制动物疫病的执业兽医,具有官方兽医属性。目前,全美80%的兽医为认证兽医,总量高达6.8万名,有效弥补了政府兽医(官)力量的不足。《美国联邦法规》第161.1条规定,NVAP的管理主要涉及认证兽医的分类、职责、培训教育、认证、复审、纪律处分等制度。 相似文献
84.
Zuo Kejing Huang Mian Tang Xiaojun Chen Xuanjiao Wen Yan Chen Tanzipeng Sa Jiaqi Liang Yuzhen Zhang Malong Peng Shiming Zhi Guanglin Wu Qirui 《畜牧与饲料科学》2018,(2)
Dialysis therapy is not a radical cure of chronic renal failure in cats,while renal transplantation is the cure method.Renal transplanta-tion requires rigorous examination of donor and receptor,and the procedure is strictly sterile.The main points of renal transplantation are:renal artery and vein sutured to abdominal aorta and posterior vena cava,respectively;ureter sutured to bladder;minimizing the time of thermal ischemia.Cats should be given immunosuppressant before the operation,and the drug should be administered throughout the life.Various indicators should be monitored regularly to prevent the occurrence of immunological rejection. 相似文献
85.
Primordial germ cells (PGCs) from day 27 porcine fetuses have often been isolated to establish pluripotent embryonic germ (EG) cell lines, but little is known regarding their imprinted gene status. In our study, we attempted to detect the imprinted gene expression of cloned embryos and EG cells derived from individual PGC of day 27 and day 35, using single nucleotide polymorphism (SNP) analysis of the paternally expression gene 10 (PEG10) as a sign of parental‐origin‐specific expression. The results showed biallelic gene expression of the SNP that occurred in EG cell colonies and almost all of the cloned blastocysts, demonstrating that aberrant imprinted gene expression of PEG10 occurs in the day 27 porcine PGCs, whereas monoallelic expression of the PEG10 gene occurs in all the PGC clones derived from day 35 PGCs. In addition, the same imprinted gene status was observed for blastocysts derived from both male and female PGCs, indicating that the parental genomic imprinting is erased in male and female germlines. 相似文献
86.
Mei-Ju Liu Hong Chen Wen Li Xin-Xia Chen Chuan-Hong Wang Qing-Yuan Sun Xue-Yuan Heng 《Animal Science Journal》2021,92(1):e13608
This study aims to investigate the morphology and distribution of mitochondria, spindles, and chromosomes in oocytes of aged mice and examine the effects of SRT1720 on oocyte maturation. C57BL/6J mice were divided into young (4–8 weeks) and aged groups (48–52 weeks). In vitro maturation media contained (0.05, 0.1, and 1.0 μM) SRT1720 and 0.1-μM dimethyl sulfoxide (DMSO control). The rate of chromosome misalignment and spindle misorientation in oocytes of aged mice were significantly higher than that of young mice (P < 0.01). Fluorescence intensity of mitochondria from oocytes of aged mice was significantly lower than that of young mice (P < 0.01). SRT1720 at 0.1 μM significantly improved oocyte maturation, fertilization, and blastocyst formation in aged mice compared with young mice (P < 0.01). Additionally, immunofluorescence intensity of mitochondria, normal spindle morphology, and chromosome alignment were notably enhanced with SRT1720 when compared with the DSMO control group for metaphase II (MII)-stage oocytes matured in vitro (P < 0.01); 0.1-μM SRT1720 enhanced the expression level of SRIT1 in oocytes from aged mice. In summary, the aged mice oocytes showed increased nuclear and cytoplasmic defects, whereas SRT1720 enhanced oocyte maturation and quality. We concluded that 0.1-μM SRT1720 was an appropriate concentration for in vitro maturation media. 相似文献
87.
果子狸细小病毒性肠炎首次诊断及防治初探 总被引:1,自引:0,他引:1
1999年 9~ 1 0月 ,湖南某果子狸驯养场发生一起以下痢、便血为主要症状的急性病毒性传染病 ,60d内造成 1 87只果子狸发病 ,1 56只果子狸死亡 ,尤其是当年生仔狸的发病率和死亡率很高 ,分别为 66 0 %和 96 2 %。根据流行病情况、临床症状、病理变化和血清学检验 ,以及病原体分离、电镜检查和生物学试验证实 ,此疫情为细小病毒感染。用此病毒与细小病毒抗体血清做交叉血清学检测反应为阳性 ,因此证明此病毒与犬细小病毒有共同抗原关系。通过对健康狸进行紧急脏器疫苗接种和用犬细小病毒弱毒疫苗加强免疫 ,以及采取其他综合防治措施 ,迅速使本病得到有效控制 相似文献
88.
89.
90.
Technology transfer is a conscious knowledge transfer and diffusion, which can promote the coordinated configuration and balanced development of technological innovation elements in geographical space. From the perspective of “space of flow”, the technology transfer network is constructed. Utilizing patent technology transaction data from 2018, this study analyzes the agglomeration differentiation and spatial polarization patterns of technology transfer from network nodes, network layers, and network partition in Guangdong–Hong Kong–Macao Greater Bay Area. The conclusions are as follows: (1) The agglomeration of technology transfer is remarkable in the network, showing “two poles and two strong” as well as proximity advantages; Shenzhen and Guangzhou have become spatial poles within the network. (2) The Matthew effect is prominent and technology transfer at the spatial level is largely caused by core node interactions, while core-edge hierarchical transmission mechanisms and geographical proximity contact characteristics are gradually developing. (3) Differences in roles between the plates are pronounced, and there is an agglomeration effect within a plate and between plates, as well as clear spillover effects. 相似文献