Engineered DNA will slow the growth of a host cell if it redirects limiting resources or otherwise interferes with homeostasis. Escape mutants that alleviate this burden can rapidly evolve and take over cell populations, making genetic engineering less reliable and predictable. Synthetic biologists often use genetic parts encoded on plasmids, but their burden is rarely characterized. We measured how 301 BioBrick plasmids affected Escherichia coli growth and found that 59 (19.6%) were burdensome, primarily because they depleted the limited gene expression resources of host cells. Overall, no BioBricks reduced the growth rate of E. coli by >45%, which agreed with a population genetic model that predicts such plasmids should be unclonable. We made this model available online for education (https://barricklab.org/burden-model) and added our burden measurements to the iGEM Registry. Our results establish a fundamental limit on what DNA constructs and genetic modifications can be successfully engineered into cells.

如果工程DNA改变了有限的资源或以其他方式干扰体内平衡，它就会减缓宿主细胞的生长。减轻这种负担的逃逸突变体可以迅速进化并接管细胞群，从而使基因工程变得不太可靠和可预测。合成生物学家经常使用质粒上编码的遗传部分，但它们的负担很少被表征。我们测量了 301 个 BioBrick 质粒如何影响大肠杆菌生长，发现其中 59 个（19.6%）是负担，主要是因为它们耗尽了宿主细胞有限的基因表达资源。总体而言，没有 BioBricks 能够将大肠杆菌的生长率降低超过 45%，这与预测此类质粒不可克隆的群体遗传模型一致。我们将此模型提供给在线教育 (https://barricklab.org/burden-model)，并将我们的负担测量添加到 iGEM 注册表中。我们的结果对 DNA 构建和基因修饰可以成功地工程化到细胞中建立了基本限制。