Large-scale recoding of a bacterial genome by iterative recombineering of synthetic DNA
Level 5 - mechanism / opinion, no new human data
Level 5 by design analogy (in vitro bacterial synthetic biology and genetic engineering study)
OpenAlex W2613162921 · doi:10.1093/nar/gkx415
What was done
The authors developed and tested a method called SIRCAS (stepwise integration of rolling circle amplified segments) to rewrite bacterial genomic DNA. Using Salmonella typhimurium LT2, they integrated 10–25 kb synthetic DNA constructs (assembled in yeast and amplified via rolling circle amplification) through direct iterative recombineering over sixteen 2-day cycles and conjugated parallelized segments for hierarchical assembly.
What was found
The SIRCAS method successfully recoded 200 kb of the S. typhimurium genome, introducing 1,557 synonymous leucine codon replacements across 176 genes. The resulting recoded bacterial strain grew at a rate similar to the wild-type strain without exhibiting major growth defects.
Why it matters
This study establishes a rapid method for genome-scale modification and demonstrates the first large-scale synthetic recoding of a bacterial genome outside of Escherichia coli.
Limits
The work is a proof-of-concept laboratory study limited to a 200 kb region of a single Salmonella strain rather than a fully synthetic whole genome. Phenotypic evaluation reported in the abstract was limited to basic growth rate comparison, with no reported data on long-term evolutionary stability, functional attenuation, or performance under stress conditions.
Cited by
- supports The first completely recoded organism genome was engineered primarily using single-stranded DNA-annealing proteins (SSAPs) and site-specific recombinases.