Fabret C, Quentin Y, Chapal N, Guiseppi A, Haiech J, Denizot F
Laboratoire de Chimie Bactérienne, Marseille, France.
Microbiology (Reading). 1996 Nov;142 ( Pt 11):3089-96. doi: 10.1099/13500872-142-11-3089.
A sequence strategy which combines a low redundancy shotgun approach and directed sequencing has been elaborated. Essentially, the sequences, as well as the size of the fragments utilized for a low coverage shotgun approach, were exploited for the construction of a physical map of the region to be sequenced. The latter considerably simplified the subsequent directed sequencing steps. We report the physical mapping of a 115 kb segment which covers nearly 100 kb of the hisA-cysB region of the Bacillus subtilis chromosome and contains previously sequenced genes sigL and sacB. Sequencing and analysis of a 21305 bp segment, which includes the sigL locus, revealed 21 ORFs, apparently belonging to at least seven transcription units. This segment has a G + C content greater than 47%, compared to 43% characteristic of the flanking regions, and mainly consists of genes whose products seem to be involved in the synthesis of an exopolysaccharide. These observations leave open the possibility that the analysed fragment has been acquired through horizontal transfer.
一种结合了低冗余鸟枪法和定向测序的序列策略已经被精心设计出来。本质上，用于低覆盖度鸟枪法的序列以及片段大小，被用于构建待测序区域的物理图谱。这极大地简化了后续的定向测序步骤。我们报告了一个115 kb片段的物理图谱，该片段覆盖了枯草芽孢杆菌染色体hisA - cysB区域近100 kb，并包含先前已测序的基因sigL和sacB。对一个包含sigL基因座的21305 bp片段进行测序和分析，发现了21个开放阅读框，显然属于至少七个转录单元。与侧翼区域43%的特征性G + C含量相比，该片段的G + C含量大于47%，并且主要由其产物似乎参与胞外多糖合成的基因组成。这些观察结果使得所分析的片段有可能是通过水平转移获得的这一可能性仍然存在。
