pNK289衍生质粒在芽孢杆菌中的分离稳定性*

报道关于一系列ｐＮＫ２８９衍生质粒分离稳定性研究结果。这些起源相同的质粒在Ｂａｃｉ－ｌｌｕｓ．ｓｕｂｔｉｌｉｓＡＳＩ．１１７６中的分离稳定性存在差异，这种差异与质粒的大小和复制方式无关，而与质粒的拷贝数有一定的关系。由于不稳定质粒ｐＮＫ２１９在Ｂ．Ｓｕｂｔｉｌｉｓ ＢＤ２２４宿主中能稳定遗传，所以推测宿主的遗传背景可能影响质粒的分离稳定性。这些研究不仅为进一步寻找与ＰＮＫ２８９衍生质粒稳定性相关的基因奠定了基础，而且为在芽孢杆中构建稳定的重组质粒提供了理论依据。

SEGREGATIONAL STABILITY OF THE pNK289-DERIVED PLASMIDS IN BACILLUS SUBTILIS

This paper reports the results of a study about the segregational stability of a series of pNK289-derived plasmids. The segregational stability in B. subtilis AS1. 1176 was found to be different among these same originated plasmids. The difference in segregational stability was shown not to be related to the sizes or replication patterns of the plasmids, but to have some relation to their copy numbers. As the unstable plasmid pNK219 can be miaintained stably in B. subtilis BD 224, it can be inferred that the host inheritable background could affect the segregational stability of plasmid. These results not only have laid a foundation for finding out some genes related to the stability of pNK289-derived plasmids, but also provided theoretical basis for constructing stable recombinant plasmid in Bacillus.