| 1. | Phz1114 was transformed into the m145 and a gene replacement strain named hxy2 was obtained and testified by southern blotting
在mmasd及sfm上培养时发现： hxy2子代菌落有表型分离现象。 |
| 2. | Prior to the vector construction , the availability of gene replacement was extensively tested in streptomyces . sp . fr - 008
在载体构建之前，我们先在链霉菌fr - 008中验证了基因置换方法的可行性。 |
| 3. | To clone large and random dna fragments , the second generation of yac , pjs97 - pjs98 was modified as gene replacement vector in streptomyces
4kb和1 . okb片段，而且还插入了勿，七刃j和spc心t厂抗性基因。 |
| 4. | For desired gene replacement , hyg / cml and str / spc gene cassettes were also incorporated into the new vector system . it is expected that hygwould be integ
为了验证新型yac载体系统的功能，我们将phz621 ~ phz622进行了适当地改造，构建了质粒phz625 。 |
| 5. | 2kb or 7 . 2kb regions abolished the productivity of antibiotic fr - 008 . the expected strain after gene replacement in the region of 5 . 2kb have not been obtained for unknown reason
尽管由于未知的原因尚未获得5 . 2kb区域的基因置换菌株，但是以上的试验证明基因置换过程是可以在链霉菌fr - 008中进行的。 |
| 6. | Phz621 - phz622 , the new gene replacement vector system , had been constructed through the insertion of the 1 . 0kb and 1 . 4kb flanking sequences of hau3r gene from wild - type s . lividans in the same natural orientation
预期在携带有大插入片段的基因置换yac分子进入野生型变铅青链霉菌后， yac分子将通过1 . 4kb或1 |
| 7. | Lividans mutant strains la1 and la2 generated by gene replacement in dndb and dndc were obtained respectively . both of these two mutants lost dnd phenotype because of disruption of a respective dnd gene
首先利用基因置换实验获得分别在dndb 、 dndc基因内部发生基因中断的突变菌株la1利la2 ，并通过southern杂交进行了验证。 |
| 8. | Secondly another vector phz1117 which for replacement of sc ( j11 . 17 / scd78 . 01 , was constructed . phz1117 was transformed into wild type strain m145 and a gene replacement strain named hxy3 was obtained
其次，构建了另一个用于置换scq11 . 17 scd78 . 01的置换载体phz1117 ，得到基因置换菌株hxy3并通过southern杂交验证，与野生型m145相比，没有观察到hxy3有明显的表型变化。 |
| 9. | In the bioassay using saccharomyces cerevisiae as indicator , bl10 and bl19 were found unable to produce antibiotic fr - 008 while the other four had no detectable changes in productivity . obviously , the gene replacements happened in the 5 . 2kb + 7
在以啤酒酵母为指示菌的生物测定中，未观察到基因中断菌株bl14 、 bl15 、 bl16和bl17的产素表型的变化，而bl10 、 bl19以及所有的双交换菌株都丧失了产生fr - 008的能力。 |
| 10. | Pfge analysis of these 21 blocked strains revealed a common chromosomal deletion in the 300kb asel fragment which might be responsible for antibiotic 5102 - iii biosynthesis . so the 300kb fragment was recovered and used as probe to hybridize with 10 - 22 genomic library . cosmids in this region were aligned and suitable fragments in this region were selected and used further for the construction of gene replacement plasmids
以此片段为探针钓出了位于该区域的文库克隆，并利用指纹印迹和杂交技术将这些文库克隆排列起来，进而以位于该区域的不同位置的片段做臂构建了用于转化和接合转移用的基因置换质粒，并试图通过基因置换将该区域置换下来，但尚未得到最终结果。 |
