突变的

To better understand the roles of LsrA protein in nodulation, a series of analyses of nodules using scanning electron microscopy, genetic and biochemical approaches have been carried out. Our analyses suggest that the lsrA1 nodules contain bacteroids in the invasion and establishing zone only. The lsrA gene expression is active early in the invasion zone and activated later than bacA genes. The lost of LsrA protein dramatically reduced the expression of nifA and fixK, and completely blocked the expression of the nifH gene for nitrogenase. LsrA protein functions early in the bacteroid development and it is essential for the development nitrogen fixing bacteroids.

前期的工作中，苜蓿中华根瘤菌Rm1021中90个候选LysR基因已经被定向插入突变，并筛选在自生生长时期、共生生长时期的表型，以期寻找更多在自生状态或共生固氮中有功能的LysR转录因子。1 针对前期鉴定出的共生固氮必需的lsrA基因，我们应用了一系列扫描电子显微镜技术、生物化学、分子遗传学等方法，发现lsrA基因主要在根瘤侵染区开始表达，表达时序也在侵染阶段左右，但晚于bacA基因表达；LsrA蛋白缺失后根瘤固氮区中缺乏具有固氮能力的类菌体，nifA和fixK基因的转录水平降低，nifH基因的转录被完全阻断，因此LsrA蛋白为根瘤发育所必需，是新的根瘤发育信号传导途径成员。2 通过表型筛选我们鉴定了苜蓿中华根瘤菌的oxyR基因，并研究了它的调节特性。oxyR突变后，苜蓿中华根瘤菌对过氧化氢敏感性提高，适应性降低。

Asked by Medscape Oncolo gy to comment on this finding, Jayne Franklyn, MD, PhD, from Queen Elizabeth Hospital, in Birmingham, United Kingdom, who was not involved with the study, said:"This is an important study, as it involved a large number of patients with a relatively rare form of thyroid cancer, specifically looking at those with the sporadic or noninherited variety of this cancer, and it presents the intriguing possibility that the presence of the mutation is associated with a prediction of tumor behavior and therefore prognosis."

Medscape肿瘤学邀请英国伊丽莎白皇后医院的Jayne Franklyn医师对此发现进行评论，未参与此研究的Franklyn医师表示，这是一个重要的研究，因为它纳入了此一少见甲状腺癌的许多病患，特别是此癌症的偶发或者非遗传变化，且展现出突变与预后有关的可能性；此外，该研究有潜在的临床冲击，但是首先，这些发现需要有其他研究证实重现；这项研究也指出各种甲状腺癌的基因突变与基因表现可提供预后资讯的远景。

Asked by Medscape Oncology to comment on this finding, Jayne Franklyn, MD, PhD, from Queen Elizabeth Hospital, in Birmingham, United Kingdom, who was not involved with the study, said: \"This is an important study, as it involved a large number of patients with a relatively rare form of thyroid cancer, specifically looking at those with the sporadic or noninherited variety of this cancer, and it presents the intriguing possibility that the presence of the mutation is associated with a prediction of tumor behavior and therefore prognosis.\"

Medscape肿瘤学邀请英国伊丽莎白皇后医院的Jayne Franklyn医师对此发现进行评论，未参与此研究的Franklyn医师表示，这是一个重要的研究，因為它纳入了此一少见甲状腺癌的许多病患，特别是此癌症的偶发或者非遗传变化，且展现出突变与预后有关的可能性；此外，该研究有潜在的临床冲击，但是首先，这些发现需要有其他研究证实重现；这项研究也指出各种甲状腺癌的基因突变与基因表现可提供预后资讯的远景。

In this study, to define the functional roles and mode of the upstream regulatory elements ofα-globin gene cluster,αMⅡwas obtained, in which the 31.7kb sequence including HS-33, HS-10、HS-8 and HS-4 was deleted by defective prophage mediated by the homologous recombination;αMⅢwas also constructed, in which the 35.4kb sequence including HS-40、HS-33、HS-10、HS-8 and HS-4 was deleted by the method of temperature sensitive shuttle vector mediated homologous recombination.

在此基础上，为了定义α-珠蛋白基因簇上游各调控元件的调控功能，并探讨其作用机制，本研究利用缺陷型原噬菌体介导的同源重组法修饰α-BAC，删除包括HS-33、HS-10、HS-8和HS-4在内长达31.7kb的序列得到BAC突变体αMⅡ；又利用温度敏感型的穿梭载体介导的同源重组法删除包括HS-40、HS-33、HS-10、HS-8和HS-4在内达35.4kb的序列，得到BAC突变体αMⅢ。

In this study, as a original strain, antagonistic bacterium Ata28 was mutated by UV, UV+LiCl, DES and Microwave irradiation; the very goal of the research is to improve the control efficiency of Ata28 strain against tobacco brown spot and obtain strains advanced both in antagonism and biological characteristics, further provides theoretics and practical experience to the production.

采用紫外线和氯化锂复合诱变Ata28菌株，通过预备实验，计算Ata28菌株在不同诱变时间的致死率和正变率，选择该菌株的最佳诱变时间10s，15s诱变；通过平板对峙培养，筛选出8个突变菌株在PDA平板上可明显抑制Tbs3的生长，抑菌带高于出发菌株Ata28，抑菌带最大值达9.7mm；经温室控病初筛和复筛试验，获得了对烟草赤星病有较好防效的突变菌株Uv1-190、Uv1-199，烟苗经Uv1-190、Uv1-199菌液处理3d后，接种Tbs3的防治效果达51.3％、54.9％，比出发菌株Ata28的防治效果好。

Ata28 strain exhibited marked suppression of Tbs3 strain which is the pathogen of tobacco brown spot on PDA plates, and the Ata28 strain had the good control efficiency of tobacco brown spot.

采用紫外线诱变Ata28菌株时，通过预备实验，计算Ata28菌株在不同诱变时间的致死率和正变率，选择该菌株的最佳诱变时间10s，20s，30s诱变；通过平板对峙培养，筛选出15个突变菌株在PDA平板上可明显抑制Tos3的生长，抑菌带高于出发菌株Ata28，抑菌带最大值达9.4 mm；在温室控病中，获得了对烟草赤星病有较好防效的突变菌株Uv-126，烟苗经Uv-126菌液处理3d后接种Tos3的防治效果达52.2％，比出发菌株Ata28的防治效果好。

Ata28 strain was mutated by UV with the most optimum mutant time, including 10, 20, 30s, that was chosen by the trial tests, considering the lethality rate and positive mutation rate of Ata28; it was found that 15 mutant strains were shown antagonism against Tbs3 strain by antagonism test on PDA plate, inhibition zone of mutant strains exceeded the original strain Ata28, and the maximum of inhibition zone reached 9.4mm; the mutant strain Uv-126 was found most effective in tobacco brown spot control and a rate of efficiency control reached 52.2% on tobacco plants three days after bacteria spraying.

采用硫酸二已酯诱变Ata28菌株，通过预备实验，计算Ata28菌株在不同诱变时间的致死率和正变率，选择该菌株的最佳诱变时间20min，40min，60min诱变；通过平板对峙培养，筛选出17个突变菌株在PDA平板上可明显抑制Tbs3的生长，抑菌带高于出发菌株Am28，抑菌带最大值达10.5 mm；经温室控病初筛和复筛试验，获得了对烟草赤星病有较好防效的突变菌株Des-66、Des-50，烟苗经Des-66、Des-50菌液处理3d后，接种Tbs3的防治效果达52.0％、56.6％，比出发菌株Ata28的防治效果好。

The phylogenetic tree was constructed using maximum evolution approach in Mega. The negative selection sites were analyzed by using Datamonkey. There is an apparent 30 bp nucleotides deletion mutation in homonids FKN comparing to that of Old World Monkeys besides other point mutations. Homology of nucleotide sequence between human and chimpanzee, gorilla, orangutan, gibbon, macaque and leaf monkey is 99.2%、98.4%、98.1%、96.5%、95.9% and 93.8% respectively. Homology of amino acid sequence of them is 98.5%、98.0%、97.7%、94.7%、93.7% and 90.5% respectively.

序列分析发现人猿超科较旧大陆猴FKN基因除了有散在的点突变外，还有一明显的30bp的核苷酸缺失突变；人FKN基因序列与黑猩猩、大猩猩、红毛猩猩、长臂猿、猕猴和叶猴的同源性分别是99.2%、98.4%、98.1%、96.5%、95.9%和93.8%，由此推导的氨基酸序列同源性分别是98.5%、98.0%、97.7%、94.7%、93.7%和90.5%；FKN基因进化树表明人与黑猩猩关系更近，FKN基因进化和通常认为的物种进化一致；Datamonkey分析结果显示FKN存在3个负选择位点53Q、84D、239N。

Mild saltationism was rejuvenated with interest in Goldschmidt's genetic hopeful monsters, but a complex saltationism that would significantly leap over transitional forms is pure heresy at the moment.

虽然温和的突变论因为对于Goldschmidt所提出的遗传学上有希望成功的怪物的兴趣而重新获得了青春，但是，到目前为止，那种认为完全不需要过渡形态就可以产生重大跳跃的复杂突变理论，却还仍然是一种纯粹的异端。

Mild saltationism was rejuvenated with interest in Goldschmidt's genetic hopeful monsters, but a complex saltationism that would significantly leap over transitional forms is pure heresy at the moment.

虽然温和的突变论因为对于高兹史密特所提出的遗传学上有希望成功的怪物的兴趣而重新获得了青春，但是，到目前为止，那种认为完全不需要过渡形态就可以产生重大跳跃的复杂突变理论，却还仍然是一种纯粹的异端。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。