Sauer Christopher, Syvertsson Simon, Bohorquez Laura C, Cruz Rita, Harwood Colin R, van Rij Tjeerd, Hamoen Leendert W
Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University , Richardson Road, NE2 4AX Newcastle, United Kingdom.
DSM Biotechnology Center , P.O. Box 1, 2600 MA Delft, The Netherlands.
ACS Synth Biol. 2016 Sep 16;5(9):942-7. doi: 10.1021/acssynbio.6b00065. Epub 2016 May 27.
A fixed gene copy number is important for the in silico construction of engineered synthetic networks. However, the copy number of integrated genes depends on their genomic location. This gene dosage effect is rarely addressed in synthetic biology. Two studies in Escherichia coli presented conflicting data on the impact of gene dosage. Here, we investigate how genome location and gene orientation influences expression in Bacillus subtilis. An important difference with the E. coli studies is that we used an unbiased genome integration approach mediated by random transposon insertion. We found that there is a strong gene dosage effect in fast growing B. subtilis cells, which can amount to a 5-fold difference in gene expression. In contrast, gene orientation with respect to DNA replication direction does not influence gene expression. Our study shows that gene dosage should be taken into account when designing synthetic circuits in B. subtilis and presumably other bacteria.
固定的基因拷贝数对于工程合成网络的计算机构建很重要。然而，整合基因的拷贝数取决于它们在基因组中的位置。这种基因剂量效应在合成生物学中很少被提及。两项关于大肠杆菌的研究给出了关于基因剂量影响的相互矛盾的数据。在这里，我们研究基因组位置和基因方向如何影响枯草芽孢杆菌中的表达。与大肠杆菌研究的一个重要区别是，我们使用了由随机转座子插入介导的无偏基因组整合方法。我们发现，在快速生长的枯草芽孢杆菌细胞中存在很强的基因剂量效应，基因表达可能相差5倍。相比之下，基因相对于DNA复制方向的方向并不影响基因表达。我们的研究表明，在设计枯草芽孢杆菌以及可能其他细菌的合成回路时应考虑基因剂量。
