But it can take a long time for the right mutation to occur, especially if there is a very small target, like the region of DNA that controls a gene.

但要得到最合适的变异基因，耗费的时间会非常长，尤其是所要达到目标非常小时，如DNA中用来控制别的基因的区域部分，将是一项旷日持久的工程。

youdao

On the basis of orthogonal design and colonial diameter as mutation target, the mutagenesis effect of NTG on Pleurotus sp. 8405 is studied.

采用正交试验设计以菌落直径为指标研究了NTG对侧耳8405的诱变效应。

youdao

The positive cells expression of P53 had an important relation to the appearance of EBL. B cells with P53 mutation strain might be a target cell to format tumors.

EBL的发生与突变的P53蛋白过表达有重要关系，携带P53突变株的B淋巴细胞可能是形成肿瘤的靶细胞。

youdao

Because existing antibiotics target specific bacterial molecules, a mutation in the bacterium can render the drugs ineffective.

FORBES: Magazine Article