Bogush Marina, Xenopoulos Panagiotis, Piggot Patrick J
Department of Microbiology and Immunology, Temple University School of Medicine, 3400 North Broad Street, Philadelphia, PA 19140, USA.
J Bacteriol. 2007 May;189(9):3564-72. doi: 10.1128/JB.01949-06. Epub 2007 Feb 23.
Bacillus subtilis undergoes a highly distinctive division during spore formation. It yields two unequal cells, the mother cell and the prespore, and septum formation is completed before the origin-distal 70% of the chromosome has entered the smaller prespore. The mother cell subsequently engulfs the prespore. Two different probes were used to study the behavior of the terminus (ter) region of the chromosome during spore formation. Only one ter region was observed at the time of sporulation division. A second ter region, indicative of chromosome separation, was not distinguishable until engulfment was nearing completion, when one was in the mother cell and the other in the prespore. Separation of the two ter regions depended on the DNA translocase SpoIIIE. It is concluded that SpoIIIE is required during spore formation for chromosome separation as well as for translocation; SpoIIIE is not required for separation during vegetative growth.
枯草芽孢杆菌在孢子形成过程中经历高度独特的分裂。它产生两个大小不等的细胞，即母细胞和前芽孢，并且在染色体起源远端的70%进入较小的前芽孢之前，隔膜形成就已完成。随后母细胞吞噬前芽孢。使用两种不同的探针来研究孢子形成过程中染色体末端（ter）区域的行为。在孢子形成分裂时仅观察到一个ter区域。直到吞噬接近完成时，才能够区分出第二个指示染色体分离的ter区域，此时一个在母细胞中，另一个在前芽孢中。两个ter区域的分离依赖于DNA转位酶SpoIIIE。得出的结论是，在孢子形成过程中，SpoIIIE对于染色体分离和易位是必需的；在营养生长期间的分离过程中则不需要SpoIIIE。
