Firrao G, Smart C D, Kirkpatrick B C
Dipartimento di Biologia Applicata alla Difesa delle Piante, Università di Udine.
J Bacteriol. 1996 Jul;178(13):3985-8. doi: 10.1128/jb.178.13.3985-3988.1996.
A physical map of the chromosome of the western X-disease phytoplasma was constructed and represents the first physical map of a phytoplasma chromosome. The western X-disease phytoplasma is a nonculturable, plant-pathogenic member of the class Mollicutes and is the causal agent of a severe disease of fruit trees in North America. The map was generated by performing restriction digests of the chromosome and resolving the restriction fragments by pulsed-field gel electrophoresis. Southern blot analysis using cloned phytoplasma probes confirmed the arrangement of contiguous restriction fragments. The locations of 20 restriction sites for the enzymes SalI, XhoI, BssHII, RsrII, SmaI, and NotI were mapped on the chromosome, which is circular and comprises approximately 670 kb. The locations or the two rRNA operons and of four previously cloned fragments of chromosomal DNA were also placed on the map.
构建了西部X病植原体染色体的物理图谱，这是首个植原体染色体的物理图谱。西部X病植原体是柔膜菌纲中一种不可培养的植物致病成员，是北美果树严重病害的病原体。该图谱通过对染色体进行限制性酶切，并利用脉冲场凝胶电泳解析限制性片段而生成。使用克隆的植原体探针进行的Southern杂交分析证实了相邻限制性片段的排列。在这个约670kb的环状染色体上，定位了SalI、XhoI、BssHII、RsrII、SmaI和NotI这6种酶的20个限制性位点。同时也在图谱上标注了两个rRNA操纵子以及四个先前克隆的染色体DNA片段的位置。
