Key Laboratory for Industrial Biocatalysis (Ministry of Education) and Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China.
Science. 2017 Mar 10;355(6329). doi: 10.1126/science.aaf3981.
We designed and synthesized a 976,067-base pair linear chromosome, synXII, based on native chromosome XII in SynXII was assembled using a two-step method, specified by successive megachunk integration and meiotic recombination-mediated assembly, producing a functional chromosome in Minor growth defect "bugs" detected in synXII, caused by deletion of tRNA genes, were rescued by introducing an ectopic copy of a single tRNA gene. The ribosomal gene cluster (rDNA) on synXII was left intact during the assembly process and subsequently replaced by a modified rDNA unit used to regenerate rDNA at three distinct chromosomal locations. The signature sequences within rDNA, which can be used to determine species identity, were swapped to generate a synXII strain that would be identified as by standard DNA barcoding procedures.
我们设计并合成了一个 976067 碱基对的线性染色体 synXII，该染色体基于天然染色体 XII。synXII 的组装采用两步法，通过连续的大片段整合和减数分裂重组介导的组装来完成，在 synXII 中产生了一个功能性染色体。在 synXII 中检测到的由 tRNA 基因缺失引起的微小生长缺陷“缺陷”可以通过引入单个 tRNA 基因的异位拷贝来挽救。在组装过程中，synXII 上的核糖体基因簇（rDNA）保持完整，随后被一个经过修饰的 rDNA 单元替换，该单元用于在三个不同的染色体位置再生 rDNA。rDNA 内可用于确定物种身份的特征序列被交换，以生成一个可以通过标准 DNA 条形码程序鉴定为 的 synXII 菌株。
